This past week a remarkable study suggested that in a very select group of women who have cancer in the sentinel node (the first lymph node to receive cancer cells from breast cancer) the removal of all their remaining lymph nodes may not be beneficial and may even hurt some. Removing the lymph nodes did not lead to better survival or decreased risk of cancer coming back.
As a surgical oncologist, there is no question in my mind that it will be a hard sell to convince my patients why a 27.3 percent chance that the lymph nodes with cancer left in their armpit will NOT affect their outcome. However, I do believe the findings are very reliable and need to be reviewed with patients in advance of their surgical treatment. Surgical oncologists will have to be more illustrative in their explanations regarding the findings in this study because patients in the U.S. seem swayed to be overly aggressive in regards to their cancer treatment and that is sometimes based on fear not facts.
Historically, breast cancer experts have removed the lymph nodes only to find out who would benefit from additional treatments such as chemotherapy after surgery. These experts have never been able to prove that removing the lymph nodes improved a patient’s chance of survival. Nearly 15 years ago, specially trained surgical oncologists invented the sentinel node biopsy technique. This reliable procedure allowed breast cancer specialists to find out which patients have cancer in their lymph nodes. Only 30 percent of all breast cancer patients have any cancer in their lymph nodes. As long as a patient has no cancer in their sentinel node, there is no need to remove the remaining lymph nodes. Removal of these lymph nodes causes unnecessary pain and other complications such as lymphedema which is a swelling of the arm.
The study examined women with smaller breast cancers (average size 2 cm) where cancer had spread to the sentinel node. All of these women completed radiation and chemotherapy as part of their treatment. The sentinel nodes were removed, but their other lymph nodes remained. These women did not have a worse survival or a higher cancer reoccurrence rate than women who had all of their lymph nodes removed. As a further benefit, these women were spared the 30 percent chances of lymphedema.
Among the women who only had the cancerous sentinel node removed, 27.3 percent of them had their other lymph nodes with microscopic cancer left in place. With the use of chemotherapy and radiation therapy there were no recurrences in the armpit or elsewhere after six years of following up with them. In most cases, if cancer is going to come back, it will show up within two years.
The study shows that in a selected number of women treated with chemotherapy and whole breast radiation after lumpectomy for small breast cancers with a positive sentinel lymph node additional surgery resulting in increasing complications such as lymphedema may be avoided after a thorough evaluation by the cancer surgeon and the breast cancer multidisciplinary treatment team.