Melanomas mostly from from new spots rather than existing ones

By Dr. Ananya Mandal, MDAug 29 2017

According to a new study appearing this week in the Journal of the American Academy of Dermatology, melanomas do not grow from existing moles and skin growths, but from new ones. Therefore it is vital that people keep a careful eye for new growths over their skin in order to detect early stages of melanomas.

Dermatologist examining melanomas. Africa Studio / Shutterstock

This latest study is an analysis or synthesis of results from 38 published studies that have together looked at 20,126 cases of melanomas. Results revealed that less than one third or 29.1 percent of all the melanoma cases came from an existing mole or spot. Most of the melanomas – 70.9 percent – came from new spots. Further the melanomas that appear from existing spots are thinner compared to those that appear on new spots. Melanomas that come up over an existing mole have a lesser chance of a poor outcome compared to the new growths.

Study researcher Caterina Longo, MD, PhD, a dermatologist at the University of Modena and Reggio Emilia in Italy, said that these results point towards the fact that patients who keep a close eye on their existing moles to detect skin cancer at the early stages are often successful at detecting them when they are best treatable. Since this study shows that new growths are the ones to watch out for, all individuals are urged to know their own skin and the moles that they have over their body and any new ones that appear.

The American Academy of Dermatology also urges the population to perform regular skin self-exams and ask partners to check for spots over backs and other areas that are difficult to see. Any new spot, itching, bleeding or change in appearance of the spots need to be checked out by a qualified dermatologist says the AAD.

Sun’s UV rays are to be avoided by staying in shade, wearing covered clothing and also applying broad-spectrum, water-resistant sunscreen with an SPF of 30 or higher says the AAD. Another recent study published in the same journal in this issue shows that only 39 percent of consumers choose effective broad spectrum sunscreens.

According to that study author, Roopal V. Kundu, MD, FAAD, an associate professor of dermatology at Northwestern University Feinberg School of Medicine in Chicago, SPF is not the only protection factor people should look out for. They should also check if the sunscreen protects against both UVA and UVB rays and is thus broad spectrum.

Melanomas

Melanomas are one of the deadliest forms of skin cancers. The cancer begins in the cells of the skin called the melanocytes. These melanocytes are normally responsible for producing melanin or a skin pigment that gives the skin its colour. Melanomas can also occur in the eyes or in the internal organs and not just over the skin.

UV radiation exposure from the sun as well as from tanning lamps and beds can increase the risk of getting melanomas. The cancer is becoming increasingly common among those under 40 and thus routine check ups for new moles and growths can help detect and treat this cancer early. Melanoma can be treated successfully if it is detected early and before it has spread to other organs.

References

• http://www.jaad.org/article/S0190-9622(17)32051-0/fulltext
• http://www.mayoclinic.org/diseases-conditions/melanoma/basics/definition/con-20026009
• https://www.cdc.gov/cancer/skin/index.htm