Site specificity of colorectal neoplasms in families without an inherited syndrome.
BACKGROUND
Relatives of patients with bowel neoplasia have an increased risk of bowel neoplasia. If there were concordance in location of neoplasia between relatives, then location-specific screening could be used. Such concordance might also assist in the understanding of the etiology of neoplasia within individual families.


METHODS
We have investigated the concordance in anatomic location of colonic neoplasia between first-degree relatives using a new statistical technique for paired data called alternating logistic regression.


RESULTS
A total of 146 families were ascertained, none of which had clinical evidence of a hereditary predisposition to edon neoplasia. Among those with neoplasia, there was an increased risk for right-sided disease with older age (40% for less than age 60 vs. 58% for at least 70 years of age, p = 0.008). As assessed by the odds ratio, we found no significant concordance within families for location of neoplasia (odds ratio = 1.2: CI [0.7, 2.2]), although there was a suggestion that location in family members of the same generation was more strongly associated (odds ratio 1.87: CI [0.82, 4.25]).


CONCLUSIONS
The lack of concordance within families for location argues against considering family-specific bowel screening protocols and indicates that the most important causes of bowel neoplasia are not sufficiently focused on one anatomic site to facilitate etiologic research.
Zauber
P
P
Department of Medicine, Saint Barnabas Medical Center, Livingston, New Jersey, USA.
Lardieri
G
G
Rathouz
P J
PJ
Khan
N
N
Bishop
D T
DT
D000236:Adenoma / Q000209:etiology / Q000235:genetics / Q000473:pathology*; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000209:etiology / Q000235:genetics / Q000473:pathology*; D002648:Child; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000209:etiology / Q000235:genetics / Q000473:pathology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000209:etiology / Q000235:genetics / Q000473:pathology; D016609:Neoplasms, Second Primary / Q000209:etiology / Q000235:genetics / Q000473:pathology; D016017:Odds Ratio; D012307:Risk Factors