Factors predicting the perineural invasion in carcinoma oral cavity.

Objective: This study to evaluate clinicopathological parameters such as age, tumor location, tumor size, grade, depth of invasion (DOI), lymphovascular space invasion (LVSI), lymph node metastasis, and stage that predict peri-neural invasion (PNI) in oral squamous cell carcinoma (OSCC).

Material and methods: A retrospective study on 1716 postoperative OSCC patients who satisfied the eligibility criteria and treated from January 2009 to December 2019 was analyzed using IBM SPSS V23. Mean and percentage were assessed using descriptive statistics. Wilcoxon-Mann-Whitney U-test was used to compare continuous variables, while Chi-square test was used to compare discrete variables between PNI-positive and PNI-negative groups. Two-tailed P < 0.05 was considered to be statistically significant.

Results: Out of 1716 patients, 553 were PNI positive. The mean age was 48.76 ± 12.42 years in PNI-positive patients while 51.52 ± 12.51 years in PNI-negative patients. Males outnumbered females. The most common primary was carcinoma buccal mucosa (204, 36.9%), followed by carcinoma of oral tongue (161,29.1%). Maximum tumor size was 3.14 ± 1.20 cm in PNI-positive patients whereas 2.78 ± 1.22 cm in PNI-negative patients. Sixty (10.84%) patients in PNI-positive group and 51 (4.38%) in PNI-negative group had LVSI positive. Lymph node involvement was observed in 305 (55.13%) patients in PNI-positive group whereas 358 (30.78%) patients in PNI-negative group. Maximum number 228 (41.3%) in PNI-positive patients were in Stage IVA disease.

Conclusion: PNI is one of the important adverse prognostic factors having a definite correlation with anatomical subsite, tumor size, grade, DOI, LVSI, lymph node involvement, and stage of the disease. PNI should be analyzed in postoperative histopathology report of OSCC that guides the clinician for adjuvant therapy.