Melanoma surgery may get more aggressive to help plan treatment and ultimately improve survival.
A study and editorial in The New England Journal of Medicine support checking the "sentinel" lymph node near melanoma for signs of cancer.
Melanoma is the most serious type of skin cancer, with more than 53,600 new cases per year diagnosed in the U.S., according to the National Cancer Institute.
The body's lymph system makes, stores, and carries white blood cells that fight infections and other diseases. Lymph nodes are part of the lymph system; they're clustered around the body.
Cancer can spread to lymph nodes. It usually first shows up in one or two "sentinel" nodes that are closest to the cancer site.
In sentinel lymph node biopsy, doctors surgically check the sentinel lymph node or nodes for signs of cancer.
If the biopsy shows cancer in the sentinel node or nodes, that means cancer has spread beyond its original location and would be more likely to be in the other lymph nodes in the area. Sentinel node biopsies are also used with other types of cancer, including breast cancer.
Sentinel Node Study
The new study comes from researchers including Donald Morton, MD, of the John Wayne Cancer Institute at Saint John's Health Center in Santa Monica, Calif.
Morton's team studied 1,269 people who had surgery to remove isolated skin melanomas of medium thickness.
The researchers randomly assigned 60% of the patients to get sentinel node biopsy. Patients with cancerous sentinel nodes had all the other lymph nodes near the sentinel nodes removed.
The remaining 40% of the patients got careful checkups every few months, without sentinel node biopsy. They kept all of their lymph nodes unless doctors suspected cancer's spread, which happened months or even years later.
Why not just automatically remove all lymph nodes closest to a melanoma? Doing so could have complications and offers no advantage if those nodes are cancer-free.
The researchers followed the patients for five years.
During that time, the overall survival rate between the two groups was similar (around 87%).
But there was an important exception for patients with cancerous lymph nodes.
Of the patients who got sentinel node biopsies that showed cancerous sentinel nodes and had their nearby lymph nodes immediately removed, 72% were alive five years later.
But the five-year survival rate was much lower -- 52% -- for patients with cancerous lymph nodes that were spotted later because they didn't get sentinel lymph node biopsy.
In patients with skin melanomas of medium thickness, sentinel node biopsy "should be preferred to observation," write Morton and colleagues.
That conclusion is "convincing" and "justified," based on the study's results, write editorialists Charles Balch, MD, and Natale Cascinelli, MD.
Balch works in Baltimore, Md., at the Johns Hopkins Medical Institutions. Cascinelli works at the National Tumor Institute in Milan, Italy.
By Miranda Hitti, reviewed by Louise Chang, MD
SOURCES: Morton, D. The New England Journal of Medicine, Sept. 28, 2006; vol 355: pp 1307-1317. Balch, C. The New England Journal of Medicine, Sept. 28, 2006; vol 355: pp 1370-1371. National Cancer Institute: "What You Need to Know About Melanoma."