Late start and insufficient S-1 dose in adjuvant chemotherapy can lead to poor prognosis in stage II/III gastric cancer

Disparities in overall survival of gastric cancer patients after radical gastrectomy: an age and rural-urban residence-based cohort study with propensity score matching analysis

This study estimated overall survival (OS) among gastric cancer patients stratified by age and rural-urban residence after radical gastrectomy. Patients (n = 286) undergoing curative gastrectomy were categorized into four groups based on age (older ≥ 60 years or younger < 60 years) and residence (rural or urban), including rural older (G1), urban older (G2), rural younger (G3) and urban younger (G4) groups. G1 presented with significantly more males, upper stomach cancers and total gastrectomies, while less patients receiving ≥ 4 cycles of adjuvant chemotherapy. The 5-year OS rates were 39.9% for G1, 61.1% for G2, 73.1% for G3, and 71.2% for G4, with a median OS of 47 months in G1 and not reached for other groups. OS was significantly worse in G1 than other groups (P < 0.05). Multivariate Cox regression identified age, type of gastrectomy, adjuvant chemotherapy, perineural invasion, pT category and pN category as independent prognostic factors. After propensity score matching, rural older patients continued to show significantly inferior OS compared to urban older (hazard ratio = 2.269 [1.274-4.042], P = 0.005) and rural younger (hazard ratio = 2.103 [1.116-3.961], P = 0.021) patients. Rural older patients suffered poorer OS after radical gastrectomy, highlighting the need for special attention and comprehensive treatment strategies.

Advantages of adjuvant chemotherapy using S-1 following minimally invasive gastrectomy for gastric cancer versus open surgery: a propensity score-matched analysis

BACKGROUND

It is essential to ensure optimal adherence to adjuvant chemotherapy regimens following gastric cancer surgery. However, treatment intensity for S-1 as adjuvant chemotherapy has not as yet been compared between minimally invasive (MI) and open (Open) surgery.

METHODS

We retrospectively compared dose modification of adjuvant S-1 between MI and Open surgery in patients undergoing R0 gastrectomy for gastric or esophago-gastric junction cancer at the Cancer Institute Hospital Tokyo, Japan, during the period from 2012 to 2022, and receiving S-1 for pStage II or S-1 plus docetaxel for pStage III as adjuvant chemotherapy. Propensity score matching (PSM) was conducted to adjust for possible confounders.

RESULTS

In total, 323 patients were initially included. After PSM, 158 patients remained, 79 in each group. The adjuvant chemotherapy completion rates were similar in the two groups. However, the proportion of patients who required S-1 dose reduction was significantly lower in the MI than in the Open group (43.0% vs. 65.8%, p = 0.004). In addition, the MI group had significantly fewer patients requiring suspension of S-1 than the Open group (46.8% vs. 64.6%, p = 0.025). Moreover, the frequency of adverse events of grade ≥ 3 was significantly lower in the MI than in the Open group (17.7% vs. 31.7%, p = 0.042).

CONCLUSIONS

In adjuvant chemotherapy for gastric cancer, minimally invasive surgery may offer better treatment intensity for oral S-1 administration than open surgery.

Preoperative low skeletal muscle volume can result in insufficient administration of S-1 adjuvant chemotherapy in older patients with stage II/III gastric cancer

BACKGROUND AND PURPOSE

Older patients are more likely to encounter difficulties receiving chemotherapy, but the factors involved in the continuation of chemotherapy in these patients remain unclear. We investigated the importance of muscle mass as a factor involved in delivering a sufficient dose of postoperative S-1 adjuvant chemotherapy (ACT) to older patients with gastric cancer.

METHODS

The subjects of this study were 79 patients aged ≥ 65 years with stage II/III gastric adenocarcinoma, who underwent curative gastrectomy and received S-1 ACT.

