Abstract
Purpose :
Although incidence of second primary malignancies (SPMs) has been investigated in patients with cutaneous melanoma and uveal melanoma, limited studies have investigated their occurrence related to conjunctival melanoma (CM). We conducted a retrospective observational study to assess incidence of SPMs in patients with CM and to identify specific age-groups and latency periods associated with elevated risk.
Methods :
Cases of first primary CM diagnosed from 2000-2016 were extracted from the national cancer database Surveillance, Epidemiology and End Results Program. The multiple-primary standardized incidence ratio algorithm within Seer*Stat was used to calculate standardized incidence ratios (SIR) and excess absolute risk (EAR) of SPMs compared to a matched cohort from the general population with similar sex, race, age-group, and calendar year. EAR was per 10,000 individuals, and a P-value of <0.05 was considered significant.
Results :
417 patients met inclusion criteria, 56 (13.4%) of whom developed secondary malignancies over an average (+/-SD) follow-up period of 74.76 (+/-53.52) months. Average age at diagnosis for the overall cohort was 59.86 (+/-18.6) years. Patients with CM demonstrated a significantly increased risk for overall SPMs (SIR 1.89; 95% confidence interval [CI], 1.43-2.45; EAR 112.02) relative to the general population. Specific sites and malignancy types with increased risk were cutaneous melanoma (SIR 8.80; 95% CI, 4.68-15.04; EAR 48.96), ophthalmic melanoma (SIR 341.41; 95% CI, 186.65-572.83; EAR 59.31), ophthalmic non-melanoma malignancies (SIR 101.33; 95% CI, 2.57-564.55; EAR 4.21), and biliary malignancies (SIR 9.86; 95% CI, 1.19-35.63; EAR 7.64). Risk of overall SPMs was significantly increased 1-10 years from date of diagnosis. Overall SPM risk by age was bimodally distributed, with increased risk in individuals 0-49 years and over 65 years.
Conclusions :
Patients with CM had an increased incidence of secondary malignancies compared to the general population. Specifically, these patients more commonly developed cutaneous, ophthalmic, and biliary malignancies. These secondary neoplasms could be due to shared pathophysiology, mutual risk factors, or treatment related. Additional studies may be necessary to further explain these findings. Patients with CM may benefit from surveillance for secondary malignancies, especially 1-10 years following diagnosis.
This is a 2020 ARVO Annual Meeting abstract.