Survival Outcomes of Two Phase 2 Studies of Adjuvant Chemotherapy with S-1 Plus Oxaliplatin or Capecitabine Plus Oxaliplatin for Patients with Gastric Cancer After D2 Gastrectomy

Short-term outcomes of a phase II trial of perioperative capecitabine plus oxaliplatin therapy for advanced gastric cancer with extensive lymph node metastases (OGSG1701)

BACKGROUND

The prognosis of advanced gastric cancer (GC) with extensive lymph node (LN) metastasis treated with surgery alone remains poor. We conducted a multicenter phase II study to evaluate the efficacy and safety of perioperative capecitabine plus oxaliplatin (CapeOx) therapy in patients with advanced GC with extensive LN metastases.

PATIENTS AND METHODS

Patients with histologically proven HER2-negative or unknown gastric adenocarcinoma with paraaortic LN (PALN) metastases and/or bulky LN metastases located at the celiac axis, common hepatic artery, and/or splenic artery were included in the study. Patients received three cycles of preoperative CapeOx every 3 weeks, followed by five cycles of postoperative CapeOx after gastrectomy with D2 or D2 + including PALN dissection. The primary endpoint was the response rate (RR) according to the RECIST v1.0 criteria.

RESULTS

Thirty patients from 14 institutions were enrolled from September 2017 to June 2022. Complete response, partial response, stable disease, and progressive disease occurred in zero, 20, eight, and one patient, respectively. One patient was not evaluated. The RR was 66.7% (90% confidence interval, 50.1-80.7%; one-sided P = 0.049). The preoperative chemotherapy completion rate and the curative resection rate were 96.7% and 93.3%, respectively. The minor (grade ≥ 1b) pathological RR was 66.7%. Grade 3 adverse events of preoperative chemotherapy included neutropenia in 3.3%, anemia in 6.7%, and anorexia in 10.0%. One treatment-related death occurred due to postoperative complications.

CONCLUSION

Preoperative CapeOx chemotherapy showed a favorable RR, curative resection rate, and acceptable adverse events in patients with advanced GC with extensive LN metastasis.

REGISTRATION NUMBER

UMIN000028749 and jRCTs051180186.

Comparison of SOX and CAPOX in patients with advanced gastric cancer after laparoscopic D2 gastrectomy: A randomized controlled trial

BACKGROUND

Optimal adjuvant chemotherapy after laparoscopic surgery in gastric cancer (GC) patients is still undefined. We aimed to evaluate the efficacy of S-1 plus oxaliplatin (SOX) and capecitabine plus oxaliplatin (CAPOX) in patients with GC after laparoscopic gastrectomy.

METHODS

A non-inferiority randomized controlled clinical trial was performed in China. Patients with advanced GC who underwent laparoscopic D2 gastrectomy were randomly assigned to receive SOX and CAPOX regimens.

RESULTS

In total, 191 patients were screened between May 2018 and June 2019, and 140 (73.3%) were included in the modified intent-to-treat analysis (mITT), of whom 69 and 71 were assigned to the SOX and CAPOX groups, respectively. The SOX group had similar 3-year overall survival (OS) and disease-free survival to the CAPOX group. Subgroup analysis revealed significantly better OS in the SOX group for male patients ([HR] = 0.395; 95% [CI], 0.153-1.019; p = 0.045), age >60 (HR = 0.219; 95% [CI], 0.064-0.753; p = 0.016), tumors in the gastric antrum (HR = 0.273; 95% [CI], 0.076-0.981; p = 0.047), and moderately differentiated tumors (HR = 0.338; 95% [CI], 0.110-1.041; p = 0.041). There were no significant differences observed in terms of adverse events and recurrence patterns between the two groups.

CONCLUSION

Adjuvant SOX was non-inferior to CAPOX treatments for patients with GC who underwent curative laparoscopic D2 gastrectomy. For male patients, aged >60 years, tumors in the gastric antrum, and moderately differentiated tumors, adjuvant SOX may achieve an improvement compared with CAPOX.

Risk factors for early recurrence after radical gastrectomy followed by adjuvant chemotherapy for stage II or III gastric cancer: a multicenter, retrospective study

BACKGROUND

Radical gastrectomy followed by adjuvant chemotherapy is the standard treatment for stage II or III gastric cancer in Asian countries. Early recurrence during or after adjuvant chemotherapy is associated with poor prognosis; however, risk factors for early recurrence remain unclear.

METHODS

In this multicenter, retrospective cohort study including six institutions, we evaluated the clinicopathological factors of 553 patients with gastric cancer undergoing gastrectomy followed by adjuvant chemotherapy between 2012 and 2016. Patients were divided into the following groups: early recurrence (recurrence during adjuvant chemotherapy or within 6 months after adjuvant chemotherapy completion) and non-early recurrence, which was further divided into late recurrence and no recurrence. Early-recurrence risk factors were investigated using multivariate Cox proportional hazard model. The chronological changes in the recurrence hazard were also examined for each factor.

RESULTS

Early recurrence and late recurrence occurred in 83 (15.0%) and 73 (13.2%) patients, respectively. Based on the Cox proportional hazards model, a postoperative serum carcinoembryonic antigen level of ≥5 ng/mL (hazard ratio: 2.220, 95% confidence interval: 1.089-4.526) and a neutrophil-to-lymphocyte ratio of >1.8 (hazard ratio: 2.408, 95% confidence interval: 1.479-3.92) were identified as independent risk factors of early recurrence, but not late recurrence. The recurrence hazard ratios for neutrophil-to-lymphocyte ratio significantly decreased over time (P < 0.001) and carcinoembryonic antigen also had the same tendency (P = 0.08).

CONCLUSIONS

A carcinoembryonic antigen level of ≥5 ng/mL and a neutrophil-to-lymphocyte ratio of >1.8 are predictors of early recurrence after radical gastrectomy and adjuvant chemotherapy for stage II or III gastric cancer.

Exploratory randomized phase II trial for optimizing treatment dosage and duration of adjuvant S-1 plus oxaliplatin in patients with stage III colon cancer: YCOG1402 (SOAP trial)

Introduction

Conventionally, the recommended duration of adjuvant chemotherapy of colon cancer had been 6 months. The IDEA Collaboration suggested that shortening capecitabin and oxaliplatin (CAPOX) adjuvant chemotherapy may be possible. S-1 and oxaliplatin (SOX) treatment is standard treatment in metastatic colorectal cancer in Japan. The aim of this study was to optimize treatment dosage and duration of adjuvant SOX in stage III colon cancer.

