Meta-analysis Findings on Radiotherapy Efficacy for T3N0 Rectal Cancer Patients

A new research paper was published in Oncotarget's Volume 13 on October 8, 2022, entitled, “Effectiveness of radiotherapy for local control in T3N0 rectal cancer managed with total mesorectal excision: a meta-analysis.” The total mesorectal excision (TME) significantly improves rectal cancer outcomes. Radiotherapy’s benefit in T3N0 rectal cancer patients managed with TME has not been clearly demonstrated. In a new study, researchers Michael Jonathan Kucharczyk, Andrew Bang, Michael C. Tjong, Stefania Papatheodoru, and Jesus C. Fabregas from Nova Scotia Cancer Centre, Dalhousie University, BC Cancer – Vancouver, Princess Margaret Cancer Centre, Harvard T.H. Chan School of Public Health, and University of Florida Health Cancer Center conducted a systematic review and meta-analysis to determine whether radiotherapy alteres the risk of locoregional recurrence (LR) in T3N0 rectal cancer patients managed with a TME. “This systematic review identified unique 7 retrospective cohort studies which evaluated whether radiotherapy reduces LR in T3N0 rectal cancer patients managed with TME.” The studies indexed on PubMed or Embase were systematically searched from inception to October 18, 2020. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were observed for the literature search, study screening and data extraction; the Newcastle Ottawa Scale evaluated bias; Grades of Recommendation, Assessment, Development, and Evaluation Working Group system evaluated certainty. All were performed independently by at least two investigators. Studies that reported LR data specific to T3N0 rectal cancer patients managed with TME, treated with and without radiotherapy, were included. Data was pooled using a random-effects model. Meta-analyses of the relative risk of local recurrence were conducted. Five retrospective cohort studies involving 932 unique patients reported LR outcomes; no prospective studies met eligibility criteria. Median follow-up ranged from 38.4–78 months. Adjuvant radiotherapy was provided in 3 studies. Chemotherapy was delivered and reported in 4 studies, providing both concurrent and adjuvant chemotherapy. A non-significant LR benefit with radiotherapy’s addition was estimated. Meta-analysis of exclusively retrospective cohort studies was concerning for biased results. Adequately powered randomized trials are warranted. “With low certainty, this meta-analysis observed a non-significant benefit with radiotherapy to 5-year LR rates among T3N0 rectal cancer patients that received a TME. Until a pragmatically sized randomized control trial is completed, our research adds a layer of data to facilitate informed and personalized treatment decisions for T3N0 rectal cancer patients, albeit with potential significant bias from solely relying on retrospective cohort studies.” DOI: https://doi.org/10.18632/oncotarget.28280 Correspondence to: Michael Jonathan Kucharczyk - michael.kucharczyk@medportal.ca Keywords: radiotherapy, meta-analysis, systematic review, rectal cancer, total mesorectal excision About Oncotarget: Oncotarget (a primarily oncology-focused, peer-reviewed, open access journal) aims to maximize research impact through insightful peer-review; eliminate borders between specialties by linking different fields of oncology, cancer research and biomedical sciences; and foster application of basic and clinical science. To learn more about Oncotarget, visit Oncotarget.com and connect with us on social media: Twitter - https://twitter.com/Oncotarget Facebook - https://www.facebook.com/Oncotarget YouTube – www.youtube.com/c/OncotargetYouTube Instagram - https://www.instagram.com/oncotargetjrnl/ LinkedIn - https://www.linkedin.com/company/oncotarget/ Pinterest - https://www.pinterest.com/oncotarget/ LabTube - https://www.labtube.tv/channel/MTY5OA SoundCloud - https://soundcloud.com/oncotarget For media inquiries, please contact: media@impactjournals.com.