Determinants of clinical outcomes of gastric cancer patients treated with neoadjuvant chemotherapy: a sub-analysis of the PRODIGY study

Timing of postoperative chemotherapy and prognosis in neoadjuvant-treated gastric cancer patients: a multicenter real-world cohort study

BACKGROUND

The optimal time to chemotherapy (TTC) in locally advanced gastric cancer (LAGC) patients treated with neoadjuvant chemotherapy (NLAGC) remains unclear.

METHODS

Consecutive 524 patients with NLAGC between Jan. 2010 and Dec. 2022 were identified. Patients were categorized into three groups: TTC < 6w, 6w ≤ TTC ≤ 8w, and TTC > 8w. Survival analysis was conducted using the Cox proportional hazards model to assess the impact of TTC on gastric cancer-specific mortality (GCSM) and all-cause mortality (ACM). Cumulative competing risk curves were employed to evaluate the incidence of competing events.

RESULTS

Overall, 451 patients were included.Cumulative competing risk curves showed that the 3-year ACM and GCSM were significantly lower in the 6w ≤ TTC ≤ 8w group (ACM: 19.7% vs. 37.2% vs. 39.7%, GCSM: 19.7% vs. 35.2% vs. 38.8%) compared to the TTC < 6w and TTC > 8w groups. Compared to patients with 6w ≤ TTC ≤ 8w, those with TTC < 6w or >8w had an increased risk of GCSM (HR: 2.792 and HR: 2.343, respectively) and ACM (HR: 3.102 and HR: 2.719, respectively) after adjusting for confounders. Furthermore, 6w ≤ TTC ≤ 8w had later peak recurrence compared to TTC < 6w and TTC > 8w (Peak months: 9.7 vs. 4.3 vs. 3.1).

CONCLUSION

A postoperative chemotherapy timing of 6-8 weeks was associated with better survival and delayed recurrence in NLAGC patients. These findings suggest that the 6-8 week time-window should be a key timeframe for personalized postoperative adjuvant chemotherapy decisions.

Longitudinal CT Radiomics to Predict Progression-free Survival in Patients with Locally Advanced Gastric Cancer After Neoadjuvant Chemotherapy

RATIONALE AND OBJECTIVES

To develop and validate a radiomics signature, utilizing baseline and restaging CT, for preoperatively predicting progression-free survival (PFS) after neoadjuvant chemotherapy (NAC) in locally advanced gastric cancer (LAGC).

METHODS

A total of 316 patients with LAGC who received NAC followed by gastrectomy were retrospectively included in this single-center study; these patients were split into two cohorts, one for training (n = 243) and the other for validation (n = 73), based on the different districts of our hospital. A total of 1316 radiomics features were extracted from the volume of interest of the gastric-cancer lesion on venous phase CT images. Four radiomics signatures were built for predicting PFS based on baseline CT (Pre-Rad), restaging CT (Post-Rad), delta radiomics (Delta-Rad) and multi-time radiomics (PrePost-Rad), respectively. Then the PrePost-Rad was combined with clinical factors to establish a nomogram (Rad-clinical model). Kaplan-Meier survival curves with log-rank tests were used to assess the prognostic usefulness of the Rad-clinical model.

RESULTS

All baseline characteristics were not statistically different between the two cohorts. The PrePost-Rad achieved improved predictive value by a C-index of 0.724 (95% CI: 0.639-0.809) in the validation cohort [Pre-Rad: 0.715 (0.632-0.798); Post-Rad: 0.632 (0.538-0.725), Delta-Rad: 0.549 (0.447-0.651)]. In terms of clinical benefit, calibration capability, and prediction efficacy, the Rad-clinical model performed well for PFS prediction, with a C-index of 0.754 (95% CI: 0.707-0.800) and 0.719 (95% CI: 0.639-0.800) in the training and validation cohorts, respectively, superior to the clinical model (cN stage and CA199) but comparable to the PrePost-Rad. Moreover, the Rad-clinical model could accurately classify gastric-cancer patients after NAC into three PFS risk groups in both training and validation cohorts. The risk stratification also performed well in most subgroups (good responders, poor responders, ypTNM Ⅱ, and ypTNM Ⅲ/Ⅳ).

CONCLUSIONS

The Rad-clinical model integrating longitudinal radiomics score and clinical factors performed well in preoperatively predicting PFS of LAGC patients after NAC and surgery.

Evaluation of the efficacy and safety of toripalimab combination therapy for treatment of advanced gastric cancer: a meta-analysis

BACKGROUND

To systematically evaluate the efficacy and safety of combination therapy with toripalimab in the treatment of advanced gastric cancer (GC).

