Biopsy pattern of invasion type to determine the surgical approach in early-stage oral squamous cell carcinoma

Depth of invasion (DOI) and pattern of invasion (POI) indicate tumor invasiveness of oral squamous cell carcinoma (OSCC). However, preoperative DOI evaluation is challenging, and the correlations between DOI and POI are unknown. We aimed to assess DOI and worst pattern of invasion (WPOI) in early-stage OSCC, and evaluate the preoperative predictive ability of biopsy pattern of invasion (BPOI) for WPOI and DOI. This retrospective study included n = 444 OSCC patients with pT1-2N0M0. The prognostic value of DOI, WPOI, and BPOI and the predictive prognostic option for WPOI and DOI by BPOI were assessed. WPOI (1-3 vs 4-5), but not BPOI, predicted the lowest survival rate and highest DOI. To evaluate the difference between WPOI and BPOI, we conducted a POI type-matching analysis of patients with BPOI1-4 and WPOI1-5. Based on each WPOI type, the false-prediction rates (FPR) of BPOI types 1 (n = 23), 2 (n = 89), 3 (n = 252), and 4 (n = 80) were 52.17%, 52.81%, 36.90%, and 0%, respectively. BPOI4 perfectly predict WPOI 4-5. As the false-predicted BPOI 1-2 was almost WPOI2-3 (79.7%), regardless of the existed FPR, patients with BPOI1-2 have longer survival and lower DOI than those with BPOI 4. However, this phenomenon was not observed in BPOI3, because all false-predicted BPOI3 were WPOI4-5 with a high DOI. We provide an alternative predictive prognostic option for WPOI and DOI by evaluating BPOI during OSCC surgical planning, with the recommendation of conservative treatment in patients with BPOI 1-2.