Preoperative immunochemotherapy versus chemotherapy as first-line treatment for patients with stage I-IIIB small-cell lung cancer

Background: To date, there remains a paucity of comparative investigations pertaining to preoperative immunochemotherapy and conventional chemotherapy in the context of limited-stage small-cell lung cancer (LS-SCLC) patients. This study conducted a comprehensive comparative assessment concerning the safety and efficacy profiles of preoperative immunochemotherapy and chemotherapy in individuals diagnosed with stage I-IIIB SCLC.

Methods: This investigation collected 53 consecutive patients diagnosed with LS-SCLC spanning stage I to IIIB who underwent preoperative immunochemotherapy or conventional chemotherapy at our hospital from January 2019 to July 2021. Patients were allocated to receive 2-4 cycles of neoadjuvant immunochemotherapy or chemotherapy, with each cycle lasting three weeks. Comprehensive analyses encompassed baseline characteristics, clinical staging, tumor response, intraoperative and postoperative outcomes, and the assessment of treatment-related adverse events (trAEs). The follow-up period is extended for a minimum of one year after surgery. The primary endpoint embraced the evaluation of the pathological response [major pathological response (MPR) and pathological complete remission (pCR)], while secondary endpoints encompassed objective response rate (ORR), trAEs, surgical resection rates, and disease-free survival (DFS).

Results: The objective response rate of the immunochemotherapy group was 89.5%, while that of the chemotherapy group was 75.0% (P = 0.206). A total of 19 patients underwent surgery among these 53 patients, with 14 patients in the neoadjuvant chemoimmunotherapy group and 5 patients in the chemotherapy group. And the surgical resection rate of the immunochemotherapy group was 48.3% (14/29), which was higher than the chemotherapy group (20.8%, 5/24, P = 0.038). The rate of MPR in the immunochemotherapy group was 57.1% (8/14) and 40.0% (2/5) in the chemotherapy group (P = 0.891). The rates of pCR in the immunochemotherapy and chemotherapy group were 50.0% (7/14) and 0.0% (0/5), respectively (P = 0.106).The median DFS for both groups were not reached (P = 0.43). The 2-year DFS rate was 21.4% for the immunochemotherapy group versus 40.0% for the chemotherapy group. There was no significant difference in the incidence of grade 3-4 adverse events between the immunochemotherapy group and the chemotherapy group.

Conclusions: For patients with stage I-IIIB SCLC, neoadjuvant immunochemotherapy is feasible and safe. Although immunochemotherapy did not significantly associated with longer DFS versus chemotherapy alone in patients with stage I-IIIB SCLC, it can produce significant downstaging and increase the possibility of surgery.