ASCO: less LE with radiation than ALND

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http://www.medpagetoday.com/HematologyOncology/BreastCancer/39560

ASCO: RT Alone OK for Some Node-Positive Breast Cancers

By Crystal Phend, Senior Staff Writer, MedPage Today

Published: June 03, 2013

Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco

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Action Points

• This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
• Breast cancer patients with a positive but nonpalpable sentinel lymph node have a reduced risk of lymphedema with radiation compared with surgery.
• Point out that recurrence rates came out similar, at 0.5% with completion axillary lymph node dissection and 1.0% with axillary radiotherapy over 5 years.

CHICAGO -- Breast cancer patients with a positive but nonpalpable sentinel lymph node may be better off with radiation than with further axillary surgery, the AMAROS trial affirmed.

Recurrence rates came out similar, at 0.5% with completion axillary lymph node dissection and 1.0% with axillary radiotherapy over 5 years, Emiel Rutgers, MD, of the Netherlands Cancer Institute in Amsterdam, and colleagues found.

Overall survival didn't differ between the groups either, they reported here at the American Society of Clinical Oncology meeting.

But surgery doubled the lymphedema risk compared with radiation alone, at 40% versus 22% at year 1 and 28% versus 14% at year 5 (both P<0.0001).

These findings were seen as largely confirmatory of those reported at the meeting 2 years ago from the ACOSOG Z0011 trial, which showed no advantage in survival or relapse prevention from routine axillary node dissection after discovering a positive sentinel node.

It also confirms the importance of radiation for these patients, commented Elizabeth Mittendorf, MD, PhD, of the MD Anderson Cancer Center in Houston, in an interview with MedPage Today.

"Those of us who have adopted Z0011, which in the U.S., we mostly have, have contended that a very important part of Z0011 was the fact that every patient was undergoing breast conservation so every patient was getting radiation," she said. "You do need some treatment but it doesn't have to be surgery, the radiation is adequate by itself without doing further surgery."

The lower lymphedema risk of radiation in AMAROS was somewhat a surprise though, she suggested.

"If you had asked me before, I would have told you surgery and radiation are probably comparable with respect to the complication of lymphedema and this clearly shows that's not true," Mittendorf said.

The randomized AMAROS trial included 1,425 women with early-stage, invasive breast tumors up to 5 cm in size that were clinically node-negative but yielded a positive sentinel lymph node biopsy. They were enrolled in the trial from 2001 to 2010.

Disease-free survival rates were 87% with completion axillary node dissection and 83% with axillary dissection, which wasn't statistically significant at P=0.1788.

Overall survival was 93% at 5 years in both treatment groups.

The surgery group also tended to have more shoulder movement impairment early in the trial and to report poorer quality of life with regard to movement but better quality of life related to swelling, but none of these differences were statistically significant.

The researchers cautioned that the planned non-inferiority test was underpowered because of an unexpectedly low number of recurrences and deaths.

Also, the trial enrolled a select group of women with relatively small tumors and no evidence of nodal metastases at presentation, so the results wouldn't generalize to those who come in with more advanced disease or have known large nodal metastases, Mittendorf added.

Another limitation was the lack of a definition for lymphedema, which can occur across the spectrum from arm swelling resulting only in a feeling of heaviness to cases requiring compression garments and lifestyle changes, she noted.

The study was supported by the European Organisation for Research and Treatment of Cancer Charitable Trust.

The researchers reported no conflicts of interest.

Mittendorf reported no conflicts of interest.

Primary source: American Society of Clinical Oncology
Source reference:
Rutgers EJ, et al "Radiotherapy or surgery of the axilla after a positive sentinel node in breast cancer patients: final analysis of the EORTC AMAROS trial" ASCO 2013; Abstract LBA1001.