Excess incidence of lung cancer among pulmonary tuberculosis patients.

Reviewing the epidemiological studies on coexistent pulmonary tuberculosis and lung cancer since 1960, it was confirmed that patients with active pulmonary tuberculosis have a higher risk of dying from lung cancer or other malignancies, in spite of a very high mortality from tuberculosis per se. Females showed a higher risk than males. An antagonistic hypothesis between the above two diseases since 1854 seemed based on the facts that tuberculosis patients had mostly died in young age groups and had had little chance of surviving to cancer age groups before the advent of modern treatments, and that the lack of an adequate disease registration system might have caused a failure to reveal any association between the two diseases. Specific causative factors of the excess incidence of cancer among active pulmonary tuberculosis patients, however, have so far not be clarified.