Colorectal cancer risk in hamartomatous polyposis syndromes

Table 1 Genetic features and prevalence of pure Hamartomatous Polyposis Syndromes

Syndrome	Mode of inheritance	Gene	Incidence
Juvenile Polyposis	AD	SMAD4/DPC4BMPR1A	1:100 to 1:160 thousand
Peutz-Jeghers	AD	STK11/LKB1	1:60 mil a 1:300 thousand
BRRS	AD	PTEN	Rare
Cowden	AD	PTEN, SDH and KLLN epimutations	1:200 thousand

BRRS: Bannayan-Riley-Ruvalacaba syndrome; AD: Autosomal dominant; SDH: Succinate dehydrogenase (B and C subunits); KLLN: p53 target gene.

Table 2 Clinical features and colon cancer risk in Hamartomatous Polyposis Syndromes, according to literature series

Syndrome	Main clinical features polyp distribution	Increased risk of other tumors	Colon cancer risk
Juvenile Polyposis	Juvenile polyps Distribution: large bowel (mainly), small bowel, stomach	Gastric and colorectal	39%-68%
Peutz-Jeghers	Peutz-Jeghers polyps Typical melanotic oral and dermic pigmentations Distribution: small bowel, large bowel, stomach	Gastric, small bowel, pancreas, colorectal, ovary, uterus, breasts, sex cords	39%-57%
PTEN	Mucocutaneous tumors (multiple trichilemmomas) Distribution: Small bowel, large bowel, stomach	Breast, thyroid, retina and uterus cancer	18%

Table 3 Cumulative cancer risk by site and age in Peutz-Jeghers Syndrome (Hearle et al[18])

Cancer/Age	20 yr	30 yr	40 yr	50 yr	60 yr	70 yr
All cancers	2	5	17	31	60	85
Gastrointestinal	-	1	9	15	33	57
Breast	-	-	8	13	31	45
Gynecological	-	1	3	8	18	18
Pancreas	-	-	3	5	7	11
Lung	-	-	2	4	13	17

Table 4 Recommendations for screening and surveillance according to the literature[17,40,48-51,53]

Syndrome	Screening	Work-up	Interval
Peutz-Jeghers	18-25 yr	Endoscopy (upper/lower)	2-3 yr
	25 yr	MRI and mammography	Annual
	10 yr	Testicular examination	Annual
	30 yr	MRI or CT (pancreas)	1-2 yr
Juvenile Polyposis	15-18 yr	Upper endoscopy	1-3 yr
		Colonoscopy	1-3 yr
		Upper endoscopy and video capsule endoscopy for HHT	3 yr
PTEN	After 25 yr	Colonoscopy Mamography/thyroid US	3-5 yr Annual

US: Ultrasound; CT: Computorized tomography; MRI: Magnetic resonance imaging; HHT: Hereditary hemorrhagic telangiectasia.