Survival and clinicopathological characteristics of different histological grades of oral cavity squamous cell carcinoma: A single-center retrospective study.

Nan-Chin Lin,Jui-Ting Hsu,Kuo-Yang Tsai,Dipak Sapkota

doi:10.1371/journal.pone.0238103

Nan-Chin Lin, Jui-Ting Hsu + Show 2 more

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https://doi.org/10.1371/journal.pone.0238103

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Abstract

The TNM staging system for oral squamous cell carcinoma (OSCC) provides clinicians a dependable foundation for patient prognosis and management decisions, but in clinical practice, treatment outcomes of patients with OSCC are sometimes unsatisfactory. This retrospective study investigated the association between survival and clinicopathological characteristics and histological grades of 2535 patients with OSCC. Additionally, the present study aimed to compare the predictive abilities of histological grades with other common prognostic factors. The enrolled patients were divided into three groups by two experienced pathologists into well-differentiated, moderately differentiated, and poorly differentiated groups, according to the WHO classification. Finally, we designed an observational, retrospective study based on the histological grading of tumors to compare their clinicopathological characteristics and conducted survival analysis among the three groups. Advanced tumor stage was diagnosed in 23.9%, 44.0%, and 55.1% of patients with grades 1-3 OSCC, respectively. By T status, T3 or T4 tumors were found in approximately 22%, 34%, and 40% of patients with grades 1-3 OSCC, respectively. By N status, lymph node metastases were found in 6.1%, 29.3%, and 45.9% of patients with grades 1-3 OSCC, respectively. Thus, significant survival differences were observed based on different OSCC histological grades. Meanwhile, in the multivariate (adjusted) analysis, N1 and N2 stages, extranodal spread, and poor differentiation were associated with a higher recurrence risk than the other common prognostic factors. In conclusion, 5% of patients in our study presented with poorly differentiated OSCC at diagnosis. Furthermore, grade 3 OSCC has worse prognosis and is more aggressive than grades 1 and 2 OSCC. In the future, we should focus on modifying individual therapy for poorly differentiated OSCC to achieve improved outcomes.

Highlights

The TNM staging system of oral squamous cell carcinoma (OSCC) has historically provided clinicians a dependable foundation for patient prognosis and management decisions
Clinicopathological prognostic factors remain insufficient for predicting recurrence and survival of OSCC; the survival of patients has remained unchanged over the last few decades [11]
We found that the presence of high-grade histology was strongly associated with advanced T stage, neck lymph node metastasis, and extranodal spread, which subsequently contributed to advanced stage and prevalent recurrence

Summary

Introduction

The TNM staging system of oral squamous cell carcinoma (OSCC) has historically provided clinicians a dependable foundation for patient prognosis and management decisions. The relative risk of neck lymph node metastasis of T1 and T2 tumors is 10% and 30%, respectively, whereas that of T3 and T4 tumors is distinctly higher [1, 2] This is significant because the most important prognostic factor in OSCC is the presence of cervical lymph node metastasis, which results in the reduction of the overall survival of these patients by 50% [3, 4]. Several studies have shown that even an early-stage tumor may cause a fatal outcome [5,6,7]. New parameters such as depth of invasion was included in the 8th edition of the American Joint Committee on Cancer’s (AJCC) Cancer Staging Manual to improve their predictive value and different stage stratification and to explain patients previously considered to have early-stage tumor but with a poor survival

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