Risk
of second primary malignancy was assessed in a population-based follow-up survey of all persons who developed cutaneous T-cell lymphoma (CI'CL) in nine geographic areas of the United States covered by the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute during the period 1973 to 1983. Among 544 patients with a first primary tumor reported as CI'CL, a second cancer developed in 35 (6%), yielding a significantly elevated relative risk (RR) of 1.7, which reflects excesses for cancers of the lung and colon and non-Hodgkin's lymphoma. Although the excess of lymphoma may be related to the evolution of CI'CL to less differentiated T-cell lymphoma, additional studies are needed to clarify the immunologic, genetic, viral, and environmental factors that may contribute to the development of second cancers. Cancer 63:1612-1615, 1989. YCOSIS FUNGOIDES and Sezary syndrome, collec-M tively termed cutaneous T-cell lymphoma (CTCL),
are uncommon neoplasms characterized by malignant proliferation of T-lymphocytes in the skin. Altered immune response in CTCL, particularly with more advanced disease,' in addition to the effects of radiation, alkylating agents, and PUVA suggest that CTCL patients may be at increased risk of second primary malignancy. A recent follow-up of 63 patients with CTCL revealed a 2.4-fold excess of subsequent malignancy of diverse sites compared to general population rates.' Various second neoplasms after CTCL have been reported in clinical series,*-" but the patterns and determinants are not yet clear.
Evaluation of second malignancy risk after CTCL has been difficult due to small numbers of patients usually available for study. Therefore, the current report analyzes the incidence of second primary cancers in a cohort of 544 CTCL patients reported to the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute, which has documented and followed since 1973 all newly diagnosed cases of cancer in selected states and metropolitan areas covering approximately 10% of the US population.