The Clinical Impact of the Tumor Stroma Ratio in Gastrointestinal Cancer Treatment

The standard treatment for gastrointestinal cancer is surgical resection and perioperative adjuvant treatment. Thus far, gastrointestinal cancer research has mainly focused on cancer cells themselves. Recently, the tumor microenvironment (TME) has been a subject of investigation. The TME is a complex system composed of various cell types, including tumor cells, endothelial cells, stromal cells, immune cells, and extracellular components. Among them, the stromal cells surrounding tumor cells are being investigated in gastrointestinal cancers. Stromal cells play a role in tumor growth, invasion, and metastasis. Moreover, stromal cells are associated with increased chemotherapy resistance and reduced chemotherapy delivery. Therefore, it is necessary to develop prognostic or predictive factors that consider the tumor-stroma interaction. The tumor stroma ratio (TSR) has recently been shown to be a promising outcome prediction tool in various malignancies. The TSR is based on the proportion of the stroma to tumor area. Recent studies demonstrated that a high amount of stroma or low TSR was associated with a poor prognosis and was a predictor of various treatment modalities. Therefore, to optimize the gastrointestinal cancer treatment, it is necessary to understand the role of the TSR in gastrointestinal cancers. This review summarizes the background, current status, and future perspectives of the TSR for gastrointestinal cancer treatment.

Prognostic Nutritional Index as a Predictor of Prognosis in Postoperative Patients With Gastric Cancer

BACKGROUND/AIM

The prognostic nutritional index (PNI) has been reported as an immunonutritional index that can easily evaluate nutritional status and immunocompetence from blood tests. The purpose of this study was to investigate the usefulness of PNI as a prognostic factor in postoperative gastric cancer patients.

PATIENTS AND METHODS

In this retrospective cohort study, we evaluated 258 patients with pStage I-III gastric cancer who underwent radical resection at Yokohama City University Hospital, from 2015 to 2021. To examine the association with prognosis, we analyzed clinicopathological factors including PNI (<47/≥47), age (<75/≥75), sex (male/female), depth (pT1/≥pT2), lymph node metastasis (pN+/pN-), lymphatic invasion (ly+/ly-), vascular invasion (v+/v-), histological type (enteric/spread) and postoperative complications.

RESULTS

In univariate analysis, PNI (p<0.001), depth of tumor invasion (p<0.001), lymph node involvement (p<0.001), age (p=0.002), lymphatic invasion (p<0.001), vascular invasion (p<0.001), and postoperative complications (p=0.003) were associated with overall survival. In multivariate analysis, PNI (HR=2.100, 95% confidence interval 1.225-3.601, p=0.007), tumor invasion, lymph node metastasis, and postoperative complications were shown as poor prognostic factors for overall survival.

CONCLUSION

PNI is an independent prognostic factor for overall and recurrence-free survival in postoperative gastric cancer patients. PNI could be implemented in clinical practice to identify patients at higher risk for poor outcomes.

The clinical impacts of lymphocyte-to-C-reactive protein ratio for esophageal cancer patients who receive curative treatment

Background

We investigated the impact of the lymphocyte-to-C-reactive protein ratio (LCR) on esophageal cancer survival and recurrence after curative treatment.

Patients and Methods

This study included 89 patients who underwent curative surgery followed by adjuvant treatment for esophageal cancer between 2008 and 2018. The risk factors for overall survival (OS) and recurrence-free survival (RFS) were identified.

Results

LCR of 12,177 was regarded to be the optimal critical point of classification considering the 1-year, 3-year, and 5-year survival rates. The OS rates at 3 and 5 years after surgery were 33.2% and 29.9% in the LCR low group, respectively, and 74.0% and 60.9% in the LCR high group, which amounted to a statistically significant difference (P = 0.001). The RFS rates at 3 and 5 years after surgery were 25.3% and 21.7% in the LCR low group, respectively, and 52.1% and 47.4% in the LCR high group, which amounted to a statistically significant difference (P = 0.001). A multivariate analysis demonstrated that the LCR was a significant independent risk factor for both the OS and RFS.

Conclusion

LCR was a risk factor for survival in patients who underwent curative treatment for esophageal cancer. It is necessary to develop the effective plan of the perioperative care and the surgical strategy according to the LCR.

Clinical Significance of Neutrophil-to-Lymphocyte Ratio/Serum Albumin Ratio in Patients With Metastatic Gastric or Gastroesophageal Junction Cancer Administered Trifluridine/Tipiracil

BACKGROUND/AIM

Trifluridine/tipiracil (FTD/TPI) is an anticancer-agent that is administered as third-line or later chemotherapy for metastatic gastric/gastroesophageal junction cancer (mGC/GEJC). Although inflammatory and nutritional statuses have attracted attention as prognostic factors for patients with mGC/GEJC in this therapy, their usefulness has not been fully clarified. Thus, this study investigated the clinical significance of prognostic nutritional index (PNI), neutrophil/lymphocyte ratio (NLR), and NLR/serum albumin (Alb) ratio in patients administered FTD/TPI.

PATIENTS AND METHODS

This retrospective study included 64 patients who underwent FTD/TPI treatment for mGC/GEJC at Kanagawa Cancer Center, Kanagawa, Japan, between October 2019 and June 2022. Patients were divided into high and low PNI, NLR, and NLR/Alb groups according to their pretreatment blood data. This study evaluated the associations between the inflammatory and nutritional indexes and survivals.

