By Charlene Laino

VIENNA,AUSTRIA — November 4, 2004 — Lack of progression is the most clinically significant predictor of a patient’s response to imatinib inpatients with gastrointestinal stromal tumours (GIST), a new analysis shows.

While clinicians traditionally use tumour shrinkage to assess the anticancer activity of a given therapy, the new study suggests that, at least in this instance, the paradigm does not fit, said co-investigator Stan N.Finkelstein, MD, a senior research scientist at Massachusetts Institute of Technology Sloan School of Management in Cambridge, Massachusetts, United States.

“If you have a patient with GIST on imatinib and the disease is not progressing, it is worth keeping therapy up — even if you don’t see tumour shrinkage on radiological scans,” Dr. Finkelstein said.”Patients with so-called stable disease do just as well as those who have a partial or complete response.”