Role of cancer antigen 125 and risk of malignancy index 3 to differentiate benign and malignant female pelvic masses followed by histopathological correlation

Introduction: Pelvic mass is a worldwide female health problem with serious consequences in mortality, morbidity, and cost to the society. The present study was designed to see the role of serum Cancer Antigen 125 (CA125) and Risk of Malignancy Index 3 (RMI3) to differentiate benign and malignant pelvic masses followed by histopathological correlation. Materials and Method: In this prospective study 70 cases of female with pelvic mass were included. Serum CA125 with other clinical covariates were measured and RMI3 was calculated. The findings were histopathologically correlated. 70 normal healthy females served as controls. Statistical analysis was done by using unpaired t-test and Fisher's exact test. Results: Serum CA125 and RMI3 were significantly elevated in 92.3% of malignant cases and only in 3.5% of benign cases. Mean of RMI3 and CA125 was 5191.6 and 608.1 U/mL in malignant cases, where 39.0 and 20.9 U/mL in benign cases respectively. The sensitivity and specificity of both CA125 (cutoff of 35U/mL) and RMI3 (cutoff of 200) for predicting malignancy was 96.49% and 92.31% respectively with 98.21% positive predictive and 85.71% negative predictive value. Conclusion: Serum CA125 and RMI3 were increased significantly in females with malignant pelvic mass in comparison to benign cases. Value of CA125 >35 U/mL and RMI3 >200 in predicting malignancy revealed modest diagnostic accuracy. Therefore combining RMI3 and CA125 helps to assess pelvic masses pre-operatively and to refer patients to gynaecological oncology center for appropriate management.