Methods

This trial was as open-label multi-center randomized phase II study. Patients with stage III colon cancer were randomly assigned to 3 months or 6 months of adjuvant SOX treatment in different doses: 130 mg/m2 (3 months) or 100 mg/m2 (6 months) of oxaliplatin. The primary endpoint was 3-year disease-free survival (DFS) and the null hypothesis for the primary endpoint was that the 3-year DFS was ≤72% in each arm and was tested with a one-sided significance level of 10%.

Results

Eighty-two patients were assigned to the 6 months arm and 81 to the 3 months arm. The 3-year DFS was 75.0% (80% CI 67.95-80.72, p = 0.282) in the 6 months arm and 76.9% (80% CI 70.1-82.38, p = 0.171) in the 3 months arm. Treatment completion rate and relative dose intensity (RDI) were higher in 3 months than 6 months arm. The adverse events (AE) were similar in both arms.

Conclusions

The 3-year DFS was not significantly superior to null hypothesis in both 3 months and 6 months arms for the stage III colon cancer. Primary endpoint was not achieved. The SOX regimen was not feasible in long-term outcomes.

Worse Survival of Patients With T1 Stage II Gastric Cancer Following Radical Gastrectomy

PURPOSE

Lymph node (LN) metastasis is a crucial factor in the prognosis of patients with gastric cancer (GC) and is known to occur more frequently in cases with an advanced T stage. This study aimed to analyze the survival data of patients with advanced LN metastasis in T1 GC.

MATERIALS AND METHODS

From January 2008 to June 2018, 677 patients with pathological stage II GC who underwent radical gastrectomy were divided into an early GC group (EG: T1N2 and T1N3a, n=103) and an advanced GC (AGC) group (AG: T2N1, T2N2, T3N0, T3N1, and T4aN0, n=574). Short- and long-term survival rates were compared between the 2 groups.

RESULTS

A total of 80.6% (n=83) of the patients in the EG group and 52.8% (n=303) in the AG group had stage IIA AGC. The extent of LN dissection, number of retrieved LNs, and short-term morbidity and mortality rates did not differ between the 2 groups. The 5-year relapse-free survival (RFS) of all patients was 87.8% and the overall survival was 84.0%. RFS was lower in the EG group than in the AG group (82.2% vs. 88.7%, P=0.047). This difference was more pronounced among patients with stage IIA (82.4% vs. 92.9%, P=0.003).

CONCLUSIONS

T1 GC with multiple LN metastases seems to have a worse prognosis compared to tumors with higher T-stages at the same level. Adjuvant chemotherapy is highly recommended for these patients, and future staging systems may require upstaging T1N2-stage tumors.

Effect of the number of cycles of docetaxel + S-1 therapy on long-term survival in adjuvant chemotherapy for stage III gastric cancer. A pooled analysis of the OGSG0604 and OGSG1002 trials

BACKGROUND

S-1 plus docetaxel (DS) therapy followed by S-1 is the standard of care in Japan in postoperative adjuvant chemotherapy for stage III gastric cancer, but long-term survival and the number of DS cycles required are unclear. The purpose of this study was to investigate the impact of the number of cycles of DS therapy on the 5-year survival in stage III gastric cancer in a pooled analysis of two phase II trials (OGSG0604 and OGSG1002).

PATIENTS AND METHODS

Patients with histologically confirmed stage III gastric cancer who underwent gastrectomy with D2 lymphadenectomy were enrolled in this pooled analysis. They received DS therapy for four or eight cycles, followed by S-1 until 1 year postgastrectomy. The 5-year overall survival (OS) and the 5-year disease free survival (DFS) by the landmark analysis was evaluated.

RESULTS

In total, 113 patients from the OGSG0604 and OGSG1002 trials were enrolled in this study. The landmark analysis showed a 5-year OS that was better with four to eight cycles of DS therapy than with one to three cycles of DS therapy, with the best 5-year OS of 77.4% (95% confidence interval, 66.5-90.1%) for eight cycles. The 5-year DFS was approximately 66% when four or eight cycles of DS therapy were given.

CONCLUSION

Although eight cycles of DS therapy may prolong prognosis, the present study did not provide a clear conclusion as to how many DS therapy cycles are needed to improve prognosis after D2 gastrectomy for stage III gastric cancer.

TRIAL REGISTRATION

Registration number: UMIN00000714 and UMIN000004440.

Solitary living worsens the continuation of adjuvant chemotherapy for gastric cancer

BACKGROUND

No studies have reported the effect of solitary living on adjuvant chemotherapy continuation in patients with gastric cancer. This study aimed to investigate the influence of solitary living on the efficacy of adjuvant chemotherapy after curative gastrectomy.

METHODS

We enrolled 155 patients with pathological stage II/III gastric cancer who underwent gastrectomy and adjuvant chemotherapy between January 2013 and March 2020. The patients were divided into two groups according to their living conditions, the solitary group (n = 34) versus the non-solitary group (n = 121). Clinicopathological features, predictive factors for the continuation of adjuvant chemotherapy, and long-term survival were compared between the two groups.

RESULTS

The median body weight loss (BWL) at one month after surgery (8.9% vs. 7.0%, p = 0.01), and the rates of failure to continue six courses of chemotherapy were higher in the solitary group (41.2% vs. 14.9%, p = 0.002) than in the non-solitary group. Multivariate analysis revealed that solitary living was an independent predictive factor for discontinuing adjuvant chemotherapy (odds ratio 3.36, 95% confidence interval [CI; 1.32-8.58], p = 0.01) as well as 10% BWL at one month after surgery (odds ratio 3.99, 95% CI [1.57-10.2], p = 0.004). The relapse-free survival was significantly worse in the solitary group (p = 0.03).

CONCLUSIONS

Solitary living may be an independent risk factor for discontinuation of adjuvant chemotherapy in patients with gastric cancer. It is necessary to examine whether social and medical support organized by medical institutes and the government improves the continuation of adjuvant chemotherapy in patients living alone.

