Increased risk of additional cancers among patients with gastrointestinal stromal tumors: A population-based study.
BACKGROUND
Most gastrointestinal stromal tumors (GISTs) are considered nonhereditary or sporadic. However, single-institution studies suggest that GIST patients develop additional malignancies at increased frequencies. It was hypothesized that greater insight could be gained into possible associations between GISTs and other malignancies with a national cancer database inquiry.


METHODS
Patients diagnosed with GISTs (2001-2011) in the Surveillance, Epidemiology, and End Results database were included. Standardized prevalence ratios (SPRs) and standardized incidence ratios (SIRs) were used to quantify cancer risks incurred by GIST patients before and after GIST diagnoses, respectively, in comparison with the general US population.


RESULTS
There were 6112 GIST patients, and 1047 (17.1%) had additional cancers. There were significant increases in overall cancer rates: 44% (SPR, 1.44) before the GIST diagnosis and 66% (SIR, 1.66) after the GIST diagnosis. Malignancies with significantly increased occurrence both before and after diagnoses included other sarcomas (SPR, 5.24; SIR, 4.02), neuroendocrine-carcinoid tumors (SPR, 3.56; SIR, 4.79), non-Hodgkin lymphoma (SPR, 1.69; SIR, 1.76), and colorectal adenocarcinoma (SPR, 1.51; SIR, 2.16). Esophageal adenocarcinoma (SPR, 12.0), bladder adenocarcinoma (SPR, 7.51), melanoma (SPR, 1.46), and prostate adenocarcinoma (SPR, 1.20) were significantly more common only before the GIST diagnosis. Ovarian carcinoma (SIR, 8.72), small intestine adenocarcinoma (SIR, 5.89), papillary thyroid cancer (SIR, 5.16), renal cell carcinoma (SIR, 4.46), hepatobiliary adenocarcinoma (SIR, 3.10), gastric adenocarcinoma (SIR, 2.70), pancreatic adenocarcinoma (SIR, 2.03), uterine adenocarcinoma (SIR, 1.96), non-small cell lung cancer (SIR, 1.74), and transitional cell carcinoma of the bladder (SIR, 1.65) were significantly more common only after the GIST diagnosis.


CONCLUSIONS
This is the first population-based study to characterize the associations and temporal relations between GISTs and other cancers by both site and histological type. These associations may carry important clinical implications for future cancer screening and treatment strategies.
Department of Radiation and Applied Sciences, Moores Cancer Center, University of California San Diego, La Jolla, California.
James D
JD
Murphy
Division of Surgical Oncology, Department of Surgery, Moores Cancer Center, University of California San Diego, La Jolla, California.|Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
Grace L
GL
Ma
Division of Surgical Oncology, Department of Surgery, Moores Cancer Center, University of California San Diego, La Jolla, California.
Joel M
JM
Baumgartner
Department of Family and Preventive Medicine, Moores Cancer Center, University of California San Diego, La Jolla, California.
Lisa
L
Madlensky
Division of Medical Oncology, Department of Internal Medicine, Moores Cancer Center, University of California San Diego, La Jolla, California.
Adam M
AM
Burgoyne
Division of Surgical Oncology, Department of Surgery, Moores Cancer Center, University of California San Diego, La Jolla, California.
Chih-Min
CM
Tang
Department of Family and Preventive Medicine, Moores Cancer Center, University of California San Diego, La Jolla, California.
Maria Elena
ME
Martinez
Division of Surgical Oncology, Department of Surgery, Moores Cancer Center, University of California San Diego, La Jolla, California.
Jason K
JK
Sicklick
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000453:epidemiology* / Q000473:pathology; D046152:Gastrointestinal Stromal Tumors / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D012307:Risk Factors; D055815:Young Adult
Surveillance, Epidemiology, and End Results (SEER); gastrointestinal stromal tumor (GIST); multiple primary neoplasm; second primary neoplasms; synchronous neoplasms