Lung cancer is the most cause of cancer death in the world. Non-small cell lung cancer (NSCLC), the second most common subtype of lung cancer, is mostly composed of lung squamous cell carcinoma (LUSC) and adenocarcinoma (LUAD). The lethality of NSCLC is generally caused by an inability to surgically remove the disease because of its diagnosis a late stage. Early detection and resection of premalignant lesions would improve patient outcome.
Before transforming into an invasive LUSC, airway basal cells proliferate and evolve to form a basal cell metaplasia (from mild and moderate to severe dysplasia) and next a carcinoma in situ (CIS). To study the early steps of transformation to LUSC, autofluorescence bronchoscopy is used to detect and biopsy CIS. It has been shown that in 30% of cases, CIS lesions spontaneously regress to a normal epithelium. Therefore, identifying the premalignant CIS lesions that will progress to invasive cancer is necessary to decide on therapeutic intervention. But the events responsible for the progression of a CIS to an invasive LUSC are still unknown.
We have started to analyse the immune microenvironment of progressive and regressive CIS using quantitative multiplex immunohistochemistry. We have evaluated the expression of 17 biomarkers per section of formalin-fixed paraffin-embedded CIS biopsy obtained from 33 patients for whom we have follow-up data (11 regressive, 22 progressive). The purpose of this study is to identify differences in the immune profile of progressive and regressive CIS to find new biomarkers predictive of disease progression and propose therapeutic strategies to treat CIS and prevent progression to invasive lung cancer.