Invasive-Front P21 Expression Is Associated With Tumor Aggressiveness in Head and Neck Squamous Cell Carcinoma

Area of Science:

• Oncology
• Cell Biology
• Cancer Research

Background:

• P21 is a cyclin-dependent kinase inhibitor linked to cellular senescence.
• Spatial expression of P21 in head and neck squamous cell carcinoma (HNSCC) compartments is not well understood.
• The relationship between P21 spatial patterns and HNSCC aggressiveness requires further investigation.

Purpose of the Study:

• To investigate the spatial distribution of P21 within HNSCC tumor regions.
• To evaluate the association between P21 spatial expression and HNSCC tumor aggressiveness, including stage and pathological features.
• To explore the potential of spatial P21 profiling in understanding HNSCC progression.

Main Methods:

• Immunohistochemistry was used to assess P21 expression in HNSCC tissue.
• P21 intensity, percent positivity, and composite scores were quantified in surface, center, and invasive-front regions.
• Spatial ratios were calculated, and non-parametric analyses compared early- vs. advanced-stage HNSCC and subgroups based on pathological features.

Main Results:

• Advanced-stage HNSCC showed significantly higher invasive-front-to-center P21 ratios (p=0.0275).
• Perineural invasion (PNI)-positive advanced HNSCC exhibited the most pronounced increases in spatial P21 ratios (p<0.05).
• No significant spatial differences in P21 were observed for extracapsular extension (ECE) or lymphovascular invasion (LVI).

Conclusions:

• P21 expression shows region-specific differences linked to HNSCC aggressiveness.
• PNI-positive HNSCC demonstrates enrichment of P21 at the invasive front.
• Spatial P21 profiling may offer insights into HNSCC tumor biology and invasive potential.