Challenges in primary biopsies of oral squamous cell carcinoma: a comparative study of factors affecting biopsy success in Finnish patients.

Objectives: The aim of this study was to investigate the factors influencing the success of biopsy quality in oral squamous cell carcinoma (OSCC) of the oral cavity.

Method and materials: This retrospective study included patient records of primary OSCC patients, diagnostic pathology reports of the primary biopsies, and corresponding resection tumor sections. The outcome variable was unsuccessful biopsy, defined as an inconclusive biopsy specimen for proper OSCC diagnosis. The primary predictor variable was the biopsy method used, grouped as punch or scalpel biopsy. Secondary predictor variables were sample area, depth, site, and number of samples. Patient- and tumor-related variables, background of the healthcare professional, and the healthcare unit were analyzed as additional predictor variables.

Results: Data from 312 OSCC patients were included in the study. Primary biopsy was inconclusive in 7.7% of the cases. Area with punch biopsies yielded smaller (P<.001) but diagnostically as accurate samples as scalpel biopsies. Biopsies from the floor of the mouth and gingiva had higher failure rates, while tongue and palate biopsies had higher success rates (P=.037). Punch and scalpel biopsies had similar diagnostic reliability. There were deficiencies in the documentation of prognostic features of the OSCC. Inflammation was the most consistently reported (33.3% in biopsies, 43.9% in resection samples), while tumor budding was documented in only one-third of biopsy samples (6.4%) compared to final resection samples (18.6%). Depth of invasion was reported in 55.1% of biopsies, with 6.1% indicating a minimum invasion depth.

Conclusion: General dentists must be both alert and properly trained to perform biopsies. However, considering the internationally varying role of general dentists in biopsy procedures, this requirement must be understood within the context of each country's healthcare system. OSCC biopsies generally yield high diagnostic success; however, small biopsy size especially impairs diagnostic accuracy. Ensuring larger or several biopsy samples in general and ensuring representative biopsies from particularly challenging areas, such as gingiva and floor of the mouth, improves the likelihood of conclusive diagnosis in primary OSCC diagnostics. Additionally, clinicians should pay more attention not only to the area but also to biopsy depth. Taken together, there may be a need for more precise biopsy guidelines and protocols for lesions suspicious for OSCC to optimize patient treatment planning.