Test for Diagnosing Spread of Melanoma Can Spare Second Operation

A rapid test that can be performed during surgery to determine if melanoma has spread to lymph nodes has been developed at the Medical College of Wisconsin. The reagent making this possible has been standardized at the Medical College and is called the “MCW Melanoma Cocktail”. The test is capable of detecting even very few melanoma cells, a significant factor in managing the disease. The test for cancer spread may spare a patient an additional operation.

Melanoma is the most deadly of skin cancers and is dramatically on the rise in the United States. According to the American Cancer Society, an estimated 55,100 new cases of melanoma will develop in 2004, with 7,910 deaths. Overall, the incidence has doubled in the past 20 years.

The “MCW Melanoma Cocktail” is used for immunostaining and detecting melanoma cells in ‘sentinel lymph nodes’ during surgery, explains lead investigator Vinod Shidham, M. D., FIAC, MRCPath, associate professor in the department of pathology and executive editor and editor-in-chief of CytoJournal. Dr. Shidham is also director of the Fine Needle Aspiration Biopsy Service at Froedtert Hospital, a major teaching hospital of the Medical College. The study’s co-investigators at the Medical College were Walter Dzwierzynski, M. D., associate professor of plastic surgery, and Marcelle Neuburg, M.D., associate professor of dermatology. Both physicians practice at Froedtert Hospital.

“The MCW cocktail is made of three antibodies and produces results in 30 minutes,” says Dr. Shidham. “If the results are positive, the surgeon may proceed with removal of the patient’s regional lymph nodes during the same anesthesia.”

Drs. Shidham and Dzwierzynski used the new test to evaluate biopsies from 25 patients (examining a total of 51 lymph nodes) at Froedtert Hospital. The new method allows rapid testing to know if the cancer has spread to the special lymph node called sentinel lymph nodes with significantly higher accuracy than conventional methods. The test is performed during the interval between two standard surgeries performed on melanoma patients – the sentinel lymph node biopsy and the wide excision of melanoma biopsy site. The sentinel lymph node biopsy determines the sentinel, or first, lymph node to which the cancer may have spread. The wide excision removes the melanoma site.

Currently, a patient evaluated by routine protocol must wait at least two days for results of sentinel lymph node biopsy. If the test shows that cancer has spread to the lymph nodes, an additional operation is performed at a later date to remove the regional nodes to which the melanoma drains. While other rapid intra-operative techniques are available such as frozen section and smear examination, they lack the high level of accuracy offered by the MCW Melanoma Cocktail.

“If the sentinel lymph nodes are affected, it’s best for the patient to have regional nodes removed during the initial procedure,” says Dr. Shidham. “It spares waiting, cost, and morbidity of an additional operation.”

The method may have applications to other cancers if appropriate antibodies are selected, says Dr. Shidham. Currently, sentinel lymph node evaluation is used for a variety of cancers and in most of these situations the present method may be applied for rapid intra-operative evaluation with specific modifications.

However, he stresses that early detection is key to curing the disease, which originates in the skin’s pigment producing cells. Unlike other skin cancers, it spreads rapidly (through the lymph nodes) to other parts of the body.

The study was supported by a $25,000.00 grant from the Medical College of Wisconsin Cancer Center.