BackgroundThe diagnosis and treatment of breast cancer can have profound effects on a young woman's family planning and fertility, particularly among women with hormone receptor–positive breast cancer.MethodsThe Young Women's Breast Cancer Study was a multicenter cohort of women aged 40 years or younger and newly diagnosed with breast cancer from 2006 to 2016. Surveys included assessments of fertility concerns, endocrine therapy (ET) preferences, and use. Characteristics were compared between women who reported that fertility concerns affected ET decisions and those who did not. Logistic regression was used to identify factors associated with having an ET decision affected by fertility concerns.ResultsOf 643 eligible women with hormone receptor–positive, stage I to III breast cancer, one‐third (213 of 643) indicated that fertility concerns affected ET decisions. In a multivariable analysis, only parity at diagnosis was significantly associated with fertility concerns affecting ET decisions (odds ratio for nulliparous vs ≥2 children, 6.96; 95% confidence interval, 4.09‐11.83; odds ratio for 1 vs ≥2 children, 5.30; 95% confidence interval, 3.03‐9.87). Noninitiation/nonpersistence was higher among women with fertility concerns versus those without fertility concerns (40% vs 20%; P < .0001). Among women with fertility‐related ET concerns, 7% (15 of 213) did not initiate ET, and 33% (70 of 213) were nonpersistent over 5 years of follow‐up. Of these women, 66% (56 of 85) reported 1 or more pregnancies or pregnancy attempts; 27% (15 of 56) had resumed ET at the last available follow‐up through 5 years.ConclusionsConcern about fertility is a contributor to adjuvant ET decisions among a substantial proportion of young breast cancer survivors. Ensuring family planning is addressed in the setting of ET recommendations should be a priority throughout the cancer care continuum.
Abstract PD2-08: Endocrine therapy non-persistence and recurrence in young women with early stage breast cancer
Abstract Background: Young age at diagnosis is an independent risk factor for recurrence and death from breast cancer (BC), with the greatest impact of young age demonstrated in hormone receptor positive (HR+) disease. Younger women are less likely to be adherent to endocrine therapy (ET), which may contribute to disparate outcomes. Methods: As part of a prospective cohort that enrolled women with BC diagnosed at age ≤40 between 2006-2016, we identified women with HR+, Stage I-III BC. Serial surveys with items assessing socio-demographic and treatment information including medication use are administered 1-2 times per year. Medical record review was used to ascertain stage and HR status and to confirm recurrent disease (locoregional, distant, or new primary breast cancer). Women who initiated ET but discontinued it <5-years post-diagnosis without resumption were classified as non-persistent. Univariable and multivariable regression models were fit to identify predictors of non-persistence and recurrence.Results: Among 607 women who initiated ET (median age at diagnosis: 36, range:17-40; 38%, 45%, 17% were Stage 1, 2, and 3, respectively).16% (99/607) were non-persistent, of whom 30% (30/99) discontinued ET ≤2 years post-diagnosis and over half had discontinued (54%, 54/99) by 3 years. In multivariable regression, those who were younger at diagnosis (age ≤30 vs. 36-40: OR: 3.39, 95% CI: 1.84-6.24; age 31-36 vs. 36-40: OR: 2.81 95% CI: 1.70-4.64) were more likely to discontinue ET while those with a higher stage at diagnosis were less likely to discontinue ET (Stage 2 vs. 1: OR: 0.46, 95% CI: 0.29-0.74; Stage 3 vs 1: OR: 0.32, 95% CI: 0.15-0.68). At a median follow-up time from diagnosis of 7.8 years (range 1-13 years), 15% of women (88/607) recurred or developed a new primary BC at a median time from diagnosis of 3.5 years (range 1-12 years). Of these, 66% (58/88) were distant recurrences, 32% (28/88) loco-regional, and 2% (2/88) new primary BCs. Rates of recurrence were higher among women who were persistent (81/508, 16%) vs. non-persistent (7/99, 7%, p=0.02). In multivariable regression, those who were non-persistent were less likely to recur (OR: 0.43, 95% CI: 0.19-0.98) while those with a higher stage were more likely to recur (Stage 3 vs. 1: OR: 2.36, 95% CI: 1.03-5.41). Sociodemographic, patient, and other treatment factors did not predict recurrence. Conclusions: Approximately 16% of young women with HR+ BC stop ET earlier than indicated, however non-persistence was not a risk factor for BC recurrence a median of 8 years following diagnosis in our cohort. Importantly, women with higher risk disease who are likely to benefit most from adherence to ET were less likely to discontinue treatment. Extended follow-up will further inform the impact of non-persistence on the incidence of late recurrences for which women with HR+ BC are at increased risk. Citation Format: Shoshana M Rosenberg, Yue Zheng, Philip Poorvu, Kathryn Ruddy, Rachel Gaither, Rulla Tamimi, Lidia Schapira, Jeffrey Peppercorn, Steven Come, Virginia Borges, Ann Partridge. Endocrine therapy non-persistence and recurrence in young women with early stage breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD2-08.
