Oyeyemi SO, et al. – In a nationally representative cohort of 96,898 women with self-reported information on lifestyle-related colorectal cancer (CRC) risk factors at baseline and at follow-up 6–8 years later in the Norwegian Women and Cancer Study, researchers ascertained whether geographical distribution of lifestyle-related CRC risk factors could determine the geographical variations in CRC incidence in Norwegian women. A total of 1,875 CRC cases were diagnosed during an average of 15.5 years of follow-up. Height, being a former smoker who smoked ≥ 10 years, or being a prevailing smoker who had smoked for ≥ 10 years were factors correlated with elevated CRC risk. Term of education (> 12 years vs ≤ 12 years) and intake of vegetables and fruits (> 300 g vs ≤ 300 g per day) were factors related to decreased CRC risk. However, between geographical areas of low and high CRC incidence, these risk factors did not account for the variations in CRC risk. This was further validated by the Karlson, Holm, and Breen method using baseline and follow-up measurements. Potential residual information, however, may lie in the heritable factors.