A narrative review of invasive diagnostics and treatment of early lung cancer

The diagnosis and treatment of early-stage lung cancer remains a clinical challenge. The broadening implementation of lung cancer screening has resulted in positive findings in numerous patients that are mostly non-malignant. Many other patients have indeterminate nodules that are difficult to assess through simple observation. The critical interpretation of such screening results remains a challenge for radiologists and multidisciplinary teams involved in screening for lung cancer. The evaluation and diagnosis of each participant suspected for malignancy should be based on the basic clinical principles such as a carefully collected medical history, physical examination, and detailed analysis of all imaging tests performed. Indeed, the decision to go ahead with more invasive diagnostics requires consideration of the both the risks and benefits, with reflection upon the complete clinical and radiological picture. Although transthoracic needle aspiration biopsy remains the first-choice method of diagnosis, several newer technologies have slowly begun to emerge as potential replacements. The guiding strategy for method selection is to choose the least harmful approach that offers the most relevant potential insights. Transthoracic biopsy is an effective method that allows the collection of cytological and tissue material from small, peripheral tumors, but it carries a moderate risk of complications. Bronchofiberoscopy, especially in combination with electromagnetic navigation, fluoroscopy or radial EBUS, also allows effective diagnosis of the peripheral pulmonary nodules. One of the most important diagnostic methods is the EBUS examination, which allows determining of staging in addition to diagnosis. Anatomical lung lobe resection and lymphadenectomy or sampling of the hilar and mediastinal lymph nodes is currently the treatment of choice for patients with stage I and II non-small cell lung cancer (NSCLC), but sublobar resections are recommended when a patient has limited pulmonary function or other significant comorbidities. Notably, several studies have highlighted the potential utility of more limited resections in small malignant lesions less than 2cm in diameter, with pure AIS histology, when more than 50% of the diameter of pulmonary nodule has ground-glass opacity (GGO) attenuation on CT, or long volume doubling time (VDT). Videothoracoscopy is the preferred surgical approach for resection of early-stage lung cancer. Patients who are not candidates for surgery or do not agree to surgery can be offered radical radiotherapy. Stereotactic body radiation therapy (SBRT) is a type of radical radiotherapy with proven effectiveness, a high rate of local control and an acceptable risk of the development of later complications. Future trials are expected to define the role of SBRT in the treatment of early lung cancer in healthy subjects.