Incidence of primary cutaneous T-cell lymphoma in Norway

BACKGROUND: Studies from different countries have reported an increased incidence of primary cutaneous lymphomas over the last decades. OBJECTIVES: To estimate the incidence rates of primary cutaneous T-cell lymphoma (CTCL) and mycosis fungoides (MF)/Sézary syndrome (SS) in Norway, and to compare these rates with those reported from other countries. METHODS: Data from the Cancer Registry of Norway on non-Hodgkin lymphomas during the period 1980-2003 were analysed. RESULTS: In total, 337 cases of CTCL were reported to the Cancer Registry during the study period, of which 262 cases were classified as MF/SS. The incidence rate of CTCL increased significantly (P(trend) < 0.001) from 0.16 (95% confidence interval, CI 0.11-0.20) per 100,000 person-years in 1980-84 to 0.29 (95% CI 0.22-0.36) per 100,000 person-years in 2000-2003. The incidence of MF/SS also increased during the same period (P(trend) = 0.05) from 0.15 (95% CI 0.10-0.19) per 100,000 person-years to 0.18 (95% CI 0.13-0.24) per 100,000 person-years. CONCLUSIONS: The incidence of both CTCL and MF/SS increased in Norway during the period 1980-2003.