Outcomes of older adults with early-stage triple-negative breast cancer (TNBC) receiving chemotherapy: a single-institution experience.

BACKGROUND: Despite lower chemotherapy use in older triple-negative breast cancer (TNBC) patients, their outcomes match younger counterparts. We compared outcomes in early-stage TNBC patients by age receiving chemotherapy at a major cancer center with a national TNBC database. METHODS: Retrospective study using institutional data on stage I-III TNBC (ER/PR < 10%) women with neoadjuvant/adjuvant chemotherapy. Based on their ages at diagnosis, patients were stratified into four categories: ≤40, 41-59, 60-69, and ≥ 70 years. Demographic and clinical characteristics recorded included race, disease stage, ER/PR positivity, treatment regimen, lymphatic or vascular invasion (LVI), histologic grade, Ki-67 level, body mass index (BMI), and pathologic complete response (pCR) following neoadjuvant treatment and are summarized using descriptive statistics. The primary endpoints were overall survival (OS), disease-free survival (DFS), and distant disease-free survival (DDFS); all were estimated using the Kaplan-Meier method. Both univariate and multivariate (MV) Cox regressions were applied to evaluate the impact of important covariates on these time-to-event endpoints. RESULTS: Of the 2336 patients studied, 492 (21.1%) were ≤ 40 years old, 1239 (53.1%) were 41-59, 461 (19.7%) were 60-69, and 144 (6.2%) were ≥ 70. In the univariate regression model of OS/DFS/DDFS, age ≥ 70 was significantly associated with worse OS (p = 0.0217); other factors associated with worse OS were non-anthracycline-based chemotherapy, higher tumor stage, and neoadjuvant chemotherapy. The multivariate Cox regression model, adjusted for race and stage, showed no significant effects of age on OS; however, patients ≥ 70 years old who received non-anthracycline treatment combinations had worse DFS (hazard ratio = 0.349 vs. 1.049, p = 0.0293) and DDFS (hazard ratio = 0.317 vs. 1.016, p = 0.0251) than patients ≤ 40 years old. DFS from MV model after adjusting for age, race, and disease stage, the hazard ratio between anthracycline + taxane treatments and anthracycline + other treatments in patients ≥ 70 years old was statistically significantly lower than in patients ≤ 40 years old (hazard ratios [HRs] = 0.349 vs. 1.049, p = 0.0293). CONCLUSIONS: Our findings indicate that outcomes such as DFS are less favorable in older compared to younger patients with early-stage TNBC, primarily in those who did not receive an anthracycline based chemotherapy regimen.

Association of Chemotherapy With Survival in Elderly Patients With Multiple Comorbidities and Estrogen Receptor-Positive, Node-Positive Breast Cancer.

Importance: Breast cancer risk and comorbidities increase with age. Data are lacking on the association of adjuvant chemotherapy with survival in elderly patients with multiple comorbidities and node-positive breast cancer. Objective: To examine the association of chemotherapy with survival in elderly patients with multiple comorbidities and estrogen receptor-positive, node-positive breast cancer. Design, Setting, and Participants: This retrospective cohort study included patients in the US National Cancer Database who were 70 years or older; had a Charlson/Deyo comorbidity score of 2 or 3; had estrogen receptor-positive, ERBB2 (formerly HER2 or HER2/neu)-negative breast cancer; and underwent surgery for pathologic node-positive breast cancer from January 1, 2010, to December 31, 2014. Propensity scores were used to match patients receiving adjuvant chemotherapy with those not receiving adjuvant chemotherapy based on age, comorbidity score, facility type, facility location, pathologic T and N stage, and receipt of adjuvant endocrine and radiation therapy. Data analysis was performed from December 13, 2018, to April 28, 2020. Exposures: Chemotherapy. Main Outcomes and Measures: The association of adjuvant chemotherapy with overall survival was estimated using a double robust Cox proportional hazards regression model. Results: Of a total of 2 445 870 patients in the data set, 1592 patients (mean [SD] age, 77.5 [5.5] years; 1543 [96.9%] female) met the inclusion criteria and were included in the initial nonmatched analysis. Of these patients, 350 (22.0%) received chemotherapy and 1242 (78.0%) did not. Compared with patients who did not receive chemotherapy, patients who received chemotherapy were younger (mean age, 74 vs 78 years; P < .001), had larger primary tumors (pT3/T4 tumors: 72 [20.6%] vs 182 [14.7%]; P = .005), and had higher pathologic nodal burden (75 [21.4%] vs 81 [6.5%] with stage pN3 disease and 182 [52.0%] vs 936 [75.4%] with stage pN1 disease; P < .001). More patients who received chemotherapy also received other adjuvant treatments, including endocrine therapy (309 [88.3%] vs 1025 [82.5%]; P = .01) and radiation therapy (236 [67.4%] vs 540 [43.5%]; P < .001). In the matched cohort, with a median follow-up of 43.1 months (95% CI, 39.6-46.5 months), no statistically significant difference was found in median overall survival between the chemotherapy and no chemotherapy groups (78.9 months [95% CI, 78.9 months to not reached] vs 62.7 months [95% CI, 56.2 months to not reached]; P = .13). After adjustment for potential confounding factors, receipt of chemotherapy was associated with improved survival (hazard ratio, 0.67; 95% CI, 0.48-0.93; P = .02). Conclusions and Relevance: This cohort study found that in node-positive, estrogen receptor-positive elderly patients with breast cancer and multiple comorbidities, receipt of chemotherapy was associated with improved overall survival. Despite attempts to adjust for selection bias, these findings suggest that physicians carefully selected patients likely to derive treatment benefit from adjuvant chemotherapy based on certain unmeasured variables. A standardized, multidisciplinary approach to care may be associated with long-term treatment outcomes in this subset of the population.