Assessment of the safety and feasibility of neoadjuvant chemotherapy (2 cycles of FLOT chemotherapy + chemoradiotherapy) followed by surgery in the treatment of locally advanced gastric cancer

The aim of the study was to analyze of the safety and feasibility of neoadjuvant chemotherapy (2 cycles of FLOT chemotherapy + chemoradiotherapy) followed by surgery in the treatment of locally advanced gastric cancer. Material and Methods. The phase II clinical trial included 47 patients with histologically verified locally advanced gastric cancer (cT3/T4a-b: 26/21 and cN0/N1–3: 20/27) treated at the A.F. Tsyba MRRC from 2018 to 2021. Lesion location was: upper third in 19 patients (esophageal invasion in 9 patients), middle third in 13 patients, lower third in 14 patients, and entire stomach in 1 patient. The tumor grade was G3 in 23 patients, G2 in 13 patients and G1 in 7 patients. Signet ring cell carcinoma was revealed in 4 patients. The patients received 2 cycles of induction chemotherapy with FLOT regimen (85 mg/m2 oxaliplatin + 200 mg/m2 calcium folinate + 50 mg/m2 docetaxel on day 1 + 2600 mg/m2 fluorouracil as 24-hour infusion from day 1; every 2 weeks) followed by 3d-conformal external beam radiotherapy (46 Gy in daily fractions of 2 Gy) combined with chemotherapy with capecitabine and oxaliplatin). The patients then underwent follow-up examination to exclude disease progression and to plan surgery. Postoperative complications were analyzed using the Clavien-dindo classification. Results. Induction chemotherapy followed by concurrent chemoradiotherapy was well tolerated. Forty-five (95.7 %) patients underwent surgery, 97.7 % of them underwent radical surgery. Postoperative complications were observed in 11 (23.4 %) patients. Grade III and more severe complications were observed in 3 (6.4 %) patients. It should be noted that postoperative mortality rate was low, amounting to 2.2 % (1 patient). Conclusion. Induction FLOT polychemotherapy followed by concurrent chemoradiotherapy was shown to be safe, feasible, and tolerable. Moreover, this treatment regimen did not reduce the frequency of R0 surgeries and did not increase incidence and severity of postoperative complications.