RESULTS

The overall median relative dose intensity (RDI) was 75.0% (18.8-93.5%). Patients were divided into two groups for receiver operating characteristic analysis according to the cutoff value. Significantly more patients in the high skeletal muscle index (SMI) group achieved > 62% RDI of S-1 ACT (p = 0.03). Conversely, more patients in the low SMI group suffered from S-1-induced nausea (p = 0.03) and discontinued chemotherapy because of adverse events (p = 0.02). Multivariate analysis identified low SMI as an independent factor for insufficient S-1 dose delivery (p = 0.03, hazard ratio = 2.87).

CONCLUSION

Preoperative SMI is an indicator of the low-dose intensity of S-1 ACT in older patients following curative gastrectomy.

Impact of Laparoscopic Gastrectomy on the Completion Rate of the Perioperative Chemotherapy Regimen in Gastric Cancer: A Swedish Nationwide Study

BACKGROUND

Omission of prescheduled chemotherapy following surgery for gastric cancer is a frequent clinical problem. This study examined whether laparoscopic gastrectomy (LG) had a positive impact on compliance with adjuvant chemotherapy compared with open (OG).

METHODS

Patients with cT2-4aN0-3M0 adenocarcinoma treated with gastrectomy and perioperative chemotherapy between 2015 and 2020 were identified in the Swedish national register. Additional information regarding chemotherapy was retrieved from medical records. Regression models were used to investigate the association between surgical approach and the following outcomes: initiation of adjuvant chemotherapy, modification, and time interval from surgery to start of treatment.

RESULTS

A total of 247 patients were included (121 OG and 126 LG, conversion rate 11%), of which 71.3% had performance status ECOG 0 and 77.7% clinical stage II/III. In total, 86.2% of patients started adjuvant chemotherapy, with no significant difference between the groups (LG 88.1% vs OG 84.3%, p = 0.5). Reduction of chemotherapy occurred in 37.4% of patients and was similar between groups (LG 39.4% vs OG 35.1%, p = 0.6), as was the time interval from surgery. In multivariable analysis, LG was not associated with the probability of starting adjuvant chemotherapy (OR 1.36, p = 0.4) or the need for reduction (OR 1.29, p = 0.4). Conversely, major complications had a significant, negative impact on both outcomes.

CONCLUSIONS

This nationwide study demonstrated a high rate of adjuvant chemotherapy initiation after curative intended surgery for gastric cancer. A beneficial effect of LG compared with OG on the completion rate was not evident.

Prediction of overall survival after radical gastrectomy using nomograms created by tumor markers

Prediction of prognosis after radical resection of gastric cancer has not been well established. Therefore, we aimed to establish a prognostic model based on a new score system of patients with gastric cancer. A total of 1235 patients who underwent curative gastrectomy at our hospital from October 2015 to April 2017 were included in this study. Univariate and multivariate analyses were used to screen for prognostic risk factors. Construction of the nomogram was based on Cox proportional hazard regression models. The construction of the new score models was analyzed by the receiver operating characteristic curve (ROC curve), calibration curve, and decision curve. Multivariate analysis showed that tumor size, T, N, carcinoembryonic antigen, CA125, and CA19-9 were independent prognostic factors. The new score model had a greater AUC (The area under the ROC curve) than other systems, and the C-index of the nomogram was highly reliable for evaluating the survival of patients with gastric cancer. Based on the tumor markers and other clinical indicators, we developed a precise model to predict the prognosis of patients with gastric cancer after radical surgery. This score system can be helpful to both surgeons and patients.

Phase II clinical trial to study the safety and efficacy of combined S-1 + oxaliplatin therapy as neoadjuvant chemotherapy for locally advanced gastric cancer in older patients

BACKGROUND

Gastrectomy with D2 dissection and adjuvant chemotherapy is the standard treatment for locally advanced gastric cancer (LAGC) in Asia. However, administering chemotherapy with sufficient intensity after gastrectomy is challenging. Several trials demonstrated the efficacy of neoadjuvant chemotherapy (NAC). However, limited studies explored the feasibility of NAC-SOX for older patients with LAGC. This phase II study (KSCC1801) evaluated the safety and efficacy of NAC-SOX in patients with LAGC aged ≥ 70 years.

