According to the Global Cancer Observatory, around 2.3 million new cases of breast cancer were diagnosed in 2022, representing 11.6% of all cancer cases and, it is the fourth leading cause of cancer mortality worldwide. Among women, breast cancer is the most common cancer and the leading cause of cancer-related death worldwide.1

Mortality rates have been falling since the early 1990s in high-income countries, reflecting the progress made through numerous therapeutic advances and improvements in early detection through screening and increased awareness.2–4 However, in low-income and middle-income countries, breast cancer incidence and mortality are rising rapidly.5–8 The rapid increase in breast cancer cases in low-income and middle-income countries, particularly in sub-Saharan Africa, could be partly explained by demographic changes (increasing age at first childbearing, ageing), changes in lifestyles and comorbidities (obesity, sedentary lifestyle, etc), decrease in breastfeeding, alcohol consumption.5 9 10 The rising mortality rate could be due to the limited access to screening, particularly mammography, late-stage disease presentation and a health system poorly equipped for the management of breast cancer.8 11 12 These differences between regions raise the question of the differences that could be observed within a country, depending on women’s country of birth. However, while studies considering place of birth have been carried out in some Western countries, with mixed results,13–15 to our knowledge this has rarely been done in France.

In France, breast cancer accounts for 33% of women’s cancers, and its incidence has been rising since the 1990s to reach a global standardised incidence rate of 99.2 per 1 00 000 women in 2023.16 In 2017, its prevalence was estimated at 913 089 people in France.17

As pointed out by the Lancet Breast Cancer Commission, equity is a major issue in breast cancer.18 A systematic review carried out at the European level shows how socioeconomic inequalities shape breast cancer patterns: the incidence of breast cancer is higher in the most educated women (due to reproductive factors such as a higher age at first child, breastfeeding and also other factors such as alcohol consumption, family history, hormonal treatments), whereas the case fatality rate is higher for disadvantaged women.19 The situation seems identical in France, as the 5-year net survival rate is lower among people living in disadvantaged areas compared with women living in advantaged areas.20 The available studies in France point to discrepancies in the use of screening according to women’s age, level of education and economic and geographical situation.21–26 Concerning the post-cancer period, the results of the VICAN5 study (Living conditions five years after a cancer diagnosis) — conducted in metropolitan France in 2015 — also showed the importance of social inequalities on the repercussions of breast cancer on women’s lives: women from a disadvantaged background experience more financial consequences of breast cancer, and they also have a lower quality of life 5 years after their diagnosis.27 A recent study based on cohort data even showed increased inequalities in quality of life over time.28 Hence, breast cancer cannot be tackled without taking health inequalities into account.

To date, and to our knowledge, there are no data in France documenting breast cancer experience according to women’s country of birth. However, all the available data suggest that immigrant women could face specific obstacles in the experience of breast cancer. First, young age is the main characteristic of breast cancer in sub-Saharan African women.29 Second, triple-negative cases of breast cancer represent more than one-third of the breast cancers in sub-Saharan Africa.30–32 In contrast, they represent less than 15% in France.33 34 Third, the age at which cancer occurs is different: 70% of women diagnosed with breast cancer in sub-Saharan Africa are under 50 years of age35 compared with a median of 64 years in women born in France.17 The characteristics of the cancer could be one element that results in more critical consequences in women’ lives. However, other factors, documented in other health areas, could also play a role: the role of poverty and precarity, difficulties in accessing health insurance and healthcare, language problems, the difficult process of settling in, which takes several years, the lack of stable financial resources, more frequent situations of isolation.36 37

The few studies on breast cancer screening that consider women’s country of birth suggest that immigrant women are indeed more likely to not have breast cancer screening (9.8% vs 7.6% among natives) and more likely to have this screening late (30.6% vs 18%).38 We have not found published studies documenting the incidence and mortality of breast cancer among immigrants in France, particularly women from sub-Saharan Africa. The few studies that do exist, which are mainly qualitative, highlight the difficulties encountered by immigrant women in accessing healthcare.39–41 In the French context, where there is still a reluctance to collect and study data according to origin,42 data are lacking to better understand immigrant women’s life trajectories with breast cancer.

