A new 10-year follow-up study concluded that conditional survival (CS) provided relevant information to determine dynamic disease-free survival (DFS) in Chinese patients who underwent radical resection of gastrointestinal stromal tumors (GISTs).
“CS is an estimate based on the survival of patients over a period of time that can be used to obtain accurate information about their future survival time,” the authors of the study explained. CS has been studied to evaluate the probability of long-term cancer patient survival in a variety of malignant cancers.
The analysis performed by Xu et al showed that the 3-year DFS rate reduced gradually, while the 3-year conditional DFS (CDFS3) rate increased over time. For instance, the 3-year DFS rate decreased from 94.0% at 3 years to 77.3% at 7 years. For the same period of time, the CDFS3 rate increased from 94.0% to 95.2%.
CS can be used for monitoring tumor recurrence when other predictors fail to be applied. Conventional clinicopathological prognostic factors had only slight to moderate effects on CDFS3.
Read more about GIST prognosis
In addition, except for the mitotic index, all prognostic factors lost their predictive significance at 5 years postprocedure.
“The estimated long-term survival of Chinese patients with GISTs changes based on the time of survival. The mitotic index can be used as a predictor of GIST stability until 5 years after surgery. The modified [National Institutes of Health] staging criteria loses the ability to reflect DFS after 2 years of survival,” the authors explained.
The study enrolled 451 Chinese patients (median age, 59 years, interquartile range, 20-88 years) diagnosed with GISTs. Most (60.5%) had gastric tumors, followed by small bowel (26.6%), duodenum (7.1%), and rectum (2.4%).
Xu S, Zhang S, Dong L, Lin G, Zhou Y. Dynamic survival analysis of gastrointestinal stromal tumors (GISTs): a 10-year follow-up based on conditional survival. BMC Cancer. 2021;21(1):1170. doi:10.1186/s12885-021-08828-y