In England, skin cancers cause 16,000 deaths each year due to the spread of the disease to other parts of the body. Previously, the best way to predict whether melanoma was likely to spread was by measuring its thickness. It was believed the thicker a tumor was, the more likely it was to spread. However, many thin melanomas spread and only 40 percent of thick ones do.
Researchers in England may have found a new way to predict whether skin cancers will spread to other organs. This may lead to earlier detection of those patients who are most in need of close follow-up.
Specialists measured the density of lymph vessels surrounding a skin cancer and followed which patients went on to develop secondary cancers within eight years. Of the 21 patients with malignant melanoma, 13 later had their cancers spread and eight were still free of any form of clinically detectable distant cancer.
Results of the study show the lymphatic density around malignant melanomas was more than twice as great in patients who subsequently developed metastasis, cancers in other organs. In addition, lymphatic density around malignant melanomas was approximately four-times higher than the density around normal skin samples. It was also three-times higher than the density around basal cell carcinoma and Merkel cell carcinoma (a skin tumor thought to spread through a vascular route). The density inside the malignant melanoma tumor was eight-times higher than inside the basal cell carcinoma and Merkel cell carcinoma. However, it was not significantly lower than the density inside normal skin.