Phase I study of adjuvant chemotherapy with nab-paclitaxel and S-1 for stage III Lauren's diffuse-type gastric cancer after D2 resection (NORDICA study)

PURPOSE

The prognosis of diffuse-type gastric cancer (DGC) is poorer than that of intestinal type, but S-1 is a potential treatment option in DGC. This study explored the maximal tolerated dose (MTD) and the recommended dose for phase II study (RP2D) of nab-paclitaxel combined with S-1 (AS regimen) as adjuvant chemotherapy in stage III DGC.

METHODS

Patients with stage III DGC were recruited into this phase I dose-escalation study between July 2019 and June 2020 in Zhongshan Hospital. Nab-paclitaxel and S-1 (80-120 mg/day, d1-14, q3w) were administrated for 6 cycles, and then 8 cycles of S-1 monotherapy were applied. The patients received nab-paclitaxel at 180, 220, or 260 mg/m² according to the 3 + 3 design based on dose-limiting toxicity (DLT). The primary endpoint was RP2D. Secondary endpoints were the 1-year disease-free survival (DFS) rate and adverse events (AEs).

RESULTS

One case experienced DLT in 180-mg/m² dose group, subsequently three additional subjects were enrolled. DLT was not observed in the 220- and 260-mg/m² dose groups (both n = 3). Therefore, the MTD has not reached, and the RP2D of nab-paclitaxel would be 260 mg/m² . Five participants showed progressive disease, with three and two participants in the 180- and 220-mg/m² dose groups, respectively. The 6-, 12-, and 18-month DFS rates were 100%, 63.6%, and 50.9%, respectively. The most frequently observed AEs were neutropenia (83.3%) and leukopenia (66.7%).

CONCLUSION

The RP2D of nab-paclitaxel as adjuvant chemotherapy in DGC was 260 mg/m² . The AS regimen had a tolerable AE profile in stage III DGC.

Effects of an oral elemental nutritional supplement in gastric cancer patients with adjuvant S-1 chemotherapy after gastrectomy: A multicenter, open-label, single-arm, prospective phase II study (OGSG1108)

AIM

Post-surgical weight loss influences chemotherapy compliance and may be a risk factor for survival. Intake of an oral elemental nutritional supplement (OENS) can reduce weight loss after gastric cancer (GC) surgery. We assessed whether therapy completion levels would increase in patients receiving postoperative adjuvant chemotherapy in combination with an OENS.

METHODS

This was a multicenter, open-label, single-arm, phase II study in GC patients who underwent curative total or distal gastrectomy (TG/DG) and received adjuvant S-1 chemotherapy. The primary endpoint was the S-1 completion rate for 1 year with a relative performance (RP) value of ≥70%; secondary endpoints included factors affecting the completion rate of S-1, RP value after eight S-1 courses, S-1 and OENS persistence rates, nutritional index, OENS compliance, and safety.

RESULTS

In 71 efficacy-evaluable patients, the S-1 completion rate was 69.0% (TG, 68.0%; DG, 69.6%) and the RP value was 87.5 (TG, 89.1; DG, 87.5). Over eight treatment courses, median persistence rates were 89.0% for S-1 and 93.8% for the OENS. The mean OENS compliance was 81.8% at the fourth S-1 course and 52.9% at the eighth course. The incidence of Grade 3 or 4 adverse events was 27.2%, most commonly neutropenia (12.3%).

CONCLUSIONS

The completion rate of S-1 for 1 year in patients who could take the OENS exceeded the pre-defined threshold level. Randomized controlled trials are warranted to confirm the role of OENS in adjuvant chemotherapy.

Appropriate Number of Adjuvant Chemotherapy Cycles for Patients with Stage 2 or 3 Gastric Cancer After Curative Gastrectomy: A Multicenter Cohort Study

BACKGROUND

Few studies have presented evidence pertaining to the adequate minimum number of adjuvant chemotherapy (AC) cycles required to achieve an oncologic benefit for gastric cancer.

METHODS

From January 2012 to December 2013, data from patients who underwent curative radical gastrectomy and consequently received AC for pathologic stage 2 or 3 gastric cancer at 27 institutions in South Korea were analyzed.

RESULTS

The study enrolled 925 patients, 661 patients (71.5%) who completed 8 cycles of AC and 264 patients (28.5%) who did not. Compared with the mean disease-free survival (DFS) of the patients who completed 8 AC cycles (69.3 months), the mean DFS of patients who completed 6 AC cycles (72.4 months; p = 0.531) and those who completed 7 AC cycles (63.7 months; p = 0.184) did not differ significantly. However, the mean DFS of the patients who completed 5 AC cycles (48.2 months; p = 0.016) and those who completed 1-4 AC cycles (62.9 months; p = 0.036) was significantly lower than the DFS of those who completed 8 AC cycles. In the multivariate Cox proportional hazards analysis, the mean DFS was significantly affected by advanced stage, large tumor size, positive vascular invasion, and number of completed AC cycles (1-5 cycles: hazard ratio 1.45; 95% confidence interval 1.01-2.08; p = 0.041).

CONCLUSION

The current multicenter observational cohort study showed that the mean DFS for 6 or 7 AC cycles was similar to that for 8 AC cycles as an adjuvant treatment for gastric cancer.

Comparison of S-1-based vs. capecitabine-based adjuvant chemotherapy for patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

S-1-based and capecitabine-based adjuvant treatments are proved efficacious for patients with gastric cancer, but conventional meta-analyses of the direct comparisons between two alternative adjuvant regimens to resection of GC have not been attempted.

AIM

The aim of this review was to compare the disease-free survival, overall survival and adverse events in patients receiving the S-1- and capecitabine-based adjuvant chemotherapies for treatment of gastric cancer (GC) patients undergoing resection.

METHODS

A search of the academic literature was performed in PUBMED, SCOPUS, CENTRAL and EMBASE databases along with manual search in relevant journals for studies in English, to identify comparative studies comparing the effect of S-1-based chemotherapy and capecitabine-based adjuvant chemotherapy (AC), used in combination with surgical resection for treatment of gastric cancer. Both qualitative and quantitative analyses was carried out for all the included studies. The hazard ratios (HR) of disease-free survival (DFS) and overall survival (OS) were pooled using generic inverse variance method. The included studies were assessed for risk of bias using ROBINS-E (risk of bias in non-randomized studies of exposures) tool.

