Impact of pCR after neoadjuvant chemotherapy and radical D2 dissection in locally advanced gastric cancers: Analysis of 1001 cases

BACKGROUND

Advances in perioperative chemotherapy have improved outcomes in patients with gastric cancers (GC). This strategy leads to tumour downstaging and may result in a pathologic complete response (pCR). The study aimed to evaluate the predictors of pCR and determine the impact of pCR on long-term survival.

METHODS

At the Department of Gastrointestinal and HPB Oncology at the Tata Memorial Centre, Mumbai, 1001 consecutive patients with locally advanced GCs undergoing radical resection following neoadjuvant chemotherapy from January 2005 to June 2022 were included.

RESULTS

At a median follow-up of 61 months, the median OS was 53 months with a 5-year OS of 46.8 %. Ninety-five patients (9.49 %) realized pCR. Non-signet and well-differentiated histology were associated with pCR. pCR was significantly associated with improved OS, 5-year OS 79.2 % vs 43.2 % (HR 0.30, p < 0.001). On multivariable analysis, the realization of pCR and completion of adjuvant chemotherapy had superior OS. Whereas, signet-ring histology, linitis-like tumours, and high lymph node ratio had adverse outcomes.

CONCLUSION

Tumour grade and signet-ring histology predict achievement of pCR in locally advanced GCs after neoadjuvant chemotherapy. Patients with pCR have significantly improved survival. Future neoadjuvant strategies should focus on enhancing pCR rates to improve overall outcomes.

Neoadjuvant chemoradiotherapy plus postoperative adjuvant XELOX chemotherapy versus postoperative adjuvant chemotherapy with XELOX regimen for local advanced gastric cancer-A randomized, controlled study

OBJECTIVE

The aim of this study was to compare the clinical efficacy of neoadjuvant chemoradiotherapy (NACRT) combined with postoperative adjuvant XELOX (Oxaliplatin +Capecitabine) chemotherapy and postoperative adjuvant chemotherapy (ACT) with XELOX for local advanced gastric cancer (LAGC).

METHODS

In this prospectively randomized trial, we investigated the effect of NACRT combined with postoperative ACT for LAGC. 60 patients were randomly divided into NACRT group and ACT group, with 30 patients in each group. Patients in NACRT group were given three-dimensional conformal radiotherapy (45 Gy/1.8 Gy/f) accompanied by synchronous XELOX of two cycles, followed by surgery, and then postoperative adjuvant XELOX chemotherapy of four cycles was performed. Patients in ACT group received surgery in advance, and then XELOX chemotherapy of six cycles was given.

RESULTS

The objective response rate of NACRT was 76.7%. The overall incidence of postoperative complications in NACRT group was not significantly different from that in ACT group (23.1% vs 30.0%, p = 0.560). The 1 year, 2 years, and 3 years progression-free survival (PFS）and overall survival (OS) in NACRT and ACT groups were 80.0% vs 56.7%, 73.3% vs 46.7%, 60.0% vs 33.3%, and 86.7% vs 80.0%, 76.7% vs 66.7%, 63.3% vs 50.0%, respectively. Patients in NACRT group showed a significantly higher R0 resection rate (84.6% vs 56.7%, p = 0.029),lower loco-regional recurrence rate (36.7% vs 11.5%, p = 0.039), longer PFS (p = 0.019) and freedom from locoregional progression(FFLP) (p = 0.004) than patients in ACT group, while there was no difference in OS (p = 0.215) and in toxicity incidence (p > 0.05).

CONCLUSIONS

NACRT combined with postoperative adjuvant XELOX chemotherapy can improve R0 resection rate, reduce loco-regional recurrence, prolong PFS and FFLP without increasing the incidence of postoperative complications in patients with LAGC.

ADVANCES IN KNOWLEDGE

Compared with postoperative adjuvant chemotherapy, locally advanced gastric cancer patients may benefit from neoadjuvant chemoradiotherapy, and toxicity associated with chemoradiotherapy was tolerant and manageable.