Background: Melanoma in situ (MIS) occurs on various body sites, in various age groups, and is managed by a variety of treatment modalities. Despite early treatment, recurrences may be encountered.
Objectives: To evaluate the influence of sex, age, body site and treatment modalities on recurrence rate in MIS. Methods Histologically confirmed cases of MIS from our dermatopathological database (n = 1351) from 1990 to 2000 were statistically analysed with respect to epidemiological characteristics, treatment modalities and outcome. Treatment modalities of the included MIS were evaluated by searching for data in the medical records and histopathological data sheets.
Results: There was a predominance of female patients (60.8%), and of involvement of the head and neck (53.4%). Total excision was performed in 95.9% of all patients; the remainder received cryotherapy, laser therapy or radiotherapy. In 265 patients, no data on definitive treatment were available. Alternatives to total excision were particularly performed in patients with advanced age and with lesions localized on the face. The mean +/- SD 5-year recurrence rate was 6.8 +/- 1.3% for surgically removed lesions, but was 31.3 +/- 8.5% for lesions treated by other modalities (log rank test: P < 0.0001). In a multivariate approach, mode of therapy and site of involvement, but not age, were significant prognostic variables (Cox proportional hazard model: P < 0.01).
Conclusions: In MIS, treatment modalities other than surgical excision may be used in certain situations, but carry a significantly increased risk of local recurrence.