TUESDAY, Sept. 21 (HealthDay News) -- Continuous treatment with imatinib (Gleevec) is recommended for patients with advanced gastrointestinal cancer, a new study suggests.

The study included 50 patients with advanced gastrointestinal stromal tumors (GIST) who'd been receiving Gleevec for three years and had no disease progression. The patients were randomly selected to either continue or stop treatment.

The patients were assessed every three months with CT scans. The median time to disease progression was nine months among patients whose treatment was interrupted and was not reached in the group who continued treatment, the investigators found.

In addition, after nearly three years of follow-up, the researchers noted that two-year survival without disease progression was 80 percent among those who continued treatment but only 16 percent among those whose treatment had been interrupted, according to the report published in the Sept. 22 online edition of The Lancet Oncology.

The findings show that three years of treatment with Gleevec does not totally eliminate cancer-causing cells, which means the disease can recur when treatment is stopped, Dr. Axel Le Cesne, of the Institute Gustave Roussy in Villejuif, France, and colleagues explained in a news release from the journal's publisher.

"There was further tumor control in all cases after the reintroduction of [Gleevec], and the time to secondary resistance to [Gleevec] was similar in the two groups, which shows that [Gleevec] interruption neither prevents nor promotes the emergence of [Gleevec] resistance in GIST cells," Le Cesne and colleagues wrote in the report.

The authors concluded that because three years of treatment with Gleevec does not eliminate the remaining dormant cancer cells and cure patients with GIST that has spread, it is not recommended that Gleevec is discontinued unless the patient experiences significant toxic effects.

Funding for the study was provided by Conticanet, the Ligue Contre Le Cancer du Rhone and Novartis, maker of Gleevec.

More information

The American Cancer Society has more about gastrointestinal stromal tumors.