The relationship between cancer and tuberculosis mortality rates

Previous lung diseases and lung cancer risk: a systematic review and meta-analysis

BACKGROUND

In order to review the epidemiologic evidence concerning previous lung diseases as risk factors for lung cancer, a meta-analysis and systematic review was conducted.

METHODS

Relevant studies were identified through MEDLINE searches. Using random effects models, summary effects of specific previous conditions were evaluated separately and combined. Stratified analyses were conducted based on smoking status, gender, control sources and continent.

RESULTS

A previous history of COPD, chronic bronchitis or emphysema conferred relative risks (RR) of 2.22 (95% confidence interval (CI): 1.66, 2.97) (from 16 studies), 1.52 (95% CI: 1.25, 1.84) (from 23 studies) and 2.04 (95% CI: 1.72, 2.41) (from 20 studies), respectively, and for all these diseases combined 1.80 (95% CI: 1.60, 2.11) (from 39 studies). The RR of lung cancer for subjects with a previous history of pneumonia was 1.43 (95% CI: 1.22-1.68) (from 22 studies) and for subjects with a previous history of tuberculosis was 1.76 (95% CI=1.49, 2.08), (from 30 studies). Effects were attenuated when restricting analysis to never smokers only for COPD/emphysema/chronic bronchitis (RR=1.22, 0.97-1.53), however remained significant for pneumonia 1.36 (95% CI: 1.10, 1.69) (from 8 studies) and tuberculosis 1.90 (95% CI: 1.45, 2.50) (from 11 studies).

CONCLUSIONS

Previous lung diseases are associated with an increased risk of lung cancer with the evidence among never smokers supporting a direct relationship between previous lung diseases and lung cancer.

Lung cancer in patients who had received thoracoplasty for pulmonary tuberculosis

BACKGROUND

In Japan in the 1950s, thoracoplasty was a powerful therapy for pulmonary tuberculosis. Now there are many aged people who have tuberculosis sequelae caused by thoracoplasty. We have encountered some cases of lung cancer among these people.

METHODS

To elucidate the features of lung cancer occurring after thoracoplasty for pulmonary tuberculosis, we reviewed for analysis 20 such cases.

RESULTS

There were 17 men and three women, aged 55 to 78 years (mean 65 years). All had respiratory dysfunction and most were cigarette smokers. Lung cancers were located in the upper lobes in nine cases, in the middle lobe in one and in the lower lobes in 10. Ten lung cancers were in the thoracoplastied lung and the remaining 10 in the opposite lung. Histologically, squamous cell carcinoma was predominant (11 cases). Eight lung cancers were detected in stages I and II and 12 in stages III and IV. Most cancer lesions were separate from tuberculosis lesions. Surgical resection was selected in only three of 11 stages I-IIIA cases in consideration of respiratory dysfunction and/or ventilatory impairment due to thoracoplasty. Chemotherapy and/or radiotherapy were performed in nine and supportive care alone was performed in eight. Fourteen patients died of lung cancer and four died of cor pulmonale due to tuberculosis sequelae. Five-year survival was achieved in only one surgical case. Eight of the nine patients who received chemotherapy or radiotherapy died within 1 year, and, further, seven of eight patients who received supportive care died within 6 months.

CONCLUSION

Lung cancer in the patients who had received thoracoplasty occurred in each lung and every lobe, independent of thoracoplasty. In addition, delay of detection was such that stage III-IV cases were in the majority, there were some limitations in therapeutic benefits related to thoracoplasty and the prognosis was very poor. Physicians should avoid delay in the detection of lung cancer through careful follow-up of such patients.