Table 6.

Colon and rectal cancer risk by time period before diagnosis for cases and interview for controls

Pack-years, cumulative up toOR* (95% CI)
All tobacco productsFiltered cigarettesNon-filtered cigarettes
Colon (1,349 case-control pairs)
    0 y ago1.05 (1.01-1.08)1.00 (0.97-1.05)1.12 (1.05-1.19)
    5 y ago1.05 (1.01-1.09)1.01 (0.96-1.06)1.11 (1.04-1.19)
    10 y ago1.06 (1.01-1.10)1.01 (0.95-1.08)1.11 (1.04-1.19)
    20 y ago1.05 (1.00-1.11)0.98 (0.90-1.07)1.11 (1.03-1.20)
    30 y ago1.04 (0.96-1.13)0.90 (0.79-1.03)1.09 (0.99-1.20)
    40 y ago1.03 (0.91-1.17)0.75 (0.57-0.98)1.04 (0.90-1.19)
    50 y ago1.08 (0.84-1.38)0.84 (0.40-1.74)0.98 (0.76-1.27)
Rectum (573 case-control pairs)
    0 y ago1.10 (1.05-1.16)1.10 (1.03-1.17)1.11 (1.03-1.19)
    5 y ago1.10 (1.03-1.16)1.09 (1.00-1.19)1.09 (1.00-1.18)
    10 y ago1.10 (1.03-1.17)1.11 (0.78-1.59)1.07 (0.99-1.17)
    20 y ago1.09 (1.00-1.18)1.08 (0.93-1.24)1.08 (0.98-1.20)
    30 y ago1.05 (0.94-1.17)0.96 (0.76-1.20)1.07 (0.94-1.21)
    40 y ago1.00 (0.85-1.18)0.86 (0.56-1.32)1.01 (0.84-1.21)
    50 y ago1.05 (0.76-1.43)0.85 (0.23-3.15)1.05 (0.75-1.47)
  • * OR and 95% CI are estimated using conditional logistic regression and represent the risk associated with an increment of 10 pack-years in the specified time period, and are adjusted for pack-years accumulated from that time to diagnosis or interview, as well as for family history of colorectal cancer, body mass index 5 y ago, lifetime hours in recreational activities and egg, total calcium, non-starch polysaccharides from vegetables, methionine and alcohol intake, and matched on age, sex, and ethnicity. Fourteen separate models were run for each subsite (seven for pack-years of all tobacco products and seven for pack-years of filtered and non-filtered cigarettes), which were modeled together.