The median age of the 1844 renal transplant patients was 42 years (interquartile range: 31–51 years). In 15
940 PY of observation (median follow-up time: 7.0 years), 104 cases of cancer, other than nonmelanoma skin cancers, were diagnosed. Standardised incidence ratios according to cancer type or site, and sex are shown in .
Standardised incidence ratio (SIR) of cancer and corresponding 95% confidence interval (CI) after renal transplantation, according to cancer site or type and sex (Italy, 1970–2003)
The SIR for all cancers was 1.8 (95% CI: 1.5–2.2), and was of similar magnitude in the two sexes. The SIR for KS was 112.6 but it was greater among women (SIR=451, 95% CI: 147–1053) than men (SIR=93, 95% CI: 55–147). A 6.6-fold increased SIR (95% CI: 3.7–11.0) was seen for NHL. Other cancers with significantly elevated SIRs included: carcinomas of the lip (SIR=14.6; 95% CI: 1.8–52.7), liver (SIR=3.9; 95% CI: 1.5–8.6), and kidney (SIR=3.9; 95% CI: 1.6–8.0). The SIRs for lip and liver cancers were more elevated in women than men, whereas the excess risk for native renal cancer was found in men only (). Standardised incidence ratios for stomach (SIR=1.2), colon (SIR=1.0), lung (SIR=0.8), and female breast cancers (SIR=0.7) were close to unity ().
Among renal transplant patients, KS was more frequent (IRR=3.0, 95% CI: 1.1–8.5) in persons aged 50 years or older at transplant than in those younger than 40. Kaposi's sarcoma was nonsignificantly more common in men than in women, whereas it was nearly six-fold more frequent (95% CI: 1.6–19.7) in patients born in southern Italy, as compared to those born in northern Italy (). A strong inverse association emerged between KS occurrence and time since renal transplant. In the first year following transplant, KS was 4.5-fold more frequent (95% CI: 1.6–12.2) than after 4 or more years ().
Incidence rate ratio (IRR) for Kaposi's sarcoma and corresponding 95% confidence interval (CI) after renal transplantation according to selected characteristics (Italy, 1970–2003)
Most of these 1844 patients (87%) received their transplant after cyclosporin came into widespread use (from 1983 onwards), and one-third after the introduction of the newer immunosuppressive drugs (from 1997 onwards). All 23 KS cases were diagnosed in 1983 or later inpatients who were treated with cyclosporin-containing regimens. No significant difference in KS IRRs was seen according to the calendar period of transplant ().