目的应用巢式病例对照研究方法，探讨原发性肝癌（HCC）的危险因素。

Purpose To explore the risk factors of hepatocellular carcinoma (HCC) with the aid of nested case control study.

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膳食纤维或全麦食品摄入量与结直肠癌发病率的前瞻性队列研究和巢式病例对照研究。

Study selection Prospective cohort and nested case-control studies of dietary fibre or whole grain intake and incidence of colorectal cancer.

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