Breast Cancer Risk Factors and Survival by Tumor Subtype: Pooled Analyses from the Breast Cancer Association Consortium
Abstract Background: It is not known whether modifiable lifestyle factors that predict survival after invasive breast cancer differ by subtype. Methods: We analyzed data for 121,435 women diagnosed with breast cancer from 67 studies in the Breast Cancer Association Consortium with 16,890 deaths (8,554 breast cancer specific) over 10 years. Cox regression was used to estimate associations between risk factors and 10-year all-cause mortality and breast cancer–specific mortality overall, by estrogen receptor (ER) status, and by intrinsic-like subtype. Results: There was no evidence of heterogeneous associations between risk factors and mortality by subtype (Padj > 0.30). The strongest associations were between all-cause mortality and BMI ≥30 versus 18.5–25 kg/m2 [HR (95% confidence interval (CI), 1.19 (1.06–1.34)]; current versus never smoking [1.37 (1.27–1.47)], high versus low physical activity [0.43 (0.21–0.86)], age ≥30 years versus <20 years at first pregnancy [0.79 (0.72–0.86)]; >0–<5 years versus ≥10 years since last full-term birth [1.31 (1.11–1.55)]; ever versus never use of oral contraceptives [0.91 (0.87–0.96)]; ever versus never use of menopausal hormone therapy, including current estrogen–progestin therapy [0.61 (0.54–0.69)]. Similar associations with breast cancer mortality were weaker; for example, 1.11 (1.02–1.21) for current versus never smoking. Conclusions: We confirm associations between modifiable lifestyle factors and 10-year all-cause mortality. There was no strong evidence that associations differed by ER status or intrinsic-like subtype. Impact: Given the large dataset and lack of evidence that associations between modifiable risk factors and 10-year mortality differed by subtype, these associations could be cautiously used in prognostication models to inform patient-centered care.
A Population-Based Study of Genes Previously Implicated in Breast Cancer
Objective: We aimed to investigate eligibility for breast conserving surgery (BCS) pre- and post-neoadjuvant systemic therapy (NST), and trends in the surgical treatment of young breast cancer patients. Background: Young women with breast cancer are more likely to present with larger tumors and aggressive phenotypes, and may benefit from NST. Little is known about how response to NST influences surgical decisions in young women. Methods: The Young Women's Breast Cancer Study, a multicenter prospective cohort of women diagnosed with breast cancer at age ≤40, enrolled 1302 patients from 2006 to 2016. Disease characteristics, surgical recommendations, and reasons for choosing mastectomy among BCS-eligible patients were obtained through the medical record. Trends in use of NST, rate of clinical and pathologic complete response, and surgery were also assessed. Results: Of 1117 women with unilateral stage I-III breast cancer, 315 (28%) received NST. Pre-NST, 26% were BCS eligible, 17% were borderline eligible, and 55% were ineligible. After NST, BCS eligibility increased from 26% to 42% (P < 0.0001). Among BCS-eligible patients after NST (n = 133), 41% chose mastectomy with reasons being patient preference (53%), BRCA or TP53 mutation (35%), and family history (5%). From 2006 to 2016, the rates of NST (P = 0.0012), clinical complete response (P < 0.0001), and bilateral mastectomy (P < 0.0001) increased, but the rate of BCS did not increase (P = 0.34). Conclusion: While the proportion of young women eligible for BCS increased after NST, many patients chose mastectomy, suggesting that surgical decisions are often driven by factors beyond extent of disease and treatment response.
