TUESDAY, July 8 (HealthDay News) -- The thicker the skin cancer tumor, the more likely it will spread or recur, according to a newly published study.

German research in the August edition of The Lancet Oncology, found that cutaneous squamous-cell carcinomas of increased tumor thickness were almost five times more likely to spread, compared to thinner lesions.

A suppressed immune system also quadrupled the likelihood of the cancer spreading, say the team from Eberhard Karls University, in Tubingen. They also found that tumors located at the ear were almost four times more likely to spread compared to tumors located elsewhere. Finally, increased horizontal size more than doubled the odds of the cancer spreading or reoccurring, the researchers report.

The study looked at 615 patients who had surgery for this most common form of skin cancer between 1990 and 2001 at a single Germany site. They found that those with tumors 2.0 millimeters or less in thickness did not have the cancer metastasize. Four percent of those with tumors between 2.1 and 6.0 millimeters thick had metastases, while 16 percent with tumors more than than 6.0 millimeters thick also did.

More information

The American Cancer Society has more about skin cancer prevention and detection.