Development and validation of a prognostic nomogram for survival in testicular and non-testicular primary choriocarcinoma (CC).
Authors: Abdalwahab Alenezy, Sakhr Abdulsalam Alshwayyat, Tala Abdulsalam Alshwayyat, Mustafa Alshwayyat, Falah Alajmi
Journal: Journal of Clinical Oncology (2024)

e17112 Background: Primary CC is a rare germ cell tumor that occurs in males. The testes are the most frequent location. However, it can also develop in extragonadal sites such as the mediastinum, retroperitoneum, or lungs. A prognostic index for estimating the clinical outcomes of CC would be attractive in the current clinical practice. We aimed to develop and validate an effective nomogram for predicting survival in patients with testicular and non-testicular CC. Methods: We analyzed data from the Surveillance, Epidemiology, and End Results database of patients diagnosed with pure CC between 2000 and 2018. Patients who were not diagnosed based on histology, previous history of cancer or other concurrent malignancies, and unknown data were excluded. Patients were divided into two groups: testicular and non-testicular CC. The clinicopathological features of each group were compared using the chi-squared test. Kaplan-Meier estimation, log-rank tests, and Cox regression analyses were used to identify the prognostic factors for OS and CSS. A nomogram was developed to predict 5-year OS, and a calibration curve was plotted to evaluate the agreement between actual (observed) outcomes and expected probabilities. Results: The study included 363 patients, with 270 (74.4%) classified as having testicular CC and 93 (25.6%) as having non-testicular CC. Testicular CC patients had better OS and CSS (HR = 0.52, 95% CI: 0.38-0.71, and HR = 0.52, 95% CI: 0.37-0.71, respectively) than non-testicular CC patients. Multivariate analyses identified the following independent prognostic factors for testicular CC: localized stage, surgery, tumor size ≥ 4 cm, radiotherapy, and chemotherapy. Interestingly, the use of radiotherapy was associated with poor OS and CSS (HR = 1.8, 95% CI: 1.17-2.85 and HR = 1.7, 95% CI: 1.05-2.73, respectively). For non-testicular CC, the independent prognostic factors for OS and CSS were age ≥ 30 years, regional stage, surgery, and chemotherapy. We developed a prognostic nomogram that integrated significant variables, including age, surgery, chemotherapy, radiation therapy, stage, and tumor size. For testicular CC, the model assigned the highest weight to surgery, followed by radiation and tumor size. The AUC was 0.702 (95% CI: 0.638–0.766) and the calibration curves exhibited a mean error of 0.034. The non-testicular CC model assigned the highest weight to chemotherapy, age, and surgery. The AUC was 0.737 (95% CI, 0.631–0.843), and the calibration curves for 5-year survival demonstrated a mean error of 0.028. Conclusions: We developed and validated a novel nomogram for predicting the survival of patients with testicular and non-testicular CC. This personalized tool, incorporating key clinical factors such as age, stage, surgery, and treatment type, empowers clinicians with objective risk assessment, aiding in patient management and treatment decision-making.