Colorectal cancer screening

[The authors respond:]

We thank Roy Preshaw for his letter in response to our editorial on colorectal cancer screening.1 He unfortunately appears to have mixed up 2 separate rates reported in the US and Canadian studies. We correctly quoted the “ever-screened” rate in the United States as 63%2; the comparable rate in Canada is 23.5%.3 The difference between the “current-for-screening” rates in the 2 countries is similar in magnitude: 37% in the United States2 and 17.6% in Canada.3

Preshaw's assertion that colorectal cancer screening rates in Canada and the United States are not so different is thus incorrect. In fact, no assertion could be further from the truth. There are overwhelming data showing that “current-for-screening” rates are approximately 43% to 55% in the United States4^,5 whereas Canadian investigators have reported dismal data. For example, a “current-for-screening” rate of only 14% in Canada was recently reported.6

The reasons for these differences are likely multifactorial. However, a recent US study indicated that among primary care physicians and adults at average risk of developing colorectal cancer, lack of patient awareness and failure of a physician to recommend screening are key barriers to screening.7 We therefore reiterate our plea for Canadian physicians to actively work to close this care gap; such action will ultimately save lives.