Conclusions
Our results suggest a benefit to joint targeting of the estrogen and inflammatory pathways for NSCLC prevention. Combining AIs with nonsteroidal anti-inflammatory drugs reduces circulating E2, proinflammatory cytokines, and macrophage recruitment in the lung microenvironment after tobacco exposure. This strategy could be particularly effective in women who have underlying pulmonary inflammatory diseases.
Methods
We utilized a tobacco carcinogen-induced lung tumor mouse model by treatment with 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), to determine whether an AI combined with nonsteroidal anti-inflammatory drugs
Results
Combination of anastrozole (0.1 mg/kg/d) with aspirin (25 mg/kg/d) after NNK exposure resulted in significantly fewer and smaller lung tumors than did single-agent treatments and was accompanied by maximum decreases in circulating β-estradiol (E2) and interleukin-6, tumor-infiltrating macrophages, and tumoral Ki67, phospho-mitogen-activated protein kinase, phospho-signal transducer and activator of transcription 3, and interleukin-17A expression. Preneoplasia arising after combination treatment showed the lowest Sox-2 expression, suggesting an inhibitory effect on proliferative capacity in the airways by blocking both E2 and inflammation. Anastrozole combined with ibuprofen instead of aspirin also showed enhanced antitumor effects. Moreover, male mice treated with NNK that received E2 in their drinking water showed greater levels of pulmonary macrophages and inflammatory markers than did the control, confirming an E2 effect on inflammation in the microenvironment. Conclusions: Our results suggest a benefit to joint targeting of the estrogen and inflammatory pathways for NSCLC prevention. Combining AIs with nonsteroidal anti-inflammatory drugs reduces circulating E2, proinflammatory cytokines, and macrophage recruitment in the lung microenvironment after tobacco exposure. This strategy could be particularly effective in women who have underlying pulmonary inflammatory diseases.