Neoadjuvant docetaxel, oxaliplatin and S-1 therapy for the patients with large type 3 or type 4 gastric cancer (OGSG1902): protocol of a multi-center, phase II study

Therapeutic strategy for scirrhous type gastric cancer

Scirrhous-type gastric cancer (SGC) is a rare but well-recognized subset of resectable gastric cancer (GC), accounting for ⁓10% of cases. Despite its long history of clinical recognition dating back to the pre-1900s, SGC remains one of the most challenging GC subtypes to treat. Traditionally, SGC has been clinically defined as Borrmann type 4 GC, with histological classifications such as signet ring cell carcinoma or diffuse-type histology serving as alternative diagnostic criteria. Therapeutic advancements for SGC have largely focused on locally advanced or oligometastatic disease, yet no SGC-specific treatment has been established. The phase III JCOG0501 trial failed to demonstrate a survival benefit of neoadjuvant S-1 plus cisplatin for Borrmann type 4 and large type 3 GC. Recent developments in biomarker-driven therapies may redefine SGC by molecular subtypes, with CLDN18.2-targeted therapy emerging as a potential option for some SGC cases. However, as the landscape of medical oncology evolves, SGC may not remain a distinct therapeutic entity. The focus should shift toward understanding the intrinsic biology of SGC. Treatment development for SGC is expected to continue advancing, becoming increasingly stratified based on molecular abnormalities while maintaining a commitment to addressing unmet needs, such as early-onset GC and GC with symptomatic peritoneal dissemination.

Neoadjuvant docetaxel, oxaliplatin, and S-1 therapy for patients with large type 3 or type 4 gastric cancer: short-term outcomes of a multicenter, phase II study (OGSG1902)

BACKGROUND

Large type 3 (≥ 8 cm) and type 4 gastric cancers (GCs) have poor prognoses and necessitate multidisciplinary treatment. A multi-institutional phase II study (OGSG1902) was conducted to assess the efficacy and safety of neoadjuvant chemotherapy (NAC) with docetaxel, oxaliplatin, and S-1 (DOS) in these patients.

METHODS

Patients with large type 3 or type 4 GC without distant metastasis, except for positive peritoneal cytology (CY), were enrolled. Patients received three courses of neoadjuvant DOS therapy (docetaxel 40 mg/m2 and oxaliplatin 100 mg/m2 on day 1 via intravenous infusion, and S-1 80 mg/m2 orally for 14 days, repeated every 3 weeks) followed by gastrectomy. After R0 resection, adjuvant docetaxel/S-1 therapy was administered for 1 year.

RESULTS

From October 2019 to February 2022, 48 patients were enrolled. NAC was completed in 91.7% of patients. The R0 resection rate was 89.6%. The pathological response rate (Grade 1b-3) was 66.7%. Among patients with measurable lesions, the response rate was 50.0%. The CY-negative conversion rate was 80.0%, and the protocol completion rate was 45.8%. Grade 3 or 4 adverse events during NAC, including neutropenia and appetite loss, occurred in 37.5% of patients. Major postoperative complications (Clavien-Dindo Grade IIIa or higher) were observed in 2.1% of patients.

CONCLUSIONS

NAC with DOS for large type 3 or type 4 GC followed by gastrectomy demonstrated promising efficacy, high pathological response rates, and an acceptable toxicity profile. Further evaluation of long-term survival outcomes is ongoing.

Therapeutic strategies and prognostic challenges in linitis plastica

Gastric cancer ranks fifth as the most common cancer and third as the leading cause of death worldwide. Risk factors include advancing age, low-fiber diets, high salt intake and Helicobacter pylori infection. Diagnosis relies on histological examination following endoscopic biopsy with staging accomplished through various imaging modalities. Early gastric cancer is primarily managed via endoscopic resection, while non-early operable cases typically undergo surgery. Advanced cases are addressed through sequential chemotherapy lines, with initial treatment usually comprising a platinum and fluoropyrimidine combination. Linitis plastica (LP) is a rare, aggressive form of gastric cancer characterized by diffuse infiltration of the gastric wall, resulting in poor outcomes even after curative resection. The absence of a standardized definition contributes to uncertainty regarding the precise incidence of these tumors. LP is often diagnosed at advanced stages, with a reported median survival rate of approximately 4%-29%, despite "curative resection". Its distinctive biological behavior includes perineural invasion, nodal metastasis, and peritoneal dissemination. The bleak prognosis for LP patients partly stems from delayed diagnosis and its aggressive biological nature, posing significant challenges for clinical management. Currently, no specialized treatment strategy exists for LP, and clinical approaches typically align with those used for general gastric cancer treatment. Surgical resection is the primary treatment, but the optimal surgical approach remains contentious. Recent studies have investigated the efficacy of neoadjuvant chemotherapy and radiotherapy in improving survival outcomes for LP patients. However, controversies persist regarding the role of adjuvant chemotherapy and postoperative radiotherapy. LP requires a multidisciplinary approach and personalized treatment strategies tailored to each patient's condition. Further research is needed to elucidate optimal therapeutic interventions and improve outcomes for LP patients.

