Asthma control in asthmatic patients treated for lung cancer

The balance of the Th1 and Th2 immune response plays an important role in the regulation of the immune system and in general health. Tumor bearing hosts are supposed to have a balance shifting to the Th2 pathway, while a favorable Th1 anti-tumor pathway is induced in tumor-resected hosts. The clinical impacts of a tumor-related Th2 environment have not been clearly studied. The present study was conducted to test the hypothesis that nonsmall cell lung cancer (NSCLC) has an impact on control of asthma, a wellknown Th2-predominant inflammatory disease.

Thirty-eight patients with the diagnoses of both asthma and lung cancer were retrospectively enrolled. Patients were divided into two groups according to their response to lung cancer treatment, the responder group (complete regression, partial regression and stable disease) and non-responder group (progression of disease). Asthma control test (ACT) scores were analyzed one year before diagnosis, at the time of diagnosis of lung cancer, and at the time of re-staging after cancer treatment.

All the asthmatics with lung cancer had worsening of their symptoms according to their ACT scores at the time of diagnosis of lung cancer compared to scores in the preceding year (21.6 ± 0.5 vs. 16.5 ± 0.8, n = 38, p < 0.001). The ACT scores in the responder group (17.3 ± 5.1) were significantly improved after effective lung cancer treatment (22.1 ± 1.8, n = 18, p < 0.01). However, the ACT scores in the non-responder group were even worse after disease progression (15.8 ± 5.0 vs. 11.6 ± 4.2, n = 18, p < 0.001).

Our observations indicate that asthmatic patients with acquisition or progression of NSCLC may have worsening of their asthma control status. Those patients with good responses to cancer treatment had improved asthma control. These observations indicate that the Th2 pathway in lung cancer may be a contributing factor in asthma control, another Th2 predominant disorder. More sophisticated clinical and biological investigations are necessary to confirm the role of Th1/Th2 counterbalance in lung cancer in the clinical impact on related immune disorders.