A nomogram to predict the individual outcomes of spindle cell sarcoma originated in limbs

Abstract

Background Spindle cell sarcoma is a relatively rare type of sarcoma that mostly originates in soft tissues, but it tends to grow rapidly, and its clinical treatment is a major challenge. From previous reports in the literature, this type of sarcoma has a high proportion of cases affecting the limbs, and research on this topic has potential clinical value. The present study developed a nomogram to effectively predict the survival of patients and analyse the independent prognostic factors of primary limb spindle cell sarcoma.Methods The clinical information of 748 primary limb spindle cell sarcoma patients was obtained from the SEER database. After applying the inclusion/exclusion criteria, 542 patients were included in our study, and they were divided into a training group and a validation group at a ratio of 2:1. The X-tile program was used to determine the best cut-off point for age and tumour size. Univariate and multivariate analyses were used to determine independent prognostic factors, and the training group data were used to construct a nomogram to predict patients’ overall survival and cancer-specific survival. The training cohort data were used for internal verification of the nomogram, and the validation cohort data were used for external verification of the nomogram. The C index was used to calculate the predictive performance of the nomogram. Additionally, we built an online forecasting website.Results The primary limb spindle cell sarcoma has high proportion of all spindle cell sarcoma, and it may have potential associations with pathologic fractures, then marital status, age, historic stage, tumour size and surgical type were identified as five independent prognostic factors, and combined with these factors, a nomogram was constructed for predicting 5-year and 10-year overall survival rates and cancer-specific survival rates. The overall survival rate and tumour-specific survival rate prediction internal validation consistency index (C index) was 0.824 (95% CI 0.794-0.854) and 0.854 (95% CI 0.825-0.883), while the externally validated C index was 0.765 (95% CI 0.706-0.824) and 0.766 (95% CI 0.700-0.832), respectively. Additionally, in order to make the nomogram more convenient and accurate, an online website was created where after entering basic clinical information. The website can help clinicians provide guidance to patients who have these rare sarcomas.Conclusions The nomogram constructed for primary limb spindle cell sarcoma can predict the survival of these patients.