Second primary cancer after in situ and invasive cervical cancer

The Swedish Family-Cancer Database was used to analyze 9,426 second primary cancers in 117,830 subjects diagnosed with in situ and 17,556 subjects with invasive cervical cancer from the years 1958-1996. We calculated standardized incidence ratios (SIRs) from age- and period-specific rates for all women. SIRs were elevated after both in situ and invasive cervical cancer for cancers of the upper aerodigestive tract, anus, pancreas, lung, other female genitals, and urinary bladder. Anus and other female genitals, known targets of human papilloma virus, showed SIRs exceeding 3.0 and 10 or more within the year of diagnosis of cervical cancer, probably implying the effects of diagnostic intensity or transient faltering of host immunosurveillance. Among the remaining sites, smoking appeared to be the major cause, but for urinary bladder cancer it only explained one-half of the excess; human papilloma virus infection, possibly through immunosuppression, could account for the remaining excess. Although urinary bladder cancer showed a relatively small SIR compared with anal cancer, because it is more common, the number of attributable cases was about equal for the two sites. Invasive cervical cancer showed an SIR of 2.3 after in situ cancer. On follow-up, we also observed increased SIRs at many radiosensitive sites 10 or more years after diagnosis of invasive cervical cancer.