Prognostic Nomograms for Predicting Overall Survival and Cancer-Specific Survival in Patients with Angiosarcoma, a Population-Based SEER Study
The TNM grading system has been universally used for the clinical prediction of prognosis for patients with soft tissue sarcomas. Nevertheless, he focused primarily on tumor size, lymph nodes, and distant metastases. Certain particular clinical factors are closely correlated with the prognosis of AS. Furthermore, soft tissue sarcoma comprised various histological subtypes among which each is heterogeneous from each other. For these reasons, a more specific and sensitive predictive system for AS is needed.
As a medical system, the nomogram can both predict independent risk factors associated with disease in individuals and help clinicians discern high-risk patients and then adopt optimal treatment regimens for them. The X-tile software was used to optimize the threshold value of the age variable. He selected 50 and 83 years as the age threshold, which can help to better understand its potential effects on the survival rate. The ability of the prediction system can be greatly improved by adding this factor.
In this study, 251 eligible AS patients from the SEER database were all diagnosed in 2010-2015. Caucasians, 50 to 82 years old, diagnosed with stage III and primary soft tissue site constituted the majority of the study population. Based on univariate and multivariate regression, gender, age, AJCC 7th ed stage group, T and N 7th ed stages, histologic grade, and primary site were recognized as the independent predictors of prognosis that were used to establish nomograms. Model C-indexes in internal and external validation were all greater than 0.7 for OS (0.757, 0.749) and CSS (0.762, 0.756). The following ROC curves showed that it was qualified to predict 3-year and 5-year survival rates.
Our study found a significant relationship between gender and prognosis of patients with non-metastatic AS. Biing Luen Lee reported that male sex was the possible predictor of poor prognosis in postoperative AS, which was consistent with us. However, some research has suggested that gender does not appear to be a clear correlation with OS, possibly due to limited sample size.4.13. As shown in the nomogram, age was also observed as an independent factor. Retrospective studies by Thérèse Dettenborn and Clothilde Lindet have concluded on this subject that advanced age (> 70 years) negatively influences the prognosis of AS.5.10. The nomograms discovered at the T and N stages were also the risk variables. Richard J. Cassidy et.al illustrated that tumor size ≥5 cm functions as a negative role in scalp angiosarcomas. Of note, they also found that age ≥ 65 was linked to poorer survival11. Inna Schott found that negative lymph node status correlated with better SG14. Regarding histological grade, a recent study concluded that AS with grade III histology tended to have shorter survival, which was consistent with our result.15. Median AS survival time was variable across different primary sites16,17,18, but which site with the highest mortality has not been well documented. Our study elaborated AS from the cardiac mediastinum which had the highest risk compared to soft tissue, bone and peritoneum. These results indicate that AS patients with the above risk factors would do better to have the relevant examinations more frequently.
The raw data was acquired from the SEER database containing abundant demographic characteristics, tumor properties and a large population of survival data from different races and countries, which is a good representative population and can better reflect the experience of the population than the studies of a single center.19. The results of the nomograms arrived at a favorable consistency between the predicted survival probabilities and the real conditions, indicating that this model allowed us to distinguish the indicators of danger and to predict the prognosis with precision.
This nomogram provides important clinical use in AS which is listed as follows. First, clinicians can more accurately and quickly estimate survival chances and recognize the personalized risk of patients with AS in order to adopt corresponding interventions. For post-operative patients, individual treatment strategies and follow-up plans can be optimized based on different patient prognoses. For example, a 45-year-old patient was diagnosed with AS originating from the soft tissues. Its tumor size was found T1b with N1 and M0 metastases. The postoperative pathology was confirmed as grade III with stage IIA. This patient achieved 175 totally scores in the OS nomogram and the corresponding predicted OS at 3 and 5 years was 26% and 16%. By following the same method, the predicted CSS can be easily obtained. This way, people at high risk had better, more frequent and detailed follow-up. Heterogeneity between patients must be taken into account when clinicians formulate clinical decision-making, so early preventive interventions can be performed to prolong survival in these high-risk populations. Second, soft tissue sarcomas, a huge mixture variety, contain more than 50 subtypes which are different from each other. Our study specifically targeted SA as a distinct category to help in its better management. Moreover, some patients with AS cannot be clearly staged for unavoidable reasons which are often staged in Tx. It is usually more difficult for clinicians to predict their prognosis and often requires multidisciplinary teamwork. Our study focused on this special wave cohort to better guide predict prognosis and treatment. Additionally, our nomograms incorporated AJCC T, N stages and showed high consistency with the training group, supporting this credible model in clinical practice. In short, this nomogram can be used as a useful stratification tool for further clinical research on AS.
Nevertheless, some important clinical variables were not available in the SEER database, such as history of chronic lymphedema, smoking or drinking habits. Research has reported that people with a smoking habit or chronic lymphedema were more susceptible to AS12.20. In addition, mutation of specific genes played an oncogenic role in AS21.22 while the SEER database did not contain information on genetic testing, so we are unable to assess these effects. Additionally, the data in this study is from the US population, whether applicable to Asians or Europeans requires further evidence-based study.