A Proposal to Revise the Histopathologic Grading System of Early Oral Tongue Cancer Incorporating Tumor Budding

: Elseragy Amr, Salo Tuula, Coletta Ricardo, Kowalski Luiz P., Haglund Caj, Nieminen Pentti, Mäkitie, Antti A., Leivo Ilmo, Almangush, Alhadi

Publisher: LIPPINCOTT WILLIAMS & WILKINS

: 2019

American Journal of Surgical Pathology

AMERICAN JOURNAL OF SURGICAL PATHOLOGY

: AM J SURG PATHOL

: 43

: 5

: 703

: 709

: 7

: 0147-5185

: 1532-0979

DOI: https://doi.org/10.1097/PAS.0000000000001241

The World Health Organization (WHO) grading system has a low prognostic value for early-stage oral tongue squamous cell carcinoma; greater prognostic power has been shown with tumor budding analysis. In this study, we combined tumor budding analysis with histopathologic grading according to WHO 2017. In our proposal, a revised grade I tumor is defined as a well differentiated cohesive tumor; revised grade II as a moderately differentiated and/or slightly dissociated tumor; and revised grade III as a poorly differentiated and/or dissociated tumor. We evaluated the prognostic value of this proposed grading system in a multicenter cohort of 311 cases of early oral tongue squamous cell carcinoma. The proposed grading system showed significant prognostic value in multivariable analysis for disease-specific survival with a hazard ratio of 3.86 and a 95% confidence interval of 1.36-10.9 (P=0.001). For disease-free survival, the proposed grading system showed good predictive power in multivariable analysis (hazard ratio, 2.07; 95% confidence interval, 1.00-4.27; P=0.009). The conventional WHO grading system showed a low prognostic value for disease-specific survival and disease-free survival (P>0.05). In conclusion, the prognostic power of the WHO histopathologic grading improved significantly with incorporation of tumor budding. Our proposed grading system can be easily included in pathology reports.