There is considerable evidence that screening of asymptomatic persons who are at average risk can detect cancers at early and curable stage, resulting in a reduction of mortality. Furthermore, some screening tests may also detect cancer-precursor lesions, which, if removed, may result in a reduced incidence of colorectal cancer.
The secondary prevention of colorectal cancer is an important cancer control strategy, both because it can relatively quickly reduce mortality, by finding disease early when it can be most easily treated and because, when pre-cancerous lesions, such as adenomas, are identified and removed, colorectal cancer is prevented.
Why has ESMO, an organisation for medical oncology, commissioned a dedicated E-Learning module on colorectal cancer screening? Oncologists must take a part in cancer prevention. They have the potential to be a large and important group of activists for cancer prevention measures. Furthermore we are faced with a rising, but still relatively low rate of screening consumption for colorectal cancer compared to screening rates for breast and cervical cancers. Therefore they should have more incentives than many others to see them implemented. Seen in this light, this module is both a timely and necessary practice tool.
There are several different tests for colorectal cancer screening, each with advantages and limitations, sensitivity and specificity, complexity, and the associated risks. The content of this E-learning module is organised around criteria which have to be met before screening should be organised, advantages and disadvantages of the two faecal occult blood tests, and the rationale for colonoscopy as a follow-up examination after a positive faecal occult blood test, with the pros and cons for doing it.
This module gives a good example of how the improvement of knowledge on secondary prevention of colorectal cancer and discussing how different assumptions about improved colorectal cancer screening can impact on colorectal cancer mortality.