The safety and efficacy of neoadjuvant PD-1 inhibitor with chemotherapy for locally advanced esophageal squamous cell carcinoma.

BACKGROUND

Neoadjuvant therapy followed by esophagectomy has been recognized as an effective treatment for locally advanced esophageal cancer, though still has a dismal prognosis. Antibodies against programmed death 1 (PD-1) protein improve survival in patients with advanced or metastatic esophageal squamous cell carcinoma (ESCC) compared with chemotherapy in second-line therapy. However, neoadjuvant PD-1 inhibitor combined with chemotherapy has not been tested in locally advanced ESCC. We conducted this study to evaluate the efficacy and safety of pd-1 inhibitor in neoadjuvant chemotherapy.

METHODS

In this study, we administered 28 adults with untreated, surgically resectable locally advanced ESCC. PD-1 inhibitor with chemotherapy [albumin paclitaxel 100 mg/m on days 1 and 8 + carboplatin with an area under the curve (AUC) of 5 on day 1] were administered every 3 weeks intravenously, and surgery was performed approximately 3-5 weeks after the second dose. The primary purpose of the study was to evaluate the feasibility and safety of this regimen.

RESULTS

In all, 28 locally advanced ESCC patients were enrolled, 27 patients received surgery, 9 (33.3%) patients' postoperative pathological specimens suggested pCR, and 11 (40.7%) patients' primary tumor suggested complete response. Neoadjuvant PD-1 inhibitor with chemotherapy had an acceptable side-effect profile, 26 patients' tumors were completely resected (96.3% were R0). According to the RESIST v.1.1, the response in all 27 patients was evaluated by a computed tomography (CT) scan before surgery, showing 12 patients with complete response (CR), 12 with partial response (PR), and 3 with stable disease (SD). For surgical procedures, 15 (55.6%) patients underwent minimal invasive surgery, 4 (14.8%) underwent right transthoracic open esophagectomy, and 8 (29.6%) underwent hybrid approaches.

CONCLUSIONS

The novel treatment of PD-1 inhibitor with chemotherapy in the neoadjuvant setting for locally advanced ESCC produced satisfactory outcomes: an unprecedentedly high pCR rate for neoadjuvant chemotherapy, a high R0 resection rate, and a low-toxicity profile were achieved. The long-term efficiency of this novel treatment and the validity of the present findings should be confirmed with longer follow-up and prospective comparative trials.