The validity of the mortality to incidence ratio as a proxy for site-specific cancer survival

• Published in: European Journal of Public Health
• Main Authors: Asadzadeh Vostakolaei, Fatemeh, Karim-Kos, Henrike E., Janssen-Heijnen, Maryska L. G., Visser, Otto, Verbeek, André L. M., Kiemeney, Lambertus A. L. M.
• Format: Text
• Language: English
• Published: Oxford University Press 2011
• Subjects: Health Services Research; Norway; Iceland
• Online Access: http://eurpub.oxfordjournals.org/cgi/content/short/21/5/573; https://doi.org/10.1093/eurpub/ckq120

Background: The complement of the cancer mortality to incidence ratio [1 – ( M / I )] has been suggested as a valid proxy for 5-year relative survival. Whether this suggestion holds true for all types of cancer has not yet been adequately evaluated. Methods: We used publicly available databases of cancer incidence, cancer mortality and relative survival to correlate relative survival estimates and 1 – ( M / I ) estimates from Denmark, Finland, Iceland, Norway, Sweden, the USA and the Netherlands. We visually examined for which tumour sites 5-year relative survival cannot simply be predicted by the 1 – ( M / I ) and evaluated similarities between countries. Results: Country-specific linear regression analyses show that there is no systematic bias in predicting 5-year relative survival by 1 – ( M / I ) in five countries. There is a small but significant systematic underestimation of survival from prognostically poor tumour sites in two countries. Furthermore, the 1 – ( M / I ) overestimates survival from oral cavity and liver cancer with >10% in at least two of the seven countries. By contrast, the proxy underestimates survival from soft tissue, bone, breast, prostate and oesophageal cancer, multiple myeloma and leukaemia with >10% in at least two of the seven countries. Conclusion: The 1 – ( M / I ) is a good approximation of the 5-year relative survival for most but not all tumour sites.