RESULTS

Seven retrospective cohort studies, two prospective cohort studies and one randomized clinical trial were included. Both S-1- and capecitabine-based adjuvant chemotherapy for treatment of stage 2 or 3 gastric cancer had similar effects on the 3-year and 5-year DFS rates, overall survival and adverse events in the included studies. There was no difference in the adjusted hazard ratios (HR) of OS and DFS (0.86 95% CI (0.68, 1.09); p = 0.21 and 0.96 95% CI (0.75, 1.24), respectively). Oral mucositis was increasingly associated with S-1-based AC, while incidences of adverse events such as neutropenia, anaemia and thrombocytopenia were similar to those of capecitabine-based regimen. The quality of the included studies was found to be low to moderate.

CONCLUSION

S-1- and capecitabine-based adjuvant chemotherapies can be used interchangeably as an adjuvant chemotherapeutic regimen postradical gastrectomy with D2 lymph node dissection.

Taxane-based versus platinum-based chemotherapy in early recurrent gastric cancer after radical surgery with S-1 adjuvant chemotherapy: A multi-institutional retrospective analysis

AIM

This study aimed to compare the efficacy of taxane-based and platinum-based regimens in patients with early recurrent gastric cancer after radical surgery with S-1 adjuvant chemotherapy.

METHODS

The medical records of 118 patients from six institutes with early recurrent stage II/III gastric cancer, who developed recurrence during adjuvant S-1 or within 6 months after completion of adjuvant therapy between January 2006 and December 2017, were retrospectively analyzed. Patients treated with second line chemotherapy were enrolled and followed to the end of December 2019. The impact of two regimens, taxane-based (n = 46) versus platinum-based (n = 31), on treatment outcome were evaluated using multivariate analysis.

RESULTS

Median overall survival was 9.0 months and median progression-free survival was 4.1 months. No difference was observed in overall survival between taxane-based and platinum-based regimens (P = 0.64). Although not significant, the response rate of platinum-based regimens was better than that of taxane-based regimens (16% vs. 6.5%, P = 0.26). Multivariate analysis identified performance status (P = 0.040), multiorgan metastases (P = 0.029), and undifferentiated histological type (P = 0.018) as independent poor prognostic factors. In undifferentiated histological type, multiorgan metastases (P = 0.013) and taxane-based regimens (P = 0.018) were independent prognosis factors characterized by multivariate analysis. Conversion rate to third-line chemotherapy or more was 51% in undifferentiated histological type and 65% in differentiated histological type (P = 0.26).

CONCLUSION

Platinum-based regimens may be recommended for undifferentiated early recurrent gastric cancer after S-1 adjuvant chemotherapy.

Factors related to compliance with adjuvant chemotherapy in patients with gastric cancer: A retrospective single-center study

PURPOSE

Adjuvant chemotherapy (AC) improves survival outcomes in patients with advanced gastric cancer (GC) after curative surgery; however, some patients do not receive or complete chemotherapy. This study aimed to identify factors related to patient compliance with chemotherapy after curative surgery for advanced GC.

METHODS

The data of patients who underwent curative gastrectomy for pathologic stage II-III GC between 2012 and 2016 were reviewed. Patients were divided into an AC completion group (group C), AC incompletion group (group I), and surgery-only group (group S). The AC regimen was either tegafur/gimeracil/oteracil (S-1) or capecitabine plus oxaliplatin (XELOX).

RESULTS

The study enrolled 417 patients; group C had 222 patients, group I had 110, and group S had 85. The most common reason for not initiating AC was poor general condition (36.5%), while chemotherapy-related complications was the common reason for AC incompletion (43.6%). In multivariate analysis, age over 65 years, Eastern Cooperative Oncology Group performance status ≥1, Charlson comorbidity index ≥1, and the presence of postoperative complications were independent risk factors for not initiating AC (odds ratio: 4.32, 2.62, 1.84, and 2.17, respectively). Age over 65 years, longer postoperative stay, and XELOX regimen were significant risk factors for incompletion of AC (odds ratio: 2.68, 1.72, and 2.23, respectively).

CONCLUSION

Old age, poor performance status, comorbidities, and postoperative complications, longer postoperative hospital stay, and XELOX regimen were associated with poor compliance with AC in GC patients. Clinicians can improve compliance with AC by managing postoperative complications and selecting the most appropriate treatment regimen.

Comparison of the Efficacy of S-1 Plus Oxaliplatin or Capecitabine Plus Oxaliplatin for Six and Eight Chemotherapy Cycles as Adjuvant Chemotherapy in Patients With Stage II-III Gastric Cancer After D2 Resection

Objective

To compare the efficacy of adjuvant chemotherapy with six or eight cycles of S-1 plus oxaliplatin (SOX) or Capecitabine plus oxaliplatin (XELOX) after D2 resection of GC.

Design and participants

We collected 470 cases of patients with TNM stage II and III GC who underwent D2 gastrectomy in the Harbin Medical University Cancer Hospital from January 2007 to December 2017 and received six or eight cycles of SOX or XELOX regimen. This study was designed to evaluate the prognosis of patients receiving six or eight cycles of SOX or XELOX chemotherapy and identify the appropriate number of chemotherapy cycles.

Results

Among the 470 study participants [340 (72.3%) males; median age, 50 years (range, 24-76 years)], 355 and 115 received XELOX or SOX regimen chemotherapy, respectively. The number of 152 patients included in this study who received 6 and 8 cycles of chemotherapy in stage II and stage III without considering chemotherapy regimens were 125 and 27. The median DFS was, respectively, 14.9 months and 26.8 months (P = 0.08), the median OS was, respectively, 30.2 months and 30.8 months (P = 0.5), the difference was not statistically significant. Comprehensive survival analysis of XELOX and SOX group showed no significant difference for DFS (P = 0.29) and OS (P = 0.61). The total number of stage III GC patients who received six and eight cycles of chemotherapy was 92 and 19, respectively. The median DFS of patients who received six and eight cycles of chemotherapy was 14.6 and 23.2 months (P = 0.3), respectively. The median OS of patients who received six and eight cycles of chemotherapy was 26 and 30.6 months (P = 0.9), respectively. Comprehensive analysis of DFS (P=0.73) and OS (P=0.6) shows no difference between the XELOX group SOX groups. Subgroup analysis revealed significant differences in the gender (P = 0.05) and histological classification (P < 0.05) distribution.

Conclusion

Regardless of the XELOX regimen or the SOX regimen, similar survival benefits are observed in patients receiving six or eight chemotherapy cycles irrespective of the regimen used. The XELOX and SOX regimens are well tolerated in patients undergoing D2 resection of GC.

