Overtreatment of Younger Adults with Gastric Cancer: More Chemotherapy Use with Unmatched Survival Gains

Abstract

Treatment options for young patients with gastric cancer (GC) remain poorly defined and their effects on prognosis are unclear. To investigate receipt of chemotherapy by age category (18-49, 50-64, and 65-85 years) and assess whether age differences in chemotherapy matched survival gains among patients with GC. Data were obtained from a Chinese multi-institutional database and the US SEER database. There were 5122 and 31363 patients aged 18 to 85 years treated between 2000 and 2014, respectively. The primary outcome measure was overall survival of patients who only received surgery and those who received both surgery and chemotherapy. The secondary outcome measure was stage-specific likelihood of receiving postoperative chemotherapy. Of the 5122 and 31363 patients in China and SEER datasets, 3489 (68.1%) and 18115 (57.8%) were men, respectively. Younger (18-49 years) and middle-aged (50-64 years) patients were more likely to receive chemotherapy compared with older patients (65-85 years) across all tumor stages. Among patients treated with surgery alone, a significantly better survival was observed for younger and middle-aged patients than their older counterparts, however, no significant differences were observed in survival between age groups among patients who received surgery and chemotherapy, especially in China dataset. The survival benefit from chemotherapy was superior among older patients (all P < 0.0001 for interaction) than among younger and middle-aged patients in stage II and III disease. We found potential overuse of chemotherapy among younger and middle-aged adults, but the addition of chemotherapy did not result in matched survival improvement. Funding: This work was supported by grants from: National Natural Science Foundation of China 81672446, 81600510, 81370575, 81570593. The National Key Research and Development Program of China 2017YFC0108300. Natural Science Foundation of Guangdong Province, 2014A030313131. Science and Technology Planning Project of Guangzhou, 2014B020228003, 2014B030301041, 2015A030312013. Key Clinical Specialty Discipline Construction Program. Director’s Foundation of Nanfang Hospital, 2016B010. Declaration of Interest: None of the authors had any potential conflicts of interest, including relevant financial interests, activities, relationships, and affiliations. Ethical Approval: The institutional review boards at Nanfang Hospital of Southern Medical University, First Affiliated Hospital of Sun Yat-sen University, and Sun Yat-sen University Cancer Center approved the retrospective analysis of anonymous data and waived the need to obtain patient informed consent.