B0100 - Prevalence and Characteristics of Therapy-Associated Polyposis: A Systematic Review

Savan Kothadia, MD¹, Daniel Marino, MD, MBA², Markos Kalligeros, MD¹, Rei Mitsuyama, MD³, Mouhand F. Mohamed, MD, MSc², Steven F. Moss, MD^4
1Warren Alpert Medical School of Brown University , Providence, RI; ²Warren Alpert Medical School of Brown University, Providence, RI; ³Brown University, Providence, RI; ⁴Rhode Island Hospital / Brown University, Providence, RI

Introduction: Therapy-associated Polyposis (TAP) is a poorly understood condition in which colorectal polyps develop in individuals with childhood and young adulthood cancers (CYAC) who were treated with chemotherapy and/or radiation, in the absence of a genetic predisposition to polyposis syndromes. We aimed to determine characteristics of these individuals and the polyposis to better understand TAP.

Methods: This systematic review was in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). PubMed and Embase were searched from when TAP was first reported (January 2014) to April 2022. Inclusion criteria: citations of cases with CYAC (diagnosed at <39 years) treated with chemotherapy and/or radiation with >10 lifetime polyps and negative genetic testing for hereditary polyposis syndromes. Data were collated into Table 1. For individuals’ characteristics we represented continuous measurements as medians (IQRs) and compared them using the Mann-Whitney-Wilcoxon test. For categorical data we used Pearson’s Chi-square test.

Results: 3766 publications were screened, 6 met inclusion criteria for 44 individuals total (Figure 1). Cases were divided into 2 groups: those aged < 18 years at diagnosis of their primary cancer versus young adults (18-39 years). The most common primary cancer was Hodgkin’s lymphoma in both groups; most cases were treated with both chemotherapy and radiation. Individuals with CYAC diagnosed as young adults developed more polyps than with CYAC as children (40.0 vs. 21.5, p=0.001), with no difference between polyp types. Most were adenomas. Children with CYAC were diagnosed with TAP earlier than young adults (43.0 vs. 50.5 years, p= 0.005). However, young adults had a shorter interval between primary cancer diagnosis and polyposis (26.0 vs 29.3 years, p=0.03). Importantly, 30% of cases with TAP developed colorectal cancer (CRC), with no significant difference in the proportion developing CRC between the groups.

Discussion: Individuals diagnosed with cancer as children developed TAP earlier than young adults, but those treated as young adults developed more polyps. There is a high incidence of CRC in TAP. Current guidelines recommend that individuals who undergo abdominal, pelvic, spinal, or total body irradiation begin CRC screening 5 years after radiation or at age 30 (whichever is later). Further investigation is necessary to determine the prevalence of TAP after CYAC and the role of early CRC screening for patients treated for CYAC.




Disclosures:


Savan Kothadia, MD¹, Daniel Marino, MD, MBA², Markos Kalligeros, MD¹, Rei Mitsuyama, MD³, Mouhand F. Mohamed, MD, MSc², Steven F. Moss, MD⁴. B0100 - Prevalence and Characteristics of Therapy-Associated Polyposis: A Systematic Review, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.