BACKGROUND & AIMS: Patients with hyperplastic polyposis are reported to have multiple and/or large hyperplastic polyps (HPs) and an increased risk of colorectal cancer, but the phenotype and genetic alterations in hyperplastic polyposis have not been studied in detail. METHODS: We evaluated clinical-pathological and molecular characteristics of 129 HPs, 6 serrated adenomas, and 3 admixed hyperplastic-adenomatous polyps from 13 patients with hyperplastic polyposis (more than 20 HPs), 5 patients with a large HP (>/=1 cm in diameter), and 5 patients with multiple HPs (5-10 HPs). RESULTS: HPs in the right colon in contrast to the left colorectum had more frequent topographic dysregulation of p21(Waf-1/Cip1) expression (94% vs. 76%, P = 0.03) and of proliferation (92% vs. 53%, P = 0. 0001), but less frequent allelic loss of chromosome 1p (4% vs. 17%, P = 0.03). K-ras mutation was present in 8% of HPs, p53 gene product overexpression in none, and microsatellite instability in 3% without relationship to microsatellite instability in synchronous cancer. Patients with a large HP differed from those with multiple HPs in having a high frequency of right-sided HP (63% vs. 22%, P = 0.01) and of right-sided colon cancer (100% vs. 8%, P = 0.003). Hyperplastic polyposis was associated with a family history of colorectal cancer (P = 0.01) and with loss of chromosome 1p in HP (21% vs. 0%, P = 0.001). CONCLUSIONS: A hyperplastic polyp/dysplasia-to-adenocarcinoma sequence can be manifested in 3 distinct phenotypes consisting of patients with hyperplastic polyposis and chromosome 1p allelic loss in some HPs, in contrast to patients who have large, right-sided HPs or small numbers of HPs that lack 1p loss.
BACKGROUND & AIMS:Patients with hyperplastic polyposis are reported to have multiple and/or large hyperplastic polyps (HPs) and an increased risk of colorectal cancer, but the phenotype and genetic alterations in hyperplastic polyposis have not been studied in detail. METHODS: We evaluated clinical-pathological and molecular characteristics of 129 HPs, 6 serrated adenomas, and 3 admixed hyperplastic-adenomatous polyps from 13 patients with hyperplastic polyposis (more than 20 HPs), 5 patients with a large HP (>/=1 cm in diameter), and 5 patients with multiple HPs (5-10 HPs). RESULTS: HPs in the right colon in contrast to the left colorectum had more frequent topographic dysregulation of p21(Waf-1/Cip1) expression (94% vs. 76%, P = 0.03) and of proliferation (92% vs. 53%, P = 0. 0001), but less frequent allelic loss of chromosome 1p (4% vs. 17%, P = 0.03). K-ras mutation was present in 8% of HPs, p53 gene product overexpression in none, and microsatellite instability in 3% without relationship to microsatellite instability in synchronous cancer. Patients with a large HP differed from those with multiple HPs in having a high frequency of right-sided HP (63% vs. 22%, P = 0.01) and of right-sided colon cancer (100% vs. 8%, P = 0.003). Hyperplastic polyposis was associated with a family history of colorectal cancer (P = 0.01) and with loss of chromosome 1p in HP (21% vs. 0%, P = 0.001). CONCLUSIONS: A hyperplastic polyp/dysplasia-to-adenocarcinoma sequence can be manifested in 3 distinct phenotypes consisting of patients with hyperplastic polyposis and chromosome 1p allelic loss in some HPs, in contrast to patients who have large, right-sided HPs or small numbers of HPs that lack 1p loss.
Authors: Joanne Young; Mark Jenkins; Susan Parry; Bruce Young; Derek Nancarrow; Dallas English; Graham Giles; Jeremy Jass Journal: Gut Date: 2007-06-12 Impact factor: 23.059
Authors: A M O'Shea; S P Cleary; M A Croitoru; H Kim; T Berk; N Monga; R H Riddell; A Pollett; S Gallinger Journal: Histopathology Date: 2008-06-28 Impact factor: 5.087