Epidemiology and familial risk of synchronous and metachronous colorectal cancer: a population-based study in Utah.
OBJECTIVE
Patients diagnosed with colorectal cancer (CRC) are at risk for synchronous and metachronous lesions at the time of diagnosis or during follow-up evaluation. We performed a population-based study to evaluate the rate, predictors, and familial risk for synchronous and metachronous CRC in Utah.


METHODS
All newly diagnosed cases of CRC between 1980 and 2010 were obtained from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database.


RESULTS
Of the 18,782 patients diagnosed with CRC, 134 were diagnosed with synchronous CRC (0.71%) and 300 were diagnosed with metachronous CRC (1.60%). The risk for synchronous CRC was significantly higher in men (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.02-2.06) and in patients aged 65 years or older (OR, 1.50; 95% CI, 1.02-2.21). Synchronous CRCs were located more often in the proximal colon (OR, 1.70; 95% CI, 1.20-2.41). First-degree relatives of cases with synchronous (OR, 1.86; 95% CI, 1.37-2.53), metachronous (OR, 2.34; 95% CI, 1.62-3.36), or solitary CRC (OR, 1.75; 95% CI, 1.63-1.88) were at increased risk for developing CRC, compared with relatives of CRC-free individuals. Four percent of first-degree relatives of patients with synchronous or metachronous cancer developed CRC at younger ages than the age recommended for initiating CRC screening (based on familial risk), and therefore would not have been screened.


CONCLUSIONS
Of patients diagnosed with CRC, 2.3% are found to have synchronous lesions or develop metachronous CRC during follow-up evaluation. Relatives of these patients have a greater risk of CRC than those without a family history of CRC. These results highlight the importance of obtaining a thorough family history and adhering strictly to surveillance guidelines during management of high-risk patients.
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah; Department of Medicine (Gastroenterology), University of Utah, Salt Lake City, Utah. Electronic address: jewel.samadder@hsc.utah.edu.
N Jewel
NJ
Samadder
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah; Department of Medicine (Genetic Epidemiology), University of Utah, Salt Lake City, Utah.
Karen
K
Curtin
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah.
Jathine
J
Wong
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah.
Thérèse M F
TM
Tuohy
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah; Department of Oncological Sciences, University of Utah, Salt Lake City, Utah.
Geraldine P
GP
Mineau
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah.
Ken Robert
KR
Smith
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah.
Richard
R
Pimentel
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah.
Lisa
L
Pappas
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah.
Ken
K
Boucher
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah; Department of Medicine (Medical Oncology), University of Utah, Salt Lake City, Utah.
Ignacio
I
Garrido-Laguna
Veterans Affairs Cooperative Studies Epidemiology Center-Durham, Durham Veterans Affairs Medical Center, Durham, North Carolina; Department of Medicine (Gastroenterology), Duke University, Durham, North Carolina.
Dawn
D
Provenzale
Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah; Department of Medicine (Gastroenterology), University of Utah, Salt Lake City, Utah; Department of Oncological Sciences, University of Utah, Salt Lake City, Utah.
Randall W
RW
Burt
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*; D005192:Family Health; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000453:epidemiology*; D016609:Neoplasms, Second Primary / Q000175:diagnosis* / Q000453:epidemiology*; D015995:Prevalence; D018570:Risk Assessment; D014589:Utah / Q000453:epidemiology; D055815:Young Adult
Colon Cancer; Heritable; Prevention; Tumor