Risk of second primary malignancies in women with cervical cancer: A population-based study in Taiwan over a 30-year period

Objective: Studies conducted in Western countries have reported an increased risk for second primary malignancies after cervical cancer. There is little documentation of ethnic differences in this increased risk, and most of the Asian studies are hospital-based studies with small case numbers. Methods: Using population-based data from the Taiwan Cancer Registry for the period 1979-2008, we quantified standardized incidence ratios (SIRs) among 52,972 women with initial diagnoses of cervical cancer. Results: Among the 52,972 women, 3061 (5.78%) developed second primary cancers during 433,571 person-years of follow-up. Overall, the SIR for developing a subsequent second cancer was significantly greater than that of the general population (1.36 [95% CI, 1.32-1.41]). There was a greater risk for cancers of the esophagus, stomach, small intestine, rectum, lung, bone, non-melanoma skin, uterine corpus, vagina/vulva, bladder, kidney, and leukemia. When further examining age at diagnosis of cervical cancer (< 50 and ≥ 50) for these 12 sites, we found that the risk of second cancers (SIR, < 50 and ≥ 50: 3.08 vs. 1.63) was higher not only in younger patients, except for non-melanoma skin cancer and endometrial cancer, but also within the first 5 years after diagnosis of cervical cancer. The median overall survival for women with cervical cancer was 18.58 years. The second cancers had a negative impact on overall survival after adjusting for age (P < 0.001). Conclusions: SIR for second cancers was significantly greater than the general population in cervical cancer patients. A young age at the diagnosis of cervical cancer predicted an increased risk. The second cancers worsened overall survival.