Early detection is the key to preventing melanoma, the deadliest form of skin cancer. Doctors have long screened potentially cancerous moles using the "ABCD" guide to help them spot troublemakers: "A" for asymmetry, "B" for border irregularity, "C" for color variability, and "D" for diameter over 6 mm. But many melanomas are smaller than 6 mm, leading researchers to look for other ways to spot a mole that could later become cancerous.

What the researchers wanted to know: Can changes in appearance or symptoms other than those now in use help patients and physicians catch malignant skin cancers early?

What they did: Researchers scanned 24 years' worth of scientific articles on "ABCD" screening and skin cancer detection, looking for other signs that consistently improve early detection.

What they found: Moles that are at risk for becoming cancer or already have turned malignant often have noticeable changes in size and shape, as well as symptoms like itching, tenderness, or bleeding. Adding an "E" (for "evolving") to "ABCD" screening could help improve the chances of heading off melanomas.

What the study means to you: Doctors rely on at-risk patients and their significant others to keep on top of mole changes. Any noticeable change, or evolution, in appearance or symptoms should be reason enough to alert your physician.

Caveats: This study was not a prospective trial in which patients with different kinds of moles were examined and then followed to see which ones turned cancerous; it was an analysis of published articles.

Find out more: The American Academy of Dermatology has extensive consumer information on melanoma and early detection.

Read the article: Abbasi, N.R. et al. "Early Diagnosis of Cutaneous Melanoma: Revisiting the ABCD Criteria." Journal of the American Medical Association. Dec. 8, 2004, Vol. 292, pp. 2771-2776.