['The aim of this study was to examine the association of risk factors including diabetes mellitus (DM) with the age of onset in Japanese pancreatic cancer (PC) patients.', 'We retrospectively reviewed 688 PC patients diagnosed at our institute. We analyzed the association between the age of onset of PC and the following variables: sex, smoking, alcohol, DM, and a family history of cancer especially PC.', 'The mean age of PC diagnosis was 67.6 years. The onset of PC occurred earlier in current smokers (63.6 years old, P < 0.001) compared with past smokers (69.5 years old) and never smokers (68.6 years old). Patients with long-standing DM (>2 years) were older (70.5 years, P < 0.001) when diagnosed with PC than patients with new-onset DM (within 2 years) (66.9 years old) and patients without DM (66.7 years old). In the multivariate analysis, current smokers and a family history of cancer other than PC were associated with earlier onset. Conversely, long-standing DM was associated with later onset.'] Are smoking , family history of cancer , and diabetes mellitus associated with the age of onset of pancreatic cancer in Japanese patients?