Adjuvant chemotherapy does not improve survival in node-positive luminal A breast cancer
Endocrine therapy alone may decrease morbidity in node-positive, luminal A breast cancer patients, a new retrospective study shows. Adjuvant chemotherapy, on the other hand, may confer only minimal benefits.
There was no significant difference in the overall survival of node-positive, luminal A breast cancer patients who received endocrine therapy alone (n=50; median age 58.7±11.7 years) and those who received adjuvant chemotherapy (n=642; median age 58.3±9.5 years;hazard ratio [HR], 4.565; 95 percent CI, 0.59 to 40.947; p=0.175).
In contrast, pathologic node stage (HR, 3.715; 0.807 to 17.106; p=0.092) and progesterone receptor (PR) status (HR, 8.627; 1.646 to 45.216; p=0.011) were both associated with overall survival, according to multivariable analysis.
Similarly, adjuvant chemotherapy did not significantly impact disease-free survival (DFS) in node-positive luminal A breast cancer patients (HR, 2.420; 0.554 to 1.0567; p=0.240). On the other hand, nuclear grade (p=0.032), PR status (p=0.001) and radiotherapy (p=0.025) all significantly influenced DFS.
The 50 women on endocrine therapy alone were matched by propensity score to a maximum of 8 women who received adjuvant chemotherapy, yielding a comparison group of 642. There were no significant differences between the groups in terms of demographic factors, tumour factors and pathologic findings.
Patients receiving treatment for invasive breast cancer were recruited from the Samsung Medical Centre. Tamoxifen or aromatase inhibitors were used for the endocrine therapy. Adjuvant chemotherapy included regimens such as doxorubicin with cyclophosphamide, paclitaxel, docetaxel and 5-fluorouracil.