Dermatologists Superior to Other Physicians at Flagging Early Melanoma

ATLANTA, April 18 -- When melanomas are diagnosed by a dermatologist, patients are likelier to have early-stage disease and longer survival than those whose lesion was diagnosed by a non-dermatologist, researchers reported.

Patients diagnosed by a dermatologist had a preponderance of thin melanoma at stages zero, or I or II, with higher survival rates at two and five years than those diagnosed by a non-dermatologist, Suephy C. Chen, M.D., of Emory University here, and colleagues reported in the April 16 issue of the Archives of Dermatology.

Melanoma is the fifth most common malignancy for men and the sixth most common for women, with a sharp increase since the 1930s. Patients diagnosed early have a 90% cure rate, compared with five-year survival rates of less than 20% for metastatic disease, the researchers wrote.

Non-dermatologists included family practitioners, internists, ob-gyns, plastic surgeons, and oncologists.

The data emerged from a retrospective analysis using Medicare claims (codes for different kinds of physician visits), and the National Cancer Institute's SEER database (cancer diagnoses and outcomes) from 1991 to 1996. The registries came from 12 U.S. sites. However, those diagnosed by a dermatologist were more likely to live in an urban area.

Of 2,020 participants in the study sample, 1,467 (73%) were diagnosed by a dermatologist and 553 (27%) were diagnosed by a non-dermatologist. Tumor detection by a dermatologist versus a non-dermatologist was associated with an earlier stage melanoma (stage 0, stage I, and stage II versus stage III and stage IV; x² test, P

Alternatively, there may be inherent differences in the types of patients who go to a dermatologist rather than a nondermatologist when they are concerned about a lesion, and these differences are not captured in the SEER data base and could not be assessed in this study, the investigators said.

A strength of the current study, the authors pointed out, is that it was population-based.

Use of the SEER data base, however, had its own limitations, they said. By definition the study population was limited to those 65 and older and the results may not be generalizable to a younger population. In addition the SEER database did not constitute a probability sample of the entire U.S.

Other limitations were mainly concerned with the determination of the responsible provider type. The definition may have over-represented those detected by nondermatologists, they noted.

It was assumed that non-dermatologists detected the melanoma if they had documented any skin-related diagnosis code within five months of diagnosis by a dermatologist. This definition, they said, was thought to be necessary to define the physician ultimately responsible for the initial melanoma detection.

At one extreme, if most of these patients were referred for an unrelated skin disease and possessed an occult, advanced melanoma, this finding would skew the outcome in favor of dermatologists, as observed in this study, the researchers wrote. At the other extreme, if referred patients possessed predominantly thin lesions, the results would skew in favor of nondermatologists.

Furthermore, the researchers said, the use of the 1997 staging system may not be the most accurate reflection of patients' prognosis, given a 2002 revision.

In conclusion, Dr. Chen and colleagues wrote that "these results suggest that increasing access to dermatologists, particularly for older patients who have higher rates of melanoma, may represent one approach to improving melanoma-related health outcomes from a health policy perspective."