Feasibility and acceptability of a personalised primary prevention strategy for women and men at high risk of breast and prostate cancer: the 3PC study protocol for a pilot randomised controlled trial

Abstract

Introduction

Several primary prevention strategies, including chemoprevention, prophylactic surgery and lifestyle modifications, have been shown to reduce the risk of breast cancer (BC) and prostate cancer (Pca). However, the uptake of these preventive measures is considered suboptimal, limiting their impact on cancer prevention. A personalised primary prevention strategy has yet to be tested for cancer prevention. Therefore, we aim to determine the feasibility, acceptability and potential benefits and harms of this strategy in women and men at high risk of BC and Pca.

Methods and analysis

This is a two-arm, parallel-group mixed-methods pilot randomised controlled trial with a 1:1 allocation. The study aims to recruit 60 women and 60 men at high risk of BC and PCa in two specialised sites: the Breast Diseases Center and the Department of Urologic Oncology of the CHU de Québec-Université Laval, Canada. Assessments include intentions to uptake, actual uptake rates of primary preventive measures and decision regret. Feasibility and acceptability of the intervention and the study will be measured by quantifying the recruitment rate, appropriateness of randomisation process and satisfaction metrics. Data will be collected using mixed methods. Quantitative measures will be assessed at baseline and 6 months post randomisation. Quantitative analysis will include descriptive statistics for all variables of interest. Generalised linear mixed models with random intercepts will be used to assess the overall intervention effect. Semistructured interviews will be conducted at the end of follow-up, and a thematic analysis will be performed using NVivo to understand participants’ perspectives.

Ethics and dissemination

The protocol was approved by the Institutional Review Board of CHU de Québec-Université Laval (4 October 2022; 2023-6315). The findings of the study will be published in a peer-reviewed journal and disseminated at national and international conferences and through social media.

Trial registration number

The protocol for this study was registered with the International Clinical Trials Registry (ISRCTN15749766) https://doi.org/10.1186/ISRCTN15749766).

Correspondence to Prof. Hermann Nabi; [email protected]

STRENGTHS AND LIMITATIONS OF THIS STUDY

• This research constitutes a unique opportunity to know whether adopting a more personalised strategy in cancer prevention is feasible and acceptable.

• The mixed-methods design will provide rich and robust evidence regarding the feasibility and acceptability of our intervention.

• The collection of objective physiological parameters of men and women will increase the reliability of the findings.

• This study will have only two measurement time points (baseline and 6 months).

• The sample size used does not allow for a fully powered test of efficacy.

Introduction

Background and rationale

Over the last three decades, significant advances in oncology have increased the survival rates of patients with breast cancer (BC) and prostate cancer (PCa) but have failed to decrease their incidence.^{1 2} Worldwide, BC and PCa remain the second most commonly diagnosed types of cancer and the second cause of cancer death in women and men, respectively.^1–6 Globally, more than 1.4 million new cases of PCa and 2.3 million new cases of BC were diagnosed in 2020.³ The American Cancer Society estimates that there will be approximately 288 300 new cases of PCa and 34 700 deaths from PCa, and 297 790 new cases of invasive BC and 43 700 deaths from BC in the USA in 2023.^{6 7} The incidence of BC will continue to rise, and it is estimated to reach 364 000 new cases in 2040.⁷ In Canada, in 2020, the incidence of these cancers increased, with BC accounting for one-quarter (25%) of all new cancer cases in women and PCa for one-fifth (20%) of all new cancer cases in men.¹ These figures are alarming and call for thorough consideration of the panoply of current primary prevention strategies available. Several studies have examined the role of primary prevention interventions in the reduction of BC and PCa risk and incidence.^8–16 Of these interventions, we will focus on those recommended in clinical guidelines for each type of cancer.^{17 18} In particular, we will focus on chemoprevention,^11–14 prophylactic surgery,¹⁵ and lifestyle modifications.¹⁶

Chemoprevention

Chemoprevention consists of the use of synthetic medicine, vitamins or other biological agents to try to reduce the risk of developing cancer.¹⁹ Chemoprevention has been shown to be a viable approach to the prevention of BC among women.^8–10 For example, tamoxifen and raloxifene are two major evidence-based medications used in reducing the risk of primary invasive BC.^{19 20} In the USA, these are the only substances approved to reduce the risk of BC.²¹ In turn, the Canadian Cancer Society confirmed that tamoxifen is the most commonly used anti-oestrogen drug in Canada.²²