RESULTS

Overall survival (OS) and progression-free survival (PFS) of patients with low PNI were significantly poorer than those with high PNI. However, low PNI was not an independent prognostic factor for OS and PFS. There was no significant association between NLR and OS or PFS. In contrast, the OS of patients with high NLR/Alb was significantly poorer than those with high PNI and low NLR/Alb. Furthermore, multivariate analysis showed that high NLR/Alb was an independent prognostic factor for OS.

CONCLUSION

The NLR/Alb may be a useful prognostic factor in patients with mGC/GEJC being administered FTD/TPI as third-line or later chemotherapy.

Incidence and Risk of Venous Thromboembolism in Patients With Resectable Pancreatic Cancer Receiving Neoadjuvant Chemotherapy

BACKGROUND/AIM

Pancreatic cancer has the highest risk of venous thromboembolism (VTE). Additionally, chemotherapy for cancer patients increases the risk of developing VTE. Due to recent advances in neoadjuvant chemotherapy (NAC) regimens, more patients with resectable pancreatic cancer will receive NAC. However, the incidence, risk, and predictors of developing VTE in these patients have not been fully evaluated.

PATIENTS AND METHODS

We retrospectively evaluated the incidence, risk, and predictors of VTE among 67 consecutive patients with resectable pancreatic cancer who received neoadjuvant combination therapy with gemcitabine+S-1 (NAC-GS) followed by surgery and 45 patients with resectable pancreatic cancer who underwent upfront surgery (Up-S).

RESULTS

The incidence of VTE in the NAC-GS and Up-S groups was 10.4% and 6.6%, respectively. Preoperative D-dimer levels were significantly higher in the NAC-GS group, and D-dimer levels were significantly increased during NAC-GS. Preoperative D-dimer level was the only predictor for VTE in patients with resectable pancreatic cancer who received NAC-GS.

CONCLUSION

There is an increased risk of developing VTE during NAC. Screening with D-dimer and taking appropriate measures to suppress critical VTE is essential to provide NAC to patients with resectable pancreatic cancer.

Association of longer telomere length in cancer cells and cancer-associated fibroblasts with worse prognosis

BACKGROUND

Telomere dysfunction has been reported to be directly involved in carcinogenesis owing to chromosomal instability and immortalization; however, the clinicopathological significance of telomeres remains controversial. We have shown that telomere shortening occurs in normal-appearing duct cells at initiation and then continues during the progression of pancreatic cancer. In this study, we determined the clinicopathological and prognostic value of telomere length (TL) in cancer progression.

METHODS

TL in both cancer cells and cancer-associated fibroblasts (CAFs) was analyzed by high-throughput quantitative fluorescence in situ hybridization using a previously reported cohort comprising 1434 cases of adenocarcinoma (ADC), squamous cell carcinoma (SCC), adenosquamous carcinoma, hepatocellular carcinoma, and renal cell carcinoma (RCC), which are known cancers with a statistically significantly low incidence of alternative lengthening of telomeres. Cases were divided into 2 groups as follows: longer and shorter telomeres, according to the median TL of cancer cells and CAFs. The statistical significance of TL in cancer cells and CAFs on clinicopathological characteristics and prognosis was analyzed.

RESULTS

There was a close association between TL in cancer cells and CAFs. Longer telomeres in cancer cells and CAFs were associated with aggressive features such as advanced stage, high mitosis score and nuclear score, poorly differentiated cancer, and desmoplastic stroma in ADC. Furthermore, a longer TL was an independent prognostic factor for ADC, SCC, and RCC.

CONCLUSIONS

Longer telomeres are associated with worse prognosis in ADC, SCC, and RCC. Thus, TL is a novel biomarker for the diagnosis of aggressive cancers with poor prognoses.

Phase 1 Study of the Liposomal Formulation of Eribulin (E7389-LF): Results From the Advanced Gastric Cancer Expansion Cohort

PURPOSE

In the dose-expansion part of this open-label, phase 1 study, we explored the efficacy and safety of E7389-LF (liposomal formulation of eribulin) in Japanese patients with advanced gastric cancer.

DESIGN

Patients with advanced gastric cancer who had been previously treated with ≥2 lines of chemotherapy received E7389-LF 2.0 mg/m2 every 3 weeks (the previously determined maximum tolerated dose, the primary objective of Study 114). Secondary objectives included objective response rate (ORR), progression-free survival (PFS), and safety; exploratory objectives included disease control rate (DCR) and clinical benefit rate (CBR), as well as pharmacodynamic measurements of serum biomarkers.

RESULTS

As of June 24, 2021, 34 patients were enrolled and treated (10 from the original dose-expansion cohort, expanded to include 24 additional patients). Six patients had partial responses, for an ORR of 17.6% (95% confidence interval [CI]: 6.8-34.5) and the median PFS was 3.7 months (95% CI 2.7-4.8). The DCR was 79.4% (95% CI 62.1-91.3), the CBR was 32.4% (95% CI 17.4-50.5). Overall, 32 patients (94.1%) experienced treatment-related adverse events, and 26 patients (76.5%) experienced grade ≥3 events, most commonly neutropenia (41.2%) and leukopenia (29.4%). Of the 8 endothelial cell/vasculature markers tested in this study, 7 were significantly increased among patients treated with E7389-LF; these changes were generally consistent regardless of best overall response.

