Association of tumor differentiation grade and survival of women with squamous cell carcinoma of the uterine cervix

Objective: To examine the association between tumor grade and survival for women with squamous cervical cancer. Methods: This retrospective observational study utilized the Surveillance, Epidemiology, and End Result program data between 1983 and 2013 to examine women with squamous cervical cancer with known tumor differentiation grade. Multivariable analyses were performed to assess independent associations between tumor differentiation grade and survival. Results: A total of 31,536 women were identified including 15,175 (48.1%) with grade 3 tumors, 14,084 (44.7%) with grade 2 neoplasms and 2,277 (7.2%) with grade 1 tumors. Higher tumor grade was significantly associated with older age, higher stage disease, larger tumor size, and lymph node metastasis (all, p<0.001). In a multivariable analysis, grade 2 tumors (adjusted-hazard ratio [HR]=1.21; p<0.001) and grade 3 tumors (adjusted-HR=1.45; p<0.001) were independently associated with decreased cause-specific survival (CSS) compared to grade 1 tumors. Among the 7,429 women with stage II-III disease who received radiotherapy without surgical treatment, grade 3 tumors were independently associated with decreased CSS compared to grade 2 tumors (adjusted-HR=1.16; p<0.001). Among 4,045 women with node-negative stage I disease and tumor size <= 4 cm who underwent surgical treatment without radiotherapy, grade 2 tumors (adjusted-HR=2.54; p=0.028) and grade 3 tumors (adjusted-HR=4.48; p<0.001) were independently associated with decreased CSS compared to grade 1 tumors. Conclusion: Our study suggests that tumor differentiation grade may be a prognostic factor in women with squamous cervical cancer, particularly in early-stage disease. Higher tumor grade was associated with poorer survival.