Salvage Chemoradiotherapy for Loco-Regional Recurrence of Esophageal Squamous Cell Carcinoma After Esophagectomy

Background/Objectives: Loco-regional recurrence (LRR) of esophageal cancer following esophagectomy presents a significant therapeutic problem. This study aimed to evaluate the effectiveness of salvage concurrent chemoradiotherapy (CCRT) and to identify the prognostic factors influencing the survival outcomes in patients with an LRR of esophageal cancer. Methods: This retrospective study included 68 patients who underwent salvage CCRT for an LRR of esophageal squamous cell carcinoma between April 2008 and June 2024. Patients were treated with either 50.4 Gy in 28 fractions or 60 Gy in 30 fractions, along with concurrent fluoropyrimidine- and platinum-based chemotherapy. Prognostic factors were identified using univariate and multivariate Cox proportional hazards models. Results: The median overall survival (OS) was 30.1 months (95% confidence interval [CI]: 21.5-110.7 months), with a 2-year OS rate of 57.4%. The median progression-free survival (PFS) was 8.9 months (95% CI: 6.3-17.7 months). In the multivariate analysis, the significant prognostic factors for OS included the interval to recurrence (>1 year vs. ≤1 year, hazard ratio [HR] = 2.307, p = 0.024) and radiotherapy dose (60 Gy vs. 50.4 Gy, HR = 2.414, p = 0.040). For PFS, the interval to recurrence and radiotherapy dose remained significant predictors (p < 0.05). The 2-year OS rate was higher in the 60 Gy arm (62.7% vs. 42.0%, p = 0.285) and in patients with recurrence occurring >1 year after surgery (73.4% vs. 29.9%, p = 0.0054). The local control rate at 2 years was 71.9%, with better outcomes observed in the 60 Gy arm (93.5% vs. 76.5%, p = 0.0651). Conclusions: Salvage CCRT is a viable treatment option for LRR of esophageal cancer, achieving favorable survival outcomes, particularly in patients with late recurrence (>1 year) and in those receiving higher radiotherapy doses.

Large Unstained Cells: A Predictive Biomarker for Recurrence and Survival in Resected Gastric Cancer

Background and Objectives: Despite advances in surgery and perioperative chemotherapy, locally advanced gastric cancer continues to pose significant challenges, creating a pressing need for biomarkers capable of predicting therapeutic efficacy and survival outcomes. This study evaluates the prognostic and predictive significance of large unstained cells (LUCs), a morphologically distinct subset of white blood cells identified in peripheral blood that remain unstained by standard hematological dyes, as potential indicators of immune competence and treatment response. Materials and Methods: This retrospective analysis included patients diagnosed with locally advanced gastric cancer (cT2-4, N0-3) at Ankara Bilkent City Hospital between January 2018 and November 2024. Primary endpoints were overall survival (OS) and disease-free survival (DFS), stratified by LUC levels. The secondary endpoint was the association between LUC levels and pathological tumor response. Results: A total of 180 patients were analyzed, with a median age of 59 years; a total of 76% were male. The median follow-up period was 16.5 months, during which OS and DFS rates were 82% and 66%, respectively. Most patients were presented with advanced-stage disease, including T3-T4 tumors (91%) and nodal positivity (81%). Stratification by LUC levels revealed significantly shorter DFS (HR: 2.12; 95% CI: 1.12-4.01; p = 0.020) and OS (HR: 3.37; 95% CI: 1.26-9.03; p = 0.015) in the low-LUC group compared to the high-LUC group. Furthermore, the high-LUC group exhibited a significantly higher tumor shrinkage rate (ypN0: 60% vs. 44%; p = 0.020), although tumor regression scores were similar across groups. Advanced tumor stage and lack of pathological response were strongly associated with reduced DFS and OS, while poorly cohesive carcinoma histology emerged as a predictor of inferior OS. Conclusions: This study demonstrates that elevated LUC levels are significantly associated with improved DFS and OS, as well as enhanced tumor shrinkage, in patients with locally advanced gastric cancer. These findings show the potential of LUCs as a promising biomarker for prognostication and therapeutic stratification in this population, offering a novel avenue for refining clinical decision-making. Further validation through prospective investigations is warranted.

Oncological similarities between large type 3 and type 4 tumors in patients with resectable gastric cancer: a propensity score-matched analysis of a multi-institutional dataset

BACKGROUND

Large type 3 (diameter ≥ 8 cm) and type 4 gastric cancers have been arbitrarily combined in Japan as a single entity. However, whether these two types are oncologically similar remain unclear. This study aimed to clarify this issue.

METHODS

In this retrospective study, we analyzed a database of 3,575 patients from nine institutions who underwent gastrectomy between 2010 and 2014. Using propensity scores to balance significant variables, we compared prognoses and tumor recurrences.

RESULTS

Of patients with clinical T3/T4 who underwent R0 resection, 75 and 73 had large type 3 and 4 tumors, respectively. Patients with type 4 tumors had significantly lower overall survival rates than those of patients with large type 3 tumors (hazard ratio [HR] 1.77; 95% confidence interval [CI] 1.14-2.74). However, among the large type 3 tumors, a remarkable difference in prognosis was observed between the differentiated and undifferentiated histological types. A comparison was made between large type 3 with undifferentiated phenotype and type 4, each with 39 patients after propensity score matching. Outcomes in both groups were similar in terms of overall survival (HR 1.28; 95% CI 0.73-2.25) and relapse-free survival (HR 1.34; 95% CI 0.80-2.27). No statistically significant differences were observed in the incidence of peritoneal recurrence (35.9% vs. 46.1%, P = 0.36) and lymph node recurrence (25.6% vs. 12.8%, P = 0.15).

CONCLUSIONS

Large type 3 tumors with undifferentiated phenotype and type 4 tumors were oncologically similar. This subgroup could be considered as a new entity for future clinical trials.

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.