Interrupting Endocrine Therapy to Attempt Pregnancy after Breast Cancer.

BACKGROUND: Prospective data on the risk of recurrence among women with hormone receptor-positive early breast cancer who temporarily discontinue endocrine therapy to attempt pregnancy are lacking. METHODS: We conducted a single-group trial in which we evaluated the temporary interruption of adjuvant endocrine therapy to attempt pregnancy in young women with previous breast cancer. Eligible women were 42 years of age or younger; had had stage I, II, or III disease; had received adjuvant endocrine therapy for 18 to 30 months; and desired pregnancy. The primary end point was the number of breast cancer events (defined as local, regional, or distant recurrence of invasive breast cancer or new contralateral invasive breast cancer) during follow-up. The primary analysis was planned to be performed after 1600 patient-years of follow-up. The prespecified safety threshold was the occurrence of 46 breast cancer events during this period. Breast cancer outcomes in this treatment-interruption group were compared with those in an external control cohort consisting of women who would have met the entry criteria for the current trial. RESULTS: Among 516 women, the median age was 37 years, the median time from breast cancer diagnosis to enrollment was 29 months, and 93.4% had stage I or II disease. Among 497 women who were followed for pregnancy status, 368 (74.0%) had at least one pregnancy and 317 (63.8%) had at least one live birth. In total, 365 babies were born. At 1638 patient-years of follow-up (median follow-up, 41 months), 44 patients had a breast cancer event, a result that did not exceed the safety threshold. The 3-year incidence of breast cancer events was 8.9% (95% confidence interval [CI], 6.3 to 11.6) in the treatment-interruption group and 9.2% (95% CI, 7.6 to 10.8) in the control cohort. CONCLUSIONS: Among select women with previous hormone receptor-positive early breast cancer, temporary interruption of endocrine therapy to attempt pregnancy did not confer a greater short-term risk of breast cancer events, including distant recurrence, than that in the external control cohort. Further follow-up is critical to inform longer-term safety. (Funded by ETOP IBCSG Partners Foundation and others; POSITIVE ClinicalTrials.gov number, NCT02308085.).

Fertility Preservation and Assisted Reproduction in Patients With Breast Cancer Interrupting Adjuvant Endocrine Therapy to Attempt Pregnancy.

PURPOSE: We investigated time to pregnancy, efficacy and safety of fertility preservation, and assisted reproductive technologies (ARTs) in women with early hormone receptor-positive breast cancer (BC) desiring future pregnancy. PATIENTS AND METHODS: POSITIVE is an international, single-arm, prospective trial, in which 518 women temporarily interrupted adjuvant endocrine therapy to attempt pregnancy. We evaluated menstruation recovery and factors associated with time to pregnancy and investigated if ART use was associated with achieving pregnancy. The cumulative incidence of BC-free interval (BCFI) events was estimated according to the use of ovarian stimulation at diagnosis. The median follow-up was 41 months. RESULTS: Two hundred seventy-three patients (53%) reported amenorrhea at enrollment, of whom 94% resumed menses within 12 months. Among 497 patients evaluable for pregnancy, 368 (74%) reported at least one pregnancy. Young age was the main factor associated with shorter time to pregnancy with cumulative incidences of pregnancy by 1 year of 63.5%, 54.3%, and 37.7% for patients age <35, 35-39, and 40-42 years, respectively. One hundred and seventy-nine patients (36%) had embryo/oocyte cryopreservation at diagnosis, of whom 68 reported embryo transfer after enrollment. Cryopreserved embryo transfer was the only ART associated with higher chance of pregnancy (odds ratio, 2.41 [95% CI, 1.75 to 4.95]). The cumulative incidence of BCFI events at 3 years was similar for women who underwent ovarian stimulation for cryopreservation at diagnosis, 9.7% (95% CI, 6.0 to 15.4), compared with those who did not, 8.7% (95% CI, 6.0 to 12.5). CONCLUSION: In POSITIVE, fertility preservation using ovarian stimulation was not associated with short-term detrimental impact on cancer prognosis. Pregnancy rates were highest among those who underwent embryo/oocyte cryopreservation followed by embryo transfer.

Employment trajectories of young women with breast cancer: an ongoing prospective cohort study in Italy and Switzerland.