CONCLUSIONS

E7389-LF 2.0 mg/m2 every 3 weeks was tolerable and showed preliminary activity for the treatment of patients with gastric cancer. www.

CLINICAL TRIALS

gov registration: NCT03207672.

The esophageal cancer cohort of a phase 2 trial of E7389-LF (liposomal formulation of eribulin) + nivolumab

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Background: E7389-LF is a liposomal formulation of the microtubule dynamics inhibitor, eribulin. Treatment with E7389-LF plus the programmed cell death 1 inhibitor nivolumab may result in an increased antitumor effect through vascular remodeling. The phase 1b part of the open-label Study 120 assessed dosing and safety of E7389-LF combined with nivolumab in patients (pts) with solid tumors; the phase 2 part assessed efficacy and safety in expansion cohorts, including an esophageal cancer (EGC) cohort. Methods: For the EGC cohort in the phase 2 part of Study 120, pts were required to have unresectable, measurable (by RECIST v1.1) EGC lesion(s) that showed progression during or after first-line chemotherapy with no other systemic chemotherapy. The primary objective of the phase 2 part was to assess objective response rate (ORR), with success defined as Bayesian posterior probability over 85% beyond threshold (20%) for best overall response (ie, 9 responders of planned 32 pts enrolled). Secondary objectives included assessment of safety and progression-free survival (PFS). The recommended phase 2 dosing regimen was previously determined to be E7389-LF 2.1 mg/m2 every 3 weeks (Q3W) plus nivolumab 360 mg Q3W. Tumor assessments were performed by RECIST v1.1 every 6 weeks. All adverse events (AEs) were monitored and recorded. Results: In the EGC cohort, 35 pts were included. Most pts (88.6%) were male, and the median age was 69.0 years (range 47–85). At data cutoff (May 31, 2022), 5 pts (14.3%) were still undergoing treatment. Discontinuations occurred in 30 pts (85.7%)—25 (71.4%) due to disease progression, 4 (11.4%) due to an adverse event, and 1 (2.9%) due to patient preference. ORR with E7389-LF + nivolumab was 22.9% (95% CI 10.4–40.1) and the disease control rate (DCR) was 62.9% (95% CI 44.9–78.5). Median PFS was 2.81 months (95% CI 1.31–4.17) and the 6-month PFS rate was 20.2% (95% CI 8.7–35.0). Median OS was not reached (95% CI 6.54–not estimable), and the 6-month OS rate was 71.4% (95% CI 53.4–83.5). Treatment-related treatment-emergent (TE) AEs of any grade and of grade ≥3 occurred in 94.3% and 80.0% of pts, respectively. The most common treatment-related TEAEs of any grade were neutropenia (65.7%), leukopenia (57.1%), and decreased appetite (45.7%). The most common treatment-related TEAEs of grade ≥3 were neutropenia (54.3%), leukopenia (34.3%), and febrile neutropenia (22.9%). TEAEs led to dose reduction of E7389-LF in 17 pts (48.6%). TEAEs led to withdrawal of either E7389-LF or nivolumab in 5 pts (14.3%): pneumonia (n=2), traumatic hemothorax (n=1), acute kidney injury (n=1), and pneumonitis (n=1). Conclusions: E7389-LF combined with nivolumab showed an ORR of 22.9% in pts with EGC. Despite this modest ORR, the DCR of 62.9% was notable. No new safety signals were observed compared to the known profiles of each monotherapy. Clinical trial information: NCT04078295 .

The Latest Treatments for Cancer Cachexia: An Overview

Cancer cachexia demonstrates the same pathology as cachexia found in patients with disease-associated malnutrition presenting with inflammation. In advanced cancer, a decrease in skeletal muscle mass progresses with an increase in cancer cell mass. Moreover, cancer cachexia causes systemic edema and cachexia, reduces the efficacy of chemotherapy, and negatively affects cancer prognosis. Early nutritional intervention and multidisciplinary care are essential to ensure sufficient nutritional requirements and minimize anabolic resistance factors. In addition, preventive care that minimizes deterioration of nutritional status and loss of skeletal muscle mass is required for the effective treatment of cachexia. Therefore, the current review sought to comprehensively describe the available evidence for the effective pharmaceutical treatment of cancer-associated cachexia. Steroids have traditionally been used for cachexia drug therapy. However, their effects are limited, and it is difficult to radically restore the highly reduced muscle mass inherent to cancer-associated cachexia. Recently, anamorelin hydrochloride, an endogenous ligand for the growth hormone release-promoting factor receptor, which has a similar pharmacological action to that of ghrelin, was developed to treat weight loss accompanied by anorexia. This medication also treats cachexia and was the first drug to be approved for this purpose. Anamorelin hydrochloride is expected to bring new advancements into the field of clinical oncology as an effective therapeutic drug for cancer cachexia, a devastating complication that, so far, has no definitive and effective treatment.