An impressive number of randomised controlled trials (RCTs) have confirmed a significant drop (over 65%) of relative risk (RR) in BC incidence among women at high risk who have undergone chemoprevention of this kind.^23–25

Prophylactic surgery

Prophylactic surgery is highly recommended for women who are at high risk of hereditary BC due to mutations in BRAC1/2 susceptibility genes.^{26 27} Prophylactic surgery has been shown to decrease the incidence of BC among patients at high risk of developing the disease.²⁶ A meta-analysis and systematic review of 15 RCTs have demonstrated that BRCA1/2-mutation carriers who have undergone prophylactic bilateral salpingo-oophorectomy and bilateral prophylactic mastectomy have a significantly reduced risk of BC incidence and mortality.²⁸

Lifestyle modifications

There is compelling evidence showing that individuals’ lifestyle is a key component in their BC and PCa risk profile.^{16 29–31} Dietary habits, physical activity, stress management, social connection and tobacco, alcohol and other substance use are the main factors influencing the risk of BC and PCa among women and men.^{30 32 33} A 2020 umbrella review study showed that nutrition and dietary choices are the two most crucial modifiable factors to reduce the risk of BC³¹ and PCa,³⁴ while another cohort study has highlighted a negative association between physical activity and PCa risk.³⁵

Uptake of primary prevention strategies

However, despite their variety and undeniable public health importance, these primary prevention strategies are underused.³⁶ The uptake of and adherence to these preventive measures are considered suboptimal, therefore limiting what could otherwise be a significant impact on cancer prevention.^37–39 A variety of reasons have been proposed in the literature to explain such low uptake. These include a lack of routine risk assessment, inadequate physician or patient knowledge, patients’ fears of side effects and time constraints in clinical settings.⁴⁰ In the case of chemoprevention, for example, in addition to these barriers, Smith et al have outlined several socio-economic and ethnic factors that appear explanatorily relevant. Women with low socio-economic status and belonging to an ethnic minority have lower rates of uptake of chemoprevention despite being at higher risk of developing BC.³⁷ The low uptake of primary prevention strategies could lead to the appearance of many avoidable cases and create a significant burden in health systems.⁴¹

A high proportion of women and men might not be aware of their risk of developing BC or PC, or of the preventative options available to them.⁴² Additional efforts and new strategies are therefore needed in primary prevention to reverse this trend. A personalised approach to disease prevention encompassing early detection and targeted management of individuals at high risk of coronary heart disease has been an important contributor to reductions in cardiovascular disease incidence since the 1970s.⁴³ However, this approach has yet to be tested for cancer prevention. There is a lack of early detection interventions specifically tailored to patients known to be at high risk of developing particular cancers.⁴⁴ To achieve a reduction in the number of new cancer cases, a personalised primary prevention strategy could be tailored to individuals’ risks of developing certain cancers while considering their needs and preferences.⁴⁵

A body of literature underlines the importance of personalised intervention in BC⁴⁶ and PCa prevention.⁴⁷ In 2019, the European Collaborative on Personalized Early Detection and Prevention of Breast Cancer highlighted the importance of identifying evidence-based, personalised interventions for BC prevention.⁴⁸ In addition, the consortium calls for urgent development of intermediate surrogate clinical and molecular markers that would enable timely assessments of the efficacy of potential BC preventive strategies in RCTs.⁴⁴

However, given the multitude of options available, decisions in the context of BC and PCa prevention are inevitably preference-sensitive, requiring each individual to be able to weigh the risks, harms and benefits of each option.⁴⁴ To do so, individuals need to be fully informed in an unbiased way about their options,⁴⁹ have the opportunity to participate in the decision-making process and consider the risks and benefits of each option as a function of their own values and goals.⁵⁰ An important question is whether a personalised primary prevention strategy tailored to individuals’ cancer risk profile, values and preferences could make a difference in the uptake of specific cancer-preventive interventions and their efficacy.

