HEURISTICALLY DERIVED TUMOR BURDEN SCORE AS A PROGNOSTIC FACTOR FOR STAGE IIIB CARCINOMA OF THE CERVIX

Purpose: A retrospective analysis of radiotherapeutic: management of locally advanced carcinoma of the uterine cervix was performed to evaluate the effect of various treatment parameters and disease extent upon treat outcome. Methods and Materials: Between 1976 and 1989, 89 patients with Stage IIIB disease were treated with external beam radiotherapy and brachytherapy. Treatment outcomes were evaluated by dose to Point A, the proportion of Point A dose delivered by brachytherapy, clinical response at 3 months, and a newly developed tumor burden scoring system that quantifies the anatomical extent of disease. Kaplan-Meier estimates of tumor control and survival parameters were determined. Results: Loco-regional control (LRC), disease-free survival (DFS), and overall survival (OVS) at 5 years were 52.9%, 45.5%, and 50.3%, respectively. Clinical response at 3 months was highly predictive of local and distant tumor control, There was no correlation between proportion of brachytherapy dose and treatment outcome. The tumor burden scoring system demonstrates that FIGO Stage IIIB disease can be clinically divided into two prognostic groups of low and high tumor burden. Five year LRC was 62.9% and 40.2% for the low and high tumor burden groups, respectively (p = 0.024). Within the high tumor burden group the LRC was 53.0% and 22.5% when the point A dose given was > 78 Gy and less than or equal to 78 Gy, respectively (p = 0.047). This correlated with improved DFS and OVS. Conclusion: The tumor burden scoring system subdivides PICO Stage IIIB cervical carcinoma into two prognostic groups, predicting for overall survival and demonstrating a dose response in the high tumor burden group. This system may serve to improve future comparison of treatment outcome and to guide selection of patients who may benefit from a more aggressive treatment approach.