Longer HRT Duration Tied to Lower Colon Cancer Rate
In women, the longer the duration, the lower the rate of distal large bowel cancer
WEDNESDAY, Aug. 11 (HealthDay News) -- Longer duration of hormone replacement therapy (HRT) use among women is linked to a greater reduction in distal large bowel cancer incidence, independent of race, according to a study published in the August issue of the American Journal of Gastroenterology.
In a population-based case-control study, Millie D. Long, M.D., of the University of North Carolina at Chapel Hill, and colleagues evaluated 443 women with distal large bowel cancer and 405 controls in North Carolina between 2001 and 2006 to assess the associations between HRT, oral contraceptive use, and distal large bowel cancer.
The researchers found that ever use of HRT was strongly linked to a reduced risk of distal large bowel cancer (odds ratio [OR], 0.52), with increased duration of use associated with further reduction of risk. For women with less than four years of HRT use, the OR for distal large bowel cancer was 0.77, with an OR of 0.64 for four to eight years of use, 0.47 for nine to 14 years of use, and 0.34 for at least 15 years of use. However, ever use of oral contraceptives and duration of oral contraceptive use were not linked to a reduced incidence of distal large bowel cancer. The researchers also found no differences by race.
"It is possible that widespread use of HRT is partially responsible for the reductions that we have observed in distal large bowel cancer incidence over time," the authors write.