Neoadjuvant Radiotherapy/Chemoradiotherapy in Locally Advanced Non-Small Cell Lung Cancer

摘要

Locally advanced non-small cell lung cancer (NSCLC) consists of a heterogeneous group of patients, and the optimal treatment is still controversial. The current standard of care is concurrent chemoradiotherapy. The prognosis is still poor, with high rates of local and distant failure despite multimodality treatment. One of the efforts to improve outcomes in these patients is to use neoadjuvant treatment to improve resectability, and downstaging the nodal disease, which has a clear impact on prognosis. Radiotherapy as the sole neoadjuvant modality has been used historically without any survival benefit, but with increased toxicity. After the demonstrating a survival benefit by combining radiotherapy and chemotherapy, phase II studies were started to determine the neoadjuvant administration of these two modalities together. Although the results of these studies revealed a heterogeneous postinduction pathologic complete response, tumor and nodal down-staging can be achieved at the cost of a slightly higher morbidity and mortality. Subsequent phase III trials also failed to show a survival benefit to surgery, but indicated that there may be a subset of patients with locally advanced disease who can benefit from resection unless pneumonectomy is not provided. In order to increase the efficacy of radiotherapy, hyperfractionated-accelerated schedules have been used with promising complete pathologic response rates, which might improve prognosis. Recently, studies applying high radiotherapy doses in the neoadjuvant setting demonstrated the safety of resection after radiotherapy, with high nodal clearance rates and encouraging long-term survival results. In conclusion, neoadjuvant treatment of locally advanced NSCLC is one of the most challenging issues in the treatment of this disease, but it can be offered to appropriately selected patients, and should be done by a multidisciplinary team. Individual risk profiles, definite role of radiotherapy with optimal timing, and dose need to be clarified by carefully designed clinical trials.