Researchers at the University of California, San Diego School of Medicine conducted the first population-based study that characterizes the association and temporal relationship between gastrointestinal stromal tumors (GIST) and other cancers. The results, now online ahead of print in Cancer (DOI: 10.1002/cncr.29434), indicate that approximately one in six patients with GIST will develop additional malignancies before and after their diagnosis.
GIST patients were found to be more likely to develop other sarcomas, non-Hodgkin's lymphoma, carcinoid tumors, melanoma, and colorectal, esophageal, pancreatic, hepatobiliary, non-small cell lung, prostate, and renal cell cancers.
"Only five percent of patients with gastrointestinal stromal tumors have a hereditary disorder that predisposes them to develop multiple benign and malignant tumors," explained the senior author, Jason K. Sicklick, MD, Assistant Professor of Surgery. "The research indicates that these patients may develop cancers outside of these syndromes, but the exact mechanisms are not yet known."
Further studies are needed to understand the connection between GIST and other cancers, but the findings may have clinical implications, the team explained in a news release.
"Patients diagnosed with gastrointestinal stromal tumors may warrant consideration for additional screenings based on the other cancers that they are most susceptible to contract," said the first author, James D. Murphy, MD, Assistant Professor of Radiation Oncology.
The results showed that when compared with the general U.S. population, people with GIST had a 44 percent increased prevalence of cancers occurring before a GIST diagnosis and a 66 percent higher risk of developing cancers after diagnosis. The most common tumors were those of the genitourinary tract, breast, respiratory, and blood.
Non-Hispanic patients had a higher incidence of other cancers before a GIST diagnosis. Patients whose tumors were smaller than 10 centimeters had a higher probability of a second cancer than patients whose growth was larger. People with tumors smaller than two centimeters had the greatest likelihood of developing additional malignancies, both before and after diagnosis.
The other coauthors were Grace L. Ma, Joel M. Baumgartner, Lisa Madlensky, Adam M. Burgoyne, Chih-Min Tang, and Maria Elena Martinez.