Analysis of the efficacy and influencing factors of preoperative P‐SOX neoadjuvant chemotherapy regimen for progressive gastric cancer—construction of a clinical prediction model

Preoperative neoadjuvant chemotherapy is one of the most common treatments for patients with advanced gastric cancer that cannot be completely removed by surgery. Nab‐paclitaxel is a nano‐formulation of paclitaxel that has been shown to be effective in treating stomach cancer. In addition, oxaliplatin + S‐1 (SOX) has been a first‐line chemotherapy regimen for gastric cancer, and it has the effect of tumor downstaging, improving the R0 resection rate, and reducing the postoperative recurrence rate, but the side effects are significant. During the application of oxaliplatin, obvious gastrointestinal reactions such as nausea and vomiting can be observed. There may also be blood system side effects such as leukopenia and thrombocytopenia, as well as serious adverse reactions such as peripheral neuropathy. Therefore, we reduced the amount of oxaliplatin in SOX and added nab‐paclitaxel on the basis of this, in order to increase the efficacy while reducing the side effects of SOX regimen. We selected 192 patients with advanced gastric cancer admitted to the Department of Gastrointestinal Oncology of Qinghai University Hospital from July 2019 to February 2022, and all were treated with nab‐paclitaxel plus oxaliplatin + S‐1 neoadjuvant chemotherapy regimen, and underwent further surgery after chemotherapy. The tumor regression grade (TRG grade) and response evaluation criteria of solid tumor 1.1 (RECIST1.1) were taken as the dependent variables. According to TRG classification, 120 patients were effective (grade 0, 1, 2 = 62.50%, age: 55.63 ± 9.02 years), 72 patients were ineffective (grade 3 = 37.50%, 55.82 ± 9.21 years), and the effective rate of chemotherapy was 62.50%. According to RECIST1.1, 116 patients were effective (CR + PR = 60.42%, mean age 55.84 ± 9.02 years), 76 patients were ineffective (SD + PD = 39.58%, 55.47 ± 9.19 years), and the effective rate was 60.42%. The factors p < 0.2 in univariate logistic regression analysis were included in multivariate logistic regression analysis, and p < 0.05 was the statistical difference, and statistically significant factors were screened out for modeling and plotted the nomogram. Among them, in the tumor regression grade, the final factors related to effective chemotherapy are the degree of differentiation, cT. stage, tumor diameter, chemotherapy cycle, and the final factors related to effective chemotherapy in the solid tumor response evaluation criteria are the degree of differentiation, cT. stage, tumor diameter. Therefore, we conclude that the regimen of nab‐paclitaxel combined with oxaliplatin and S‐1 has certain positive significance in the treatment of advanced gastric cancer.