SUNDAY, June 1 (HealthDay News) -- Chemotherapy may be more effective on melanoma tumors if a protein frequently found in the growth can first be disabled, a new study reports.

Researchers at the Duke Comprehensive Cancer Center found the drug ADH-1, which makes it difficult for cells to properly bind to one another, helped chemotherapy completely destroy the tumors in twice as many patients than with chemo alone. Sixteen people with regionally advanced melanoma, in which the cancerous growths appear and spread mainly on the limbs, participated in the pilot study.

"Eight of the patients in the study had complete responses to therapy, meaning their tumors completely disappeared," study lead investigator Dr. Georgia Beasley, a medical student at Duke, said in a prepared statement. "This is very encouraging, and we look forward to continuing this study and then eventually moving on to a phase III trial."

Without ADH-1, patients generally have complete responses about 25 percent to 35 percent of the time.

"When chemotherapy was applied to the tumor in this weakened state, it was much more effective compared to conventional therapy alone," study senior investigator Dr. Douglas Tyler, a surgeon at Duke and the Durham Veterans Affairs Medical Center, said in a prepared statement.

The researchers were expected to present their findings Sunday at the American Society of Clinical Oncology annual meeting, in Chicago.

"These early results really speak to the importance of developing combination therapies," Beasley said. "Earlier animal results showed that using ADH-1 alone was not an effective treatment, but in combination with chemotherapy, the results, both pre-clinically and clinically, have been very exciting."

Malignant melanoma is increasing at a rate faster than any other cancer -- 60,000 new cases are expected to be diagnosed this year in the United States alone. When the growths spread beyond the primary site, the disease is rarely curable, and treatment is limited.

More information

The American Academy of Family Physicians has more about melanoma.