['As the incidence of cutaneous melanoma continues to rise, more individuals will be at risk for developing second primary melanomas. We hypothesize that patient education and follow-up surveillance will lead to the early detection of subsequent primary melanomas as demonstrated by a decrease in Breslow thickness at diagnosis.', 'A computer-based investigation was performed to identify patients who had developed a second primary melanoma following treatment of in situ and American Joint Commission on Cancer (AJCC) Stage I or II melanoma. Patients are routinely educated on the increased risk of developing a second primary lesion and characteristic clinical features of melanoma. Patient surveillance was performed on a regular basis. Differences in Breslow thickness between the initial and subsequent primary melanomas were analyzed by a paired t-test.', 'Among 877 individuals identified in the Mount Sinai School of Medicine Department of Dermatopathology database with in situ or AJCC Stage I or II melanoma, 111 developed a second primary melanoma. The mean thickness was 0.239 +/- 0.661 mm for the initial melanoma and 0.1135 +/- 0.319 mm for the subsequent melanoma. By paired t-test, the difference in tumor thickness was statistically significant (P = 0.019).'] Does patient education and regular surveillance result in earlier diagnosis of second primary melanoma?