Attitudes and factors influencing contraception use over time in premenopausal women with early breast cancer in the prospective CANTO study

Abstract BACKGROUND: With an increased lifespan, survivorship has become a crucial component of breast cancer (BC) care. Among survivorship concerns, adequate contraception counseling is needed in premenopausal patients (pts) not seeking to become pregnant. However, very limited evidence exists on attitudes and factors influencing contraception use over time in premenopausal women with early BC. METHODS: CANTO is a multicenter, prospective cohort study of 12,012 pts with stage I-III BC (NCT01993498). This analysis included women aged ≤50 years with known premenopausal status at BC diagnosis. Contraception use and type were longitudinally evaluated at diagnosis, year-1 (T1) and 2 (T2) after diagnosis. Multivariable logistic regression models assessed associations between clinical, socio-economic, treatment, toxicity (CTCAE) and pts-reported outcome (PROs, EORTC QLQ-C30/BR23) variables, with contraception use after diagnosis. RESULTS: Among 2,900 pts included, mean age at diagnosis was 43.1 (SD 5.6) years, 96.0% of pts already had children at BC diagnosis, 70.8% and 80.0% received chemotherapy and endocrine therapy (ET), respectively. Among patients treated with ET, 80.2% received tamoxifen alone and 19.8% other therapies (either tamoxifen or an aromatase inhibitor or a combination) plus ovarian function suppression (OFS). Following diagnosis, 45.0% of pts at T1 and 65.7% at T2 reported consulting a gynecologist. At diagnosis, 54.2% of pts reported contraception use, with the majority (62.6%) using hormonal methods. Prevalence of contraception use significantly decreased at T1 and T2 (38.9% and 41.2%, respectively; ptrend<0.05), when the majority of pts reported use of mechanic (94.2% and 95.3%, respectively) reversible methods (copper intrauterine devices or condom in ~90% pts at both T1 and T2). In univariate analyses, pts reporting contraception use after diagnosis were more likely to be younger, with higher socio-economic status, partnered with children, and scored better on PROs scales assessing post-treatment body image, sexual functioning, global health, physical, emotional, role and social functioning (all p<0.05). In the final multivariable model, factors associated with contraception use at T1 included prior contraception use at diagnosis (adjusted Odds Ratio vs no, 4.02 [95% CI 3.15-5.14]), younger age (for each decreasing year, 1.10 [1.07-1.13]), better sexual function (for 10-unit increment, 1.13 [1.07-1.19]), having children (vs no, 4.21 [1.80-9.86]), reporting leucorrhea (vs no, 1.32 [1.03-1.70]), receipt of tamoxifen alone (vs any other ET combined with OFS, 1.39 [1.01-1.92]) and having consulted with a gynecologist over the course of the previous year (vs no, 1.29 [1.02-1.63]). Similar factors were associated with contraception use at T2 including receipt of tamoxifen alone (vs. any other ET combined with OFS, 2.16 [1.48-3.15]) and having consulted with a gynecologist over the course of the previous year [vs no, 1.39 [1.04-1.86]). In addition, partnered status (vs not, 1.61 [1.07-2.44]) emerged as significantly associated with contraception use at T2. CONCLUSION: This large analysis of CANTO data provides unique insights on the attitudes and factors influencing contraception use over time in premenopausal women with early BC, being highly relevant to raise awareness and improve contraception counseling in these pts at both diagnosis and during oncology follow-up. Several factors were shown to be important in contraception decision making. Among them, consulting a gynecologist after diagnosis impacted contraception use, pointing at the need to promote long-term follow-up care by the oncofertility units beyond access to fertility preservation strategies in the growing, vulnerable population of premenopausal breast cancer survivors. Citation Format: Matteo Lambertini, Claudia Massarotti, Julie Havas, Barbara Pistilli, Anne-Laure Martin, Alexandra Jacquet, Charles Coutant, Florence Coussy, Asma Dhaini Merimeche, Florence Lerebours, Olivier Tredan, Christelle Jouannaud, Olivier Rigal, Marion Fournier, Patrick Soulie, Maria Alice Franzoi, Lucia Del Mastro, Ann H. Partridge, Fabrice Andre, Ines Vaz-Luis, Antonio Di Meglio. Attitudes and factors influencing contraception use over time in premenopausal women with early breast cancer in the prospective CANTO study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-11-20.