Pathological regression patterns following neoadjuvant chemo-immunotherapy in head and neck squamous cell carcinoma:...

Area of Science:

• Oncology
• Surgical Pathology

Background:

• Neoadjuvant chemoimmunotherapy (NACI) is increasingly used for Head and Neck Squamous Cell Carcinoma (HNSCC) to improve outcomes and preserve organ function.
• The impact of NACI on tumor regression patterns and its implications for surgical extent remain subjects of debate.

Purpose of the Study:

• To investigate the patterns of tumor pathological regression following NACI in HNSCC.
• To evaluate the potential for reduced surgical margins based on observed regression patterns.

Main Methods:

• A pilot study involving 52 HNSCC patients treated with NACI.
• Whole-mount histopathological analysis of resected tumors to characterize regression patterns.
• MRI assessments before and after NACI to determine objective response rate (ORR).

Main Results:

• The overall ORR was 75%, with a pathological complete response (pCR) rate of 15.4% and a major pathological response (MPR) rate of 40.4%.
• Centripetal regression was the predominant pattern, observed in 71.2% of patients.
• Non-centripetal regression occurred in 28.8% of patients. Predictive factors for centripetal regression included pre-NACI CPS > 20 or post-NACI 18F-FDG SUVmax reduction > 50%.

Conclusions:

• Centripetal regression is the primary pattern following NACI in HNSCC.
• These findings suggest that a reduced surgical extent may be feasible for select HNSCC patients post-NACI.
• Further research is needed to identify precise predictive factors for regression patterns to guide surgical decision-making.