Risk of second cancers in patients with colorectal carcinoids.
BACKGROUND
It is often stated that patients with colorectal carcinoid tumors have an increased risk of developing other malignancies. However, this risk has not been conclusively documented. A comprehensive evaluation is needed to more thoroughly assess the risk of second cancers in patients with colorectal carcinoids.


METHODS
A search of the National Cancer Institute Surveillance, Epidemiology, and End Result database from 1973 to 1996 revealed 2,086 patients with colorectal carcinoids. This subset of patients was examined for occurrence of second cancers. The observed incidence of cancer for each site was compared with the expected incidence based on the gender-adjusted and age-adjusted cancer rates in the remaining Surveillance, Epidemiology, and End Result file. A Poisson distribution probability was used to determine the significance of these comparisons.


RESULTS
Patients with colorectal carcinoids had an increased rate of cancer in the colon and rectum (P < 0.001), small bowel (P < 0.001), esophagus/stomach (P = 0.02), lung/bronchus (P < 0.001), urinary tract (P = 0.005), and prostate (P < 0.001), when compared with a control population. Most of the gastrointestinal tract cancers were synchronous cancers, whereas lesions outside the gastrointestinal tract were most commonly metachronous tumors.


CONCLUSIONS
A significantly increased risk of synchronous colorectal, small-bowel, gastric, and esophageal cancers and metachronous lung, prostate, and urinary tract neoplasms is clearly demonstrated. After the diagnosis of colorectal carcinoid tumors, patients should undergo appropriate screening and surveillance for cancer at these sites.
Tichansky
David S
DS
Department of Surgery, Thomas Jefferson University Hospital and Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA.
Cagir
Burt
B
Borrazzo
Edward
E
Topham
Allan
A
Palazzo
Juan
J
Weaver
Eric J
EJ
Lange
Andrea
A
Fry
Robert D
RD
D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002276:Carcinoid Tumor / Q000453:epidemiology* / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D004067:Digestive System Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology* / Q000473:pathology*; D016012:Poisson Distribution; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D012042:Registries / Q000706:statistics & numerical data*; D012142:Respiratory Tract Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D018570:Risk Assessment; D017678:Sex Distribution; D014571:Urologic Neoplasms / Q000453:epidemiology* / Q000473:pathology*