An examination of the online nomogram Sarculator demonstrated it is as effective at predicting overall survival of certain patients with sarcoma in the United States as it is in Europe, according to research presented by Voss et al at the Society of Surgical Oncology 2021 International Conference on Surgical Cancer Care (Poster 84).
About Sarculator
A nomogram is a diagram representing the relations between three or more variable quantities by means of several scales. Sarculator is an online validated nomogram that predicts the overall survival of patients with resected primary extremity and trunk sarcomas, mostly created using European data from patients treated at high-volume centers. However, its ability to accurately predict outcomes in patients with sarcoma in the United States was unknown.
A research team sought to compare Sarculator-predicted overall survival to actual overall survival in U.S. patients using the National Cancer Database.
Analysis
Voss evaluated 9,738 patients from the National Cancer Database (2006–2016) with stage I to III primary extremity or trunk sarcoma who underwent R0/R1 resection and had completed demographic and treatment data. The predicted overall survival was calculated using the Sarculator algorithm, which includes patient age, tumor size (cm), grade (I–III), and histology. The predicted overall survival was compared to the actual overall survival, and the Harrell’s C index was calculated to determine the discrimination of the Sarculator predicted overall survival model (0.7 = good model, 0.8 = strong model, 1.0 = perfect model).
Results
The analysis showed that undifferentiated pleomorphic sarcoma (17%), leiomyosarcoma 15.7%), and myxoid liposarcoma (10.9%) were the most common individual histologies. Of the patients analyzed, 8,829 (90%) underwent R0 resection, 1,599 (16.3%) received chemotherapy, and 5,832 (59.5%) received radiation therapy.
The five-year predicted overall survival was 73.7%, compared to an actual overall survival of 68.9%. The C index for the entire cohort was 0.726. By stage, the C index was 0.730 for stage I, 0.708 for stage II, and 0.679 for stage III disease. By histology, the C index was highest for leiomyosarcoma (0.745), myxoid liposarcoma (0.719), and other histologies (0.719), and it was lowest for malignant peripheral nerve sheath tumor (0.656), liposarcoma (0.679), and synovial sarcoma (0.694).
“Overall, Sarculator is a good predictor of actual overall survival for U.S. [patients with] primary extremity and trunk sarcoma…. Sarculator performs slightly better for earlier stages (I/II) and best for leiomyosarcoma, myxoid liposarcoma, and other histologies, and it is a good clinical tool for surgeons and oncologists to help with survival prognostication,” reported the poster authors.
