Table 1_Pathological regression patterns following neoadjuvant chemo-immunotherapy in head and neck squamous cell carcinoma: a pilot study.pdf

IntroductionNeoadjuvant chemoimmunotherapy (NACI) has drawn considerable attention in Head and neck squamous cell carcinoma (HNSCC) owing to its potential in functional preservation and treatment-failure reduction. Yet whether the surgical extent can be narrowed following NACI is largely debatable due to a potential non-centripetal tumor regression may result in scattered microfoci residing beyond the narrowed margin.
MethodsIn this pilot study, we characterized the tumor regression pattern in a post-NACI HNSCC cohort using a whole-mount histopathological approach. The MRI examinations before and after NACI were used to evaluate the objective response rate (ORR).
ResultsOf the 52 patients enrolled, the ORR was 75%. Pathological complete response (pCR) rate was 15.4%, and the major pathological response (MPR) rate was 40.4%. Two major regression patterns were identified in whole-mount tumor sections, centripetal regression and non-centripetal regression. Centripetal regression was observed in 37 patients (71.2%) and was subcategorized into complete regression (Ia, 15.4%), unifocal centripetal regression (Ib, 36.5%), and multifocal centripetal regression (Ic, 19.2%). Non-centripetal regression was seen in 15 patients (28.8%) and was subcategorized into scattered regression (IIa, 25.0%) and non-regression (IIb, 3.8%). Moreover, we found a pre-NACI CPS higher than 20 or post-NACI (18)F-FDG SUVmax reduction exceeding 50% were potential predictive factors for the centripetal regression pattern.
DiscussionWe revealed for that centripetal regression was the predominant pattern of regression after NACI in HNSCC. Hence, our data presumably supports a reduced surgical extent in post-NACI HNSCC patients. Future studies should focus on identifying accurate predictive factors for the regression pattern, which may eventually assist in risk stratification and surgical decision making.
ConclusionsThe pattern of tumor pathological regression after NACI for HNSCC is mainly divided into centripetal and non-centripetal regression, with the former accounting for the major portion of the regression.

引言
新辅助化学免疫治疗（Neoadjuvant chemoimmunotherapy, NACI）因具备实现功能保留、降低治疗失败风险的潜力，在头颈部鳞状细胞癌（Head and neck squamous cell carcinoma, HNSCC）领域受到广泛关注。然而，新辅助化学免疫治疗后是否可缩小手术切除范围仍存在较大争议，原因在于潜在的非向心性肿瘤消退可能导致散在微病灶残留于缩小后的手术切缘之外。
方法
本先导性研究采用整体组织病理学检测方法，对新辅助化学免疫治疗后头颈部鳞状细胞癌队列的肿瘤消退模式进行了表征。同时利用新辅助化学免疫治疗前后的磁共振成像检查评估客观缓解率（Objective Response Rate, ORR）。
结果
本研究共纳入52例患者，客观缓解率为75%。病理完全缓解（Pathological Complete Response, pCR）率为15.4%，主要病理缓解（Major Pathological Response, MPR）率为40.4%。在整体组织肿瘤切片中可识别出两种主要消退模式：向心性消退与非向心性消退。其中37例患者（71.2%）观察到向心性消退，进一步分为完全消退（Ia型，15.4%）、单灶性向心性消退（Ib型，36.5%）及多灶性向心性消退（Ic型，19.2%）。15例患者（28.8%）出现非向心性消退，进一步分为散发性消退（IIa型，25.0%）及无消退（IIb型，3.8%）。此外，本研究发现，新辅助化学免疫治疗前CPS评分高于20，或新辅助化学免疫治疗后18F-氟代脱氧葡萄糖（18F-FDG）最大标准化摄取值（SUVmax）降幅超过50%，均为向心性消退模式的潜在预测因子。
讨论
本研究明确，新辅助化学免疫治疗后头颈部鳞状细胞癌的主要肿瘤消退模式为向心性消退。据此，本研究数据或可支持对新辅助化学免疫治疗后的头颈部鳞状细胞癌患者缩小手术切除范围。未来研究应聚焦于识别肿瘤消退模式的精准预测因子，以助力风险分层与手术决策制定。
结论
头颈部鳞状细胞癌患者接受新辅助化学免疫治疗后的肿瘤病理消退模式主要分为向心性消退与非向心性消退，其中向心性消退占主导地位。