TY - JOUR
T1 - Familial risk of small intestinal carcinoid and adenocarcinoma
AU - Kharazmi, Elham
AU - Pukkala, Eero
AU - Sundquist, Kristina
AU - Hemminki, Kari
N1 - Funding Information:
Funding Supported by the Swedish Council for Working Life and Social Research, ALF funding of Region Skane, and the German Cancer Aid.
PY - 2013/8
Y1 - 2013/8
N2 - BACKGROUND & AIMS: Small intestinal cancer (SIC) is rare, and its etiology is poorly understood. We compared clusters of families with SICs of different histologic subtypes. METHODS: By using the nationwide family cancer data sets of Sweden and Finland, we identified a cohort of 9964 first-degree relatives of 1799 patients with SIC, diagnosed from 1961 through 2009. Data were collected from time periods as long as 47 years (mean, 35.4 y), and cancer incidence was determined. Standardized incidence ratios (SIRs) were calculated and stratified by sex, age, time period, and cancer type, using the incidence rates for the entire national population as the reference. RESULTS: Among the 1799 SIC cases, 1.1% had a sibling with SIC, so the SIR was 11.8 (95% confidence interval [CI], 7.2-18.2); 1.1% had a parent or child with SIC (SIR, 3.5; 95% CI, 2.0-5.6). The SIR of concordant carcinoid histology of SIC among siblings was 28.4 (95% CI, 14.7-49.6; n = 12) and in parent-child pairs was 9.9 (95% CI, 5.4-16.6; n = 14). The familial risk of concordant histologic subtypes increased for siblings diagnosed with adenocarcinoma, but only 2 familial cases were identified. In family members of patients with SIC of the adenocarcinoma subtype, risks of colorectal and bladder cancer were modestly but significantly increased compared with the general population. Family members of patients with SIC of the carcinoid subtype had an increased risk for kidney cancer and polycythemia vera. CONCLUSIONS: Based on data from our population-based study, first-degree relatives of patients with small intestinal carcinoid tumors have developed these tumors with high incidence. Because of the rareness of this tumor, the absolute risk remains moderate even within families. Gastroenterologists could inform patients with small intestinal carcinoids about the familial risk and encourage counseling for their first-degree relatives. Studies are needed to identify genetic factors that affect susceptibility to SIC.
AB - BACKGROUND & AIMS: Small intestinal cancer (SIC) is rare, and its etiology is poorly understood. We compared clusters of families with SICs of different histologic subtypes. METHODS: By using the nationwide family cancer data sets of Sweden and Finland, we identified a cohort of 9964 first-degree relatives of 1799 patients with SIC, diagnosed from 1961 through 2009. Data were collected from time periods as long as 47 years (mean, 35.4 y), and cancer incidence was determined. Standardized incidence ratios (SIRs) were calculated and stratified by sex, age, time period, and cancer type, using the incidence rates for the entire national population as the reference. RESULTS: Among the 1799 SIC cases, 1.1% had a sibling with SIC, so the SIR was 11.8 (95% confidence interval [CI], 7.2-18.2); 1.1% had a parent or child with SIC (SIR, 3.5; 95% CI, 2.0-5.6). The SIR of concordant carcinoid histology of SIC among siblings was 28.4 (95% CI, 14.7-49.6; n = 12) and in parent-child pairs was 9.9 (95% CI, 5.4-16.6; n = 14). The familial risk of concordant histologic subtypes increased for siblings diagnosed with adenocarcinoma, but only 2 familial cases were identified. In family members of patients with SIC of the adenocarcinoma subtype, risks of colorectal and bladder cancer were modestly but significantly increased compared with the general population. Family members of patients with SIC of the carcinoid subtype had an increased risk for kidney cancer and polycythemia vera. CONCLUSIONS: Based on data from our population-based study, first-degree relatives of patients with small intestinal carcinoid tumors have developed these tumors with high incidence. Because of the rareness of this tumor, the absolute risk remains moderate even within families. Gastroenterologists could inform patients with small intestinal carcinoids about the familial risk and encourage counseling for their first-degree relatives. Studies are needed to identify genetic factors that affect susceptibility to SIC.
KW - Genetics
KW - Inherited
KW - Pathogenesis
KW - Risk factor
UR - http://www.scopus.com/inward/record.url?scp=84880612781&partnerID=8YFLogxK
U2 - 10.1016/j.cgh.2013.02.025
DO - 10.1016/j.cgh.2013.02.025
M3 - Article
C2 - 23500615
AN - SCOPUS:84880612781
SN - 1542-3565
VL - 11
SP - 944
EP - 949
JO - Clinical Gastroenterology and Hepatology
JF - Clinical Gastroenterology and Hepatology
IS - 8
ER -