A new study suggests that age may not be the most important factor to consider for chemotherapy in breast cancer patients, who may still benefit from the treatment even at an older age.
“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,” the study authors explained.
Patients from the U.S. National Cancer Database were retrospectively reviewed. Eligibility criteria included age ≥70 years; Charlson/Deyo comorbidity score of 2 or 3; estrogen receptor–positive, ERBB2 (formerly HER2 or HER2/neu)–negative breast cancer; and having underwent operative treatment for pathologic node–positive breast cancer between 2010 and 2014. Patients who received adjuvant chemotherapy were matched to patients who did not based on age, comorbidity score, facility type and location, pathologic T and N stage, and receipt of adjuvant endocrine and radiation therapy.
A total of 1,592 patients (mean [SD] age, 77.5 [5.5] years), nearly all of whom (n=1,543; 96.9%) were female, were included in the nonmatched analysis. Most of these patients (n=350; 22) received chemotherapy; the remaining 1,242 (78%) did not. Patients who received chemotherapy, versus those who did not, tended to be younger (mean age, 74 vs. 78 years; P<0.001), had bigger primary tumors (pT3/T4 tumors: 72 [20.6%] vs. 182 [14.7%]; P=0.005), and had higher pathologic nodal burden (stage pN3 disease: 75 [21.4%] vs. 81 [6.5%]; stage pN1 disease: 182 [52.0%] vs. 936 [75.4%]; P<0.001). The chemotherapy cohort was more likely than the non-chemotherapy patients to receive endocrine therapy (309 [88.3%] vs. 1,025 [82.5%]; P<0.01) and radiation therapy (236 [67.4%] vs. 540 [43.5%]; P<0.001). Patients in the matched analysis were followed for a median 43.1 months (95% confidence interval [CI], 39.6 to 46.5 months); median overall survival did not largely differ between patients who were versus were not receiving chemotherapy (78.9 months [95% CI, 78.9 months to not reached] vs. 62.7 months [95% CI, 56.2 months to not reached]; P=0.13). Adjusted analyses observed that chemotherapy was correlated with greater survival (hazard ratio, 0.67; 95% CI, 0.48 to 0.93; P=0.02).
The study was published in JAMA Oncology.
“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,” summarized the study authors.