Partridge, Ann HNiman, Samuel MRuggeri, MonicaPeccatori, Fedro AAzim, Hatem AColleoni, MarcoSaura, CristinaShimizu, ChikakoSætersdal, Anna BarbroKroep, Judith RMailliez, AudreyWarner, EllenBorges, Virginia FAmant, FrédéricGombos, AndreaKataoka, AkemiRousset-Jablonski, ChristineBorstnar, SimonaTakei, JunkoLee, Jeong EonWalshe, Janice MBorrego, Manuel RuízMoore, Halle CfSaunders, ChristobelCardoso, FatimaSusnjar, SnezanaBjelic-Radisic, VesnaSmith, Karen LPiccart, MartineKorde, Larissa AGoldhirsch, AronGelber, Richard DPagani, Olivia2023-02-092023-02-092021-08-03http://hdl.handle.net/10668/18376Premenopausal women with early hormone-receptor positive (HR+) breast cancer receive 5-10 years of adjuvant endocrine therapy (ET) during which pregnancy is contraindicated and fertility may wane. The POSITIVE study investigates the impact of temporary ET interruption to allow pregnancy. POSITIVE enrolled women with stage I-III HR + early breast cancer, ≤42 years, who had received 18-30 months of adjuvant ET and wished to interrupt ET for pregnancy. Treatment interruption for up to 2 years was permitted to allow pregnancy, delivery and breastfeeding, followed by ET resumption to complete the planned duration. From 12/2014 to 12/2019, 518 women were enrolled at 116 institutions/20 countries/4 continents. At enrolment, the median age was 37 years and 74.9 % were nulliparous. Fertility preservation was used by 51.5 % of women. 93.2 % of patients had stage I/II disease, 66.0 % were node-negative, 54.7 % had breast conserving surgery, 61.9 % had received neo/adjuvant chemotherapy. Tamoxifen alone was the most prescribed ET (41.8 %), followed by tamoxifen + ovarian function suppression (OFS) (35.4 %). A greater proportion of North American women were The characteristics of participants in the POSITIVE study provide insights to which patients and doctors considered it acceptable to interrupt ET to pursue pregnancy. Similarities and variations from a regional, sociodemographic, disease and treatment standpoint suggest specific sociocultural attitudes across the world.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Breast cancerEndocrine therapyPregnancy desirePremenopausal womenTreatment interruptionYoung womenAdultAntineoplastic Agents, HormonalBreast NeoplasmsCancer SurvivorsChemotherapy, AdjuvantFemaleHormonesHumansMastectomyPregnancyPremenopauseTamoxifenresearch article34390999open access10.1016/j.breast.2021.07.0211532-3080PMC8365381http://www.thebreastonline.com/article/S096097762100429X/pdfhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC8365381/pdf