Abstract Background. The increase in breast cancer risk during pregnancy and postpartum is well known; however, the molecular phenotype of breast cancers occurring shortly after pregnancy has not been well studied. Given this, we investigated whether nulliparity and the time interval since pregnancy among parous women affects the breast cancer phenotype in young women. Materials and Methods. We examined molecular phenotype in relation to time since pregnancy in a prospective cohort of 707 young women (aged ≤40 years) with breast cancer. Parity was ascertained from study questionnaires. Using tumor histologic grade on central review and biomarker expression, cancers were categorized as luminal A- or B-like, HER2 enriched, and triple negative. Results. Overall, 32% were luminal A-like, 41% were luminal B-like, 9% were HER2 enriched, and 18% were triple negative. Although, numerically, patients diagnosed >5 years after pregnancy had more luminal A-like subtypes than women with shorter intervals since pregnancy, there was no evidence of a relationship between these intervals and molecular subtypes once family history of breast cancer and age at diagnosis were considered. Conclusion. Distribution of breast cancer molecular phenotype did not differ significantly among young women by parity or time interval since parturition when important predictors of tumor phenotype such as age and family history were considered. Implications for Practice: Distribution of breast cancer molecular phenotype did not differ among parous young women by time interval since pregnancy. The implication of these findings for clinical practice suggests that pregnancy-associated breast cancers may be seen up to 5 years beyond parturition.
Abstract P2-10-03: Decision-making surrounding adjuvant chemotherapy in young women with early stage breast cancer
Cancer Research | May 4, 2015 | Volume: 75 | Issue: 9_Supplement | Pages: P2-10-03-P2-10-03
Abstract Background: There is an increasing recognition that many young women with breast cancer will have favorable outcomes without chemotherapy. We sought to characterize decision-making surrounding adjuvant chemotherapy treatment (CT) in this population for whom chemotherapy has historically been a standard of care. Methods: As part of an ongoing, multi-center, prospective cohort of young women diagnosed with breast cancer at age 40 and younger, we identified 657 women with Stage I-III breast cancer. Participants were asked to complete surveys by mail that included questions about socio-demographics, decision-making, and treatment history within the first year following diagnosis. Tumor characteristics were ascertained via pathology and medical record review. We used Chi-square tests to compare: decisional involvement (patient-driven vs. shared vs. physician-driven), degree of confidence, and feeling informed about the CT decision (the latter two measured on a 0-10 scale, categorized as follows: 0-5=low; moderate=6-8; 9-10=high) between women who did and did not receive CT. To explore clinical appropriateness of the CT decision, we used logistic regression to assess the relationship between tumor characteristics and non-receipt of CT among women with Stage I/II disease. Results: Among women with Stage I (n=250), II (n=312), and III (n=95), disease, 66%, 95%, and 100%, received CT, respectively. A greater proportion of women who had CT were highly confident with their decision compared with women who did not have CT (80% vs. 60%, p<0.0001); women who did not have CT were more likely to report a low level of feeling informed about the CT decision compared to women who received CT (20% vs. 5%, p<0.0001). Women who did not have CT were also more likely to report the final CT decision as made by their doctor (49% vs. 28%) and less likely to report a shared decision (33% vs. 59%, p<0.0001). Non-receipt of CT in women with Stage I/II disease (n=546) was associated within having node negative disease, T1 (vs. T2 or larger), Her2- negative, and hormone receptor positive tumors. Conclusion: Although non-receipt of CT would be expected to be viewed favorably by patients and doctors, we found that women who received CT felt more confident and better informed than those who received no CT. Given that women who did not have CT were also less likely to perceive the CT decision as shared, improved communication together with better decisional support may be beneficial, especially for women who do not receive adjuvant chemotherapy. Citation Format: Shoshana M Rosenberg, Karen Sepucha, Kathryn J Ruddy, Lidia Schapira, Steven Come, Virginia Borges, Evan Morgan, Nancy U Lin, Shari Gelber, Rulla M Tamimi, Ann H Partridge. Decision-making surrounding adjuvant chemotherapy in young women with early stage breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-10-03.
Abstract 3279: Dense and non-dense mammographic area and risk of breast cancer by age and tumor characteristics
Cancer Research | May 1, 2015 | Volume: 74 | Issue: 19_Supplement | Pages: 3279-3279
Abstract Introduction: We recently reported the percentage of mammographic density (MD) to be a breast cancer risk factor across tumor characteristics and age groups. Yet, we noted stronger associations for tumors of large size and positive lymph nodes across all ages, and ER-negative status among women ages <55 years, suggesting high MD may play an important role in tumor aggressiveness, especially in younger women. We extend this initial study to investigate whether these associations with aggressive disease are due to the underlying associations of absolute dense or non-dense area, or both, with breast cancer risk. Methods: Data were pooled from six studies including 3517 women with invasive breast cancer and 8558 without. Dense area and non-dense area were assessed from digitized film-screen mammograms using a computer-assisted threshold technique. We standardized dense and non-dense area measurements made within each study and categorized into quartiles based on the control distribution for pooled analyses. We used polytomous logistic regression to calculate breast cancer odds according to tumor type, histopathological characteristics, and receptor (ER, PR) status by age (<55, 55-64, and ≥65 years), adjusting for continuous age, body mass index, and study site. Results: Absolute dense area was associated with increased breast cancer risk [odds ratios (ORs) Q1 vs Q2: 0.67, Q3 vs Q2: 1.25, Q4 vs Q2: 1.62] and non-dense area was associated with decreased breast cancer risk (ORs: Q1 vs Q2: 1.44, Q3 vs Q2: 0.89, Q4 vs Q2: 0.71) overall and across all age groups. Positive associations for absolute dense area were observed across all invasive tumor characteristics. Stronger associations were noted for larger tumors across all ages (p-trend <0.01). Among women <55 years, stronger associations were observed for ER+ vs ER- [p-heterogeneity (het) = 0.02] and PR+ vs PR- tumors (p-het = 0.02). Non-dense area was inversely associated with all tumor characteristics evaluated except for tumors <1.1 cm, for which no association was present. The inverse association was stronger for larger tumors, particularly for women <55 years (p-trend <0.01). Also among women <55 years, a stronger inverse association with non-dense area was observed for ER- vs. ER+ tumors (p-het = 0.02). Conclusion: These results suggest the strong association we previously observed of high percent MD and ER-negative disease in women <55 years could be explained by the low amount of non-dense area in these women. Further research is warranted to clarify the possible differential associations of absolute dense and non-dense area on breast cancer risk according to tumor characteristics. Citation Format: Kimberly A. Bertrand, Christopher G. Scott, Rulla M. Tamimi, Matthew R. Jensen, V. Shane Pankratz, Aaron Norman, John Shepherd, Yunn-Yi Chen, Karla Kerlikowske, Celine M. Vachon. Dense and non-dense mammographic area and risk of breast cancer by age and tumor characteristics. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3279. doi:10.1158/1538-7445.AM2014-3279
Novel Associations between Common Breast Cancer Susceptibility Variants and Risk-Predicting Mammographic Density Measures
Cancer Research | April 10, 2015 | Volume: 75 | Issue: 12 | Pages: 2457-2467