External validation of nomograms for prediction of survival outcome in retroperitoneal sarcoma using the North East England patient cohort

Author Info

Abdullah Malik Derek Manas George Watkinson Jeffry Hogg Jeremy French John Lunec

Corresponding Author

George Watkinson
Foundation Doctor, NHS Lothian Foundation Trust, Edinburgh, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, UK EH16 4SA

A B S T R A C T

Introduction: Retroperitoneal sarcoma is a rare tumour that does not present nor progress in a manner typical for other soft tissue sarcomas. As a result of this the conventional AJCC staging manual for peripheral STSs is not applicable to RPS and does not allow for stratification of patient groups. This has been recognised by other research groups and has led to their development of nomograms, incorporating statistically significant clinical characteristics on retrospective multivariate analysis of patient cohorts. We applied two of these nomograms to the North East England (NEE) RPS database. Methods: Nomograms published by Gronchi et al. (to predict 7 year overall and disease-free survival) and Anaya et al. (to predict 3 year and 5-year overall survival) were applied retrospectively to the 79 patients in the NEE RPS database. Statistical analysis was performed by use of concordance index to assess capacity to correctly predict an expected outcome. Results: The nomogram for predicting 3-year OS published by Anaya et al. gave a concordance index of 0.792 (95% CI 0.70-0.89), p-value <0.001. For 5-year OS, the model has a concordance index of 0.803 (95% CI 0.70 - 0.91), p-value <0.001. The nomogram published by Gronchi et al. to predict 7-year OS was also applied to our cohort and produced a concordance index of 0.539 (95% CI 0.34-0.74), p value 0.70. No patients in our cohort were disease free at 7 years and so analysis could not be performed. Conclusion: The nomogram published by Gronchi et al. was not able to accurately predict the seven-year survival outcome for patients in the NEE RPS database however the nomogram published by Anaya et al. provided an accurate prediction of 3 and 5 year survival in our cohort. This warrants further external validation of this cohort using a larger cohort and incorporating a version of this nomogram into the next edition of the AJCC Staging Manual should be considered.

Article Info

Article Type

Research Article

Publication history

Received: Wed 21, Nov 2018
Accepted: Wed 05, Dec 2018
Published: Mon 17, Dec 2018

Copyright

© 2023 George Watkinson . This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Hosting by Science Repository.
DOI: 10.31487/j.COR.2018.03.106