OBJECTIVE: Oral squamous cell carcinoma (OSCC) is one of the most common head and neck carcinomas and corresponds to 95% of all oral cancers with an increasing morbidity and mortality. Its prognosis is affected by several clinicopathologic factors, one of which is pattern of invasion (POI). The histological features of OSCC may differ widely, but there is general agreement that the most useful prognostic information can be deduced from the invasive front of the tumor. In this retrospective study, our aim was to compare the POI, the status of connective tissue and the status of inflammation at the tumor-host interface in primary and recurrent (secondary) OSCC and test the validity of POI, to serve as a potential marker to assess the prognosis of the patient.
METHODS: Differentiation of tumors, POI, status of connective tissue and inflammation was assessed in 168 cases of primary and recurrent cases of OSCC.
METHODS: Fisher\'s exact test was used to determine the statistical significance and P < 0.05 was considered to be statistically significant.
RESULTS: Our study showed that majority of the primary and secondary tumors were well differentiated, 117 [95.9%] and 34 [73.9%], respectively. Predominant POI in the primary and secondary tumor group was Pattern II and least was Pattern V. Worst pattern in primary tumor and highest distribution was seen for Pattern III (53.3%), and least for Pattern V (0.00%). In secondary tumors, the predominant worst pattern was Pattern IV (50.0%) and least distribution was seen for Pattern I (0.00%). Connective tissue status for both primary and secondary tumors showed the predominance of loose type (85.2% and 79.2%) and least was variable type (0.8% and 0.6%), respectively. Status of inflammation in the primary tumor group showed a predominance of moderate grade of inflammation (50.0%) and very mild grade of inflammation (6.6%) was the least type. In the secondary tumor group, moderate grade (43.5%) of inflammation was predominant and very mild grade (5.4%) was the least. All the parameters showed a statistically significant difference on the application of Fisher\'s exact test between the two groups.
CONCLUSIONS: Our study showed that POI could serve as an individual prognostic marker irrespective of the histologic differentiation of tumor. Tumor desmoplasia could be considered as an important reflection of the tumor-host interaction, especially in aggressive cancers. Host immune defense, especially tumor infiltrating lymphocytes must be noted as critical factors related to survival rate in OSCC patients. Assessment of mentioned parameters may lead to sound prognostic assessment and appropriate treatment planning thus reducing the possibility of recurrence or relapse. Hence, the parameters evaluated in our study could serve as independent or interdependent prognostic markers.

OBJECTIVE: Oral cancer constitutes 3% of all neoplasms and is the eighth most frequent cancer in the world. Oral squamous cell carcinoma (OSCC) corresponds to 95% of all oral cancers. It is associated with severe morbidity, recurrence and reduced survival rates. Its prognosis is affected by several clinicopathologic factors, one of which is perineural invasion (PNI). It is the third most common form of tumor spread exhibited by neurotropic malignancies that correlate with aggressive behavior, disease recurrence and increased morbidity and mortality. In this retrospective study, our aim was to assess the presence of PNI in different grades of both primary and recurrent cases of OSCC correlating it with tumor size and lymph node status. The various patterns of PNI we encountered were also noted.
METHODS: PNI was assessed in 117 cases of primary and recurrent cases of OSCC. PNI was correlated with tumor thickness, lymph node status and with the different histologic grades. Location of PNI, density of PNI and various patterns of PNI were also assessed.
METHODS: Chi-square test.
RESULTS: Our study showed that 47 out of 117 patients (40.5%) showed PNI. Both primary and recurrent tumors showed PNI of 42.50% and 40.50%, respectively. PNI was present in 34 out of 69 cases (49.3%) of clinically positive nodes. Around 79% of the nerves involved by PNI were intratumoral in location, 80% of the cases showed PNI density of 1-3 nerves per section and incomplete and/or \"crescent-like\" encirclement was the most common pattern of PNI noted in our study.
CONCLUSIONS: Our study showed that the incidence of PNI was as high as 40% in OSCC. PNI was present in both primary and recurrent tumors, irrespective of its histologic grading. Tumor thickness and lymph node status correlated well with PNI. Therefore, the presence of PNI should be checked in every surgical specimen with OSCC as it gives significant prognostic value, influences treatment decisions, recurrence and distant metastasis. The presence of PNI necessitates more aggressive resection, coincident management of neck lymph nodes and the addition of adjuvant therapy. Also, targeted drug therapy for this type of tumor spread can open up new avenues in the treatment of OSCC.