Efficacy analysis of neoadjuvant PD-1 inhibitor combined with chemotherapy in various subanatomical sites of locally advanced and recurrent resectable head and neck squamous cell carcinoma: A retrospective real-world study.

Abstract

6067 Background: Clinical research on Head and Neck Squamous Cell Carcinoma (HNSCC) often considers the disease as a whole. However, the therapeutic outcomes may vary significantly across different subanatomical sites, as well as between locally advanced (LA) and recurrent resectable (RR) HNSCC. Therefore, we stratified HNSCC according to specific anatomical sites and initial diagnosed versus recurrent tumors, and analyzed the efficacy of neoadjuvant PD-1 inhibitor + chemotherapy. Methods: Retrospectively analyzed patients with LA and RR HNSCC admitted to Hunan Cancer Hospital from October 2021 to December 2024, who received neoadjuvant PD-1 inhibitor and chemotherapy. Post-treatment efficacy was evaluated using imaging, endoscopy, or pathology. Differences in efficacy outcomes between different subanatomical sites and between LA and RR tumors were classified and statistically analyzed. Results: 1) A total of 482 patients were included: 434 with LA HNSCC(90.04%) and 48 with RR HNSCC (9.96%), 453 males (93.98%) and 29 females (6.02%). Patient ages ranged from 17 to 77 years, with a mean age of 52.43 ± 9.83 years. 2). The top three types of LAHNSCC that underwent neoadjuvant therapy were: tongue (N=157, 36.180%), buccal oris (N=105, 24.19%),and hypopharynx (N=92, 21.20%). 3)The objective response rates (ORR) following neoadjuvant therapy were as follows: 90.32% for oropharyngx, 83.33% for gingiva, 80.25% for tongue, 79.35% for hypopharynx, 68.57% for buccal oris, and 56.25% for RR HNSCC. The highest pathological deep response rates (pCR+MPR) was observed in tongue (34.40%), followed by oropharynx (29.04%), gingiva (26.67%), and only 33% for RR HNSCC. Conclusions: There are significant variations in the sensitivity of HNSCC to neoadjuvant immunotherapy + chemotherapy across different subanatomical sites. Oropharynx exhibits the highest response to this regimen, whereas RR cases demonstrate relatively poor responsiveness. In terms of pathological deep response, tongue, oropharynx, and gingiva show favorable response rates, while RR cases exhibit significantly lower response rates. Disease status Tongue Buccal oris Hypopharynx Oropharynx Gingiva Others Recurrent Resectable HNSCC Number 157 105 92 31 30 19 48 CR 31(19.75%) 12(11.43%) 13(14.13%) 8(25.81%) 3(10.00%) 7(36.84%) 4(8.33%) MPR 23(14.65%) 13(12.38%) 7(7.61%) 1(3.23%) 5(16.67%) 0(0.00%) 0(0.00%) PR 72(45.86%) 47(44.76%) 53(57.61%) 19(61.29%) 17(56.67%) 10(52.63%) 23(47.92%) SD 20(12.74%) 18(17.14%) 11(11.96%) 2(6.45%) 1(3.33%) 0(0.00%) 16(33.33%) PD 8(5.10%) 11(10.48%) 7(7.61%) 0(0.00%) 3(10.00%) 0(0.00%) 10(10.42%) NA 3(1.91%) 4(3.81%) 1(1.09%) 1(3.23%) 1(3.331%) 2(10.53%) 0(0.00%) ORR 126(80.25%) 72(68.57%) 73(79.35%) 28(90.32%) 25(83.33%) 17(89.47%) 27(56.25%)