Phenotypic diversity in patients with multiple serrated polyps: a genetics clinic study.
OBJECTIVE
Hyperplastic polyposis is a colonic polyposis condition of unknown aetiology. The purpose of this study was to examine the spectrum of phenotypic variation in patients with multiple serrated polyps as a basis for gene discovery.


METHODS
One hundred and twenty-six patients with multiple (> or = 5) serrated polyps were recruited to the study. Polyp counts were extracted from histology and colonoscopy reports. Ethnicity was self-reported. Family history of cancer data were derived from pedigrees. Ascertainment status was classified as either index case or identified by screening.


RESULTS
The average reported polyp count was 39. Patients with highest polyp numbers were more likely to be male (P = 0.02). Colorectal cancer (CRC) was identified in 49 of 119 patients (41%) and 28% of these patients had multiple CRC. Young onset patients had higher polyp numbers (P = 0.03) and were more likely to have their CRC in the distal colon (P = 0.02). CRC was significantly associated with the presence of adenomas (P = 0.03). Patients were divided into moderate polyposis (5-79 serrated polyps) and dense polyposis (80 or more) categories. The dense polyposis category was associated with a lack of family history for CRC (P = 0.034) and male gender (P = 0.014), independent of ascertainment status and recruitment site.


CONCLUSIONS
Multiple serrated polyps were associated with an increased personal risk of CRC. A subset of patients with the highest polyp numbers was more likely to be male and to have no family history of CRC. This result suggests heterogeneous modes of inheritance and has implications for studies investigating the genetic basis of multiple serrated polyps.
Buchanan
Daniel D
DD
Familial Cancer Laboratory, QIMR, Herston, Brisbane Q 4006, Australia.
Sweet
Kevin
K
Drini
Musa
M
Jenkins
Mark A
MA
Win
Aung Ko
AK
Gattas
Michael
M
Walsh
Michael D
MD
Clendenning
Mark
M
McKeone
Diane
D
Walters
Rhiannon
R
Roberts
Aedan
A
Young
Alasdair
A
Hampel
Heather
H
Hopper
John L
JL
Goldblatt
Jack
J
George
Jill
J
Suthers
Graeme K
GK
Phillips
Kerry
K
Young
Graeme P
GP
Chow
Elizabeth
E
Parry
Susan
S
Woodall
Sonja
S
Tucker
Kathy
K
Muir
Amanda
A
Field
Michael
M
Greening
Sian
S
Gallinger
Steven
S
Green
Jane
J
Woods
Michael O
MO
Spaetgens
Renee
R
de la Chapelle
Albert
A
Macrae
Finlay
F
Walker
Neal I
NI
Jass
Jeremy R
JR
Young
Joanne P
JP
D003111:Colonic Polyps / Q000235:genetics* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012044:Regression Analysis; D012307:Risk Factors