METHODS

Patients received three cycles of SOX130 (oxaliplatin 130 mg/m2 on day 1, oral S-1 40-60 mg twice daily for two weeks every three weeks) as NAC, followed by gastrectomy with lymph node dissection. The primary endpoint was the dose intensity (DI). The secondary endpoints were safety, R0 resection rate, pathological response rate (pRR), overall survival, and relapse-free survival.

RESULTS

The median age of 26 enrolled patients was 74.5 years. The median DI in NAC-SOX130 was 97.2% for S-1 and 98.3% for oxaliplatin. Three cycles of NAC were administered in 25 patients (96.2%), of whom 24 (92.3%) underwent gastrectomy with lymphadenectomy. The R0 resection rate was 92.3% and the pRR (≥ grade 1b) was 62.5%. The major adverse events (≥ grade 3) were neutropenia (20.0%), thrombocytopenia (11.5%), anorexia (11.5%), nausea (7.7%), and hyponatremia (7.7%). Postoperative complications of abdominal infection, elevated blood amylase, and bacteremia occurred in one patient each. Severe diarrhea and dehydration caused one treatment-related death.

CONCLUSIONS

NAC-SOX130 is a feasible therapy for older patients, although systemic management and careful monitoring of adverse events are necessary.

Relative dose intensity and 1-year psoas muscle index reduction rate as prognostic factors in gastric cancer patients with postoperative adjuvant chemotherapy

BACKGROUND

Higher relative dose intensity (RDI) of chemotherapy improves the clinical outcomes of various cancers. The psoas muscle index (PMI) is related to sarcopenia, and patients with low PMI have worse prognoses. However, few studies have demonstrated its clinical relevance in gastric cancer.

METHODS

This retrospective study included 188 stage II/III gastric cancer patients who had undergone curative gastrectomy between January 2013 and March 2017, 124 of whom had received postoperative S-1 adjuvant chemotherapy.

RESULTS

Per receiver operating characteristic analysis, patients were divided into high and low RDI groups, between which relapse-free survival differed marginally significantly and disease-specific survival differed significantly. In patients who received adjuvant chemotherapy, multivariate analysis found that high RDI and low PMI reduction rate 1 year after surgery were significantly associated with better relapse-free survival. Low RDI can be predicted by a combination of low preoperative PMI and non-distal gastrectomy, whereas high PMI reduction rate at 1 year can be affected by non-distal gastrectomy.

CONCLUSION

High RDI with preserved psoas muscle up to 1 year after gastrectomy may be associated with prognoses in gastric cancer requiring postoperative adjuvant chemotherapy. Since RDI and PMI reduction rate can be predicted preoperatively, respectively, interventional consideration is possible for optimal adjuvant therapy in gastric cancer.

Helicobacter pylori modulated host immunity in gastric cancer patients with S-1 adjuvant chemotherapy

BACKGROUND

Paradoxically, Helicobacter pylori-positive (HP+) advanced gastric cancer patients have a better prognosis than those who are HP-negative (HP-). Immunologic and statistical analyses can be used to verify whether systemic mechanisms modulated by HP are involved in this more favorable outcome.

METHODS

A total of 658 advanced gastric cancer patients who underwent gastrectomy were enrolled. HP infection, mismatch repair, programmed death-ligand 1 (PD-L1), and CD4/CD8 proteins, and microsatellite instability were analyzed. Overall survival (OS) and relapse free survival (RFS) rates were analyzed after stratifying clinicopathological factors. Cox proportional hazards regression analysis was performed to identify independent prognostic factors.

