UCSD: Researchers at UC 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, published by Cancer on April 30, indicate that one in 5.8 patients with GIST will develop additional malignancies before and after their diagnosis.
Specifically, patients with GIST are more likely to develop other
sarcomas, non-Hodgkin’s lymphoma, carcinoid tumors, melanoma,
colorectal, esophageal, pancreatic, hepatobiliary, non-small cell lung,
prostate and renal cell cancers.
“Only 5 percent of patients with gastrointestinal stromal tumors have
a hereditary disorder that predisposes them to develop multiple benign
and malignant tumors,” said Jason K. Sicklick, MD, assistant professor
of surgery and UC San Diego Moores Cancer Center surgical oncologist.
“The research indicates that these patients may develop cancers outside
of these syndromes, but the exact mechanisms are not yet known.”
The researchers said further studies are needed to understand the
connection between GIST and other cancers, but the findings may have
clinical implications.
“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 co-author James D. Murphy,
MD, assistant professor of radiation oncology and UC San Diego Moores
Cancer Center radiation oncologist.
When compared to the United States population, the researchers found
that 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 2 cm had the greatest
likelihood of developing additional malignancies, both before and after
diagnosis.