METHODS

We conducted a thorough search for relevant studies in PubMed, Embase, Cochrane Library, and Web of Science. Effect estimates were computed utilizing Stata software (version 14.0) and either random or fixed effects models, as applicable. A subgroup analysis was undertaken to assess the effect of various combination therapies on overall response rate (ORR). Begg and Egger's tests were employed to assess publication bias.

RESULTS

The study consisted of 8 trials, which included 277 participants with advanced gastric cancer. The overall ORR was 41.4% (95% CI, 32.4%-50.3%), with a disease control rate (DCR) of 83.6% (95% CI, 74.6%-92.7%), a median overall survival (mOS) of 11.0 months (95% CI, 9.6-12.4), and a median progression-free survival (mPFS) of 4.2 months (95% CI, 2.5-6.0) for the combination therapy with toripalimab. Subgroup analysis revealed that the combination of toripalimab and chemotherapy achieved a greater ORR compared to the non-chemotherapy group, with ORR rates of 49.8% (95% CI, 42.2%-57.4%) and 31.9% (95% CI, 26.7%-37.1%), respectively. The combination therapy with toripalimab led to adverse events (AEs) of any grade at 94.0% of cases (95% CI, 89.5%-98.5%) and grade 3 AEs at 32.4% (95% CI, 17.8%-47.1%). The sensitivity analysis indicated that no single study affected the overall results.

CONCLUSIONS

Combination therapy of toripalimab can improve clinical efficacy, although with increased but manageable toxicity. Additional clinical trials are required to assess comprehensively the efficacy and safety of alternative toripalimab regimens. The review agreement has been recorded with PROSPERO (CRD42024585696).

Phase 2 study of neoadjuvant durvalumab plus docetaxel, oxaliplatin, and S-1 with surgery and adjuvant durvalumab plus S-1 for resectable locally advanced gastric cancer

BACKGROUND

Based on the phase 3 PRODIGY study, neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) have emerged as a viable treatment option for Asian patients with resectable locally advanced gastric cancer (LAGC). This phase 2 study evaluated the efficacy and safety of combining neoadjuvant durvalumab with DOS, followed by surgery and adjuvant durvalumab plus S-1 chemotherapy, for resectable LAGC.

METHODS

Patients with LAGC with cT2/3N+or cT4Nany tumors were enrolled in this study. Patients with proficient mismatch repair protein (pMMR) tumors received three cycles of neoadjuvant durvalumab plus DOS, administered every 3 weeks, followed by surgery and adjuvant S-1 plus durvalumab (main study arm). The primary endpoints were the rate of pathologic complete regression (pCR) and safety. An exploratory arm evaluated patients with deficient mismatch repair protein (dMMR) tumors, who received three cycles of neoadjuvant durvalumab and tremelimumab, followed by surgery and adjuvant durvalumab.

RESULTS

In the main study arm, 50 pMMR patients were enrolled, and received at least one dose of neoadjuvant treatment. The median age was 63 years, with 72.0% being men. 18 and 32 patients presented with clinical stage II and III tumors, respectively. 49 (98.0%) underwent surgery, with 45 achieving R0 resection. A pCR rate of 30.0% was observed, meeting the prespecified primary efficacy endpoint. With a median follow-up of 21.8 months, the 3-year progression-free survival and overall survival rates were 69.9% and 88.1%, respectively. 10% of patients experienced predefined unacceptable severe toxicities, including febrile neutropenia (n=3) and persistent G4 neutropenia (n=2) lasting more than 7 days, thereby meeting the primary safety endpoint. Nine patients with dMMR tumors were enrolled in the exploratory arm. All nine underwent surgery, with a pCR rate of 22.2%.

CONCLUSIONS

This study met its primary efficacy and safety endpoints. The combination of neoadjuvant durvalumab plus DOS, followed by surgery and adjuvant durvalumab plus S-1 chemotherapy, warrants further investigation in a phase 3 trial for Asian patients with LAGC.

CLINICAL TRIAL INFORMATION

04221555.

