(RxWiki News) Some early-stage breast cancers can and do spread to the lymph nodes. While lymph node involvement is never good, new studies show that radiation helps keep these cancers from returning.
Radiation therapy is effective in decreasing the risks of breast cancers recurring (returning) in cases where the cancer has spread or is likely to spread to the regional lymph nodes. Regional lymph nodes are near where the tumor started. In breast cancer, these nodes are located in the armpit on the side of the body where the cancer began and are called the axillary lymph nodes.
"Lymph node radiation can help prevent breast cancer recurrence."
Treating node-positive (cancer found in the lymph nodes) breast cancer usually involves removing both the tumor and the axillary lymph nodes with surgery. Radiation therapy is then given to the entire breast. Radiation may also be given to the lymph nodes if the tumor is larger than 5 cm or if up to three lymph nodes contain cancer.
This study looked at the benefit of adding radiation therapy to the regional lymph nodes in women who would normally not have undergone this treatment.
The study participants included 1,832 women with node-positive breast cancer or high-risk, node-negative breast cancer. They had undergone breast-conserving surgery (lumpectomy) and chemotherapy or hormone therapy. After these treatments, participants received radiation therapy either to the breast only or to the breast and regional lymph nodes.
After five years, about 3 percent of the women who had received regional lymph node radiation had a recurrence of the disease near the tumor, and 8 percent had cancer return to other areas of the body.
These numbers are significantly lower than recurrence rates seen in women who did not receive the regional lymph node radiation. Among this group, 6 percent saw recurrences around the tumor, and 13 percent saw cancer return in other areas.
And while not statistically significant (can't be attributed solely to the treatment), women who received the node radiation were also more likely to live longer.
These results will encourage doctors to offer their patients with node-positive breast cancer the choice of having regional lymph node radiation, says lead investigator Timothy J. Whelan, BM, BCh, Professor of Oncology and Division Head of Radiation Oncology at McMaster University in Ontario, Canada.
He summarized that this course of treatment "improved disease-free survival, lowered the risk of recurrences, and there was a positive trend toward overall survival, while not greatly increasing side effects.”