Five-year survival rate

The five-year survival rate is a term used in medicine for estimating the prognosis of a particular disease.[1]

Analysis performed against the Surveillance, Epidemiology, and End Results database (SEER) facilitates calculation of Five-year survival rates.[2][3]

Lead time bias due to earlier diagnosis can affect interpretation of the five-year survival rate.[4]

Relative and absolute rates

Five-year relative survival rates are more commonly cited in cancer statistics;[5] five-year absolute survival rates may sometimes also be cited.[6]

The fact that relative survival rates above 100% were estimated for some groups of patients appears counter-intuitive on first view. It is unlikely that occurrence of prostate cancer would increase chances of survival compared to the general population. A more plausible explanation is that this pattern reflects a selection effect of PSA screening, as screening tests tend to be used less often by socially disadvantaged population groups, who, in general, also have higher mortality.[7]

Uses

Five-year survival rates can be used to compare the effectiveness of treatments.

Use of 5-year survival statistics is more useful in aggressive diseases that have a shorter life expectancy following diagnosis (such as lung cancer) and less useful in cases with a long life expectancy such as prostate cancer.

Improvements in rates are sometimes attributed to improvements in diagnosis, rather than improvements in prognosis.[8]

To compare treatments (independent of diagnostics) it is better to consider survival from reaching a certain stage of the disease.

References

  1. ^ "Cancer survival rate: A tool to understand your prognosis - MayoClinic.com". http://www.mayoclinic.com/health/cancer/CA00049. Retrieved 2009-10-11. 
  2. ^ Gloeckler Ries LA, Reichman ME, Lewis DR, Hankey BF, Edwards BK (2003). "Cancer survival and incidence from the Surveillance, Epidemiology, and End Results (SEER) program". Oncologist 8 (6): 541–52. doi:10.1634/theoncologist.8-6-541. PMID 14657533. http://theoncologist.alphamedpress.org/cgi/pmidlookup?view=long&pmid=14657533. 
  3. ^ Cosetti M, Yu GP, Schantz SP (April 2008). "Five-year survival rates and time trends of laryngeal cancer in the US population". Arch. Otolaryngol. Head Neck Surg. 134 (4): 370–9. doi:10.1001/archotol.134.4.370. PMID 18427002. http://archotol.ama-assn.org/cgi/pmidlookup?view=long&pmid=18427002. 
  4. ^ Gordis, Leon (2008). Epidemiology: with STUDENT CONSULT Online Access. Philadelphia: Saunders. pp. 318. ISBN 1-4160-4002-1. 
  5. ^ Varricchio, Claudette G. (2004). A cancer source book for nurses. Boston: Jones and Bartlett Publishers. pp. 30. ISBN 0-7637-3276-1. 
  6. ^ "ACS :: How Is Colorectal Cancer Staged?". http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_How_is_colon_and_rectum_cancer_staged.asp. Retrieved 2009-10-11. 
  7. ^ a b Brenner H, Arndt V (January 20, 2005). "Long-term survival rates of patients with prostate cancer in the prostate-specific antigen screening era: population-based estimates for the year 2000 by period analysis". J Clin Oncol 23 (3): 441–7. doi:10.1200/JCO.2005.11.148. PMID 15572727. http://jco.ascopubs.org/cgi/reprint/23/3/441.pdf. 
  8. ^ Welch HG, Schwartz LM, Woloshin S (June 2000). "Are increasing 5-year survival rates evidence of success against cancer?". JAMA 283 (22): 2975–8. doi:10.1001/jama.283.22.2975. PMID 10865276. http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=10865276.