Adjuvant radiation therapy improves local control of melanoma following therapeutic lymph node dissection for lymph node-metastatic disease and may improve disease-specific survival, according to the results of a study published in Cancer.
Skin cancer is the most common form of cancer in the United States, with more than 1 million new cases each year. Skin cancer is often divided into two broad categories: melanoma and non-melanoma. Melanoma is less common than non-melanoma skin cancer, but tends to be much more aggressive. Of the more than 1 million new diagnoses of skin cancer each year, roughly 68,000 involve melanoma. More than 8,000 people die of melanoma each year in the United States. What makes melanoma so dangerous is that it is more likely than other types of skin cancer to spread (metastasize) to other parts of the body.
Historically, surgery has been the primary treatment for patients with melanoma; however, high recurrence rates have led to the search for new and more effective approaches. Researchers from the M. D. Anderson Cancer Center conducted a study that included 615 patients with Stage III melanoma. These patients underwent therapeutic lymphadenectomy. All patients were considered to be at high risk for regional recurrence; 106 patients underwent surgery alone, and 509 patients underwent surgery plus radiation therapy.
After a median follow-up of five years, 10.2% of patients who underwent surgery plus radiation developed a regional recurrence compared with 40.6% of patients who received surgery alone. The rate of distant recurrence was 55.4% in the radiation group compared with 73.6% in the surgery-alone group. Table 1 shows the five-year regional control rate based on the area of lymph node treatment.
Table 1: Regional control rates in patients with Stage III melanoma who received surgery plus radiation vs. surgery alone
The researchers concluded that the addition of radiation therapy to therapeutic lymphadenectomy in patients with Stage III melanoma was associated with a significantly lower risk of regional recurrence. Furthermore, they observed that radiation therapy may improve survival from melanoma.
 Agrawal S, Kane JM, Guadagnolo BA, et al. The benefits of adjuvant radiation therapy after therapeutic lymphadenectomy for clinically advanced, high-risk, lymph node-metastatic melanoma. Cancer [early online publication]. August 21, 2009.