Comparison between upfront surgery and neoadjuvant chemotherapy in patients with locally advanced gastric cancer: A systematic review

BACKGROUND: Gastric cancer (GC) is a major health concern worldwide. Surgical resection and chemotherapy is the mainstay treatment for gastric carcinoma, however, the optimal approach remains unclear and should be different in each individual. Chemotherapy can be administered both pre- and postoperatively, but a multidisciplinary approach is preferred when possible. This is particularly relevant for locally advanced GC (LAGC), as neoadjuvant chemotherapy (NAT) could potentially lead to tumor downsizing thus allowing for a complete resection with curative intent. Even though the recent progress has been impressive, European and International guidelines are still controversial, thus attenuating the need for a more standardized approach in the management of locally advanced cancer. AIM: To investigate the effects of NAT on the overall survival (OS), the disease-free survival (DFS), the morbidity and the mortality of patients with LAGC in comparison to upfront surgery (US). METHODS: For this systematic review, a literature search was conducted between November and February 2023 in PubMed, Cochrane Library and clinicaltrials.gov for studies including patients with LAGC. Two independent reviewers conducted the research and extracted the data according to predetermined inclusion and exclusion criteria. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses was used to form the search strategy and the study protocol has been registered in the International Prospective Register of Systematic Reviews. RESULTS: Eighteen studies with 4839 patients with LAGC in total were included in our systematic review. Patients were separated into two groups; one receiving NAT before the gastrectomy (NAT group) and the other undergoing upfront surgery (US group). The OS ranged from 41.6% to 74.2% in the NAT group and from 30.9% to 74% in the US group. The DFS was also longer in the NAT group and reached up to 80% in certain patients. The complications related to the chemotherapy or the surgery ranged from 6.4% to 38.1% in the NAT group and from 5% to 40.5% in the US group. Even though in most of the studies the morbidity was lower in the NAT group, a general conclusion could not be drawn as it seems to depend on multiple factors. Finally, regarding the mortality, the reported rate was higher and up to 5.3% in the US group. CONCLUSION: NAT could be beneficial for patients with LAGC as it leads to better OS and DFS than the US approach with the same or even lower complication rates. However, patients with different clinicopathological features respond differently to chemotherapy, therefore currently the treatment plan should be individualized in order to achieve optimal results.