Identification and external validation of a prognostic signature associated with DNA repair genes in gastric cancer

The aim of this study was to construct and validate a DNA repair-related gene signature for evaluating the overall survival (OS) of patients with gastric cancer (GC). Differentially expressed DNA repair genes between GC and normal gastric tissue samples obtained from the TCGA database were identified. Univariate Cox analysis was used to screen survival-related genes and multivariate Cox analysis was applied to construct a DNA repair-related gene signature. An integrated bioinformatics approach was performed to evaluate its diagnostic and prognostic value. The prognostic model and the expression levels of signature genes were validated using an independent external validation cohort. Two genes (CHAF1A, RMI1) were identified to establish the prognostic signature and patients ware stratified into high- and low-risk groups. Patients in high-risk group presented significant shorter survival time than patients in the low-risk group in both cohorts, which were verified by the ROC curves. Multivariate analysis showed that the prognostic signature was an independent predictor for patients with GC after adjustment for other known clinical parameters. A nomogram incorporating the signature and known clinical factors yielded better performance and net benefits in calibration plot and decision curve analyses. Further, the logistic regression classifier based on the two genes presented an excellent diagnostic power in differentiating early HCC and normal tissues with AUCs higher than 0.9. Moreover, Gene Set Enrichment Analysis revealed that diverse cancer-related pathways significantly clustered in the high-risk and low-risk groups. Immune cell infiltration analysis revealed that CHAF1A and RMI1 were correlated with several types of immune cell subtypes. A prognostic signature using CHAF1A and RMI1 was developed that effectively predicted different OS rates among patients with GC. This risk model provides new clinical evidence for the diagnostic accuracy and survival prediction of GC.

Locally advanced gastroesophageal junction cancer with pathological complete response to neoadjuvant therapy: a case report and literature review

Most gastric cancer and gastroesophageal junction carcinoma (GEJ) patients are already in the advanced stage at the time of diagnosis. Thus, the probability of radical gastrectomy is low, and surgical treatment alone has a poor prognosis due to the high recurrence rate. In order to reduce the recurrence and distant metastasis after surgery, there have been many attempts made to improve the perioperative treatment of advanced localized gastric cancer, but no uniform criteria exist. Over recent years, immunotherapy has revolutionized cancer treatment, and immune checkpoint inhibitors (ICIs) have shown excellent efficacy across various types of tumors, becoming a potential treatment after surgery, chemotherapy, radiotherapy, and targeted therapy. However, the efficacy of single-agent ICIs for gastric cancer is still unsatisfactory. As comprehensive, chemotherapy-based treatment has become the standard care for locally advanced gastric cancer, exploring combination treatment with immune checkpoint inhibitors (ICIs) may be valuable to improving survival outcomes. Here, we report a 66-year-old male with dysphagia diagnosed with GEJ and was defined as clinical stage (cT4N2M0) and Siewert type II, characterized as mismatch repair proficient (pMMR) and programmed cell death ligand-1 (PD-L1) negative; surprisingly, with anti-PD-1 antibody plus SOX (S-1: a combination of tegafur, gimeracil, and oteracil+ oxaliplatin) as perioperative therapy, the patient achieved pathological complete remission (pCR), which indicates that the addition of ICIs to chemotherapy as a perioperative comprehensive treatment might provide a promising strategy option for GEJ. In addition, we review the current status of perioperative comprehensive treatment, in hope that this may provide some reference value for clinical decision-making.

Comparison of Long-Term Efficacy in S-1 and Capecitabine With Oxaliplatin as Adjuvant Chemotherapy for Patients With Gastric Cancer After Curative Surgery: A Retrospective, Single-Center Observational Study

Purpose: Various adjuvant chemotherapies have been introduced for gastric cancer patients after gastrectomy with D2 lymph node dissection. Although the mainstream regimen of adjuvant chemotherapy in Korea includes S-1 monotherapy (TS-1) and capecitabine with oxaliplatin (XELOX), few studies have compared the long-term efficacies of these 2 regimens. Methods: Between January 2010 and June 2017, 2021 patients were diagnosed with gastric cancer and underwent curative resection with adjuvant chemotherapy at our institution. Of 1461 patients with stage IB-III gastric cancer, 825 received TS-1 and 636 received XELOX as adjuvant chemotherapy. We retrospectively reviewed their medical records and analyzed the postoperative 5-year overall survival (OS) and disease-free survival (DFS) of these 2 groups. Results: The patients in the XELOX group had more advanced stage of cancer than the TS-1 group (stages III and II: 56.6% and 43.1%, respectively, in XELOX and 35.3% and 57.0% in TS-1; P < .001). The DFS did not differ significantly between the 2 study groups at any pathologic stage. The OS differed significantly only at pathologic stages IIA (P = .024) and IIB (P = .015). In a multivariate analysis of stage II patients, type of regimen was an independent prognostic factor of OS (XELOX vs TS-1; hazard ratio: 0.47, 95% confidence interval: 0.25-0.89, P = .021). Conclusion: There were similar long-term efficacies between these 2 regimens in advanced gastric cancer patients who underwent curative surgery. However, the XELOX regimen might be favorable for OS of stage II patients.

Maintenance Chemotherapy with S-1 Following SOX Regimen Chemotherapy Improves Prognosis of Stage 3 Gastric Cancer After D2 Gastrectomy: A 5-Year Analysis

Objective

To assess the effectiveness and safety of treatment consisting of maintenance chemotherapy (MCT) with S-1 following S-1 plus oxaliplatin (SOX) chemotherapy for stage 3 gastric cancer (GC) after D2 gastrectomy.

Methods

In this retrospective study, we enrolled 255 patients with stage 3 GC who underwent D2 gastrectomy between February 2011 and May 2014. The SOX regimen chemotherapy was administrated to all of the patients as adjuvant therapy. The SOX regimen consisted of S-1 (for patients with a body surface area [BSA] of less than 1.25 m², 80 mg/d; 100 mg/d for BSA=1.25 m²- <1.5 m², and 120 mg/d for BSA≥1.5 m², in 2 divided doses for 14 d) and oxaliplatin (130 mg/m² given on Day 1), repeated every 21 d for 8 cycles. Following SOX chemotherapy, 122 of these patients received maintenance chemotherapy (the MCT group) with S-1, whereas 133 patients (the control group) received no MCT. The MCT consisted of S-1 (80, 100, or 120 mg daily based on BSA, in 2 divided doses for 14 d), repeated every 21 d for 8 cycles at most. The chemotherapy was discontinued if unacceptable toxicity or disease progression occurred or upon the request of the patient. All cases were followed up, and overall survival (OS), recurrence-free survival (RFS), and toxicities were compared.

