Melanoma: Earlier Detection by Dermatologists

Individuals whose melanoma is diagnosed by a dermatologist may be more likely to have early-stage cancer and to survive five years than those with melanoma diagnosed by a non-dermatologist.

If melanoma is removed at an early stage, when the tumour is still relatively thin (less than 1 millimeter thick), patients have a 90 percent cure rate. However, metastastic melanoma that has spread to other areas usually requires both surgery and chemotherapy and five-year survival rates are less than 20 percent. "

Michelle L. Pennie, M.D., Emory University School of Medicine, Atlanta, and colleagues attempted to determine whether such a difference exists using data from two databases for 2,020 patients.

Of the 2,020 patients, 1,467 (73 percent) were diagnosed with melanoma by a dermatologist and 553 (27 percent) were diagnosed by a non-dermatologist. Tumours diagnosed by dermatologists were thinner on average than those diagnosed by non-dermatologists (.86 millimeters vs. 1 millimeter).

"We also looked at melanoma stage at diagnosis and observed significant differences between provider types, with a preponderance of thin melanoma (stage zero, or stage I or II) in the dermatologist group and a preponderance of thick melanoma (stage III or stage IV) in the non-dermatologist group," the authors of the article which appeared in the Archives of Dermatology write.

After six months, two years and five years, patients whose cancer was diagnosed by a dermatologist had a higher survival rate than those diagnosed by a non-dermatologist. "The two-year and five-year survival rates were 86.5 percent and 73.9 percent for the dermatologist group compared with 78.8 percent and 68.7 percent for the non-dermatologist group," the authors write. "When looking at the mortality rates by cause of death, both groups had similar non-cancer–related mortality rates. However, the dermatologist group had lower cancer-related mortality rates and a lower overall mortality rate."