Carbon Ion Radiotherapy Versus Perioperative Adjuvant Chemotherapy and Curative Surgery for Resectable Pancreatic Cancer

BACKGROUND/AIM

The standard treatment for resectable pancreatic cancer is preoperative adjuvant chemotherapy (NAC) + curative surgery + adjuvant chemotherapy. Although excellent local control results of carbon ion radiotherapy (CIRT) for pancreatic cancer have been reported, no reports have compared CIRT with the standard treatment for resectable pancreatic cancer. In this study, we compared the results of CIRT for resectable pancreatic cancer with those of standard therapy and investigated the usefulness of CIRT.

PATIENTS AND METHODS

The subjects were 35 patients who underwent CIRT for clinical cT1-2, N0-1, and M0 cancers at Kanagawa Cancer Center, Yokohama, Japan, from September 2018 to September 2021, and 110 patients who underwent standard treatment (NAC + curative surgery + adjuvant). Overall survival (OS) and recurrence-free survival (PFS) were compared between the two groups using propensity score-matching (PSM).

RESULTS

Twenty-three CIRT monotherapy patients were matched with NAC + curative surgery + adjuvant chemotherapy patients by PSM. Although there was no significant difference in RFS between the two groups, OS was significantly poorer in the CIRT monotherapy group than in the NAC + curative surgery + adjuvant chemotherapy group.

CONCLUSION

This single-centre retrospective propensity score-matched comparison of CIRT and NAC + curative resection + adjuvant chemotherapy as the standard therapy for resectable pancreatic cancer showed an inferiority of CIRT in terms of OS, but no difference in PFS. Therefore, CIRT monotherapy may be a treatment strategy for patients with contraindications for standard treatment of curative surgery plus perioperative chemotherapy.

Gastric cancer (GC) cohort of a phase 2 trial of E7389-LF (liposomal formulation of eribulin) in combination with nivolumab

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Background: Due to a lack of efficacy and long-term survival seen in previously-studied therapies, new therapies for pretreated advanced GC are warranted. E7389-LF is a new formulation that uses liposomes to encapsulate eribulin; this is anticipated to improve eribulin concentration in tumor tissues. E7389-LF and nivolumab have both shown efficacy as monotherapy in pretreated GC. E7389-LF may also synergize well with PD-1 inhibitors by acting as a cytotoxic therapy and by modulating the tumor microenvironment. Methods: Patients (pts) with unresectable and measurable GC, esophageal cancer, or small cell lung cancer who were previously treated with 1 (2 for GC) chemotherapy regimens were enrolled in the phase 2 part of Study 120 and treated with E7389-LF 2.1 mg/m2 plus nivolumab 360 mg every 3 weeks (Q3W). In the GC cohort, pts had to show disease progression from combination therapy including a platinum drug + fluoropyrimidine (1st-line therapy) and a taxane-containing regimen (2nd-line therapy). The primary objective of the phase 2 part was to evaluate the objective response rate (ORR); secondary objectives included safety, progression-free survival (PFS), and pharmacokinetics. Other efficacy (including overall survival [OS]) and biomarker objectives were exploratory. Tumor responses were assessed by the investigators per RECIST v1.1. Results: 31 GC pts were included; median age was 63 years; 18 pts were male, 13 were female. By the data cutoff date (May 31, 2022), 29 pts discontinued (26 due to disease progression, 3 due to adverse events). 8 Pts had a partial response (PR); the ORR was 25.8% (95% CI 11.9–44.6). The median PFS was 2.69 months (95% CI 1.91–2.99). The median OS was 7.85 months (95% CI 4.47–not estimable). The 6-month OS rate was 61.3%; the 9-month OS rate was 44.7%. 30 Pts had ≥1 treatment-related TEAE, most commonly neutropenia (n = 24); 25 pts had at least 1 grade ≥3 treatment-related TEAE, most commonly neutropenia (n = 22). 16 Pts had ≥1 TEAE resulting in dose reduction of E7389-LF. 4 Pts had ≥1 TEAE resulting in withdrawal of E7389-LF or nivolumab, including asthma, cerebral hemorrhage, decreased appetite, pulmonary edema, and upper gastrointestinal hemorrhage (each n = 1). 29 Pts had an evaluable PD-L1 combined positive score (CPS); 5 of 20 pts (25.0%) with a CPS of < 5 and 2 of 9 (22.2%) with a CPS of ≥5 had a PR. Increases in pharmacodynamic markers including vasculature-related markers were observed; antitumor immunity was observed per changes in interferon gamma (IFNγ) and IFNγ-related markers. Conclusions: E7389-LF 2.1 mg/m2 in combination with nivolumab 360 mg Q3W had promising efficacy for pretreated GC, as evidenced by the notable ORR of 25.8% as well as by PFS and OS. No new safety signals were identified for this combination. Biomarker changes suggested vascular remodeling activity and enhancement of antitumor immunity via IFNγ signaling. Clinical trial information: NCT04078295 .