Results

The MCT group exhibited a distinctly higher 5-year OS (P=0.0425) and RFS (P=0.0479) than those of the control group. The incidence of hand-foot syndrome was markedly greater in the MCT group (P=0.0026). No toxicity-related death occurred.

Conclusion

Maintenance chemotherapy with S-1 following the SOX regimen chemotherapy provides significant survival benefit for stage 3 GC after D2 gastrectomy.

Contribution of chemotherapy to improved prognosis in stage 4 gastric cancer: trend analysis of a regional population-based cancer registry in Japan

OBJECTIVES

Little is known about time trends in the prognosis of gastric cancer (GC), since the introduction of new chemotherapeutic agents. This study aimed to analyze how the increased number of available chemotherapeutic options affected the prognosis of GC and which patient types benefited within in a large population.

METHODS

From a population-based cancer registry in Japan, 35,751 cases of GC were identified. Of these, 8214 cases were stage 4. The time trend for 3-year survival in stage 4 GC according to patient characteristics (age and tumor location) was estimated in relation to the introduction of new anticancer drugs. Multiple imputation was performed for sensitivity analysis to strengthen the missing data. In addition, we estimated the 5-year survival rate for distal-GC (DGC) and proximal-GC (PGC), and the hazard ratio (HR) was estimated by Cox proportional hazard model.

RESULTS

Improvement of overall survival was accelerated in stage 4 cases over time. The prognosis was improved from 11.4% to 13.2%, subsequent to the approval of several oncologic drugs since 2009. Younger patients were more likely to have improved survival rates in response to the increase in chemotherapy options (< 60-year-old, 5.4%: 60-70, 2.2%; 70-80, 0.3%) from 2007 to 2015. The HR for DGC vs. PGC was 1.11 (95% CI 1.08-1.15), and PGC showed a higher rate of improved outcomes (2.4% vs. 0.6%).

CONCLUSIONS

This analysis showed that improvement in the GC survival rate was accelerated by the introduction of new chemotherapeutic strategies and it was most evident among younger patients and in patients with PGC.

Prognosis of Adjuvant SOX vs XELOX Chemotherapy for Gastric Cancer After D2 Gastrectomy in Chinese Patients

Introduction

To compare the prognosis of adjuvant SOX (S-1 and oxaliplatin) vs XELOX (capecitabine and oxaliplatin) chemotherapy in Chinese patients with gastric cancer (GC) after D2 gastrectomy.

Methods

This was a real-world study of patients with GC (stages II-III) who underwent D2 gastrectomy and received adjuvant SOX or XELOX between 01/2010 and 06/2017 in Zhongshan Hospital affiliated to Fudan University. The patients were matched by propensity score matching. The primary and secondary endpoints were disease-free survival (DFS) and overall survival (OS), respectively. Adverse events (AEs) were compared.

Results

A total of 552 patients were included. The median follow-up time was 24.9 months. There were no differences in DFS (median, 44.4 vs 41.2 months; HR=1.17, 95% CI: 0.92-1.48) and OS (median, 61.5 vs 65.3 months; HR=1.01, 95% CI: 0.73-1.39) between the XELOX and SOX groups. Both DFS and OS had no significant differences between SOX and XELOX for all subgroups based on sex (P=0.949, P=0.990), age (P=0.303, P=0.392), Lauren type (P=0.362, P=0.573), type of gastrectomy (P=0.607 P=0.989), and pathological TNM stage (P=0.899, P=0.888). A total of 86 patients in the SOX subgroup (34.2%) experienced AEs, similar to the rate found in the XELOX subgroup (104 patients or 41.4%; P=0.098).

Discussion

The results suggested that adjuvant SOX chemotherapy has similar survival benefits compared to XELOX chemotherapy in Chinese patients with pathological stage II or III GC after D2 gastrectomy.

An integrated classifier improves prognostic accuracy in non-metastatic gastric cancer

The American Joint Committee on Cancer (AJCC) staging system is insufficiently prognostic for gastric cancer (GC) patients and complementary factors are in urgent need. Here we aimed to develop a comprehensive model, consisting of both immune signatures and cancer signaling molecules, which was expected to accurately improve survival prediction in non-metastatic gastric cancer (GC). We first validated the prognostic value of a combination of 18 immune features and 52 cancer-signaling molecules in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. Then, their expression and distribution were analyzed in consecutive 1180 GC patients using immunohistochemistry. We developed and validated a novel protein-based prognostic classifier using CDH1, an epithelial–mesenchymal transition (EMT) marker, and five immune features (CD3, CD4, CD274, GZMB, and PAX5) by Cox regression model with group LASSO penalty. We observed significant differences in the overall survival of the high- and low-prognostic risk groups (66.8% VS 27.0%, P < .001). A combination of this classifier with age and pTNM stage had better prognostic value than pTNM alone. The model was further validated in both treatment-naive patients and those treated with neoadjuvant chemotherapy. Moreover, GC patients with high-risk score exhibited a favorable prognosis to adjuvant chemotherapy. This integrated classifier could be automatically analyzed and effectively predict survival of GC patients and may provide a new clinically applicable strategy to identify patients who are more likely to benefit from adjuvant chemotherapy.

S1 versus Doublet Regimens as Adjuvant Chemotherapy in Patients with Advanced Gastric Cancer after Radical Surgery with D2 Dissection-A Propensity Score Matching Analysis

BACKGROUND

Fluoropyrimidine- and platinum-based doublet regimen is the standard treatment of adjuvant chemotherapy (AC) for gastric cancer (GC). Our study aims to compare S1 with doublet regimens as AC in patients with advanced GC after radical surgery with D2 dissection.

METHODS

Patients who were diagnosed with GC and underwent a curative surgery with D2 dissection followed by AC were enrolled into our study. A propensity score matching analysis was performed to reduce the selection bias. Kaplan-Meier curves were estimated for recurrence-free survival (RFS) and overall survival (OS). Cox regression models were conducted for survival.

