Patients with melanoma in situ (stage 0) have melanoma cells only in the outer layer of skin (epidermis). There is no invasion of the deeper layer (dermis) and therefore essentially no potential for spread. Melanoma in situ is curable by adequate removal with surgery. The following is a general overview of the treatment of melanoma in situ. Circumstances unique to your situation may ultimately influence how these general treatment principles are applied. The information on this Web site is intended to help educate you about your treatment options and to facilitate a shared decision-making process with your physician.
Patients with melanoma in situ are treated by surgical removal of the lesion with the goal of obtaining minimal surgical margins that are free of any evidence of melanoma cells when examined under the microscope. Virtually all patients with melanoma in situ are cured following an adequate excision. The surgical guidelines for adequate excision are to remove the entire lesion (melanoma in situ) with a 0.5 cm margin of normal skin surrounding the lesion. This is confirmed by a pathologist who examines the removed specimen under the microscope. Inadequate excision of a melanoma in situ can lead to a recurrence of the lesion or progression in the area to a more advanced melanoma.
For example, in one clinical study involving 121 patients with stage 0 melanoma, there were only 6 local recurrences (5%). Moreover, all local recurrences were treated successfully with more extensive surgery.
Cure rates are so high with melanoma in situ that there are essentially no outstanding treatment issues. However, there are outstanding issues for the prevention of the development of additional melanomas. The diagnosis of melanoma in situ, which is believed to be a precursor for invasive melanoma, may be an indication that genetic and environmental influences may be present in an individual that place them at increased risk for developing other in situ or melanomas in the future. Individuals with melanoma in situ should have routine skin evaluations performed by dermatologists bi-annually.
Avoiding the major cause of cutaneous melanoma, sun exposure, is of crucial importance in preventing new melanomas. The guidelines from the American Academy of Dermatology include:
- Use a broad-spectrum sunscreen with a SPF of at least 15 on all exposed skin, including the lips, even on cloudy days.
- If exposed to water, either through swimming or sweating, a water-resistant sunscreen should be used.
- Reapply sunscreen frequently.
- Wear a broad-brimmed hat and sunglasses.
- Sit in the shade whenever possible.
- Wear protective, tightly-woven clothing.
- Plan outdoor activities early or late in the day to avoid peak sunlight hours between 10 am and 4 pm.