Decision aids (DAs) are considered to have the potential to facilitate the understanding of the potential benefits and harms of various options and help individuals make decisions in line with their own values and preferences.^50–54 Several interventional studies have shown the value of tailored DAs in supporting women at an elevated risk of developing BC to make informed choices about BC prevention.^{53 55–64} However, all these studies focused on a single prevention option, namely, chemoprevention. As a result, the ability of patients to compare alternative options and decide, in light of their particular circumstances, which one is most suitable to them is unknown.⁶⁵ This is important, given that options for BC prevention are generally used in combination and may include lifestyle modifications, chemoprevention and risk-reducing surgery.⁴⁴ To date, we are unaware of other studies that have assessed the feasibility and acceptability of tailored prevention strategies incorporating all possible prevention pathways in their design to allow women and men at risk for BC and PCa make explicit comparisons of their benefits and risks and decide accordingly. The present research aims to address this gap.

Study aims and objectives

The overall aim of the study is to determine the feasibility, acceptability and potential benefits and harms of a personalised primary prevention strategy in women and men at high risk of BC and PCa, respectively.

• Our primary objective is to evaluate uptake intentions and uptake rates of each preventive option proposed to each group of individuals, and their level of comfort with each option.

• Our secondary objective is to explore the associations between actual uptake of each preventive option and clinico-biological markers linked to BC or PCa, as well as psychosocial outcomes.

Methods and analysis

This protocol was prepared in agreement with the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 guidelines⁶⁶ and adapted as recommended when reporting protocols of feasibility trials. A SPIRIT checklist has been included as online supplemental appendix 1.

Study design

This is a randomised feasibility study with two arms and parallel assignment. A mixed-methods trial^{67 68} will be undertaken to examine the feasibility and acceptability of a personalised primary prevention strategy for women and men at high risk of BC and PCa. Our intention in combining quantitative and qualitative methods is to gain a multidimensional understanding of the feasibility of the intervention and its potential benefits and harms.⁶⁷ Qualitative data will be used both to contextualise the quantitative data⁶⁸ and to expand on it to inform the future implementation strategy of our intervention.

Study setting and eligibility criteria

High-risk women and men will be identified primarily in two specialised sites: the Breast Diseases Center and the Department of Urologic Oncology of the CHU de Québec-Université Laval. French- and/or English-speaking adult women (>18 years old) will be eligible if they meet at least one of the following criteria: having a first-degree family history of BC, having a personal history of breast atypical hyperplasia, having an extreme breast density (BI-RADS category D) or being a mutation carrier in high (eg, BCRA1/2, PTEN, TP53) or moderate (eg, CHECK2, PALB2, ATM) penetrance genes. French- and/or English-speaking adult men (>18 years old) will be eligible if they meet at least one of the following criteria: being a BCRA1/2 mutation carrier, having an elevated prostate-specific antigen (PSA≥4 ng/mL), having a first-degree family history of Pca or being of African descent.

Recruitment procedure

Participants will be identified through electronic health records (EHRs), prospective referrals and publicity about the study in the community. All women and men identified as meeting the eligibility criteria in EHRs will be mailed the study invitation letter including an explanation of the study objectives, participation conditions and study timeline and a link to access the study site and consent form. As we have successfully done previously,⁶⁹ we will collaborate with the PULSAR platform at Laval University (https://pulsar.ca/en/home). Potential participants from prospective referrals will be approached during a medical visit by a member of the medical team and, on their consent, subsequently called by a research assistant or nurse who will explain the study, confirm their eligibility and obtain their written consent. To test the possibility of extending our recruitment to high-risk women and men in the community, we will organise a series of webinars at university family medicine groups and super clinics⁷⁰ from the Quebec City area in order to inform physicians and nurses about the study. On agreement, they will be asked to provide the study invitation letter to potential eligible women and men who could log into the study website to learn more about the study, be screened for eligibility and enrol. Finally, high-risk women and men for BC and PCa will also be recruited through posts on social media (eg, Facebook, Twitter) in collaboration with our institutional networks.

Intervention

After randomisation, both groups (intervention vs control group) will receive an informational booklet via their PULSAR online study portal. In addition to the booklet, women and men in the intervention group will receive the Ottawa Personal Decision Guide (OPDG) (see online supplemental appendix 2) in an interactive PDF format. A 45–60 min phone or virtual consultation with the study nurse or healthcare social worker will be offered to participants of the intervention group who will need assistance to navigate through the tool or have questions about the information provided

Informational booklet

This booklet will be intended to provide general information about BC and PCa cancers, but also their risk factors and recommended preventive options. It will be written at approximately an eighth-grade reading level to minimise health literacy and health numeracy demands. Canadian experts in BC and PCa prevention will develop the content of the booklet. Furthermore, a purposeful sample of volunteer men and women from the general population will help determine whether the content is clear and presented adequately. The informational booklet will be available in both French and English.

