Diehl, Thomas M.

ABSTRACT Background and Objectives Surgery is the mainstay of treatment for localized colorectal cancer (CRC); however, little is known about survival outcomes following CRC surgery in low‐ and middle‐income countries (LMICs). Here, we examine the available data on long‐term outcomes following CRC resections in LMICs. Methods A systematic review and meta‐analysis were conducted on primary research studies reporting survival data after CRC resection with curative intent in LMICs. Disease‐free survival (DFS) and overall survival (OS) data were extracted, and random effects modelling was used to estimate the pooled survival rates. Results One hundred and fifty‐four studies representing 20,589 CRC patients were analyzed. Notably, only 27 (20%) of the 137 LMICs were represented in the literature. The pooled 5‐year OS estimate was 88% (95% CI: 77–95), 76% (69–81), and 57% (49–64) for Stages I, II, and III, respectively. 5‐year DFS estimates were 82% (71–90), 76% (67–84), and 59% (51–65) for stages I, II, and III, respectively. Combined OS and DFS estimates for all three stages were 76% and 69%, respectively. Survival rates varied considerably across the included studies and between income groups. Conclusions With the rising incidence of CRC globally, our work highlights the dearth of data on long‐term outcomes following CRC operations in most LMICs and emphasizes the urgent need for research capacity building.

Abstract Purpose: Colorectal Cancer (CRC) is a leading cause of death from cancer globally. Surgery is the mainstay of treatment for localized CRC; however, little is known about survival outcomes following CRC surgery in low- and middle-income countries (LMICs). In this study, we examine the published literature for data on long-term outcomes following CRC resections in LMICs. Methods: We systematically reviewed PubMed, Web of Science, Embase, and Global Index Medicus for original research articles reporting survival data after CRC resection with curative intent in LMICs, published between January 2005 and May 2022. LMICs were defined according to the 2020 World Bank categories. We excluded studies without English full text or involving pediatric populations (<18 years), non-primary colorectal, benign disease, and endoscopic/transanal resection only. Studies from China dominated the published literature and were excluded. Abstracts and full texts were reviewed by two independent reviewers, and a third reviewer resolved conflicts. Disease-free survival (DFS) and overall survival (OS) data were extracted, and random effects modelling was used to estimate the pooled survival rates. Results: Our search returned 32,261 articles. After deduplication, 20,729 abstracts were assessed for eligibility, with 154 articles meeting inclusion criteria, representing a total of 20,589 CRC patients. 98 (63.6%) studies were from upper-middle-income (UM) countries, 55 (35.7%) from lower-middle-income (LM) countries and only one was from a low-income (L) country. Notably, only 27 (20%) of the 137 LMICs were represented in the literature. Turkey accounted for the highest frequency (29%) of included articles. Most (60%) of the studies were retrospective cohort design, and only three (3) were randomized controlled trials. The pooled 5-year OS estimate was 88% (95% CI: 77–95) for Stage I disease, 76% (69–81) for Stage II, and 57% (49–64) for Stage III. 5-year DFS estimates were 82% (71–90), 76% (67–84), and 59% (51–65) for stages I, II and III respectively. Survival rates varied considerably between income groups, with the strongest disparity seen with Stage III OS data at 18 months: 89% in UM, 86% in LM, and 50% in L (p=0.0005). Conclusion: With the rising incidence of CRC in LMICs, our work highlights the dearth of data on long-term outcomes following CRC operations in LMICs and emphasizes the urgent need for research capacity building, especially in low-income countries. Citation Format: Oluwasegun Afolaranmi, Thomas M. Diehl, Sehar Salim Virani, Qiuyu Yang, Kenechukwu Okwunze, Adel H. Khan, Nabiha Akhlaq Mughal, Daniel Schroeder, Sheida Pourdashti, Leslie Christensen, Sadaf Khan, Syed Nabeel Zafar. Survival Following Colorectal Cancer Surgery in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis [abstract]. In: Proceedings of the 13th Annual Symposium on Global Cancer Research; 2025 Sep 16. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(12_Suppl):Abstract nr 84.

AbstractWilms tumor (WT) is the most common renal malignancy in children. Children with favorable histology WT achieve survival rates of over 90%. Twelve percent of patients present with metastatic disease, most commonly to the lungs. The presence of a pleural effusion at the time of diagnosis of WT may be noted on staging imaging; however, minimal data exist regarding the significance and prognostic importance of this finding. The objectives of our study are to identify the incidence of pleural effusions in patients with WT, and to determine the potential impact on oncologic outcomes. A multi‐institutional retrospective review was performed from January 2009 to December 2019, including children with WT and a pleural effusion on diagnostic imaging treated at Pediatric Surgical Oncology Research Collaborative (PSORC) participating institutions. Of 1259 children with a new WT diagnosis, 94 (7.5%) had a pleural effusion. Patients with a pleural effusion were older than those without (median 4.3 vs 3.5 years; P = .004), and advanced stages were more common (local stage III 85.9% vs 51.9%; P < .0001). Only 14 patients underwent a thoracentesis for fluid evaluation; 3 had cytopathologic evidence of malignant cells. Event‐free and overall survival of all children with WT and pleural effusions was 86.2% and 91.5%, respectively. The rate and significance of malignant cells present in pleural fluid is unknown due to low incidence of cytopathologic analysis in our cohort; therefore, the presence of an effusion does not appear to necessitate a change in therapy. Excellent survival can be expected with current stage‐specific treatment regimens.