The development and validation of a tumor-specific death predictive nomogram in patients with ovarian cancer: a cohort study

Background: Ovarian cancer has a high mortality rate. Accurate identification of risk factors for mortality is crucial to improve treatment strategies. Regretfully, prognostication tools are limited. In recent years, quantitative parameters of contrast enhanced ultrasound have shown economic, reproducible, and highly accurate advantages in predicting the prognosis of ovarian cancer patients. The purpose of this study was to develop a nomogram prediction model for the oncological outcome of patients with ovarian cancer based on quantitative parameters of contrast-enhanced ultrasound. Methods: Data from 357 patients with ovarian cancer admitted to The Fourth People’s Hospital of Zhenjiang from January 2018 to December 2019 were retrospectively collected and constructed the training set. Data from 153 cases admitted to The People’s Hospital of Zhaoyuan during the same period were collected and constructed the validation set. All patients were treated with primary cytoreductive surgery, and were followed up for 5 years after surgery. The differences in clinical characteristics and quantitative parameters of contrast-enhanced ultrasound were compared between patients who passed away within 5 years and those which did not. Results: Peak systolic velocity (PSV), stage III, poor differentiation, and ascites were independent risk factors for tumor-specific mortality in patients with ovarian cancer, with their relative risk being 2.011 (95% confidence interval: 1.680–2.407), 13.480 (95% confidence interval: 4.540–40.022), 2.997 (95% confidence interval: 1.206–7.452), and 2.997 (95% confidence interval: 1.206–7.452), respectively. Time to peak (TTP) was a protective factor of tumor-specific mortality in patients with ovarian cancer, with a relative risk of 0.800 (95% confidence interval: 0.731–0.875). The area under the receiver operating characteristic (ROC) curve in the training set was 0.948 (95% confidence interval: 0.926–0.969), and the area under the ROC curve in the validation set was 0.860 (95% confidence interval: 0.802–0.917). Conclusions: The nomogram prediction model for prognosis of patients with ovarian cancer based on quantitative parameters of contrast-enhanced ultrasound has good efficacy and reliability.