The Ottawa Personal Decision Guide

The OPDG is a widely used tool, validated in French and English, which aims to help people make informed health and lifestyle decisions.⁷¹ This tool can be self-administered, which gives it an undeniable advantage over tools that must be completed with health professionals. This tool was selected for two purposes. First and most importantly, to convey, via the PULSAR platform, an individualised (personalised) prevention action plan with relevant validated preventive options tailored to each participant’s BC or PCa risk profile and personal characteristics (eg, age, ethnicity). For each prevention option, the associated benefits (risk reduction) and possible side effects estimates will be pre-entered on the OPDG. BC and PCa risks and risk reduction strategies will be presented using words, percentages, visual scales or pictograms and graphs. Previous work from members of our team has demonstrated that the use of multiple formats to display risk information reduces bias in how the numbers may be perceived, while also increasing understanding.⁷² The second reason is to help each woman and man identify their decision-making needs, clarify their values and preferences, take an informed decision and eventually share and discuss their views with their healthcare provider, family members, and friends.

Randomisation and allocation

After completing the eligibility screening, consent form and baseline questionnaire (T1) assessing sociodemographic, health-related and psychosocial variables, participants will be randomised (allocation ratio: 1:1) into the intervention or control groups, separately for men and women, using a computer-based system overseen by a statistician (Ms Myrto Mondor) not involved in the study. A minimisation procedure⁷³ will be used to ensure that the study groups are balanced according to four dichotomous risk variables. The first participant will be assigned to one of the study groups randomly. For each subsequent participant, a score will be calculated using the four variables to determine which group he/she should be allocated in order to minimise the imbalance. An element of randomness will be introduced by using a probability of 80% of being assigned to the group indicated by the minimisation score; in 20% of the cases, the participant will be allocated to the other group. The four risk variables will have the same weight when calculating the minimisation score. If the information is missing for some of the risk variables, the score will be calculated using the remaining variables. If all four variables are missing, the participant will be allocated randomly. A random allocation will also be used if the score favours each group equally.

Data collection timeline

Data will be collected on two occasions: baseline (T1, pre-randomisation) and 6 months (T2) post-randomisation. At baseline (T1), an online questionnaire will be administered to gather participants’ sociodemographic characteristics, self-rated health status, psychological factors (BC and PCa risk perceptions and worry, perceived self-efficacy about cancer risk reduction, psychological distress) and health-related behaviours.^{69 74–77} Health literacy⁷⁸ and health numeracy⁷⁹ will also be assessed. At follow-up assessment (T2), the online questionnaire will assess the stage of decision-making or change,⁸⁰ primary and secondary outcomes described below and several psychological factors of the baseline questionnaire. Qualitative data will be collected at T2 through semistructured interviews with a purposeful sample of 15–20 voluntary women and men from both intervention and control groups, who will have completed all the study phases, via video-conferencing platforms or over the phone at their convenience. Thematic analysis⁸¹ will be the primary method for analysing the data, allowing for the identification, organisation and presentation of themes within the data.⁸¹ A thematic tree illustrating participants' experiences, meanings and perceptions of the intervention will also be constructed, in line with the study’s objective of evaluating feasibility and acceptability. At least two members of the research team will conduct the analysis. The combination of qualitative and quantitative methods is intended to leverage the strengths of both approaches. Qualitative methods offer greater depth and detail, while quantitative methods address the limitations of qualitative approaches. By combining these methods, we aim to enhance the reliability and validity of the findings as data triangulation from multiple sources helps mitigate biases inherent to individual methods.⁸²

Research team members

This study will be conducted by an interdisciplinary, multifaculty and diverse team, including senior, mid-career and junior academic investigators in the field of molecular epidemiology and cancer genetics; health psychology and behavioural sciences; health promotion; lifestyle medicine and primary care; and basic cell and molecular biology. The team also integrates clinical investigators specialised in BC and PCa prevention and treatment; cancer risk assessment; implementation of personalised approaches; and community-based participatory and intervention research. Finally, we have also engaged patient partners during various steps of our research study. This diversity enhances innovation and leads to greater creativity in our study.⁸³