In 1982, Bury introduced the notion of biographical disruption in analysing the experience of chronic diseases based on the example of patients with rheumatoid arthritis.43 He argued that “illness, and especially chronic illness, is precisely that kind of experience where the structures of everyday life and the forms of knowledge which underpin them are disrupted”. Thus, the disease’s arrival marks a rupture, a ‘before’ and an ‘after’ in the life trajectory of individuals. To understand how breast cancer affects different dimensions of women’s lives (occupation, residential, family, etc) across times, a life course approach seems necessary.

Two dimensions, in particular, could be usefully investigated through a life course approach that are seldom present in other longitudinal (cohort) data. The first one is to study how the experience of illness also calls for a reconstruction of identity that advocates continuity and involves gender issues.44 Research carried out in France has shown the strong presence of gender norms and stereotypes in the cancer care pathways, and the strongly gendered dimension of the body being treated. Meidani and Alessandrin note that in relationships with the body, to relatives, and to sexual and aesthetic issues, gender is always present.44 The authors thus suggest that gender is present at all stages of the fight against the disease, particularly in the various stages of identity reconstruction. A recent study, conducted as part of the international SENOVIE project (figure 1), showed that among women living in Mali, undergoing a mastectomy prevented them from performing typically female functions in society (such as cooking or sexuality), thus challenging their female identity.45

Another dimension which is crucial in understanding immigrant women’s experience of cancer is to be able to understand how the diagnosis appears in relation to a context of migration. In this regard, two different situations can be found: the first one is that women are diagnosed while they have been living in France for some time. Depending on the timing of diagnosis regarding migration (are they well settled? Do they already have a personal home or a job?), the consequences of the diagnosis could be different. Another situation is the one of women who came to France after being diagnosed with breast cancer in their country of origin for treatment. Their coming to France can be related to what is called therapeutic mobility.46–48 Concerning therapeutic mobilities, previous qualitative research showed that women who had undertaken therapeutic mobility had very heterogeneous profiles: some belonged to a high socioprofessional category, but others had low social and economic capital and had complex backgrounds. For these women, therapeutic mobility was seen as a unique chance of survival. In addition, access to care for these women is in precarious conditions related to housing, administrative situation and emotional life.41 Thus, the consequences of the diagnosis could be even more dramatic, and the trajectories in France even more difficult for these women who left their countries to find healthcare.

To contribute to the understanding of social health inequalities in breast cancer in France, the aim of our study is to understand the life trajectories of women born in France and in sub-Saharan Africa treated for breast cancer.

The SENOVIE France study is taking place in the greater Paris area, in the four partner structures of the study, namely: the Saint Louis Hospital in Paris, the Delafontaine Hospital Center in Saint-Denis, the Robert Ballanger Intercommunal Hospital Center in Aulnay-sous-Bois and the Avicenne Hospital in Bobigny. The project was developed in collaboration with the heads of the oncology and senology departments of these hospitals in order to recruit, during consultations, women treated for breast cancer in these hospitals. Given that the study aims to recruit women born in France and in sub-Saharan Africa, the study was designed taking into account the diversity of patients consulting in the hospitals as well as their locations, in particular Saint-Denis, Aulnay-sous-Bois and Bobigny, which are cities in the Seine Saint-Denis department with a more significant share of immigrant population than Paris. In 2020–2021, immigrants represented 32% of the population of Seine-Saint-Denis compared with 10% of the population in France excluding Mayotte.49

Based on the eligibility criteria specified above, healthcare professionals will identify eligible patients before or during the consultation. For each health professional, the register lists all eligible patients present at the consultation. It consists of two sections: an anonymous section and a nominative section, which is detached before the registers are handed over to the research team. The register indicates for each eligible patient whether she accepts or refuses to participate, as well as some sociodemographic data such as age, country of birth and activity. The analysis of the registers will enable us to measure participation rates and characteristics associated with non-participation.

