en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background:</span></span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">This study examines the clinicopathological characteristics, recurrence patterns, and survival outcomes of early-onset gastric cancer (EOGC) patients treated with radiotherapy, comparing them with non-early-onset gastric cancer (NEOGC) patients to evaluate prognostic differences and the effectiveness of radiotherapy-based treatments. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Materials and Methods: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">A retrospective cohort study was conducted using the Surveillance, Epidemiology, and End Results (SEER) database (2010-2015), analyzing 814 EOGC and 4,997 NEOGC patients who underwent radiotherapy. Descriptive statistics characterized clinical and pathological features. Kaplan-Meier survival analysis and log-rank tests compared overall survival (OS). Cox proportional hazards regression models identified independent prognostic factors. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Results: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">EOGC patients showed a higher proportion of females (42.3%) and advanced-stage disease (44.3%) compared to NEOGC. Signet-ring cell carcinoma was more prevalent in EOGC (26.8% vs. 14.7%, P < 0.001). Tumors in EOGC were predominantly located in the gastric body, fundus, and greater curvature (P < 0.001). Adjuvant radiotherapy was more common in EOGC (78.9% vs. 68.3%, P < 0.001). Survival analysis indicated that radiotherapy alone provided superior OS compared to combined chemoradiotherapy or surgery-radiotherapy approaches. Cox regression identified tumor stage, histological subtype, and radiotherapy modality as key prognostic factors. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Conclusion: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">EOGC treated with radiotherapy exhibits distinct clinicopathological features, including more aggressive histological subtypes. Radiotherapy as monotherapy offers better long-term survival than multimodal treatments. These findings underscore the need for personalized radiotherapy strategies to optimize prognosis in EOGC.</span></span></span></span></span></span></span></span></span></div> Early-onset gastric cancer, stomach neoplasms, radiotherapy, prognosis, survival analysis. 619 625 http://ijrr.com/browse.php?a_code=A-10-1-1552&slc_lang=en&sid=1 X. Kang 7900319475328460034131 7900319475328460034131 No Baotou Medical College, Inner Mongolia University of Science & Technology, Baotou, 014000, China X. Meng 7900319475328460034132 7900319475328460034132 No Department of Gastroenterology, Second Affiliated Hospital of Baotou Medical College, Baotou, 014000, China G. Guo 7900319475328460034133 7900319475328460034133 No Interventional Department, Second Affiliated Hospital of Baotou Medical College, Baotou, 014000, China Y. Nian nianyuanyuannina@163.com 7900319475328460034134 7900319475328460034134 Yes Department of Gastroenterology, Second Affiliated Hospital of Baotou Medical College, Baotou, 014000, China