How Effective is Cancer Treatment?

Currently in the developed countries half of patients with cancer are curable. That figure is closer to one-third in the developing setting. Beyond that generality more can be said as follows:

Site   

Rank Order of

Fatality
Ratio

5 Year Survival
Deaths Survival Male (%) Female (%)
All cancers    - - 0.53 - -
Lung        1 15 0.83 9 15
Colorectal 2 8 0.39 49 47
Breast    3 7 0.37 - 73
Prostate    4 5 0.32 63 -
Lymphoma 5 10 0.47 43 46
Bladder    11 3 0.23 70 70
Body of Uterus 14 1 0.18 - 84
Stomach     7 13 0.68 17 17
Leukemia    8 12 0.63 38 38
Oral    13 6 0.34 77 63
Pancreas    6 16 0.98 3 3
Melanoma 15 2 0.20 83 83
Kidney        12 9 0.43 43 43
Brain    9 14 0.73 25 25
Ovary    10 11 0.63 37 37
Cervix        16 4 0.29 66 66

Adapted from: DeVita VT Jr, Hellman S and Rosenberg SA Eds (1997) Cancer. Principles and Practice of Oncology. Ed 5. Lippincott-Raven, Philadelphia.

The fatality ratio is the mortality/incidence ratio, and is an indication of survival (Jensen et al (1991) Cancer Registration: Principles and Methods. IARC Scientific Publications No95. Lyon). It is often used in countries where it is impossible to do a comprehensive follow-up of registered cases by a cancer registry in order to compute survival. There is a very close linear relationship with 5-year survival, with a fatality ratio of 1.0 corresponding to a 5-year survival of 0%, and a ration of 0.0 to a survival of 100%. In a developed setting where state of the art cancer treatment is available to all, the ratio is an indication of the effectiveness of current therapeutic modalities, as indicated above. 83% of cases of lung cancer can be expected to die, reflected also in the poor 5-year survival rates, indicating the relative ineffectiveness of currently available therapy. In contrast, with melanoma only 20% of cases will die, reflecting the high surgical curability of primary lesions diagnosed early (reflected in the higher 5-years survival rates). Compared to the above figures, in a developing country the discrepancies in the ratios will indicate the inadequacy of available treatment programs. In developing countries 5-year standardized relative survivals for the top 14 cancer sites is 21% for men and 32% for women (Pisani, Parkin & Ferlay (1993) Int. J. Cancer 55:891-903). Note also that the term 5-year survival is a relative concept also. Since most tumors run their course in 2 - 3 - 5 years on the average it is a practical estimate of survival. But 10-year survivals are sometimes used, and with some tumors like breast cancer or melanoma, late recurrences out to 20 years or more are not unheard of.

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