GIST Patients Prone to More Cancer

Approximately 1 in 6 patients suffering from gastrointestinal stromal tumors (GIST) are likely to develop malignant cancers before or after diagnosis, according to the inaugural population-based study recently conducted by researchers at the UC San Diego School of Medicine.

The study results, published in the April issue of Cancer, scrutinized the relationship between GIST and other cancers. Researchers found that GIST patients were particularly more susceptible to carcinoid tumors, melanoma, non-Hodgkin’s lymphoma, sarcomas, colorectal, esophageal, pancreatic, hepatobiliary, non-small cell lung, prostate, and renal cell cancers.

Results indicated that patients afflicted with GIST experienced a 44% increased prevalence of cancers occurring prior to GIST diagnosis and a 66% higher risk of developing cancers following diagnosis. The most common tumors were those of the “genitourinary tract, breast, respiratory, and blood”.

Additionally, findings surprisingly noted patients with tumors smaller than 10 centimeters were likely to develop a second cancer than patients whose growth was larger. Furthermore, individuals with tumors smaller than 2 cm had the greatest probability of developing additional malignancies, before and after the diagnosis.

Jason K. Sicklick, MD, assistant professor of surgery, UC San Diego Moores Cancer Center, said, “Only 5% of patients with gastrointestinal stromal tumors have a hereditary disorder that predisposes them to develop multiple benign and malignant tumors. The research indicates that these patients may develop cancers outside of these syndromes, but the exact mechanisms are not yet known.”

Experts understand the necessity for continued research to better understand the link between GIST and other cancers.

"Patients diagnosed with gastrointestinal stromal tumors may warrant consideration for additional screenings based on the other cancers that they are most susceptible to contract," commented James D. Murphy, MD, assistant professor of radiation oncology and radiation oncologist at UC San Diego Moores Cancer Center.