Clinical therapeutic effects of neoadjuvant chemotherapy in resectable pancreatic cancer

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Background: Results from the phase III Prep-02/JSAP-05 trial demonstrated the efficacy and safety of gemcitabine plus S-1 as neoadjuvant chemotherapy for resectable pancreatic cancer. However, consensus on neoadjuvant chemotherapy for pancreatic cancer has not yet been established, and the effects of neoadjuvant therapy on clinical features of the tumor and improvement in prognosis have not been fully investigated. We aimed to investigate the effect of neoadjuvant chemotherapy on resectable pancreatic cancer. Methods: Between 2013 and 2021, 291 patients who underwent curative resection for resectable pancreatic cancer at our hospital were enrolled. The patients were categorized into groups of those who received neoadjuvant chemotherapy (NAC group: n = 91) and those who received up-front surgery (US group: n = 200). Prognostic predictors were examined in (i) all patients, (ii) US group, and (iii) NAC group. Statistical significance was considered at p < 0.05. Results: The median follow-up periods were 20.7 and 33.2 months in the NAC and US groups, respectively. In the NAC group, 84 of the 91 patients (94.5%) received gemcitabine-based chemotherapy, and three (3.3%) received chemoradiotherapy. There was no difference in overall survival (OS) and recurrence free survival (RFS) between the two groups. In the background, the NAC group had lower preoperative CA19-9 levels, lower lymph node ratio (LNR), and smaller tumor size than in the US group. During multivariable analysis of OS, preoperative CA19-9 levels, LNR, modified Glasgow prognostic score (mGPS), resection margin, and tumor size were identified as possible prognostic predictors in all patients and in the US group, whereas LNR and mGPS were identified in the NAC group. Conclusions: The prognostic significance of preoperative CA19-9 level, tumor size, and LNR were counteracted in the NAC group. These findings may indicate the effect of neoadjuvant chemotherapy for resectable pancreatic cancer.

Clinical Course of Vitamin B12 Deficiency and Associated Risk Factors in Patients After Total Gastrectomy for Gastric Cancer

BACKGROUND/AIM

Patients are at-risk for vitamin B12 deficiency after total gastrectomy due to a lack of intrinsic factors. The aim of the study was to clarify the clinical course and risk factors for vitamin B12 deficiency after total gastrectomy for gastric cancer patients.

PATIENTS AND METHODS

Patients who underwent curative resection for gastric cancer were selected from the medical records of the Yokohama City University from 2000 to 2020. A logistic regression analysis was performed to identify risk factors for vitamin B12 deficiency.

RESULTS

We evaluated 47 patients. The median serum vitamin B12 levels before surgery were 359 pg/ml, while those at 3, 6, 9, and 12 months after surgery these were 255 pg/ml, 197.5 pg/ml, 195 pg/ml, and 206 pg/ml, respectively. Univariate analyses to identify factors associated with vitamin B12 deficiency at 6 months after surgery showed that the occurrence of postoperative complications was a significant risk factor (OR=6.347, 95%CI=1.607-25.774, p=0.009), while adjuvant chemotherapy was a marginally significantly risk factor (OR=3.562, 95%CI=0.877-14.477, p=0.076).

CONCLUSION

Almost half of the patients were diagnosed with vitamin B12 deficiency at 6 months after total gastrectomy for gastric cancer. In addition, the occurrence of postoperative complications and adjuvant chemotherapy were risk factors for vitamin B12 deficiency at 6 months after surgery.

Non-CpG sites preference in G:C > A:T transition of TP53 in gastric cancer of Eastern Europe (Poland, Romania and Hungary) compared to East Asian countries (China and Japan)

AIM

Mutation spectrum of TP53 in gastric cancer (GC) has been investigated world-widely, but a comparison of mutation spectrum among GCs from various regions in the world are still sparsely documented. In order to identify the difference of TP53 mutation spectrum in GCs in Eastern Europe and in East Asia, we sequenced TP53 in GCs from Eastern Europe, Lujiang (China), and Yokohama, Kanagawa (Japan) and identified the feature of TP53 mutations of GC in these regions.

SUBJECTS AND METHOD

In total, 689 tissue samples of GC were analyzed: 288 samples from East European populations (25 from Hungary, 71 from Poland and 192 from Romania), 268 from Yokohama, Kanagawa, Japan and 133 from Lujiang, Anhui province, China. DNA was extracted from FFPE tissue of Chinese, East European cases; and from frozen tissue of Japanese GCs. PCR products were direct-sequenced by Sanger method, and in ambiguous cases, PCR product was cloned and up to 8 clones were sequenced. We used No. NC_000017.11(hg38) as the reference sequence of TP53. Mutation patterns were categorized into nine groups: six base substitutions, insertion, deletion and deletion-insertion. Within G:C > A:T mutations the mutations in CpG and non-CpG sites were divided. The Cancer Genome Atlas data (TCGA, ver.R20, July, 2019) having somatic mutation list of GCs from Whites, Asians, and other ethnicities were used as a reference for our data.

RESULTS

The most frequent base substitutions were G:C > A:T transition in all the areas investigated. The G:C > A:T transition in non-CpG sites were prominent in East European GCs, compared with Asian ones. Mutation pattern from TCGA data revealed the same trend between GCs from White (TCGA category) vs Asian countries. Chinese and Japanese GCs showed higher ratio of G:C > A:T transition in CpG sites and A:T > G:C mutation was more prevalent in Asian countries.

CONCLUSION

The divergence in mutation spectrum of GC in different areas in the world may reflect various pathogeneses and etiologies of GC, region to region. Diversified mutation spectrum in GC in Eastern Europe may suggest GC in Europe has different carcinogenic pathway of those from Asia.