RESULTS

After propensity sore matching, 64 patients with S1 and 64 patients with doublet regimens were identified. The median RFS (p = 0.355) and OS (p = 0.309) were both insignificant between S1 and ST. Cox regression analysis demonstrated that pathologic stage and lymph node ratio (LNR) were independently correlated with survival. Patients were then stratified into low risk and high risk groups. The median RFS (p < 0.001) and OS (p < 0.001) had significant differences between low risk and high risk. In the high-risk group, doublet regimens were strongly associated with survival (p = 0.020) as compared with S1. While in the low-risk group, doublet regimen and S1 did not have statistically different survival benefits.

CONCLUSIONS

Our study demonstrated that doublet regimens are superior to S1 in high-risk groups, and that survival outcomes are similar between doublet regimens and S1 in low-risk groups. Our prognostic model might have clinical implications for AC.

Comparison of Docetaxel + Oxaliplatin + S-1 vs Oxalipatin + S-1 as Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer: A Propensity Score Matched Analysis

Background

What is the optimal neoadjuvant chemotherapy (NAC) regimen for locally advanced gastric cancer (LAGC) remains debatable. The objective of this study was to compare the efficacy of docetaxel+oxaliplatin+S-1 (DOS) vs oxaliplatin+S-1 (SOX) as NAC for LAGC.

Methods

Data of 248 LAGC patients who received either DOS or SOX as NAC in our hospital between January 2010 and January 2018 were reviewed retrospectively. Propensity score matched (PSM) analysis was applied to minimize the selection bias in both groups. Prognostic factors were screened by univariate and multivariate Cox regression analyses.

Results

Of the 248 LAGC patients included, 180 patients were subjected to the PSM analysis. Patients in DOS group showed a better tumor response to NAC, higher radical resection rate and R0 resection rate than those in SOX group. The overall survival (OS) rate in DOS group was better than that in SOX group, although the overall incidence of Grade 3/4 NAC-related toxicity in DOS group was higher, as represented by leukopenia and neutropenia. Multivariate analysis revealed that the NAC regimen, cTNM stage and the R0 resection rate were independent prognostic factors. In addition, patients with TLND less than 16 population showed a worse OS rate. Subgroup analysis indicated that patients benefited from the addition of docetaxel regardless of the clinical T stage, but those with high clinical N stages (N2-3) did not.

Conclusion

DOS is a safe and feasible NAC regimen for LAGC, which is worth popularizing in clinical practice.

Long-term Efficacy of S-1 Monotherapy or Capecitabine Plus Oxaliplatin as Adjuvant Chemotherapy for Patients with Stage II or III Gastric Cancer after Curative Gastrectomy: a Propensity Score-Matched Multicenter Cohort Study

PURPOSE

To compare long-term disease-free survival (DFS) between patients receiving tegafur/gimeracil/oteracil (S-1) or capecitabine plus oxaliplatin (CAPOX) adjuvant chemotherapy (AC) for gastric cancer (GC).

MATERIALS AND METHODS

This retrospective multicenter observational study enrolled 983 patients who underwent curative gastrectomy with consecutive AC with S-1 or CAPOX for stage II or III GC at 27 hospitals in Korea between February 2012 and December 2013. We conducted propensity score matching to reduce selection bias. Long-term oncologic outcomes, including DFS rate over 5 years (over-5yr DFS), were analyzed postoperatively.

RESULTS

The median and longest follow-up period were 59.0 and 87.6 months, respectively. DFS rate did not differ between patients who received S-1 and CAPOX for pathologic stage II (P=0.677) and stage III (P=0.899) GC. Moreover, hazard ratio (HR) for recurrence did not differ significantly between S-1 and CAPOX (reference) in stage II (HR, 1.846; 95% confidence interval [CI], 0.693-4.919; P=0.220) and stage III (HR, 0.942; 95% CI, 0.664-1.337; P=0.738) GC. After adjustment for significance in multivariate analysis, pT (4 vs. 1) (HR, 11.667; 95% CI, 1.595-85.351; P=0.016), pN stage (0 vs. 3) (HR, 2.788; 95% CI, 1.502-5.174; P=0.001), and completion of planned chemotherapy (HR, 2.213; 95% CI, 1.618-3.028; P<0.001) were determined as independent prognostic factors for DFS.

CONCLUSIONS

S-1 and CAPOX AC regimens did not show significant difference in over-5yr DFS after curative gastrectomy in patients with stage II or III GC. The pT, pN stage, and completion of planned chemotherapy were prognostic factors for GC recurrence.

Delaying adjuvant chemotherapy in advanced gastric cancer patients: Risk factors and its impact on survival outcome

Adjuvant chemotherapy following the curative resection could improve the survival outcome of advanced gastric cancer (GC) patients. However, it is unclear whether delayed initiation of adjuvant chemotherapy had a negative impact on survival outcome in GC patients. The purpose of this study was to review current published literature about the impact of delaying adjuvant chemotherapy on survival outcome and summarize risk factors for delaying adjuvant chemotherapy. Delayed initiation of adjuvant chemotherapy was quite frequent in GC patients who underwent gastrectomy due to postoperative complications, poor nutritional status, comorbid diseases and socioeconomic status. Therefore, it is important for these patients to have a sufficient and smooth transition from surgery to initiation of adjuvant chemotherapy. Based on current available evidence, there is no specific timing interval for the initiation of adjuvant chemotherapy in GC patients. Earlier initiation of adjuvant chemotherapy (<4 weeks) may not be mandatory for GC patients who underwent curative resection. However, the patients should be recommended to receive adjuvant chemotherapy within 6-8 weeks if their performance status and nutritional status were deemed to be appropriate. Minimizing postoperative complications and providing requisite nutritional advice may be helpful for timely initiation of adjuvant chemotherapy.

Five-year outcomes of a phase II study of adjuvant chemotherapy with S-1 plus docetaxel for stage III gastric cancer after curative D2 gastrectomy (OGSG1002)

BACKGROUND

Adjuvant S-1 monotherapy is standard of care for stage II and III gastric cancer (GC), but there is still a need to improve the efficacy of treatment for stage III disease. We conducted phase II study of eight cycles of S-1 plus docetaxel (DS) followed by S-1 monotherapy for up to 1 year after D2 gastrectomy for stage III GC.

