(RxWiki News) Mastectomy surgery often includes the removal of cancerous lymph nodes under the arm. One common therapy after this procedure might improve recovery.
A recent study showed that women who had positive, cancerous lymph nodes removed had a lower rate of cancer recurrence and death when followed up with radiotherapy.
This study also showed that the benefit was the same even if the women had received chemotherapy or hormone therapy as part of their treatment after mastectomy.
A mastectomy is the removal of breast tissue usually associated with a diagnosis of breast cancer and can include any cancerous lymph nodes to help keep the cancer from spreading. Radiotherapy uses ionizing radiation to control or kill malignant cancer cells by breaking them down at the molecular level.
"Discuss recovery from mastectomy with your surgeon."
This study was led by Paul McGale, PhD, a senior statistician in the Early Breast Cancer Trialists' Collaborative Group at the Clinical Trial Service Unit in Oxford, U.K.
Dr. McGale and his team looked at the results of 14 randomized trials from 1964 to 1982, which included the results from 3,786 women who had received mastectomies along with the surgical removal of lymph nodes under the arm.
The women were randomized to receive either radiotherapy to the chest wall and surrounding region or no radiotherapy. Radiotherapy uses ionizing radiation to control or kill malignant cancer cells.
The women were further broken down into three groups: those with no cancer in the lymph nodes, those with one to three cancerous lymph nodes and those with four or more cancerous lymph nodes.
The researchers then followed up with the women an average of 11 years later and collected data on the number of deaths and recurrences of cancer as of 2009.
"In 700 women in whom the pathologists could find no sign that the nodes were affected, radiotherapy did not reduce the risk of recurrence or of dying from breast cancer," said Dr. McGale. "However, in the 1,314 women who had between one and three positive nodes, radiotherapy reduced the recurrence rate by nearly a third (32 percent) and the breast cancer death rate by a fifth (20 percent). Giving radiotherapy to these women led to nearly 12 fewer recurrences of breast cancer per 100 women after ten years, and eight fewer deaths per 100 women after 20 years."
The data showed that the 405 women with only one positive lymph node had a similar rate of death and recurrence as women with two and three cancerous nodes.
The study revealed a 21 percent reduction in recurrences of cancer for the women who received radiotherapy after mastectomy when they had four or more positive nodes. The death rate among these women also decreased by 13 percent.
Dr. McGale and team noted that the benefit remained the same for women who received chemotherapy, hormone therapy or no therapy at all in their trials.
A total of 65 percent of women with one to three positive nodes received chemotherapy and 21 percent received hormone therapy.
"It is already accepted that women with four or more positive nodes benefit from radiotherapy after mastectomy, and these findings confirm this benefit," he said. "However, it is for women with between one and three positive nodes where the previous evidence has been unclear."
The authors concluded that while advances in treatments may reduce the overall number of patients who may need post-mastectomy radiotherapy today, the benefit for those who do need it are likely to be at least as big.
This study was published March 19 in the Lancet.
The study was funded by Cancer Research UK, the British Heart Foundation and the UK Medical Research Council.
The authors made no disclosures.