Should the splenic hilar lymph node be dissected for the management of adenocarcinoma of the esophagogastric junction?

BACKGROUND

Splenic hilar lymphadenectomy is not recommended for advanced proximal gastric cancer that does not invade the greater curvature according to the results of the previous studies. The efficacy of splenic hilar lymphadenectomy for type II and type III adenocarcinomas of the esophagogastric junction and easy spread to the greater curvature of the stomach remains unclear. This study aimed to investigate the efficacy of splenic hilar lymphadenectomy and identify the risk factors for metastasis to splenic hilar nodes.

METHODS

We examined patients who underwent R0/1 gastrectomy for Siewert types II and III at a single high-volume center in Japan. We analyzed the metastatic incidence, therapeutic value index, and risk factors for splenic hilar lymph node metastasis.

RESULTS

We examined 126 patients (74, type II; 52, type III). Splenectomy was performed in 76 patients. Metastatic incidence and the therapeutic value index of splenic hilar lymph nodes in patients with type II and type III tumors were 4.5% and 0, and 21.9% and 9.4, respectively. In the patients who underwent splenectomy, we identified Siewert type III tumors (odds ratio: 6.93, 95% confidence interval: 1.24-38.8, p = 0.027) and tumor location other than the lesser curvature (odds ratio: 7.36, 95% confidence interval: 1.32-41.1, p = 0.023) to be independent risk factors. The metastatic incidence (46.2%) and therapeutic value index (15.4) were high in patients with both risk factors.

CONCLUSIONS

Splenic hilar lymphadenectomy may contribute to the survival of patients with Siewert type III tumors, especially when the predominant location is not the lesser curvature.

The Albumin-Bilirubin Score Is a Prognostic Factor for Gastric Cancer Patients Who Receive Curative Treatment

BACKGROUND/AIM

The albumin-bilirubin (ALBI) score is a promising tool for the evaluation of the perioperative hepatic function. The present study aimed to evaluate the clinical impact of the preoperative ALBI status in patients with gastric cancer (GC) who received curative treatment.

PATIENTS AND METHODS

The present study included 244 patients who underwent curative treatment for GC between 2005 and 2018. The risk factors for overall survival (OS) and recurrence-free survival (RFS) were identified.

RESULTS

Based on the 3- and 5-year OS rates, we set the cut-off value for the ALBI score at -2.7849. The 3- and 5-year OS rates were 87.3% and 80.9%, respectively, in the ALBI-low group, and 66.9% and 60.6% in the ALBI-high group; these differences were statistically significant (p<0.001). The ALBI score was included in the final multivariate analysis model [Hazard ratio (HR)=2.120, 95% confidence interval (CI)=1.177-3.818, p=0.012]. Similar results were observed for RFS. In addition, the ALBI score correlated with the introduction of postoperative adjuvant chemotherapy.

CONCLUSION

The preoperative ALBI score correlated with both the OS and RFS of GC patients as well as the clinical course of adjuvant chemotherapy. Taken together, the ALBI score is a promising prognostic factor for GC.

Clinical Significance of EREG Gene Expression in Gastric Cancer Tissue After Curative Surgery

BACKGROUND/AIM

Epiregulin (EREG) is a ligand of the epidermal growth factor receptor (EGFR) and promotes tumour progression mainly by stimulating the EGF pathway. We investigated the clinical significance of EREG mRNA expression in cancer tissues from patients with gastric cancer (GC) in pathological (p) Stage II/III who have undergone curative surgery.

PATIENTS AND METHODS

Expression of EREG mRNA was measured in cancer tissues obtained from 253 patients with pStage II/III GC who underwent curative surgery. Patients were divided into groups based on high or low expression of EREG mRNA. We examined the relationship between EREG mRNA expression levels and clinicopathological features and survival.

RESULTS

Clinicopathological features did not vary between the high and low EREG mRNA expression groups. Overall survival was significantly lower in the high-expression group compared to that in the low-expression group (5-year survival probability: 55.0% vs. 73.0%; p=0.005). Multivariate analysis showed EREG mRNA expression to be an independent predictor of poor survival (hazard ratio=1.794; 95% confidence interval=1.186-2.712; p=0.006).

CONCLUSION

Expression of EREG mRNA in cancer tissue from patients with pStage II/III GC may be a useful prognostic marker after curative surgery.

Phase II Study of a Multi-center Randomized Controlled Trial to Evaluate Oral Vitamin B12 Treatment for Vitamin B12 Deficiency After Total Gastrectomy in Gastric Cancer Patients

BACKGROUND/AIM

This prospective multi-central randomized phase II trial evaluated the efficacy and safety of oral Vitamin B12 500 μg/day replacement compared with oral Vitamin B12 1,500 μg/day in patients with Vitamin B12 deficiency after total gastrectomy for gastric cancer.

PATIENTS AND METHODS

Patients were randomly assigned to receive oral Vitamin B12 500 μg/day or Vitamin B12 1,500 μg/day in a 1:1 ratio with a minimization method. The primary endpoint was the incidence of a normal serum Vitamin B12 level at three months after treatment.