Patient and public involvement

Patient partners have been involved in the study’s conception, the development of research questions and the protocol, as well as the funding application. Moving forward, they will contribute to the development and pre-testing of questionnaires to ensure clarity, relevance and understanding, playing a key role in refining our research tools. Additionally, we will involve patient partners in the dissemination of results to ensure our findings are communicated effectively to study participants and the broader patient community. Lastly, patient partners will be included as coauthors of the scientific articles resulting from this research, recognising their significant contribution to the project.

Outcomes

Primary outcomes measures

• Intentions to uptake primary preventive measures for BC or PCa will be measured at 6-month (T2) using a multiple-choice question (Based on what you know right now, how likely do you think you are to adopt each of the following prevention options for BC (or PCa) recommended to you?) on a 5 Likert-type scale ranging from ‘not all’ to ‘extremely likely’. A drop-down menu will be provided.

• Actual uptake of primary preventive measures for BC or PCa will also be measured at 6-month (T2) by asking a multiple-choice question. The following question will be asked to intervention participants: “Have you made a decision about whether or not you are going to take any of the prevention options for BC (or PCa) recommended to you?” (1=‘no decision yet’, 2=‘I decided to adopt option 1’, 3= ‘I decided to take option 2’, 4=‘I decided to take option 3’, 5=‘I decided to take no option’). The corresponding question for the control group will be: “Have you made a decision about whether or not you are going to take any of the prevention measures for BC (or PCa)?” (‘1=no decision yet’, 2=‘I decided to take measure 1’, 3=‘I decided to take measure 2’, 4=‘I decided to take measure 3’, 5= ‘I decided to take no measure’). Individuals who will respond that they had made a decision will be subsequently asked, “Did you actually take the option or the measure? And how?”. For those who did not make a decision, the following question will be asked: “How close are you to making a decision?” (1=‘not at all close to making a decision’ to 4= ‘extremely close to making a decision’).

• Decision regret: Both intervention and control groups will be asked to complete the French or English version of the decision regret scale,⁸⁴ which measures distress or remorse after a health decision. This five-item, easy and quick-to-complete scale demonstrated strong correlation with decision satisfaction, decisional conflict, and quality of life.⁸⁵

Secondary outcomes measures

For secondary outcomes, we are interested in whether the personalised primary prevention intervention is feasible and acceptable to participants. In addition, we intend to assess the clinical and biological markers for BC and PCa.

• Feasibility of the intervention: The feasibility of the study will be assessed by quantifying the recruitment rate, appropriateness of randomisation process, number of participants who use the study materials, number of participants who call for receiving support and completion of data collection tools. All of this information will be recorded automatically by the PULSAR platform. Based on previous studies, the study will be considered feasible if >10% of eligible men and women consent to participate, ≥75% of participants complete baseline, postintervention assessments, and<20% are lost to follow-up.^86–88

• Acceptability of the intervention: The acceptability of the intervention will be measured at the 6-month follow-up by assessing participants’ satisfaction with the intervention materials (ie, the informational booklet plus the decision aid and the provided support) through a qualitative pragmatic approach⁸⁹) and by measuring the time spent consulting it globally by section through the PULSAR platform.

• Clinical and biological measures: On consent, levels of PSA⁹⁰ in men and breast density⁹¹ in women will be extracted from participants’ medical charts at T2, whether or not participants have taken preventive measures. We will test the acceptability for participants to provide a blood specimen at follow-up (T2) to assess inflammatory markers,⁹² insulin-like growth factor,^{93 94} steroid hormones,^95–97 metabolites levels⁹⁸ and DNA methylation,^{99 100} and explore whether some of these measures could be linked to the uptake of preventive measures status (yes vs no). The samples will be collected in accordance with the Canadian Standard Operating Procedures for biospecimen collection and stored in one of our investigators’ laboratory for analysis (CD).

Participants’ timeline

A schedule of participants’ activities (time schedule of enrolment, interventions assessments, etc) is outlined in online supplemental appendix 3.