PURPOSE: Despite extensive research on cancer and work-related outcomes, evidence from longitudinal cohort studies is limited, especially in young women with breast cancer (BC). We aimed to investigate employment trajectories in young BC survivors and to identify potential factors associated with changes in work activity. METHODS: The HOHO European prospective multicenter cohort study enrolled 300 young women (≤ 40 years) with newly diagnosed BC. Women completed surveys at baseline and every 6 months for 3 years, then yearly for up to 10 years to assess, among other variables, employment status, sociodemographic, medical, and treatment data. Symptoms were assessed by the Breast Cancer Prevention Trial symptom scales and single items from the Cancer Rehabilitation Evaluation System. Univariable and multivariable multinomial logistic regression analyses identified factors associated with changes in employment status. RESULTS: Among the 245 women included in this analysis, 85% were employed at the last individual post-baseline assessment (1 to 10 years). At 5 years, women had a 29.4% probability (95% CI: 23.6-35.5) of experiencing any reduction and a 14.9% probability (95% CI: 10.6-19.9) of experiencing any increase in work activities. Being enrolled in Switzerland (vs. Italy) and reporting more trouble in performing daily activities were significantly associated with work reduction. CONCLUSION: Our results suggest that most young BC survivors remain employed in the long-term. IMPLICATIONS FOR CANCER SURVIVORS: Regular evaluation of symptoms which may interfere with daily life and identification of financial discomfort is critical in providing timely and individually tailored interventions and in limiting unwanted reductions in work activities.

Who are the women who enrolled in the POSITIVE trial: A global study to support young hormone receptor positive breast cancer survivors desiring pregnancy.

BACKGROUND: Premenopausal 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. METHODS: 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. FINDINGS: 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 <35 years at enrolment (42.7 %), had mastectomy (59.0 %) and received tamoxifen alone (59.8 %). More Asian women were nulliparous (81.0 %), had node-negative disease (76.2%) and received tamoxifen + OFS (56.0 %). More European women had received chemotherapy (69.3 %). INTERPRETATION: 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.

Estimation of historical control rate for a single arm de-escalation study - Application to the POSITIVE trial.

BACKGROUND: Although randomized controlled clinical trials are optimal to evaluate the effect of an experimental therapy, single-arm trials are required whenever randomization is unethical or not feasible, such as de-escalation studies. We propose using prospectively identified historical controls to place results of single-arm, de-escalation trials into context. METHODS: POSITIVE is a prospective, single-arm study in young women with hormone-receptor-positive early breast cancer to determine if temporarily interrupting adjuvant endocrine therapy in order to become pregnant increases the risk of a breast cancer event. After 272 women enrolled in POSITIVE, we identified a cohort of 1499 SOFT/TEXT patients potentially eligible to enroll in POSITIVE who did not interrupt endocrine therapy. Method I used the SOFT/TEXT cohort to calculate annualized hazard rates by a piecewise exponential model. Method II used the SOFT/TEXT cohort to group-match SOFT/TEXT patients to POSITIVE patients; sample sets of SOFT/TEXT patients were randomly drawn 5000 times to obtain sets having patient, disease, and treatment characteristics more balanced with POSITIVE participants. RESULTS: Compared with SOFT/TEXT, POSITIVE participants were younger, less likely to be overweight/obese, had fewer positive nodes, and fewer received aromatase inhibitor or chemotherapy. The estimated 3-year breast cancer free interval event rates were 9.5% (95% CI: 7.9%,11.1%) for Method I and 9.4% (95% CI: 7.8%,10.9%) for Method II, compared with 5.8% initially assumed when POSITIVE was designed. CONCLUSION: External control datasets should be identified before launching single-arm, de-escalation trials and methods applied during their conduct to provide context for interim monitoring and interpretation of the final analysis.

Pregnancy after breast cancer: Are young patients willing to participate in clinical studies?

Young patients with breast cancer (BC) are often concerned about treatment-induced infertility and express maternity desire. Conception after BC does not seem to affect outcome, but information in estrogen-receptor positive (ER+) disease is not definitive. From September 2012-March 2013, 212 evaluable patients with ER+ early BC, <37 years at diagnosis, from 5 regions (Europe/US/Canada/Middle-East/Australia) answered a survey about fertility concerns, maternity desire and interest in a study of endocrine therapy (ET) interruption to allow pregnancy. Overall, 37% of respondents were interested in the study; younger patients (≤30 years) reported higher interest (57%). Motivation in younger patients treated >30 months was higher (83%) than in older women (14%), interest was independent of age in patients treated for ≤30 months. A prospective study in this patient population seems relevant and feasible. The International-Breast-Cancer-Study-Group (IBCSG), within the Breast-International-Group (BIG) - North-American-Breast-Cancer-Groups (NABCG) collaboration, is launching a study (POSITIVE) addressing ET interruption to allow pregnancy.