The incidence of second primary invasive melanoma in Queensland, 1982-2003.

OBJECTIVE: To describe the incidence of second primary invasive melanoma.
METHODS: Data describing 52,997 subjects with melanoma notified to The Queensland Cancer Registry between 1982 and 2003. We calculated incidence rates of second primary invasive melanoma (per 1,000 person-years) by sex, age, and characteristics of the first primary.
RESULTS: The rate of second primary invasive melanoma was relatively constant over 20 years of follow-up at 6.01 per 1,000 person-years indicating a high, constant lifetime risk of second primary invasive melanoma. Rates were 62% higher in males than in females and increased with age at first diagnosis with the rate in older patients (80+ years) more than double the rate observed in younger patients (40-49 years). Rates in patients with melanomas thicker than 2 mm were over 50% higher than in patients with thinner melanomas.
CONCLUSIONS: Melanoma patients are at high risk of a second primary invasive melanoma. This risk does not diminish with time and does not differ significantly between patients first diagnosed with lentigo maligna, in situ melanoma or invasive melanoma. These results indicate that all melanoma patients require lifetime surveillance. Current treatment guidelines should be modified to reflect this.