Clinical efficacy of protein-bound polysaccharide K in patients with gastric cancer undergoing chemotherapy with an oral fluoropyrimidine (S-1)

Research Progress on the Mechanisms of Polysaccharides against Gastric Cancer

Gastric cancer is a common type of cancer that poses a serious threat to human health. Polysaccharides are important functional phytochemicals, and research shows that polysaccharides have good anti-gastric cancer effects. We collated all relevant literature published from 2000 to 2020 and found that more than 60 natural polysaccharides demonstrate anti-gastric cancer activity. At the present, the sources of these polysaccharides include fungi, algae, tea, Astragalus membranaceus, Caulis Dendrobii, and other foods and Chinese herbal medicines. By regulating various signaling pathways, including the PI3K/AKT, MAPK, Fas/FasL, Wnt/β-catenin, IGF-IR, and TGF-β signaling pathways, polysaccharides induce gastric cancer cell apoptosis, cause cell cycle arrest, and inhibit migration and invasion. In addition, polysaccharides can enhance the immune system and killing activity of immune cells in gastric cancer patients and rats. This comprehensive review covers the extraction, purification, structural characterization, and mechanism of plant and fungal polysaccharides against gastric cancer. We hope this review is helpful for researchers to design, research, and develop plant and fungal polysaccharides.

Protein-bound polysaccharide K prolonged overall survival in gastric cancer patients from a non-Japanese Asian country who received gastrectomy and adjuvant chemotherapy

Adding protein-bound polysaccharide K (PSK) to adjuvant chemotherapy with mitomycin and fluorouracil after gastrectomy for gastric cancer was demonstrated to improve survival in a previous study in Japan. However, the efficacy of PSK outside Japan and in combination with other adjuvant chemotherapeutic agents remains unclear. The aims of this study were to evaluate the efficacy of PSK. We conducted a population-based historical cohort study using the National Health Insurance Research Database of Taiwan. We performed sensitivity analysis with propensity score matching to control for possible confounders. Patients who used PSK (PSK group) were matched at a 1:4 ratio to those who had never used PSK (control group) after adjusting for covariates including sex, age, urbanization, income and comorbidities. The primary outcome was overall survival. Multivariate hazard ratios from competing risk analysis were calculated by adjusting for demographic data and all confounding factors. From 1999 to 2008, we identified 10,617 patients with gastric cancer received gastrectomy and adjuvant chemotherapy. 1295 patients used PSK (PSK group) and 5180 patients never used PSK (control group) were analyzed after propensity score matching. The median overall survival was 6.49 years (95% confidence interval [CI] 5.22-7.63) in the PSK group and 3.59 years (95% CI 3.38-3.80) in the control group. After adjusting for age, sex, urbanization, income, and comorbidities, adding PSK to adjuvant chemotherapy was the most significant prognostic factor for improved survival (hazard ratio 0.76, P < .0001). Adjuvant chemotherapy combined with PSK significantly prolonged overall survival in gastric cancer patients after gastrectomy.

Successful Conversion Surgery for Advanced Gastric Cancer With Multiple Liver Metastases Following Ramucirumab Plus Paclitaxel Combination Treatment

AIM

To present the case of a patient with unresectable gastric cancer showing a remarkable effect by second-line drug treatment with ramucirumab plus paclitaxel and conversion surgery.

CASE REPORT

A 68-year-old woman who was diagnosed with gastric cancer was referred to us. Esophagogastroduodenoscopy showed an ulcerated lesion with an irregular nodulated border in the lower third of the stomach, and histology of biopsied specimens indicated a poorly differentiated adenocarcinoma. Enhanced computed tomography revealed extensive invasion of the liver, and the patients was treated using S-1 plus oxaliplatin as first-line chemotherapy. Because she developed liver metastases, the treatment regimen was changed to ramucirumab plus paclitaxel as the second-line treatment. After four cycles of weekly paclitaxel with ramucirumab treatment, the liver metastases had completely disappeared. Because no other metastatic lesions in other organs were detected, we performed total gastrectomy with D2 lymphadenectomy. The macroscopic findings of the surgically resected specimen revealed an ulcerated lesion with an irregularly modulated lesion measuring 9.5×4.5 cm. Pathological analysis demonstrated a poorly differentiated adenocarcinoma in the stomach, with invasion to the liver through the serosal layer, and seven lymph node metastases. The postoperative course was unremarkable, and she received ramucirumab in combination with paclitaxel treatment. However, liver metastasis appeared at 4 months after the operation, for which she was treated with irinotecan. Although the patient continued to receive irinotecan chemotherapy for 10 months, her general condition gradually deteriorated, and she was started on best supportive care 13 months after conversion surgery.