Sample size and power calculation

As this is a pilot feasibility trial, a formal power calculation is not required.¹⁰¹ According to several rules of thumb used to determine an appropriate sample size for a pilot study, a sample size of 60 high-risk women (30 per arm) and 60 high-risk men (30 per arm) will be recruited to provide sufficient data on the feasibility, acceptability and preliminary efficacy of our intervention, even though we recognise that the scope of this pilot study does not allow for a fully powered test of efficacy.^102–104

Data management and analyses

Statistical analyses

Quantitative results will be based on data collected through online questionnaires, medical charts and biological markers. Data will be analysed and reported according to the Consolidated Standards of Reporting Trials guidance extension to feasibility studies.¹⁰⁵ Descriptive statistics will be calculated for all variables of interest by using means and SDs (for continuous measures) and counts and percentages for categorical measures. The adequacy of randomisation will be examined using univariate analyses to assess differences between the two groups on baseline possible covariates, particularly sociodemographic characteristics and the risk profile. Differences in continuous variables (eg, biological markers) will be assessed using two-sample, two-sided t-tests, whereas categorical variables (eg, clinical variables) will be assessed using χ² tests or Fisher’s exact tests where appropriate. Generalised linear mixed models with random intercepts will be performed for primary outcomes measures collected to assess the overall intervention effect and the effect at fixed follow-up time point (T2) adjusted for baseline values. For binomial primary outcomes (uptake intentions and actual uptake will be dichotomised), RRs and 95% CI comparing intervention and controls groups will be estimated. For continuous primary outcome (decision regret), mean differences and 95% CI between the groups will be estimated. Among the participants who will have had made a decision at T2, multinomial logistic regressions will be used to examine the stage of decision-making at T2 between the intervention and control groups. We will apply ordinal regression and Mann-Whitney U tests methods tailored to ordinal data.

Qualitative analyses

A qualitative data analysis will occur at study completion only. All interviews will be audio-recorded and transcribed verbatim. Furthermore, we will generate qualitative field notes (memos) that capture observations made during the study process. All interview transcripts will be read several times for data familiarisation purposes. An inductive and deductive thematic analysis¹⁰⁶ will be undertaken using NVivo V.12 to aid data management. Our analysis will follow three fundamental and related steps: (1) assigning codes, (2) generating themes (thematisation or categorisation) and (3) examining how the themes are connected (organising themes, identifying aggregate dimensions, links between themes and making visual representations of codes and themes by thematic map or thematic cartography). Three different thematic analysis plans will be generated; however, only one will be retained after team consensus.

Ethics and dissemination

All data will be housed and stored in REDCap. Personal information about participants will be encrypted within password-protected and securely maintained on REDCap before, during and after the trial.¹⁰⁷ Only authorised individuals will have access to this information. Furthermore, for qualitative data, all personal information such as name, gender and ethnicity will be hidden during the data transcription and analysis phases. Our study coordinator will be responsible for storing all audio recordings in a password-protected folder. All data will be retained for 10 years following completion of the study and will be discarded according to the CHU de Québec-Université Laval end-of-trial policies. The trial will be conducted in compliance with the principles of the Declaration of Helsinki. Patient consent forms in English (see online supplemental appendix 4) and French (see online supplemental appendix 5) are provided as additional files.

We anticipate no serious adverse events due to the nature of our study. If adverse events occur, we will resolve them in an expedited manner and will determine the seriousness and the causality. Participants could have emotional responses when thinking about family history of BC and PCa. Our research team is multidisciplinary, which include mental health professionals that will likely be able to help those in need. The protocol was approved by the Institutional Review Board of CHU de Québec-Université Laval (4 October 2022; 2023-6315).

Our knowledge transfer (KT) activities will be guided by the CIHR’s Guide to Knowledge Translation Planning. For researchers, we will use traditional dissemination strategies, including publications in relevant peer-reviewed journals related to implementation science, oncology, health services research, prevention and public health. In addition, to foster debate and engage with potential collaborators, we will present study results and lessons learnt at relevant conferences and workshops (eg, BRCA meeting in Montreal, Canadian Association for Health Services and Policy Research annual conference, Canadian Cancer Research Conference). We will also share our reports using free public repositories such as Open Science Framework and Research Gate. The dissemination of this project starts with the publication of the protocol. For knowledge users and stakeholders, we will use a number of strategies to disseminate our work. Summary briefs presenting a synthesis of evidence and observations from the study team will be disseminated to study participants at the end of the study. The summary briefs will also be posted on our social media platforms and published in institutional newsletters (eg, le Chuchoteur at the CHU de Québec-Université Laval) to inform patients, the general population and other health professionals about the study findings. In addition, results will be disseminated among local and regional public health units, organisations involved in BC and PCa prevention and early detection, and among those conducting BC and PCa prevention and early detection research. Feedback that will be received from these dissemination activities will inform about conditions in large-scale implementation of our prevention strategy. This is important given that our research team includes several clinicians with the capacity to offer BC and PCa services and guide prevention organisations in Quebec. Finally, we will use external dissemination strategies through social media platforms (Facebook, Twitter and LinkedIn).

