HBV infection and extra-hepatic cancers in adolescents and 20s: A retrospective study in China. (August 2018) - Lu, Tingna
Highlights: HBV infection is associated with increased incidence rates of extra-hepatic cancers in adolescents and 20s. Lymphatic system is particularly susceptible to alteration by HBV infection. The association between HBV and extra-hepatic cancers is stronger in young males than females. Abstract: Background: The mean age at cancer diagnosis is younger in hepatitis B virus (HBV) infected than non-infected patients. It remains unknown whether this association reflects an increase in the incidence rates of extra-hepatic cancers in adolescents and younger. Methods: We examined 10 common extra-hepatic cancers (lung, breast, gastric, prostate, esophageal, rectal, cervical, nasopharyngeal, lymphatic, and urinary bladder) among patients diagnosed at three Chinese hospitals during 2007–2016. We compared the percentage distribution (frequencies at each age point are shown as a percentage of the total frequency) of HBsAg+ with HBsAgˉ patients, and calculated the standardized incidence ratio for each age group. Results: A total of 60, 323 patients were identified. The mean age at cancer diagnosis was 1.5–5.5 years younger in hepatitis B surface antigen (HBsAg) positive patients compared to HBsAgˉ patients (p ≤ 0.001). Lymphoma patients had the highest prevalence rate of HBV infection (20.7%). Among the pooled HBsAg+ cancer patients, 14.8% (1138/7666) were aged ≤39 years; by contrast, 9.7% (5122/52657) of HBsAgˉ cancer patients were in the same age range, giving an odds ratio of 1.6 [95%CI1.509–1.733)]. The observations were similar when each cancer was considered individually. The odds ratio was greater in pooled male patients aged ≤39 years [1.9(95%CI1.705–2.085)] compared with females [1.6(95%CI1.382–1.83)]. The ratio of the observed to the expected number of HBsAg+ patients aged 15–19, 20–24, and 25–29 years were 3.3, 4.8 and 2.0, respectively, higher than 1.2–1.7 observed for older age-groups. Conclusion: HBV infection is a risk factor for diverse extra-hepatic cancers in adolescents and 20s.