Surgical treatment after neoadjuvant / induction therapy

Abstract

Lung cancer is the most common cause of cancer-related deaths in Europe and the United States. Approximately 85% of lung cancers are non-small cell lung cancers (NSCLC) [1]. Treatment options include chemotherapy, immunotherapy, targeted therapy, radiation therapy, and surgery, depending on the patient's condition and the stage of the disease. In early stages (Stage I-II), surgical treatment provides the best survival outcomes and is the preferred option. However, there is insufficient data on the role of neoadjuvant/induction (N/I) therapy in this stage, so it is not recommended [2]. Stage III disease is a highly heterogeneous group of lung cancer according to the 8th TNM staging system, with 16 different TNM stages (T4N0-3 / T3N1-3 / T1-2N2-3). Depending on the \"T\" factor, it can involve spread to surrounding tissues or have multiple locations. Depending on the \"N\" factor, it can be N0-3. Additionally, several other subgroups [N1 (single-multiple N1, N1 (station 10 according to), N2 (skip N2, single-multiple station N2, microscopic N2, large N2, unexpected N2, persistent N2, resectable-unresectable N2), N1 and N2] have been shown to affect survival rates [3,4]. Therefore, there is no difference in the definition of lymph nodes in the new staging system, but it is recommended to address the classification of lymphatic involvement in detail as preparation for the next staging [5]. In this section, the role of N/I therapy for stage IIIA will be discussed, excluding the stage IIIB-C patient group for whom surgical treatment is not recommended [6]. When evaluating the studies and literature in this section, it should be considered that in the past twenty years, there have been changes in the definition of stage III and lymph node mapping (N1-N2 differentiation), stage III is a highly heterogeneous group, there are different definitions used by authors (large N2, complete response, multiple station-region N2, resectable N2, etc.), advancements in technology such as PET-CT, endobronchial ultrasound (EBUS), esophageal ultrasound (EUS), video-mediastinoscopy have made mediastinal staging more accurate, the use of minimally invasive surgery has become more common, there has been a decrease in postoperative complications and mortality, changes in chemotherapy agents used over the years, advancements in radiation therapy technology, and changes in CT doses. For example, in the new staging system, compared to the previous version, there are shifts between stage IIB and IIIA-B [3,7].