Simplified Breast Risk Tool Integrating Questionnaire Risk Factors, Mammographic Density, and Polygenic Risk Score: Development and Validation
Abstract Background: Clinical use of breast cancer risk prediction requires simplified models. We evaluate a simplified version of the validated Rosner–Colditz model and add percent mammographic density (MD) and polygenic risk score (PRS), to assess performance from ages 45–74. We validate using the Mayo Mammography Health Study (MMHS). Methods: We derived the model in the Nurses' Health Study (NHS) based on: MD, 77 SNP PRS and a questionnaire score (QS; lifestyle and reproductive factors). A total of 2,799 invasive breast cancer cases were diagnosed from 1990–2000. MD (using Cumulus software) and PRS were assessed in a nested case–control study. We assess model performance using this case–control dataset and evaluate 10-year absolute breast cancer risk. The prospective MMHS validation dataset includes 21.8% of women age <50, and 434 incident cases identified over 10 years of follow-up. Results: In the NHS, MD has the highest odds ratio (OR) for 10-year risk prediction: ORper SD = 1.48 [95% confidence interval (CI): 1.31–1.68], followed by PRS, ORper SD = 1.37 (95% CI: 1.21–1.55) and QS, ORper SD = 1.25 (95% CI: 1.11–1.41). In MMHS, the AUC adjusted for age + MD + QS 0.650; for age + MD + QS + PRS 0.687, and the NRI was 6% in cases and 16% in controls. Conclusion: A simplified assessment of QS, MD, and PRS performs consistently to discriminate those at high 10-year breast cancer risk. Impact: This simplified model provides accurate estimation of 10-year risk of invasive breast cancer that can be used in a clinical setting to identify women who may benefit from chemopreventive intervention. See related commentary by Tehranifar et al., p. 587
Pregnancy after breast cancer: Results from a prospective cohort of young women with breast cancer
BackgroundMany young women with newly diagnosed breast cancer are interested in future pregnancies. Prospective data regarding fertility interest and reproductive patterns after diagnosis are needed to counsel patients.MethodsThe Young Women's Breast Cancer Study is a multicenter, prospective cohort of women who were diagnosed with breast cancer at age ≤40 years between 2006 and 2016. Women complete surveys at baseline, every 6 months for 3 years, then annually. Here, the authors describe fertility interest and pregnancies within 5 years of diagnosis for women with stage 0 through III breast cancer.ResultsOf 1026 eligible participants, 368 (36%) reported interest in future biologic children at least once within 5 years after diagnosis, including 16% at 5 years after diagnosis. Among 130 women who attempted to become pregnant, 90 (69.2%) conceived; and, among 896 women who did not attempt to conceive, 18 (2.0%) became pregnant, with a total of 152 pregnancies resulting in 91 live births. Factors associated with pregnancy included younger versus older age at diagnosis (aged ≤30 vs 36‐40 years: odds ratio [OR], 6.63; 95% CI, 3.18‐13.83; P < .0001; aged 31‐35 vs 36‐40 years: OR, 5.86; 95% CI, 3.37‐10.17; P < .0001) and being nulliparous versus parous (OR, 2.66; 95% CI, 1.56‐4.53; P = .001). The receipt of endocrine therapy versus no endocrine therapy (OR, 0.35; 95% CI, 0.20‐0.59; P = .001) was inversely associated with pregnancy.ConclusionsMany women remain interested in future fertility in the 4 years after a breast cancer diagnosis, indicating that longitudinal fertility discussions are needed. Although a minority of those interested in having children attempted to become pregnant in the first 5 years, most who attempted to conceive did so and had live births.
