Does it matter how much healthy tissue is removed during surgery for patients with breast cancer who received chemotherapy first?

This study examined if there was a difference in patients with breast cancer first treated with chemotherapy that had a wide or narrow margin of healthy tissue removed during surgery. The results showed that the outcomes were similar regardless of how much healthy tissue was removed.

Traditionally, mastectomy (the removal of the whole breast) is used to treat patients with breast cancer (BC) if the cancer is widespread throughout the breast. For patients with smaller tumors, it is possible to just remove the tumor and not the breast. Patients are often given chemotherapy before surgery to shrink the tumor and make surgery more effective. 

After chemotherapy and before surgery, patients are examined for cancer cells remaining in healthy tissue surrounding the tumor and in nearby lymph nodes. The results determine how much of the healthy tissue surrounding the tumor should also be removed. Wide margins are over 1 cm of healthy tissue and narrow margins are less than 1 cm. It is unclear which margin is more effective at preventing a return of BC over the long term.

Data from 406 patients with BC was analyzed. Patients received chemotherapy before having surgery. 48 patients had almost no healthy margin removed. 74 patients had a narrow margin of healthy tissue removed. 284 patients had a wide margin of healthy tissue removed. Patients were followed for an average of 84.3 months.

The size of the margin did not significantly affect patients’ survival. After 5 years, 85.1% of patients with a narrow margin, 88% of patients with a wide margin and 96.4% of patients with no margin were alive. 

BC did not return within the breast in 94.2% of patients with a narrow margin, 90.6% of patients with a wide margin and 95% of patients with no margin. BC did not return anywhere in the body in 71.9% of patients with a narrow margin, 74.1% of patients with a wide margin and 87.2% of patients with no margin.

Patients who did not have cancer detected in lymph nodes had a 54% higher chance of survival. They also have a 54% higher chance of not developing a return of BC anywhere in the body and a 37% higher chance in the breast.

The authors concluded that the size of the margin of healthy tissue removed during surgery does not impact the effectiveness of treatment in patients with BC first treated with chemotherapy.

The use of medical records data in this study means that not all information was available for every patient, such as HER2 mutation status and use of radiotherapy after surgery. This study was also limited by the small number of patients that had almost no margin removed and a narrow margin removed.