Introduction/Background*Human epididymis protein 4 (HE4) has been reported as a promizing biomarker in the assessment of the risk of malignancy in patients, diagnosed with pelvic mass. Howewer, reference limits of HE4 do not provide clinically relevant discrimination between malignant and benign ovarian diseases. The clinical significance of well-known Risk of Ovarian Malignancy Algorithm (ROMA), which includes both HE4 and CA125, and its superiority over CA125 alone are still questionable.

The aim of this study was to elaborate a new algorithm, based on serum CA125, HE4 and age, to assess the risk of malignancy in premenopausal patients with pelvic mass

Methodology The training dataset included 284 premenopausal patients operated because of presence of pelvic mass, out of which 35 and 249 had malignant and benign disease respectively. A novel algorithm, based on serum HE4, CA125 and patient’s age as variables, has been developed by using the scenario of discrimination “benign diseases versus all stages of epithelial ovarian cancer (EOC ) together with borderline ovarian tumors (BOT ) FIGO stage 1c2–3c ”. This algorithm was named Risk of Ovarian Cancer Kazan Index (ROCK-I). The validating dataset consisted of consecutively operated premenopausal patients with pelvic mass out of which there were 187 cases of benign diseases, 20 EOC and 4 BOT FIGO stage 1c2–3c. An analysis with inclusion of BOT stage 1a-1c1 and non-EOC will be reported separately.

Result(s)*In the validating dataset the specificities of ROCK-I and ROMA were 92% and 85% respectively (p<0.05). When the above-mentioned scenario of discrimination was used the sensitivities of ROCK-I and ROMA were 95.8% and 91.7% respectively, accuracies 92.4 and 85.8%, positive predictive values 60.5% and 44% respectively. Areas under receiver-operating-characteristic curves (ROC-AUC) of ROCK-I, ROMA and CA125 were 0.984, 0.94 and 0.901 respectively. The difference in ROC-AUC between ROCK-I and CA125 was statistically significant (p=0.03). A more detailed comparison of the performance of algorithms is shown in table 1 and figure 1.

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Abstract 1128 Figure 1

The ROC-curves of ROCK-I, ROMA and CA125 in the validating dataset

Conclusion*The proposed ROCK-I has demonstrated greater diagnostic performance than both ROMA and CA125 in the analyzed dataset. If an independent validation will show similar or even slightly lower difference between ROCK-I and ROMA it may provide a new basis of routine-use of HE4 in premenopausal patients with pelvic mass.