Researchers at University of California San Diego School of Medicine have conducted the first population-based study that characterises the association and temporal relationship between gastrointestinal stromal tumors (GIST) and other cancers. The results 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% of patients with gastrointestinal stromal tumours have a hereditary disorder that predisposes them to develop multiple benign and malignant tumours," said Dr Jason K Sicklick, assistant professor of surgery and UC San Diego Moores Cancer Centre 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 tumours may warrant consideration for additional screenings based on the other cancers that they are most susceptible to contract," said co-author Dr James D Murphy, assistant professor of radiation oncology and UC San Diego Moores Cancer Centre radiation oncologist.
When compared to the US population, the researchers found that people with GIST had a 44% increased prevalence of cancers occurring before a GIST diagnosis and a 66% higher risk of developing cancers after diagnosis. The most common tumours 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 tumours were smaller than 10cm had a higher probability of a second cancer than patients whose growth was larger. People with tumours smaller than 2 cm had the greatest likelihood of developing additional malignancies, both before and after diagnosis.
[link url="http://www.eurekalert.org/pub_releases/2015-05/uoc–pwg050115.php"]University of California, San Diego School of Medicine material[/link]
[link url="http://onlinelibrary.wiley.com/doi/10.1002/cncr.29434/abstract"]Cancer abstract[/link]