Purpose:
Tumor grade is one of the more controversial factors with limited prognostic information in squamous cell carcinomas (SCC) of the uterine cervix.
Methods:
Histologic slides of 233 surgically treated cervical SCC (FIGO IB1) were re-examined regarding the prognostic impact of the WHO-based grading system, using the different degree of keratinization, categorizing the tumors in G1, G2 andG3 (conventional tumor grade).
Results:
45.1% presented with well-differentiated tumors (G1), 29.2% with moderate (G2) and 25.8% with poor differentiation (G3). Tumor grade significantly correlated with decreased recurrence-free and overall survival. However, detailed analyses between G1- and G2- tumors failed to show any correlation with either recurrence-free or overall survival. G1- and G2- tumors were therefore merged into low-grade tumors and were compared to the high-grade group (G3-tumors). This binary conventional grading system showed an improved 5-years recurrence-free (low-grade: 90.2% vs. high-grade: 71.6%; p = 0.001) and overall survival rates (low-grade: 89.9% vs. high-grade: 71.1%; p = 0.001) for low-grade tumors. On multivariate analysis adjusted for lymph node metastasis, high-grade tumors represented a hazard ratio of 2.4 [95% CI: 1.3 – 4.7] for reduced recurrence-free and 2.4 [95% CI: 1.2 – 4.6] for overall survival. High-grade tumors showed a significantly higher risk for pelvic lymph node involvement (OR 2.7 [95% CI: 1.4 – 5.5]; p = 0.003). The traditional three-tired grading system failed to predict pelvic lymph node metastases.
Conclusion:
A binary grading model for the conventional tumor grade (based on the degree of keratinization) in SCC of the uterine cervix may allow a better prognostic discrimination than the traditionally used three-tired system.
