Second primary malignancies in females with primary fallopian tube cancer.

Primary fallopian tube cancer (PFTC) is a rare disease, and its aetiological factors are poorly understood. Studies on PFTC in the setting of 2nd primary malignant neoplasms can provide clues on aetiology and also define the possible side effects of different treatment modalities for PFTC. A cohort of 2,084 cases with first PFTC was extracted from the data from 13 cancer registries from Europe, Canada, Australia and Singapore and followed for second primary cancers within the period 1943-2000. Standardized incidence ratios (SIRs) were calculated and Poisson regression analyses were done to find out the RRs related to age at, period of and time since the PFTC diagnosis. There were 118 cancer cases observed after first PFTC (SIR 1.4, 95%CI 1.1-1.6). Elevated SIRs were seen for colorectal cancer (1.7, 95%CI 1.0-2.6), for breast cancer (1.5, 95%CI 1.1-2.2), for bladder cancer (2.8, 95%CI 1.0-6.0), for lung cancer (1.8, 95% CI 0.9-3.2) and for nonlymphoid leukaemia (3.7, 95%CI 1.0-9.4). Significant risk increases were detected for colorectal cancer during the 2nd to 5th year after the first PFTC diagnosis, for breast cancer in follow-up 10+ and for nonlymphoid leukaemia during the 2nd to 10th year. The clustering of cancers of the lung and bladder in PFTC patients may suggest shared smoking aetiology. The excess of colorectal and breast cancers after PFTC may indicate a genetic aetiology.