Sweeter Breast Cancer Ride

Radiotherapy causes less lymphedema than surgery for node positive early breast cancer

(RxWiki News) The body’s lymph system is a super highway for cancer to travel to other locations. A new study may change the way physicians treat women whose early breast cancer has spread to the lymph nodes. And this change could make the after-cancer ride a whole lot sweeter.

When breast cancer was detected in the lymph nodes, the new study discovered, radiation therapy was just as effective as surgery for overall and disease-free survival.

There was one big difference, though.

Patients who underwent radiation suffered far less from lymphedema (painful swelling of the arm nearest the treated breast) than did the women who had surgery to remove lymph nodes. The lower rates of lymphedema may make radiotherapy the preferred treatment method for node-positive early breast cancer, according to the study authors.

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Emiel J. Rutgers, MD, a surgical oncologist at the Netherlands Cancer Institute in Amsterdam, and colleagues followed hundreds of women whose breast cancer had been detected in one or more lymph nodes.

Sentinel lymph node biopsies are used to see if the lymph nodes closest to the tumor contain breast cancer cells. If cancer is found, the standard of care has been to surgically remove the lymph nodes in the armpit.

These are called the axillary lymph nodes, and the surgery is known as an axillary lymph node dissection (ALND).

This is serious surgery that leaves many women with lymphedema, a condition that can — and often does — linger for years.

Axillary radiation therapy (ART) is given at the same time as whole breast or chest-wall radiation. Radiation is nearly always given to kill any cancer cells still present after a lumpectomy (breast-conserving surgery).

This study found that ART was just as effective as the surgery in preventing breast cancer from returning, but with far lower rates of lymphedema.

Breast radiation oncologist at The University of Texas MD Anderson Cancer Center, Benjamin D. Smith, MD, told dailyRx News, “Both complete axillary dissection and axillary radiation provided outstanding rates of disease control in the axilla. Risk of lymphedema, a potentially debilitating side effect, was much lower in patients undergoing axillary radiation.”

This trial — known as the AMAROS (After Mapping of the Axilla: Radiotherapy or Surgery?) — randomly assigned node-positive breast cancer survivors to receive either ART (681 women) or ALND (744 women). Study members were followed for an average of six years.

The researchers found that five years after treatment less than one percent (0.54 percent) of women treated with ALND saw axillary recurrence compared to 1.03 percent of women who had ART.

For perspective, the recurrence rate in women who had no cancer in the axillary nodes was 0.8 percent.

Five-year overall survival was similar between the groups (93.7 ALND versus 92.52 percent ART).

Five-year disease-free survival (period during which there was no cancer) was 86.90 percent in women who had received surgery and 82.65 percent in those who had been treated with radiation.

Lymphedema was the big differentiation between the groups.

One year after surgery, 40 percent of the surgically treated women had lymphedema compared to 22 percent of women who’d had radiation.

After five years, 28 percent of women in the surgical group were still suffering from lymphedema, while only 14 percent of the ART women had arm swelling.

“These findings will significantly impact how we approach management of pathologically [as detected by sentinel node biopsy] positive axilla,” Dr. Smith said.

“Specifically, for those patients who will be receiving radiation, omission of axillary dissection in favor of axillary radiation will become a very attractive option. It will be important for all radiation oncologists to integrate this option into their treatment armamentarium,” he said.

Findings from this study were presented June 3 at the 2013 American Society of Clinical Oncology (ASCO) Annual Meeting.

This research was supported by the European Organisation for Research and Treatment of Cancer Charitable Trust. No conflicts of interest were disclosed.

It should be noted that all research is considered preliminary before it is published in a peer-reviewed journal.

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Review Date: 
June 1, 2013