, Volume 471, Issue 11, pp 3398-3404
Date: 03 Jul 2013

Conditional Survival Is Greater Than Overall Survival at Diagnosis in Patients With Osteosarcoma and Ewing’s Sarcoma

Abstract

Background

Conditional survival is a measure of the risk of mortality given that a patient has survived a defined period of time. These estimates are clinically helpful, but have not been reported previously for osteosarcoma or Ewing’s sarcoma.

Questions/purposes

We determined the conditional survival of patients with osteosarcoma and Ewing’s sarcoma given survival of 1 or more years.

Methods

We used the Surveillance, Epidemiology, and End Results (SEER) Program database to investigate cases of osteosarcoma and Ewing’s sarcoma in patients younger than 40 years from 1973 to 2009. The SEER Program is managed by the National Cancer Institute and provides survival data gathered from population-based cancer registries. We used an actuarial life table analysis to determine any cancer cause-specific 5-year survival estimates conditional on 1 to 5 years of survival after diagnosis. We performed a similar analysis to determine 20-year survival from the time of diagnosis.

Results

The estimated 5-year survival improved each year after diagnosis. For local/regional osteosarcoma, the 5-year survival improved from 74.8% at baseline to 91.4% at 5 years—meaning that if a patient with localized osteosarcoma lives for 5 years, the chance of living for another 5 years is 91.4%. Similarly, the 5-year survivals for local/regional Ewing’s sarcoma improved from 72.9% at baseline to 92.5% at 5 years, for metastatic osteosarcoma 35.5% at baseline to 85.4% at 5 years, and for metastatic Ewing’s sarcoma 31.7% at baseline to 83.6% at 5 years. The likelihood of 20-year cause-specific survival from the time of diagnosis in osteosarcoma and Ewing’s sarcoma was almost 90% or greater after 10 years of survival, suggesting that while most patients will remain disease-free indefinitely, some experience cancer-related complications years after presumed eradication.

Conclusions

The 5-year survival estimates of osteosarcoma and Ewing’s sarcoma improve with each additional year of patient survival. Knowledge of a changing risk profile is useful in counseling patients with time. The presence of cause-specific mortality decades after treatment supports lifelong monitoring in this population.

Level of Evidence

Level II, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

One of the authors (BJM) certifies that he has received, during the study period, funding from the NIH (T32 Training Grant CA148062-01).
All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request.
Each author certifies that his or her institution approved or waived approval for the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.
A comment to this article is available at http://dx.doi.org/10.1007/s11999-013-3247-5.