Andrew Maguire, Jorge Puelles, Patrick Raboisson, Rajeev Chavda, Sylvie Gabriel, Susan Thornton
DOI: 10.2340/00015555-3367

Most patients with mycosis fungoides are diagnosed with early-stage disease. However, prevalence of early-stage disease is unknown, and evidence of its burden is scarce. The aim of this study is to estimate the prevalence of early-stage mycosis fungoides, how long patients live with early-stage disease and to characterise these patients. Data were obtained from 4 key publications and from US cancer registries (Surveillance, Epidemiology and End Results Program; SEER). The derived incidence of early-stage mycosis fungoides was 0.26/100,000 (UK), 0.29/100,000 (US) and 0.38/100,000 (US-SEER) and the prevalence was 4.8/100,000 (UK), 5.2/100,000 (US) and 6.6/100,000 (US-SEER). Early-stage disease may last for 18 years. From SEER registries, 3,132 were diagnosed at early stage (mostly stage IA). Median age at diagnosis was 58 years. Compared with stage IA, the relative risk of death was 1.3 for stage IB and 3.5 for stage IIA. We confirm the rarity of early-stage mycosis fungoides, a differential prognosis and the potential for elevated burden of disease.

Most patients with mycosis fungoides are diagnosed with early-stage disease: European Organisation for Research and Treatment of Cancer stages IA, IB and IIA. However, prevalence of early-stage disease is unknown. Using results from key publications and US cancer registry data we estimated prevalence of 4.8/100,000 (UK), 5.2–6.6/100,000 (US) and that early-stage disease may last for 18 years. The cancer registries provided 3,132 early-stage mycosis fungoides patients. Compared with stage IA, the age and sex-adjusted relative risk of death was 1.3 for stage IB and 3.5 for stage IIA. This confirms the rarity of early-stage mycosis fungoides and a differential prognosis in early-stage.