PATIENTS AND METHODS

Sixty-two patients with stage III GC were enrolled. They received oral S-1 (80 mg/m²/day) for 2 consecutive weeks and intravenous docetaxel (40 mg/m²) on day 1, repeated every 3 weeks for 8 cycles, followed by S-1 until 1 year postgastrectomy. Treatment safety, tolerability, and survival were evaluated.

RESULTS

The completion rate for eight cycles of DS therapy was 77.4% [95% confidence interval (CI) 65.0-87.1%]. Subsequent S-1 monotherapy for 1 year was feasible in 71.0% (95% CI 58.1-81.8%) of patients. The incidence of neutropenia, leukopenia, anorexia, and fatigue of grade 3 or higher was 10% or higher. There were no treatment-related deaths. The 5-year overall survival (OS) and disease-free survival (DFS) rates were 72.4% (95% CI 62.1-84.5%) and 60.0% (95% CI 48.8-73.9%), respectively. Subgroup analyses by disease stage showed 5-year OS and DFS rates of 74.5% (95% CI 60.7-91.5%) and 59.3% (95% CI 43.8-80.2%) for stage IIIA and 70.0% (95% CI 55.4-88.5%) and 60.0% (95% CI 44.8-80.4%) for stage IIIB, respectively.

CONCLUSIONS

Adjuvant eight cycles of DS therapy might be safe and manageable and has promising OS and DFS for stage III GC.

Concordance Between Watson for Oncology and a Multidisciplinary Clinical Decision-Making Team for Gastric Cancer and the Prognostic Implications: Retrospective Study

Background

With the increasing number of cancer treatments, the emergence of multidisciplinary teams (MDTs) provides patients with personalized treatment options. In recent years, artificial intelligence (AI) has developed rapidly in the medical field. There has been a gradual tendency to replace traditional diagnosis and treatment with AI. IBM Watson for Oncology (WFO) has been proven to be useful for decision-making in breast cancer and lung cancer, but to date, research on gastric cancer is limited.

Objective

This study compared the concordance of WFO with MDT and investigated the impact on patient prognosis.

Methods

This study retrospectively analyzed eligible patients (N=235) with gastric cancer who were evaluated by an MDT, received corresponding recommended treatment, and underwent follow-up. Thereafter, physicians inputted the information of all patients into WFO manually, and the results were compared with the treatment programs recommended by the MDT. If the MDT treatment program was classified as “recommended” or “considered” by WFO, we considered the results concordant. All patients were divided into a concordant group and a nonconcordant group according to whether the WFO and MDT treatment programs were concordant. The prognoses of the two groups were analyzed.

Results

The overall concordance of WFO and the MDT was 54.5% (128/235) in this study. The subgroup analysis found that concordance was less likely in patients with human epidermal growth factor receptor 2 (HER2)-positive tumors than in patients with HER2-negative tumors (P=.02). Age, Eastern Cooperative Oncology Group performance status, differentiation type, and clinical stage were not found to affect concordance. Among all patients, the survival time was significantly better in concordant patients than in nonconcordant patients (P<.001). Multivariate analysis revealed that concordance was an independent prognostic factor of overall survival in patients with gastric cancer (hazard ratio 0.312 [95% CI 0.187-0.521]).

Conclusions

The treatment recommendations made by WFO and the MDT were mostly concordant in gastric cancer patients. If the WFO options are updated to include local treatment programs, the concordance will greatly improve. The HER2 status of patients with gastric cancer had a strong effect on the likelihood of concordance. Generally, survival was better in concordant patients than in nonconcordant patients.

Perioperative chemotherapy for locally advanced gastric cancer in Japan: current and future perspectives

The standard treatment for locally advanced gastric cancer differs across the world. In western countries, perioperative chemotherapy or postoperative adjuvant chemoradiotherapy are the preferred treatment options, whereas in Asia, D2 gastrectomy followed by postoperative adjuvant chemotherapy is standard. In Japan, adjuvant chemotherapy with S-1 is the standard treatment for pStage II gastric cancer, whereas adjuvant chemotherapy with a doublet regimen is preferred for pStage III gastric cancer. The efficacy of preoperative neoadjuvant chemotherapy using S-1 plus cisplatin, has been investigated in selected patients with expected poor survival outcomes. To expand the indications for neoadjuvant chemotherapy, a clinical trial investigating the efficacy of preoperative S-1 plus oxaliplatin in patients with cStage III (cT3-4N1-3) gastric cancer (JCOG1509) is ongoing in Japan. The addition of immune checkpoint inhibitors to cytotoxic chemotherapy also seems promising and is being investigated in international randomized clinical trials. Although we have to await the final results of these studies, preoperative neoadjuvant chemotherapy is a promising treatment strategy and likely to become standard treatment for locally advanced gastric cancer in Japan.

Progress in the treatment of gastric cancer in Japan over the last 50 years

There have been remarkable changes in gastric cancer treatments in Japan, resulting in superb improvement of prognosis in patients with this disease. In this paper, the last 50 years have been divided into three eras: before 1990; the 1990s; and the era of evidence, which means after 2000. Changes of treatments and prognosis were analyzed by several factors, such as surgery, chemotherapy, informed consent, clinical trials, and others, as improvement of prognosis is not due to one factor but several ones influencing each other.

Implications of clinical research on adjuvant chemotherapy for gastric cancer: Where to go next?

Postoperative adjuvant chemotherapy (ACT) confers superior gastric cancer (GC) survival in the Eastern cohort. However, is the current standard of ACT already excessive, or is it still necessary to increase its intensity for specific subgroups? Tailored ACT strategies for GC depend on gradual exploration by clinical trials in selected patients. Thus, understanding the implications of previous and current research can help us respond wisely and design effective, rational trials, save medical resources and make better decisions in clinical practice. After reviewing and analyzing studies on ACT for GC patients undergoing curative resection, we found that research strategies for conducting "addition" ACT for specific stages of the disease have achieved great progress in making ACT more tailored and personalized in consideration of pathology stages. Furthermore, trials indicate that "addition" ACT strategies for GC patient subgroups based on histological characteristics might be helpful to move toward a more specific tailored and personalized management approach. Designing ACT research focused on different node statuses should also be conducted according to the biological specificity of lymph node (LN) metastasis. Therefore, future trials designed to determine tailored treatment based on histological and biological characteristics for specific subgroups are urgently needed and conducted as the theme of the 2019 American Society of Clinical Oncology (ASCO): Caring for Every Patient, Learning from Every Patient.