Early life exposure to Chinese famine and risk of digestive system cancer in midlife

To investigate whether early-life exposure to the Great Famine of 1959-1961 in China was associated with the risk of digestive system cancer. The prospective cohort study involved 17 997 participants from the Kailuan Study (Tangshan, China) that began in 2006. All participants were divided into three groups based on their date of birth. The unexposed group (born from 1 October 1962 to 30 September 1964), fetal-exposed group (born from 1 October 1959 to 30 December 1961), and early-childhoodexposed group (born from 1 October 1956 to 30 December 1958). The Cox proportional hazards model was used to analyze the association between early famine exposure and digestive system cancer. During the mean follow-up period of (10.4 +/- 2.2) years, a total of 223 digestive system cancer events occurred. Including 54 cases in the unexposed group (62.14/100 000 personyears), 57 cases in the fetal-exposed group (114.8/100 000 person-years), and 112 cases in the early-childhood-exposure group (122.2/100 000 person-years). After adjusting covariates, compared with the unexposed group, the HR and 95% CI were 1.85 (1.28, 2.69) for participants in the fetal-exposed group and 1.92 (1.38, 2.66) for participants in the early-childhood-exposed group. No interactions were observed in our study. After classifying digestive system cancers, the HR and 95% CI were 2.02 (1.03, 3.97) for colorectal cancer for participants in the fetal-exposed group and 2.55 (1.43, 4.55) for participants in the earlychildhood-exposed group. The HR and 95% CI were (1.13, 3.83) of liver cancer for participants in the fetal-exposed group and 1.15 (0.63, 2.10) for participants in the early-childhood-exposed group. Early-life famine exposure was associated with a higher risk of digestive system cancer in adulthood. Fetal-exposed individuals might increase the risk of colorectal cancer and liver cancer, and early childhood-exposed might increase the risk of colorectal cancer.