RESULTS

Among 491 cases that were analyzed, 175 (36%) and 316 (64%) cases were HP+ and HP⁻, respectively. Analysis of RFS indicated an interaction of HP status among the subgroups for S-1 dose (Pinteraction=0.0487) and PD-L1 (P = .016). HP+ patients in the PD-L1⁻ group had significantly higher five-year OS and RFS than HP- patients (81% vs. 68%; P = .0011; HR 0.477; 95% CI, 0.303-0.751 and 76% vs. 63% P = .0011; HR 0.508; 95% CI, 0.335-0.771, respectively). The five-year OS and RFS was also significantly higher for HP+ compared to HP- patients in the PD-L1-/S-1-reduced group (86% vs. 46%; P = .0014; HR 0.205; 95% CI, 0.07-0.602 and 83% vs. 34%; P = .001; HR 0.190; 95% CI, 0.072-0.498, respectively). Thus, HP status was identified as one of the most potentially important independent factors to predict prolonged survival.

CONCLUSION

This retrospective study suggests that an HP-modulated host immune system may contribute to prolonged survival in the absence of immune escape mechanisms of gastric cancer.

Impact of loss of skeletal muscle mass within 6-12 months after gastrectomy and S1 adjuvant chemotherapy on the survival prognosis of elderly patients with gastric cancer

BACKGROUND AND PURPOSE

We investigated the impact of postoperative changes in the psoas muscle mass index (PMI) after gastrectomy and S1 adjuvant chemotherapy (AC) on the long-term outcomes of elderly patients with gastric cancer.

METHODS

We reviewed the medical records of 228 patients aged over 75 years, who underwent distal, proximal, or total gastrectomy between January, 2013 and March 2017. Among these patients, 78 with pStage IIA-IIIC who survived for at least 1 year without recurrence after gastrectomy were the subjects of this analysis.

RESULTS

The log-rank test using the cut-off value from the rate of change in PMI from 6 to 12 months after gastrectomy (late rate of decrease) showed significantly poorer prognosis for the group above the cut-off value for both overall survival (OS) and recurrence-free survival (RFS) (RFS: PMI decrease ≥ 1.55%, p < 0.001; OS: PMI decrease ≥ 1.55%, p < 0.001). Patients with a relative dose intensity of S1 below 68.7% and a late rate of decrease in PMI above 1.55% were found to have a poor prognosis.

CONCLUSION

It is necessary to prevent decline in the PMI of elderly patients from 6 months after gastrectomy and to administer adjuvant chemotherapy with about two-thirds or more RDI of S1 to improve their survival prognosis.

Clinical impact of postoperative interval until adjuvant chemotherapy following curative gastrectomy for advanced gastric cancer

Background: Adjuvant chemotherapy (AC) following curative gastrectomy for stage II/III gastric cancer (GC) is recommended in Japan. However, for various reasons, patients cannot always start AC at the appropriate time. This study was designed to investigate the effect of the postoperative interval until adjuvant chemotherapy (PIAC) and cumulative S-1 dose on prognosis.

Methods: Between 2008 and 2014, consecutive 81 GC patients who underwent postoperative S-1 monotherapy were enrolled in this study.

Results: Postoperative complications of Clavien-Dindo grade II or higher and postoperative peak C-reactive protein of 8.1 mg/dl or higher were significantly associated with delayed AC. The cut-off value of PIAC selected to most effectively stratify prognosis was 7 weeks. For relapse-free survival (RFS), patients with PIAC ≥ 7 weeks had an insignificantly poorer prognosis than those with PIAC < 7 weeks. A multivariate analysis showed that PIAC ≥ 7 weeks [p = 0.024; hazard ratio (HR) 2.45] and the cumulative S-1 dose/body surface area (BSA) ≥ 12,000 mg/m² [p = 0.004; HR 3.27] were independent prognostic factors. In patients with the cumulative S-1 dose/BSA ≥ 12,000 mg/m², there were no prognostic differences between patients with and without PIAC ≥ 7 weeks.

Conclusions: Seven weeks after surgery could be a limit indicator starting AC. A cumulative S-1 dose/BSA of more than 12,000 mg/m² might be a key dose for diminishing the poor prognostic effects of delaying AC.

