Purpose: The eye and its adnexal structures can give rise to first or consecutive primary malignancies or to encounter metastasis. Our aim was to define the characteristics of the second primary neoplasms affecting the eye and its adnexa and find the risk modifying factors for them after malignancies elsewhere in the body.
Methods: We have queried the Surveillance, Epidemiology and End-Results "SEER"-9 program of the National Cancer Institute for the malignancies of the eye and its adnexa that occurred between 1973 and 2015. The malignancies were ordered chronologically according to their incidence: first or second primary malignancies. The tumors were classified according to ICD-O-3 classification. Standardized incidence ratios (SIR) and survival probabilities were calculated for subgroups.
Results: Among 3,578,950 cancer patients, 1203 experienced a second malignancies of the eye and its adnexa. The first malignancy was diagnosed between 50 and 69 years of age in 58.94% of them. The eyelid showed 280 events, while 50 in lacrimal gland, 181 in the orbit, 21 in the overlapping lesions, 15 in optic nerve, 148 in the conjunctiva, 9 in the cornea, 6 in the Retina, 379 in the choroid, and 93 in the ciliary body. The SIR of a second malignancy after a prior non-Hodgkin lymphoma was 2.42, and in case of previous skin carcinomas it was 3.02, melanoma of skin, and 2.13 and 1.58 in oral cavity/pharynx malignancies. The second ocular and adnexal neoplasms increased steadily over the 5-year periods on contrary to first primary neoplasms. The survival of patients affected with first ocular and adnexal neoplasms was significantly higher than those with second ocular and adnexal neoplasms. On the other side, second primary ocular and adnexal tumors showed a better survival than second primary malignancies elsewhere.
Conclusions: The epidemiological differences between first and second ocular and adnexal primaries suggest different underlying mechanisms. Careful ocular examination should be integrated in the long-term follow-up plan of cancer patients. Special attention should be given to patients with non-Hodgkin's lymphoma and melanoma as first primary.
Keywords: Epidemiology; Eye; Ocular adnexa; Orbit; Second malignancies.