Surgery or radiation for breast cancer may be unnecessary after successful chemotherapy

Surgery or radiation may not be the best option for continued treatment once women with breast cancer have successfully responded to chemotherapy, new research shows.

Overall survival was no different between women who received surgery or radiation (loco-regional treatment, LRT) following chemotherapy and those who did not. And though not statistically significant, researchers noted a 7 percent increased rate of death among women who received surgery or radiation. [Abstract S2-02]

“It aligns with previous preclinical findings that suggest surgical removal of the primary tumor bestows a growth advantage on the metastases,” said lead researcher Dr. Rajendra Badwe, director of the Tata Memorial Hospital in Mumbai, India. “I’m sure a lot of oncologists who believe in conventional wisdom and don’t provide loco-regional treatment will feel a lot more comfortable looking at these results.”

The trial included 350 women randomized to receive LRT (n=173) or no treatment (n=177). These women were metastatic breast cancer patients who responded to chemotherapy (six cycles) and both arms were matched for age, clinical tumor size, hormone receptor and HER2 receptor status, and disease spread.

LRT patients had surgery for partial or complete mastectomy and removal of axillary lymph nodes. They then received radiation therapy. The no-LRT arm received neither treatment but continued with chemotherapy. Both study arms received hormone therapy if necessary.

Overall survival was not different between the two study arms (p=0.98). The researchers adjusted for age, hormone receptor and HER2 status, site of disease spread, and the number of tumors in organs beyond the breasts.

The researchers recorded 111 deaths in the LRT arm and 107 in the no-LRT arm over median follow up of 17 months. Nine LRT patients and three no-LRT patients could not complete the study and were not included in the final analysis.

Between the LRT and no-LRT arms, median overall survival was 18.8 and 20.5 months (p=0.6) and overall survival after 2 years was 40 percent and 43.3 percent, respectively.

“We were unable to identify any subgroups that are likely to benefit from LRT,” the researchers said. “Such treatment should be reserved for women who need it for palliative reasons.”