Tuberculosis is associated with increased lung cancer mortality

Elderly persons living in the community in Hong Kong.

To examine the association between tuberculosis (TB) and lung cancer.

Elderly clients enrolled in a health programme from 2000 to 2003 were retrospectively cross-matched with the territory-wide TB notification registry for TB before enrolment. The cohort was followed up prospectively through linkage with the territory-wide death registry for cause of death until 31 December 2011. All subjects with suspected malignancy or recent weight loss (≥5%) at enrolment and deaths within the first 2 years of follow-up were excluded.

Of the 61,239 subjects included, 516 had TB before enrolment. After 490,258 person-years of follow-up, respectively 1344, 910 and 2003 deaths were caused by lung cancer, other tobacco-related malignancies and non-tobacco-related malignancies. TB before enrolment was associated with death due to lung cancer (Mantel-Haenszel weighted relative risk 2.61, 95%CI 1.82-3.74, P < 0.001) but not other malignancies after stratification by sex. TB remained an independent predictor of lung cancer death (adjusted hazard ratio 2.01, 95%CI 1.40-2.90; P < 0.001), after adjustment for multiple potential confounders.

TB was independently associated with subsequent mortality due to lung cancer. This finding calls for intensification of tobacco control and better targeting of lung cancer screening in high TB burden areas.