Comparison of gemcitabine-based chemotherapies for advanced biliary tract cancers by renal function: an exploratory analysis of JCOG1113

JCOG1113 is a randomized phase III trial in patients with advanced biliary tract cancers (BTCs) (UMIN000001685), and gemcitabine plus S-1 (GS) was not inferior to gemcitabine plus cisplatin (GC). However, poor renal function often results in high toxicity of S-1. Therefore, we examined whether GS can be recommended for patients with low creatinine clearance (CCr). Renal function was classified by CCr as calculated by the Cockcroft-Gault formula: high CCr (CCr ≥ 80 ml/min) and low CCr (80 > CCr ≥ 50 ml/min). Of 354 patients, 87 patients on GC and 91 on GS were included in the low CCr group, while there were 88 patients on GC and 88 patients on GS in the high CCr group. The HR of overall survival for GS compared with GC was 0.687 (95% CI 0.504–0.937) in the low CCr group. Although the total number of incidences of all Grade 3–4 non-haematological adverse reactions was higher (36.0% vs. 11.8%, p = 0.0002), the number of patients who discontinued treatment was not different (14.1% vs. 16.9%, p = 0.679) for GS compared with GC in the low CCr group. This study suggests that GS should be selected for the treatment of advanced BTC patients with reduced renal function.

Real-World Therapeutic Outcomes of S-1 Adjuvant Chemotherapy for pStage II/III Gastric Cancer in the Elderly

BACKGROUND

The predictive factors for discontinuation of S-1 administration and prognostic factors in elderly patients with pStage II/III gastric cancer receiving S-1 adjuvant chemotherapy remain unclear.

METHODS

Between January 2004 and December 2016, 80 elderly gastric cancer patients (≥70 years) undergoing curative D2 gastrectomy were enrolled in this study. Predictive factors for completion of S-1 administration over 1 year, adverse events due to S-1 administration, and prognostic factors for overall survival (OS) and relapse-free survival (RFS) were evaluated.

RESULTS

Twenty-eight patients (35%) completed 8 courses of S-1. The median relative dose intensity was 82.1% (IQR 31.1-100%). The incidence rates of hematological and nonhematological adverse events were acceptable. Distal gastrectomy was an independent predictive factor for completion of S-1 administration (odds ratio [OR] 0.364; 95% confidence interval [CI] 0.141-0.939; p = 0.037). Higher postoperative neutrophil count/lymphocyte count (N/L) ratio and more advanced stage adversely influenced OS. Multivariate analysis revealed that a higher postoperative N/L ratio and more advanced stage adversely affected RFS.

CONCLUSION

To complete adjuvant S-1 administration to elderly patients with pStage II/III gastric cancer, total gastrectomy should be avoided if possible. A new regimen for elderly gastric cancer patients with higher postoperative N/L ratios and more advanced stage should be established.

The efficacy and toxicity of adjuvant S-1 schedule with 2-week administration followed by 1-week rest in gastric cancer patients

Background

This study aimed to investigate the clinical outcome of adjuvant S-1 with 2-week administration followed by a 1-week rest for locally advanced gastric cancer (GC) patients.

Methods

The current study was a single retrospective cohort study that focused on the efficacy and toxicity of adjuvant S-1 with a 3-week schedule. A total of 60 patients who underwent total or subtotal gastrectomy plus D2 lymph node dissection and adjuvant S-1 treatment were identified. S-1 treatment began within 4 weeks after the operation; it was administered orally for 2 weeks, followed by a 1-week rest. The dose of S-1 was adjusted depending on adverse events (AEs), with at least 80 mg administered daily. The completion of 1-year S-1 was defined as S-1 continuation for 1 year with over 70% of the planned dose. Patients were followed up with for 5 years postoperatively and underwent hematologic tests and assessments of clinical symptoms every 3-6 weeks for 1 year after surgery. Computed tomography of the abdomen and panendoscopy were performed every 6 months during the first 2 years and at 1-year intervals thereafter until year 5 after surgery.