For each patient eligible for the study, the healthcare professional will invite the patient to read the study information note carefully. The healthcare professional will then propose the study to the patient. Once the patient agrees to participate in the study, the healthcare professional will complete two copies of the consent form and have them signed by the patient. The healthcare professional will keep one copy and give the second copy to the patient. For each patient agreeing to take part in the survey, the healthcare professional will stick a label with an identification number on an anonymity card and give it to the patient. The patient will give this anonymity card to the interviewer with whom she will complete the questionnaire. The identification number on this card will be used as the sole identifier for the various survey questionnaires (patient questionnaire, biographical grid and medical questionnaire). Women who agree to take part in the study can, if available, meet the interviewer to complete the questionnaire immediately, or make an appointment with the interviewer to complete the questionnaire later, in the days following recruitment and at the hospital where the patient is recruited. Neither the interviewer nor the research team will know the patient’s identity. Informed consent is requested from each patient before the questionnaires are administered. All women participating in the study will receive a €10 voucher as compensation for their participation.

Quantitative data collection is carried out using a patient questionnaire combining a Computer-Assisted Personal Interviewing (CAPI) individual questionnaire (online supplemental appendix 2) and a life event biographical grid (online supplemental appendix 3), as well as a CAPI medical questionnaire (figure 2 and online supplemental appendix 4). The life event biographical grid is a paper where the main events that occurred in the patients’ lives are recorded, year by year, from their birth to the time of the survey. A unique patient identification number will be used to merge data from these questionnaires. The CAPI individual questionnaire and the biographical grid will be administered through face-to-face interviews with a trained interviewer on the premises of the project’s hospital partners, in offices that guarantee the confidentiality of the interview. The biographical grid has been shown to help minimise memory bias, as respondents can use both dates and age to remember the order of events, and can put events in relation to each other (eg, a woman may not know when she first gained access to health coverage, but will remember that she obtained it during her second pregnancy).57 The CAPI individual questionnaire and the paper biographical grid will be used to collect detailed information year by year on different dimensions of the life course (online supplemental appendices 2–4):

The medical questionnaire contains questions on the characteristics of the cancer and the treatments received by the women. It will be filled in by hospital staff at partner centres on a secured server. More information is provided in the data management plan.58

Collecting data about breast cancer using a life course approach can bring up painful life stories for both the interviewees and the interviewers. To deal with this, the interviewees can call on the psychologists in the health services where they are recruited. The interviewers have weekly exchanges with the research team to share the experiences they have encountered, and they can also call on the psychologists of the institution to which they are attached.

In terms of statistical analysis, descriptive statistics will be used to precisely describe the medical status, social characteristics and living conditions of women born in France and women born in Sub-Saharan Africa living with breast cancer in the greater Paris area. These statistics may also be age standardised if, as expected, women from sub-Saharan Africa are younger than their native-French counterparts. Descriptive trajectory visualisation tools such as sequence analysis could be used for these analyses.59

To measure the social consequences of breast cancer diagnosis and treatments, specific statistical methods for longitudinal data (Cox models,60 discrete-time logistic regressions61 that allow taking different temporalities into account (time since migration, since diagnosis, since treatment, etc) will be used. Specific attention will be paid to how healthcare trajectories may have been impacted between 2020 and 2021 by the COVID-19 sanitary crisis as observed elsewhere,62 and also to examine whether all women were affected in the same way (missing medical follow-ups, delayed surgeries). Special attention will also be paid to the social determinants and social impacts of breast reconstruction. All analyses will be adjusted for the characteristics of the women surveyed to control possible variations. For women born in sub-Saharan Africa, for example, the analyses will be adjusted for length of stay in France and administrative status.

The study is currently being carried out by research teams. Patients were not involved in the design of this research. However, contacts are being established with associations of women with breast cancer so that they can participate in the project's dissemination plans in the future.

Not applicable.