1669 Cancer Within the Family Tree: The Risks, Diagnosis, and Treatment of Juvenile Polyposis Syndrome

Abstract

INTRODUCTION: Juvenile Polyposis Syndrome (JPS) is characterized by the development of numerous hamartomatous polyps in the GI tract, increasing individuals’ risk of colorectal and gastric cancer by as much as 68% by age 60. These odds are further compounded by the syndrome’s autosomal dominant (AD) mode of inheritance, placing children at a 50% risk of transmission from an affected parent. Bone Morphogenic Protein Receptor type-1A (BMPR1A) genes located on chromosome 10q22-23 are strongly associated with JPS, with nearly 60% of cases testing positive for the mutation. Effects of this anomaly cascade down the transforming growth factor-beta (TGF-beta) pathway, resulting in patients developing tens to hundreds of polyps within their lifetime, often by the first decade. Mutations in SMAD4 proteins can also lead to JPS and Hereditary Hemorrhagic Telangiectasia (HHT) as they are also vital in TGF-beta signaling. JPS is clinically diagnosed by the absence of other hamartomatous polyposis syndromes (eg, Peutz-Jeghers or Cowden) and the presence of either >5 juvenile polyps in the colorectum, multiple juvenile polyps elsewhere in GI tract, or any polyps with a family history of juvenile polyps. CASE DESCRIPTION/METHODS: A 41-year-old female with intermittent IBS symptoms presented for colon cancer screening. Two years earlier, the patient’s mother had been diagnosed at age 64 with multiple juvenile colon polyps and colon cancer testing positive for BMPR1A gene mutation. Patient’s initial colonoscopy revealed multiple 3–4 cm irregularly shaped pedunculated polyps, many less than 1cm and an irregularly shaped mass in the mid-ascending colon. The mass was circumferential, broad-based at 4–5 cm and nearly completely obstructing. Polyps removed revealed tubular adenomas and tubular villous adenomas. Though none of these were documented as juvenile polyps, the patient did test positive for BMPR1A mutation suggestive of JPS. The patient was referred to general surgery for resection of the mass and upper endoscopy. DISCUSSION: JPS is a rare polyposis syndrome with AD inheritance. In at-risk patients, it is imperative that genetic testing be performed to determine appropriate cancer screening. Testing should include both SMAD4 and BMPR1A gene mutations, with positive SMAD4 mutations undergoing evaluation for HHT. Current guidelines recommend screening the stomach and colon early, as the length of time to diagnosis remains the single most influenceable and impacting factor in the outcomes of patients and their families.