Results

The completion rate of 1-year adjuvant S-1 was 71.7%, and the 3-year disease-free survival and overall survival rates were 70.2% and 79.5%, respectively. Seventeen patients did not complete S-1 for 1 year, including 11 patients with tumor recurrence and 6 patients who developed intolerance. Most AEs of S-1 were grade 1-2, and the most frequent AEs (>20%) included anemia, fatigue, pigmentation, nausea, and diarrhea. The most common grade 3-4 AE was fatigue, which was observed in 6.7% of patients. Most patients tolerated the side effects.

Conclusions

The results of our study confirm that the efficacy and safety of schedule modification of adjuvant S-1 treatment in patients with GC who underwent gastrectomy with D2 lymph node dissection are equal to those in a previous phase 3 study.

Impact of postoperative infectious complications on adjuvant chemotherapy administration after gastrectomy for advanced gastric cancer

BACKGROUND

The aim of this study was to investigate the impact of postoperative infectious complications on adjuvant chemotherapy administration in patients with gastric cancer.

METHODS

A retrospective review of 308 patients who underwent curative resection for gastric cancer was performed. Patients were divided into two groups based on the presence (90 patients, 29.2%) or absence (218 patients, 70.8%) of postoperative infectious complications to analyze clinicopathological characteristics, treatment factors and survival.

RESULTS

Fewer patients with postoperative infectious complication received adjuvant chemotherapy compared to those without postoperative infectious complication. The proportion of patients who started treatment within 6 weeks after surgery was significantly lower in patients with postoperative infectious complication. The treatment completion rate was significantly lower in patients with postoperative infectious complication. The number of treatment cycles and relative dose intensity was significantly lower in patients with postoperative infectious complication. In univariate analysis, only postoperative infectious complication was significantly associated with continuation of adjuvant chemotherapy. Multivariate analysis demonstrated tumor depth, nodal involvement, postoperative infectious complication and adjuvant chemotherapy were significantly associated with overall survival.

CONCLUSION

Postoperative infectious complications are significantly associated with the delay of adjuvant chemotherapy and predict adverse clinical outcome in patients with gastric cancer.

Comparison of 2- and 4-week S-1 administration as adjuvant chemotherapy for advanced gastric cancer

BACKGROUND

A 4-week administration of tegafur/gimeracil/oteracil (S-1) followed by a 2-week rest is the standard adjuvant chemotherapy for surgically resected advanced gastric cancer. This study aimed to evaluate the oncological feasibility of a 2-week S-1 administration followed by a 1-week rest, which is frequently applied in clinical practice to reduce toxicity and improve drug adherence.

METHODS

We retrospectively enrolled patients with stage II/III gastric cancer who received S-1 adjuvant chemotherapy following radical gastrectomy from 2006 to 2016 in three institutions. Two-week and 4-week regimen cohorts were compared for relative dose intensity (RDI) as a primary outcome, and treatment completion rate, adverse event incidence, overall survival (OS), and relapse-free survival (RFS) as secondary outcomes. Confounders were adjusted for using propensity score matching (PSM).

RESULTS

One hundred and thirty-four patients received the 2-week regimen and 121 patients received the 4-week regimen. Ninety-five patients were extracted from each group after PSM. The RDIs of S-1 in the 2-week and 4-week cohorts were 73.5 and 69.9%, respectively (p = 0.35), which were not significantly different. The treatment completion rate (54.7 vs. 53.7%, p = 1.0), incidence of grade ≥3 adverse events (7.4 vs. 12.6%, p = 0.33), 3-year OS (76.4 vs. 82.7%, p = 0.78), and 3-year RFS (71.3 vs. 73.4%, p = 0.70) did not significantly differ between both cohorts.

CONCLUSIONS

The 2-week S-1 adjuvant chemotherapy could not improve drug adherence in terms of RDI, but its relapse rates were not significantly different compared with those of the 4-week regimen. The 2-week regimen might be considered as an option depending on the patient's status.