RESULTS

From January 2018 to December 2021, 3 institutions collaborated with the present study, and 74 patients were registered from these 3 institutions. The study was prematurely closed due to poor accrual after reaching almost 50% of its goal. Among the 74 recruited patients, 36 were allocated to the Vitamin B12 500 μg/day arm and 38 to Vitamin B12 1,500 μg/day arm. The incidences of patients with a normal Vitamin B12 level at 3 months (serum Vitamin B12 level >200 pg/ml) were 91.7% (33/36) in the Vitamin B12 500 μg/day arm and 100% (38/38) in the Vitamin B12 1,500 μg/day arm (p=0.3587). The types of clinical symptoms with Vitamin B12 deficiency that improved with Vitamin B12 treatment and the degree of improvement were also similar.

CONCLUSION

Although the primary endpoint of the present study was not met, it was found that oral Vitamin B12 500 μg/day replacement is as effective and safe as oral Vitamin B12 1,500 μg/day replacement for Vitamin B12 deficiency.

Feasibility and Safety of Oral Nutritional Supplementation with High-Density Liquid Diet After Total Gastrectomy for Gastric Cancer

INTRODUCTION

Patients requiring total gastrectomy for gastric cancer experience a decrease in food intake leading to severe body weight loss after surgery. This loss may be prevented using a high-density liquid diet of high caloric content and minimal volume. This phase II study evaluated the feasibility and safety of a high-density liquid diet (UpLead^®; Terumo Corporation, Tokyo, Japan) after total gastrectomy.

METHODS

UpLead^® (1 pack, 100 mL, 400 kcal/day) was administered after surgery for 28 days. The primary endpoint was the % relative dose intensity of 28 days of UpLead intake^®. The secondary endpoint was % body weight loss at 1 and 3 months after surgery. The sample size was 35 considering expected and threshold values of 80 and 60%, respectively, with a one-sided alpha error of 10% and statistical power of 80%.

RESULTS

Among 35 patients enrolled before surgery between April 2018 and December 2019, 29 patients who could initiate UpLead^® after surgery were analyzed. Seven patients had interrupted UpLead^® intake due to taste intolerance (n = 6) and due to a duodenal stump fistula (n = 1). The remaining 22 patients completed 28 days of UpLead^® intake, including temporary interruption, with no associated adverse events. The median relative dose intensity was 25.8% (95% confidence interval: 20.6-42.0%). The median body weight loss at 1 and 3 months after surgery was 7.2% (range: 3.2-13.9%) and 13.1% (range: 2.5-20.4%), respectively.

CONCLUSIONS

Oral nutritional supplementation with a high-density liquid diet (UpLead^®) was safely administered but was not feasible after total gastrectomy for gastric cancer. Clinical trial registration number UMIN000032291.

Phase IIb study of pembrolizumab combined with S-1 + oxaliplatin or S-1 + cisplatin as first-line chemotherapy for gastric cancer

The KEYNOTE‐659 study evaluated the efficacy and safety of first‐line pembrolizumab plus S‐1 and oxaliplatin (SOX) (cohort 1) or S‐1 and cisplatin (SP) (cohort 2) for advanced gastric/gastroesophageal junction (G/GEJ) cancer in Japan. Herein, we update the results of cohort 1 and describe the results of cohort 2. This open‐label phase IIb study enrolled patients with advanced programmed death‐ligand 1 (PD‐L1)‐positive (combined positive score ≥ 1) human epidermal growth factor receptor 2 (HER2)‐negative G/GEJ adenocarcinoma. The primary end‐point was the objective response rate (ORR). Other end‐points were duration of response (DOR), disease control rate (DCR), progression‐free survival (PFS), overall survival (OS), and safety. One hundred patients were enrolled. In cohorts 1 and 2, median follow‐up time was 16.9 and 17.1 months; ORR (central review), 72.2% and 80.4%; DOR, 10.6 and 9.5 months; DCR (central review), 96.3% and 97.8%; median PFS (central review), 9.4 and 8.3 months; and median OS, 16.9 and 17.1 months, respectively. Treatment‐related adverse events (TRAEs) occurred in all patients, including peripheral sensory neuropathy (94.4%, cohort 1), decreased neutrophil count (82.6%, cohort 2), nausea (59.3% and 60.9% in cohorts 1 and 2), and decreased appetite (61.1% and 60.9% in cohorts 1 and 2). Grade 3 or higher TRAEs were reported by 59.3% (cohort 1) and 78.3% (cohort 2), including decreased platelet count (14.8%, cohort 1) and decreased neutrophil count (52.2%, cohort 2). Pembrolizumab in combination with SOX or SP showed favorable efficacy and safety in patients with PD‐L1‐positive, HER2‐negative G/GEJ adenocarcinoma.

