Breast Cancer Treatment: Learn Why Less is More
By Dr. Seth Kaufman, radiation oncologist, Baystate Regional Cancer Program, for the Daily Hampshire Gazette
“Less is more” was the theme of an educational session at the San Antonio Breast Cancer Symposium last December, which looked at ways to minimize or “de-escalate” therapies for breast cancer.
Dr. Grace Makari-Judson, chair of the Baystate Health Breast Network, attended the symposium. “When we talk about de-escalation of cancer treatment, we mean trying to accomplish the same goal to be cancer-free but using treatments with fewer side effects that are carefully selected for each individual,” she said. “That means limiting surgery, omitting or limiting radiation, and omitting chemotherapy whenever possible.”
Dr. Kaufman explains some of the ways this is happening.
Q: How has the practice of removing under-arm lymph nodes changed for breast cancer patients in recent years?
A: For the past two decades, sentinel lymph node biopsy has allowed doctors to avoid unnecessary lymph node removal for women whose breast cancer has not spread to the lymph nodes. It allows the surgeon to identify and remove just the first few lymph nodes — typically three or less — that cancer cells might travel to as their first exit point from the breast.
If no cancer is identified in these nodes, there is an excellent chance that no cancer will be found in any additional nodes under the arm. Removal of additional nodes — 10 or more in a standard axillary node dissection — leads to increasing risk of permanent arm swelling called lymphedema.
The logic of performing axillary dissections for a woman with cancer found in her sentinel nodes was that other forms of cancer treatment, such as radiation, chemotherapy and hormone therapy, are not as effective as surgery at killing off every cancer cell in an affected lymph node.
However, in the last five years, the standard of care has changed. Two large trials – called the AMAROS trial in Europe and the ACOSOG Z-11 trial in the United States — made direct comparisons for women with early-stage breast cancer and positive sentinel nodes.
The studies randomly assigned these women to have their under-arm lymph nodes removed or not. All of the patients underwent radiation, and the vast majority had some form of systemic therapy, such as chemotherapy, hormone therapy, or both.
While about one-third of the women who had lymph node surgery had more cancer found in those nodes, there was no significant difference in the rates of cancer recurring, either under the arm or elsewhere in the body, between the two groups.
As a result, for women with early-stage breast cancer who have one or two positive sentinel nodes and have not undergone chemotherapy before breast surgery, axillary lymph node removal is no longer done.
Q: Are there still instances where it is necessary to remove under-arm lymph nodes?
A: Women with more advanced breast cancer, those with cancerous lymph nodes that are enlarged to the touch, and those who require mastectomy, typically still require surgery to remove under-arm lymph nodes.
However, the practice continues to change. At Baystate Medical Center, we are participating in two large national trials looking at whether surgery and radiation are still needed for women with cancerous lymph nodes, swollen to the touch, that become normalized following chemotherapy before surgery.
The hope of these trials is to show that even more patients will not need removal of the lymph nodes under the arm, and some may not even need radiation to that area.
Q: What about shorter courses of radiation?
A: Standard breast radiation in the United States has traditionally been performed over five to six weeks, while in Britain and Canada the standard for several decades has been a three to four-week course.
Recent long-term trial results from both countries have shown this shorter course of radiation — using fewer treatments at a higher dose, but the same total dose — to be just as effective and less toxic for certain women. Those who qualify are those with early-stage breast cancer not involving the lymph nodes who have not undergone mastectomy or been given chemotherapy. It is not advised for women under the age of 50.
Q: Are there times when omitting radiation for women with breast cancer would be appropriate?
A: Two recently published trials have shown a minimal benefit for breast radiation in patients age 70 and over with early-stage breast cancers that do not involve the lymph nodes. For these women, adding radiation to surgery and hormone therapy increases the chance of keeping the cancer in check by 4% at 5 years. This increases to 8% at 10 years.
There is no demonstrated benefit for overall survival. For many women, this low benefit is not enough to warrant the potential side effects of radiation. However, this is a very personal decision that should be made only after discussing the options with a radiation oncologist.
Q: When can chemotherapy be omitted?
A: Molecular testing now helps oncologists identify individuals with early-stage breast cancers who really need chemotherapy, and which ones have an excellent prognosis with hormone therapy alone.
Recent studies have validated these tests and demonstrate that women with low scores do very well with hormone treatment alone. Thanks to molecular testing, doctors are now prescribing 20 to 30% less chemotherapy compared to 10 years ago.