Association of Breast Cancer Surgery With Quality of Life and Psychosocial Well-being in Young Breast Cancer Survivors
514 Background: The 21- gene Breast Recurrence Score predicts benefit from adjuvant chemotherapy in estrogen receptor positive (ER+), HER-2 negative (-) breast cancer (BC). We aimed to examine whether the 21-gene assay predicts response to neoadjuvant chemotherapy (NAC). Methods: We identified patients with stage I-III ER+/HER2− BC treated with NAC from the Young Women's Breast Cancer Study, a prospective cohort of women diagnosed with BC at age ≤ 40 years. The 21-gene assay was performed on tumor specimens removed prior to NAC either as part of clinical care or retrospectively for research. Pathologic complete response (pCR) was defined as no residual invasive tumor (ypT0/is ypN0). The relationship between Recurrence Score result (RS) and pCR was evaluated using logistic regression modeling. Results: 76 women in the cohort had undergone NAC for ER+, HER2- BC and were eligible for this analysis: 5 had undergone clinical 21-gene assay testing, 71 had banked specimens retrospectively tested. Median age at diagnosis was 36.7 (24.3-40). Most tumors were of ductal histology (78%), high grade (51%), progesterone receptor (PgR) positive (86%), ≥T2 (88%), clinically node positive (74%), and anthracycline and taxane containing protocols were administered in 86% of cases. RS ranged between 5-75 with 50% > 25 and only 4 < 11. Mean RS was significantly higher among tumors achieving pCR vs. non-pCR response (51.9 vs. 26.6, pwilcoxon= 0.0005). pCR rate in patients with RS > 25 was 21% (8/38) vs. 5% in patients with RS < 25 (2/38), with both pCRs in the <25 group in patients with RS 21-25. In univariable analysis, PgR negativity (odds ratio (OR) 5.62, 95% confidence interval (CI) 1.27-24.89, p = 0.02), high grade (OR 9.03, 95%CI 1.07-76.32, p = 0.04) and higher RS as a continuous variable (OR 1.08, 95%CI 1.04-1.13, p = 0.0003) were associated with a greater likelihood of pCR. In multivariable analysis only RS remained significantly associated with pCR (OR: 1.07, 95%CI 1.01-1.12, p = 0.01): a 7% increase in the odds of pCR for every 1-point increase in RS. Conclusions: In young women with ER+, HER2- BC who received NAC, higher pretreatment RS was associated with an increased likelihood of pCR. Genomic expression profiling assays may have a role in decision-making in young women in need of neoadjuvant therapy. For women with low likelihood of benefiting from NAC, alternative approaches are clearly warranted. Given the demonstrated efficacy of neoadjuvant endocrine therapy in post-menopausal women, further evaluation in young women should be pursued.
Combined Associations of a Polygenic Risk Score and Classical Risk Factors With Breast Cancer Risk
Abstract We evaluated the joint associations between a new 313-variant PRS (PRS313) and questionnaire-based breast cancer risk factors for women of European ancestry, using 72 284 cases and 80 354 controls from the Breast Cancer Association Consortium. Interactions were evaluated using standard logistic regression and a newly developed case-only method for breast cancer risk overall and by estrogen receptor status. After accounting for multiple testing, we did not find evidence that per-standard deviation PRS313 odds ratio differed across strata defined by individual risk factors. Goodness-of-fit tests did not reject the assumption of a multiplicative model between PRS313 and each risk factor. Variation in projected absolute lifetime risk of breast cancer associated with classical risk factors was greater for women with higher genetic risk (PRS313 and family history) and, on average, 17.5% higher in the highest vs lowest deciles of genetic risk. These findings have implications for risk prevention for women at increased risk of breast cancer.