Combination of oligo-fractionated irradiation with nivolumab can induce immune modulation and replacement of T cell clones in patients with gastric cancer (phase I/II clinical study)

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Background: Although basic, translational and clinical research suggest a possibility of synergistic effect of radiation-induced immunogenic cell death with immune checkpoint inhibitors, the effectiveness of the combination therapy is not fully established. Therefore, we conducted a single-arm, phase 1/2 trial (ClinicalTrials.gov, NCT03453164) in gastric cancer (GC) patients treated with a combination of nivolumab and oligo-fractionated irradiation (22.5 Gy/5 fractions/5 days). Methods: Eligible patients (n = 40) had un-resectable advanced or recurrent GC which progressed after primary and secondary chemotherapy with more than one lesion assessable in diagnostic imaging (one lesion must be ≥2cm). PBMCs from enrolled patients underwent high-dimensional flow cytometry-based, multiplexed MHC multimer analysis using a total of 46 tumor-associated antigens (TAA) and 10 virus epitopes and next-generation sequencing-based repertoire analysis of TCR β-chain. Results: The disease control rate (DCR) for the non-irradiated target as abscopal effect as the primary endpoint was 22.5%, and the DCR for the irradiated lesion was 40.0%. The median survival time was 230 days (157-330 days, 95%CI) and probability of 1-year survival rate was 28.6%. Although most TAA-specific T cells could be tracked longitudinally pre- and post-treatment, some several novel TAA-specific CD8 T cells were detected de novo after irradiation, indicating that potential irradiation-driven antigen spreading. Moreover, irradiation was associated with phenotypical changes of TAA-specific CD8 T cells towards higher expressions of KLRG1, HLA-DR, TIGIT and CD160 and lower expression of CD27 and CD127. Furthermore, the T cell clonality evaluated by the inverted Pielou’s evenness indicated that longer survival patients had more diverse TCR beta repertoire during treatment in comparison to shorter survivors. Also, we confirmed several new sequence-reads after radiation and nivolumab treatment in the top 30 most frequent clonotypes. Conclusions: Taken together, our results suggest that irradiation may induce, through immunogenic cell death, an immune-modulating effect with potential antigen spreading and a more diverse TCR repertoire, ultimately resulting in better survival during combination therapy of radiation with nivolumab. Clinical trial information: NCT03453164.

Chemotherapy-induced Reversion of Mutant RAS to Wild-type RAS in Metastatic Colorectal Cancer

BACKGROUND/AIM

Secondary mutation of mutated RAS, induced by chemotherapy, is thought to be rare. However, introduction of liquid biopsy (LB) has made it possible to monitor RAS status in patients' plasma throughout the course of chemotherapy for metastatic colorectal cancer (mCRC), and disappearance of the RAS mutation (RAS-mt), i.e., the NeoRAS-wt phenomenon, has been reported and is receiving attention, especially with respect to treatment implications.

PATIENTS AND METHODS

A prospective study of 129 patients undergoing chemotherapy for mCRC (RAS-wt, n=65; RAS-mt, n=64) was carried out. Plasma RAS status was monitored in these patients by LB. Relations between secondary genetic change, chemotherapy, and 6-month disease outcomes were analyzed. The effect of anti-EGFR mAb therapy on NeoRAS-wt mCRC was also examined.

RESULTS

NeoRAS-wt was detected in 27 (43.5%) RAS-mt patients overall and in all patients with a G12S or Q61H mutation. First-line treatment was more effective among NeoRAS-wt patients than non-NeoRAS-wt patients (70.9% vs. 48.6% overall response rate, p=0.087), and the time from treatment to LB was shorter in this group. Six-month outcomes were significantly better in the NeoRAS-wt group (p<0.001), and conversion to NeoRAS-wt was found to be predictive of a good outcome (OR=7.886, 95% CI=2.458-25.30; p<0.001). Anti-EGFR mAb therapy was found to restrict disease progression in NeoRAS-wt patients.

CONCLUSION

Conversion to NeoRAS-wt is relatively frequent, and it may predict good responses to treatment. Anti-EGFR mAb therapy was effective for our NeoRAS-wt patients. Detection of NeoRAS-wt by LB may significantly change the indication for anti-EGFR mAb therapy and the mCRC treatment strategy.

The Systemic Inflammation Score Is an Independent Prognostic Factor for Esophageal Cancer Patients who Receive Curative Treatment

BACKGROUND/AIM

Perioperative systemic inflammation affects the long-term oncological outcomes in cases of malignancies. We evaluated the clinical impact of the preoperative systemic inflammation score (SIS) in resectable esophageal cancer patients who received curative treatment.

PATIENTS AND METHODS

This study included 168 patients who underwent curative surgery followed by perioperative adjuvant chemotherapy for esophageal cancer between 2005 and 2018. The risk factors for overall survival (OS) and recurrence-free survival (RFS) were identified.

RESULTS

Based on the 3- and 5-year OS rate, we set the cut-off value for SIS at 2 in the preset study. Among the 168 total patients, 119 were categorized as the Low-SIS group, and 49 were categorized as the High-SIS group. The respective 3- and 5-year OS rates were 61.9% and 52.4% in the Low-SIS group and 33.3% and 26.6% in the High-SIS group. There were significant differences in OS (p<0.001). The SIS was therefore selected for the final multivariate analysis model (hazard ratio=2.094, 95% confidence interval=1.355-3.234, p<0.001). On comparing the perioperative clinical course between the High- and Low-SIS groups, there were significant differences in the rate of postoperative anastomosis leakage of grade ≥2 between the groups (61.5% in the High-SIS group vs. 30.3% in the Low-SIS group; p=0.021).

CONCLUSION

The systemic inflammation score had a clinical effect on the long-term oncological outcomes in esophageal cancer patients, suggesting that it might be a promising prognostic factor for esophageal cancer patients.