Epidemiology of cancer

The age-adjusted death rate from cancer per 100,000 inhabitants, 2004.[1]
  no data
  less than 55
  55–80
  80–105
  105–130
  130–155
  155–180
  180–205
  205–230
  230–255
  255–280
  280–305
  more than 305
Age adjusted, new cases of cancer, 2017.[2]
The percent of new US cancer cases by age, 2023

The epidemiology of cancer is the study of the factors affecting cancer, as a way to infer possible trends and causes. The study of cancer epidemiology uses epidemiological methods to find the cause of cancer and to identify and develop improved treatments.

This area of study must contend with problems of lead time bias and length time bias. Lead time bias is the concept that early diagnosis may artificially inflate the survival statistics of a cancer, without really improving the natural history of the disease. Length bias is the concept that slower growing, more indolent tumors are more likely to be diagnosed by screening tests, but improvements in diagnosing more cases of indolent cancer may not translate into better patient outcomes after the implementation of screening programs. A related concern is overdiagnosis, the tendency of screening tests to diagnose diseases that may not actually impact the patient's longevity. This problem especially applies to prostate cancer and PSA screening.[3]

Some cancer researchers have argued that negative cancer clinical trials lack sufficient statistical power to discover a benefit to treatment. This may be due to fewer patients enrolled in the study than originally planned.[4]

  1. ^ "WHO Disease and injury country estimates". World Health Organization. 2009. Retrieved Nov 11, 2009.
  2. ^ "Cancer incidence". Our World in Data. Retrieved 20 February 2020.
  3. ^ Brawley OW (2004). "Prostate cancer screening: clinical applications and challenges". Urol. Oncol. 22 (4): 353–7. doi:10.1016/j.urolonc.2004.04.014. PMID 15283896.
  4. ^ Bedard PL, Krzyzanowska MK, Pintilie M, Tannock IF (2007). "Statistical power of negative randomized controlled trials presented at American Society for Clinical Oncology annual meetings". J. Clin. Oncol. 25 (23): 3482–7. doi:10.1200/JCO.2007.11.3670. PMID 17687153.