Here’s a tip that probably will not appeal to you; however, it can benefit your health: participate in Colon Cancer Awareness Month by having a colonoscopy. According to a new study, the procedure can reduce the risk of late-stage colorectal cancer by 70%. Early detection can nip the condition in the bud, while late-stage disease is incurable for most patients. Researchers affiliated with the Perelman School of Medicine, University of Pennsylvania, published their findings online on March 4 in the journal Annals of Internal Medicine.
The researchers noted that the effectiveness of screening colonoscopy in average-risk adults is uncertain, particularly for right colon cancer. Therefore, they conducted a study to examine the association between screening colonoscopy and risk for incident late-stage colorectal cancer. The study group comprised 1,039 average-risk adults enrolled for at least five years in one of the health plans. The case patients were between the ages of 55 and 85 on their diagnosis date (reference date) of stage IIB or higher (late-stage) colorectal cancer during 2006 to 2008. One or two control patients were selected for each case patient, matched on birth year, sex, health plan, and prior enrollment duration.
Medical record audits were conducted to identify patients that had undergone colorectal cancer screening three months to 10 years before the reference date. The case patients and control patients were compared regarding undergoing a screening colonoscopy or sigmoidoscopy by using conditional logistic regression analysis that accounted for health history, socioeconomic status, and other screening exposures. (Logistic regression is a type of regression analysis used for predicting the outcome of a categorical dependent variable (in this case colorectal cancer) that can take on a limited number of categories based on one or more predictor variables (as described above in this case).)
The researchers conducted their analyses restricted on 471 eligible case patients and their 509 matched control patients. Because screening colonoscopy was relatively uncommon during the study period, the authors noted that study precision was limited by the low number of participants. They found that 13 case patients (2.8%) and 46 control patients (9.0%) had undergone screening colonoscopy for any late-stage colorectal cancer. Among the study group, 92 case patients (19.5%) and 173 control patients (34.0%) underwent a screening sigmoidoscopy.
The authors concluded that screening with colonoscopy in average-risk individuals was associated with reduced risk for diagnosis of late-stage CRC, including right-sided colon cancer. For sigmoidoscopy, this association was seen for left colorectal cancer; however, the association for right colon late-stage cancer was not statistically significant.
Take home message:
This study notes the benefits of colonoscopy for colorectal cancer screening for early diagnosis. Colonoscopy is a superior procedure to sigmoidoscopy because the latter procedure only examines a portion of the colon. The study also illustrates the low percentage of individuals who avail themselves of a screening procedure. The study patients all had medical insurance; thus, cost was not a significant factor for undergoing colonoscopy.