Global cancer incidences are substantially under-estimated due to under-ascertainment in elderly cancer cases.
BACKGROUND
The cancer incidence in developing countries is 7-19% under-estimated due to under-ascertainment of elderly cases in cancer registry data. The global cancer incidence, as a mixture of incidence in all countries, could thus be under-estimated as well. This study was conducted to report corrected global cancer incidence.


METHODS
The corrected rate in age group 65+ for 'all sites excluding skin cancer' was calculated by summing 1/3 of the original age-specific rate and 2/3 of anti-logarithm of 'the predicted value of the logarithm of rate in age group 65+' multiplied by a sex-specific coefficient. Cancer data were obtained from GLOBOCAN 2002.


RESULTS
The global cancer incidence estimate by the GLOBOCAN 2002 was 8.7% (men 13.3%; women 3.4%) under-estimated due to under-ascertainment in elderly cases, which means, worldwide, new cancer cases in 2002 were 11,810,000 (6,574,000 men; 5,236,000 women), topping the original estimate by 1 million.


CONCLUSIONS
The global cancer incidence estimate is substantially under-estimated due to under-ascertainment in elderly cases. This correction is performed mathematically; the results, however, emphasize the need for practical strategies to prevent under-ascertainment in the elderly.
Fallah
Mahdi
M
Tampere University Hospital, Tampere, Finland. Mahd.Fallah@gmail.com
Kharazmi
Elham
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D003906:Developing Countries; D005260:Female; D005544:Forecasting; D014943:Global Health; D006801:Humans; D015994:Incidence; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D011237:Predictive Value of Tests; D012042:Registries