| Popis: |
Cancer incidence with special reference to nonmelanoma skin cancer was studied by combining the results of the two largest follow-up studies on trioxsalen (TMP) bath PUVA. The study cohort comprised 527 psoriasis patients treated at the Oulu University Hospital, Finland, in 1977–1988 and 597 patients treated with TMP bath PUVA at the Uppsala University Hospital, Sweden, in 1974–1985, of whom two thirds had psoriasis and the remaining on third other skin diseases. The average follow-up time in the combined cohort was 10 years. The observed and expected numbers of cases from the two studies were added up, and the combined standardized incidence ratios (SIR) were calculated. The expected numbers of cases were based on the national cancer incidence rates in the respective countries. Two cases of squamous cell skin carcinoma were found, while the expected number was 1.8 (SIR 1.1,95% CI 0.1-4.0). A fourfold or higher excess risk could be excluded. The overall risk of cancer was significantly increased in women (SIR 1.9,95% CI 1.4-2.6), but not in men. Kidney cancer (SIR 8.3,95% CI 2.7-19) and non-Hodgkin’s lymphoma (SIR 6.5,95% CI 1.4-19) were significantly more common than expected in women. In conclusion, the occurrence of squamous cell skin carcinoma was not increased in patients treated with TMP bath PUVA. The result indicates that TMP bath PUVA is a safer treatment than oral methoxsalen PUVA. |
