Abstract 63P
Background
Gastrointestinal stromal tumours (GIST) represent the most common intra-abdominal sarcoma and have variable malignant potential. Risk classification systems have been proposed to identify tumour properties that correlate to patient outcomes. However, determining treatment strategies as well as the need for, and length of, routine follow-up has been debated.
Methods
We conducted a retrospective observational study of all patients diagnosed with GIST at Sahlgrenska University Hospital between January 2004 and December 2020. Medical records were reviewed for clinical details regarding diagnosis, treatment and follow-up, and correlated to recurrence-free survival (RFS), disease-specific survival (DSS) and overall survival (OS).
Results
Some 468 patients, whereof 223 females, with a mean age of 67 (24-93) years were included; 200 high-, 73 intermediate-, 144 low- and 51 very low-risk tumours according to the revised NIH criteria. The most frequent tumour site was the stomach (66 %) followed by the small intestine (29 %). Without pretreatment, non-radical resections occurred in 17% and in 9% after pretreatment with imatinib (p<0.05). Among the 388 patients who had surgery with a curative intent, the overall five-year RFS was 82%, and 68%, 100%, 93% and 100% for high, intermediate low and very low-risk groups, respectively (p<0.001). The 5-year overall DSS was 87.5% in the whole group, 78% in the high-risk group and 98.6-100% in the other risk groups (p<0.001). The difference remained statistically significant after adjusting for age and comorbidities. The overall survival was 76% without significant difference between the risk groups in the initial analysis but after adjusting for age and comorbidities, the low-risk group had significantly better OS compared to the high risk-group (HR: 0.6, 95% CI: 0.39−0.94) (p<0.01).
Conclusions
We show that in our cohort, the significant difference in RFS, DSS and OS between risk groups questions the value of current follow-up recommendations for risk groups other than the high-risk group.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.