Retracted: Worst Pattern Of Invasion and occult cervical metastases for oral squamous carcinoma

Worst pattern of invasion in oral squamous cell carcinoma is an independent prognostic factor

Introduction

Biologic aggressiveness of OSCC (Oral Cavity Squamous Cell Carcinoma), has intrigued research in various prognosticating histopathological markers over past few decades. DOI (Depth of Invasion) is one such histopathological factor which affects outcomes and was included in the AJCC 8th edition TNM staging. Pattern of Invasion (POI) has been widely reported as an adverse prognostic factor associated with higher locoregional failure and poor prognosis. However, these factors are not utilized for treatment decision making and for outcome assessment.

Materials and methods

This is a retrospective analysis of 320 patients with OSCC who underwent treatment, from October 2018-February 2020. Clinic demographic details were extracted from electronic medical records. Univariate and multivariate analysis was done for the parameters. WPOI (Worst Pattern of Invasion) was correlated with all histopathological prognostic factors. Survival analysis was done using Kaplan Meier for WPOI type's I-V. DFS (Disease free Survival) was evaluated for different grades of WPOI.

Results

We analyzed the results comparing, early and advanced T (Tumor) stages, cohesive WPOI I-III, non-cohesive WPOI IV-V. Univariate analysis showed a significant association of T-stage (p = 0.001), N (Nodal) -stage (p = 0.002), DOI (p = 0.008), PNI (Peri-neural invasion) (0.001) and Tumor differentiation Grade (p = 0.001). On multivariate analysis, non-cohesive WPOI (IV & V) showed significant association with grade, PNI, DOI (0.002, 0.033 & 0.033 respectively). Non-cohesive WPOI had significantly higher locoregional failures and short DFS.

Conclusion

Presence of invasive WPOI is associated with advanced T stage, poor differentiation, PNI, greater depth of invasion, and higher chances of nodal metastasis. WPOI is associated with poor DFS, treatment intensification in early stage disease with WPOI type IV & V may improve survival.

Postoperative radiotherapy is dispensable for OSCC patients with micrometastases in lymph nodes

Lymph node metastasis is a decisive factor for performing postoperative radiotherapy for oral squamous cell carcinoma (OSCC). However, whether OSCC patients with only micrometastasis need postoperative radiotherapy is unclear. In this study, OSCC patients (n = 311) with negative (n = 247), only micrometastasis (n = 44) and macrometastasis (n = 20) were detected and selected by HE staining. Micrometastasis was re-assessed using immunohistochemical staining of cytokeratin (CK) in HE-negative patients to find out the false negative cases. The results indicated that, among the negative lymph node cases (n = 247), the positive rate of CK was 4.94% (n = 12). Besides, the clinical features of the primary tumor in relation to the only micrometastatic status and the value of the postoperative radiotherapy on the only micrometastasis patients were evaluated. Patients with only micrometastasis had higher T stage and inferior worst pattern of invasion (WPOI) than patients without micrometastasis, but they had longer overall survival (OS), metastasis-free survival (MFS), and disease-free survival (DFS) than macrometastasis patients. However, the survival time of only micrometastasis patients with or without postoperative radiotherapy was comparable, even in patients with inferior WPOI. Radiotherapy, however, may only benefit patients with IV/V levels of micrometastasis. These data indicated that postoperative radiotherapy is dispensable for only micrometastasis OSCC patients.