Discussion

The goal of our research is to know whether it is feasible and acceptable to implement a primary cancer prevention strategy, encompassing an individualised action plan with support and follow-ups, in men and women at high risk of PCa and BC, respectively. We also want to document how well each prevention plan correlates with relevant biological, clinical and psychosocial outcomes associated with BC and PCa. To date, we are unaware of other studies that have assessed the feasibility and acceptability of tailored prevention strategies incorporating all possible prevention pathways in their design in order to allow women and men at risk for BC and PCa to make an explicit comparison of their benefits and risks and decide accordingly. This paper summarises the protocol we will use to address this gap. The results will allow us to understand the potential for success of our intervention and design principles. Furthermore, using both quantitative and qualitative methods will provide rich and robust evidence regarding the feasibility and acceptability of our intervention.¹⁰⁶

In summary, it is now possible to stratify healthy individuals as a function of their personal risk of cancer using genetic and/or environmental risk factors¹⁰⁸ and subsequently tailor preventive recommendations. Moving from a ‘one-size-fits-all’ prevention strategy to a more ‘personalised or stratified’ strategy holds the prospect of achieving targeted and effective preventive interventions for individuals who are more likely to benefit from them, while sparing those at lower risk from the potential serious inconveniences of these interventions, which ultimately could affect favourably the incidence of cancer. In addition to matching their risk profile, the person will be able to choose the options that best match their values and preferences

Our study constitutes a unique opportunity to document whether adopting a more personalised strategy in cancer prevention is feasible and acceptable. This personalised primary prevention strategy has the potential to enable men and women to better understand their personal risk, properly compare the preventive options available to them and choose among these options based on their values and preferences, thereby improving uptake and adherence. If our intervention is deemed feasible and acceptable, the next step will be to determine if it can be applied to a wider population.

Trial status

The trial is open for recruitment. The Standard Protocol Items Recommendations for Trials (SPIRIT) checklist has been added as online supplemental additional file 1.

We would like to extend our sincere thanks to all the coauthors in our study, who generously shared their time, experiences and insights with us. Notably, Arian Omeranovic, Asma Boubaker and Johanne Lessard were essential in the writing, reviewing and submission of this manuscript. The completion of this research project would not have been possible without our sponsors, including the Canadian Cancer Society, the Canadian Institutes of Health Research and the Quebec Breast Cancer Foundation.

Ethics statements

Patient consent for publication

Not applicable.

Footnote

Contributors All authors have contributed to the development of this protocol. IS participated in the conceptualisation of the protocol, researched and developed all aspects of the methodology, wrote the first draft of this manuscript and approved the final version as submitted. HN, JL, JK-M and PF participated in the conceptualisation of the project, critically reviewed and commented on drafts of this manuscript and approved the final version submitted. JC, MD, CD, SL, EA-W, SB, MC, CB, NC, J-SP, YF, JS and VF critically reviewed and commented on the drafts of this manuscript and approved the final version submitted. HN, serving as the guarantor of the study, assumes full responsibility for the work, including the conduct of the study and the integrity of the data. His oversight has been crucial in maintaining the highest standards of research quality and ethical conduct.

Funding This work was supported by grants: 1. The Canadian Cancer Society (CCS) - National Office (Toronto). 2. The Canadian Institutes of Health Research (CIHR) - Breast Cancer Initiative. 3. The Quebec Breast Cancer Foundation (Canada).

Competing interests None declared.

Patient and public involvement Patients and/or the public were involved in the design, or conduct, or reporting, or dissemination plans of this research. Refer to the Methods section for further details.

Provenance and peer review Not commissioned; externally peer reviewed.

Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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