“If radiation therapy is deemed necessary, you can radiate the axilla [underarm area] at the same time and achieve similar local control as full lymph node dissection in the axilla.”
– Emiel J. Rutgers, MD, PhD
It appears that radiation therapy to the axilla may replace axillary node dissection for local cancer control for selected patients with involvement of sentinel nodes. The European Organization for the Research and Treatment of Cancer (EORTC) AMAROS trial was recently presented.
Background: For patients with cancer in a sentinel node, it is often important to treat the regional lymph nodes, as recurrence there increases the risk of death. In the USA, many patients with a positive (involved) sentinel node with go on to additional surgery to reduce the chance of a return of cancer to the node area.
Current study: The study was designed to compare axillary dissection with radiation therapy to the axilla 12 years ago. The AMAROS study included 4,806 patients, with tumors up to 5cm and no palpable nodes. About 30% had a positive axillary node on sentinel node removal. At a median follow-up of 6.1 years, the risk of a recurrence in the axilla was 0.5% in the surgery group, and 1% in the radiation therapy group. Disease-free survival rates were similar, as were the overall survival chances.
The rates of lymphedema (arm swelling) were higher for surgery than radiation therapy at various intervals: At 1 year, surgery 40% and radiation therapy 22%; at 3 years, 30% (surgery) and 17% (radiation), and at 5 years 28% (surgery) versus 14% (radiation).
My take: This study illustrates that in the sentinel node era, less can be more. For patients with an involved sentinel node, radiation therapy (including to the axilla) appears reasonably safe and offers a high chance of local control. This (and other) studies will likely change the standard of care for selected patients. I’m Dr. Michael Hunter.
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