Adjuvant treatment for locally advanced gastric cancer: an Asian perspective

Standard adjuvant treatment for locally advanced gastric cancer (LAGC) is regionally different. Whereas perioperative chemotherapy is the standard in Western populations, D2 gastrectomy followed by adjuvant chemotherapy has been the standard in East Asia. Recently, the pivotal phase 3 PRODIGY and RESOLVE studies have demonstrated survival benefits of adding neoadjuvant chemotherapy to surgery followed by adjuvant chemotherapy over up-front surgery followed by adjuvant chemotherapy in Asian patients. Based on these results, neoadjuvant chemotherapy is considered one of the viable options for patients with LAGC. In this review, various aspects of neoadjuvant chemotherapy will be discussed for its optimal application in Asia. Candidates for neoadjuvant chemotherapy should be carefully chosen in consideration of the inaccurate aspects of radiological clinical staging and its potential benefit over up-front surgery followed by a decision on adjuvant chemotherapy according to the pathological stage. Efforts should continuously be made to optimally apply neoadjuvant chemotherapy to patients with LAGC, considering various factors, including a more accurate radiological assessment of the tumor burden and the optimization of post-operative chemotherapy. Future neoadjuvant trials involving novel agents for Asian patients should be designed based on proven Asian regimens rather than adopting Western regimens.

DNA mismatch repair deficiency and outcomes of patients with locally advanced gastric cancer treated with preoperative docetaxel, oxaliplatin, and S-1 plus surgery and postoperative S-1 or surgery plus postoperative S-1: a sub-analysis of the phase 3 PRODIGY trial

BACKGROUND

The benefit of adjuvant chemotherapy for locally advanced gastric cancer (LAGC) patients with DNA mismatch repair (MMR) deficiency (D-MMR) is controversial due to concerns about its potential detrimental effect. The PRODIGY trial showed the survival benefit of adding preoperative docetaxel, oxaliplatin, and S-1 (DOS) to surgery plus postoperative S-1 for LAGC patients. In this sub-analysis, we evaluated the benefit of preoperative DOS according to MMR status.

METHODS

Among patients enrolled in the PRODIGY trial treated with either preoperative DOS followed by surgery and postoperative S-1 (CSC arm), or surgery and postoperative S-1 (SC arm) at Asan Medical Center (n = 249), those in the full analysis set with available tissue to assess MMR status were included in the present analysis.

RESULTS

A total of 231 patients (CSC arm, n = 108; SC arm, n = 123) were included (median age, 58 years [range, 27-75]), and 21 patients (CSC arm, n = 8 [7.4%]; SC arm, n = 13 [10.6%]) had D-MMR tumors. Progression-free survival and overall survival tended to be superior in the CSC arm than in the SC arm among D-MMR patients (HR 0.48 [95% CI 0.09-2.50]; log-rank P = 0.37 and HR 0.55 [95% CI 0.11-2.86]; log-rank P = 0.46, respectively), as well as among proficient MMR (P-MMR) patients (HR 0.68 [95% CI 0.46-1.03]; log-rank P = 0.07 and HR 0.75 [95% CI 0.49-1.14]; log-rank P = 0.17, respectively).

CONCLUSION

Preoperative DOS followed by surgery and postoperative S-1 may be considered a treatment option for LAGC patients regardless of MMR status.

Effect of neoadjuvant chemotherapy combined with arterial chemoembolization on short-term clinical outcome of locally advanced gastric cancer

BACKGROUND

The purpose of this study was to explore the short-term efficacy and safety of neoadjuvant chemotherapy combined with arterial chemoembolization for locally advanced gastric cancer (LAGC).

METHODS

We retrospectively analyzed the clinical data of 203 patients with LAGC who received neoadjuvant therapy from June 2019 to December 2021. The patients were divided into a neoadjuvant chemotherapy combined with arterial chemoembolization group (combined group, n = 102) and a neoadjuvant chemotherapy group (conventional group, n = 101). The adverse events of chemotherapy, postoperative complications and pathological complete response (pCR) rate were compared between the two groups. Univariate and multivariate analyses were performed to evaluate the potential factors affecting pCR.

RESULTS

A total of 78.8% of the patients were in clinical stage III before neoadjuvant therapy. A total of 52.2% of the patients underwent surgery after receiving two cycles of neoadjuvant therapy. There were 21.2% patients with ≥ grade 3 (CTCAE 4.0) adverse events of chemotherapy and 11.3% patients with Clavien-Dindo classification ≥ grade 3 postoperative complications. Compared with the conventional group, the combination group did not experience an increase in the adverse events of chemotherapy or postoperative complications. The pCR rate in the combined group was significantly higher than that in the conventional group (16.7% vs. 4.95%, P = 0.012). The multivariate analysis showed that arterial chemoembolization, pre-treatment neutrophil-to-lymphocyte ratio (NLR) and pre-treatment platelet-to-lymphocyte ratio (PLR) were independent factors affecting pCR.

CONCLUSION

Neoadjuvant chemotherapy combined with arterial chemoembolization contributed to improving the pCR rate of LAGC patients. Arterial chemoembolization, pre-treatment NLR and pre-treatment PLR were also predictors of pCR.