Expert consensus on neoadjuvant immunotherapy for non-small cell lung cancer

Lung cancer is the leading cause of cancer-related death worldwide and in China (1). According to the statistics of the National Cancer Center of China, there were 733,300 new cases of non-small cell lung cancer (NSCLC) and approximately 610,200 related deaths in 2015 (2). For patients with early staged disease, surgery is the mainstay of treatment, and it is commonly followed by adjuvant chemotherapy for patients with locally advanced resectable NSCLC. Although complete surgical resection may be curative for NSCLC, 25–70% of patients (with different proportion according to stage) eventually relapse despite complete resection (3). Platinum-based adjuvant chemotherapy has been shown to marginally increase the 5-year survival rate of patients by 4–8% (4-6). Even after treatment with surgery and indicated adjuvant therapies in eligible cases, approximately 20–30% of stage I, 50% of stage II, and 60% of stage IIIA patients still die within 5 years (7). In the past decade, experts have conducted a number of investigations on the perioperative management of resectable NSCLC; however, progress remains slow, and patients still have a high risk of recurrence and death. Neoadjuvant therapy is defined as any therapy delivered prior to definitive local therapy intended to increase the cure rate. It provides several theoretical benefits in managing such patients with NSCLC. In the setting of, neoadjuvant therapy given prior to radical surgery this approach can also have the goals of downstaging, improving the resection rate, and more promptly treating subclinical micro-metastases than adjuvant approaches, delivered after the definitive local therapy. In addition, the compliance with neoadjuvant therapy has been shown to be better than in the adjuvant setting, and the biological effect of the neoadjuvant therapy can be analyzed directly in the resected tumor specimens (8). A meta-analysis on patients with stage IB‒IIIA NSCLC that compared chemotherapy plus subsequent surgery vs. surgery alone showed that the 5-year survival rate was 5% higher after receiving neoadjuvant chemotherapy (NCT) (9). Therefore, the comprehensive NSCLC data suggest that, for resectable NSCLC, NCT improves survival compared with surgery alone but appear to show no significant survival benefit compared with adjuvant chemotherapy (10). In the last 5 years, immune checkpoint inhibitors (ICIs) have profoundly changed the treatment paradigm for patients with advanced NSCLC (11-15). Immunotherapy has provided hope for long-term survival benefits to a minority of patients with metastatic lung cancer. For treatment-naive patients with driver mutation-negative NSCLC, the 5-year survival rate of single agent pembrolizumab was 23.2%; for the previously treated patients with driver mutation-negative NSCLC, the 5-year survival rates of single agent pembrolizumab and nivolumab were 15.5% and 16%, respectively (16,17). Given the profound impact made by immunotherapy drugs for patients with advanced disease, significant attention has been directed in recent years toward investigating the potential role for early-stage NSCLC patients, and whether they, too, can achieve long-term benefits from the inclusion of immunotherapy into their treatment algorithms. Many phase Ib/II clinical trials have reported promising results, and a series of large-scale phase III clinical trials are underway. However, these various investigations have employed different strategies of neoadjuvant immunotherapy, in terms of the specific regimens as well as number of treatment cycles (18). To better guide Chinese thoracic surgeons in the neoadjuvant immunotherapy of NSCLC, well-known thoracic surgeons in China participated in an in-depth discussion on the hot topics and controversial issues of neoadjuvant immunotherapy and formed the Expert consensus on neoadjuvant immunotherapy for non-small-cell lung cancer by incorporating the latest evidence on neoadjuvant immunotherapy.