CONCLUSION

Conversion surgery may prolong survival not only through first-line but also second-line treatments in selected patients with unresectable advanced gastric cancer; however, assessments of additional cases and further studies are required to establish this treatment strategy.

Herb-drug interactions between the medicinal mushrooms Lingzhi and Yunzhi and cytotoxic anticancer drugs: a systematic review

BACKGROUND

Lingzhi and Yunzhi are medicinal mushrooms commonly used with cytotoxic chemotherapy in cancer patients in Asian countries. The current systematic review aims to identify potential pharmacokinetic or pharmacodynamic interactions from the existing literature to ensure their effective and safe combination usage in cancer patients.

METHODS

A systematic search was conducted on nine major Chinese and English databases, including China Journal Net, Allied and Complementary Medicine Database, and Ovid MEDLINE®, etc., to identify clinical, animal, and in-vitro studies that evaluate the effect of combined use of Lingzhi or Yunzhi with cytotoxic drugs. The Jadad scale was used to assess the quality of clinical studies.

RESULTS

This search identified 213 studies, including 77 clinical studies that reported on the combined use of cytotoxic drugs with Yunzhi (n = 56) or Lingzhi (n = 21). Majority of these clinical studies demonstrated modest methodological quality. In clinical practice, the most commonly used cytotoxic drugs with Lingzhi were cisplatin, 5-fluorouracil (5-FU) and paclitaxel, whereas Tegafur/uracil (UFT)/Tegafur, 5-FU, and mitomycin were the ones used more often with Yunzhi. Only two clinical pharmacokinetic studies were available showing no significant interactions between Polysaccharide K (PSK) and Tegafur. From the pharmacodynamic interactions perspective, combination uses of Yunzhi/Lingzhi with cytotoxic drugs in clinical practice could lead to improvement in survival (n = 31) and quality of life (n = 17), reduction in tumor lesions (n = 22), immune modulation (n = 38), and alleviation of chemotherapy-related side effects (n = 14) with no reported adverse effects.

CONCLUSION

Our findings suggest that the clinical combination use of Lingzhi or Yunzhi with cytotoxic drugs could enhance the efficacy and ameliorate the adverse effects of cytotoxic drugs, leading to improved quality of life in cancer patients. More high quality clinical studies including pharmacokinetic herb-drug interactions studies are warranted to verify these observations and mechanisms involved. Based on the high quality clinical data, pharmacoepidemiology methods and bioinformatics or data mining could be adopt for further identification of clinical meaningful herb-drug interactions in cancer therapies.

Pathological Complete Response by S-1 Chemotherapy in Advanced Gastric Cancer

A pathological complete response (pCR) to treatment for gastric cancer is a rare event, even when powerful treatment regimens are used. Herein, a case of 61-year-old male referred to our hospital with advanced gastric cancer who achieved a pCR following chemotherapy using S-1, and subsequently underwent total gastrectomy is reported. His initial esophagogastroduodenoscopy (EGD) revealed an irregular, nodular, ulcerated lesion in the upper third of the stomach that was analyzed by biopsy to be a moderately differentiated adenocarcinoma. Abdominal contrast-enhanced computed tomography (CT) showed gastric wall thickening and lymph node swelling in the perigastric area. The patient was clinically diagnosed with cT3N1M0, stage IIB advanced gastric cancer. The patient decided against curative surgery due to his work circumstances and was started on S-1 (80 mg/m2) chemotherapy administered orally twice a day for 4 weeks, followed by 2 weeks of no chemotherapy. After four such courses of systemic S-1 chemotherapy, EGD showed a small, reddened lesion with aggregated, whitish lines. The gastric wall thickening and lymphadenopathy in the perigastric area were also reduced remarkably. The patient subsequently agreed to surgery, undergoing total gastrectomy with D2 lymphadenectomy. Gross examination of the surgically resected specimen showed a slightly erythrogenic, flat lesion measuring 1.5×1.0 cm. Pathological examination of the resected specimen and harvested lymph nodes detected no malignant cells. The postoperative course was uneventful. The patient has continued to receive S-1 chemotherapy, with no evidence of recurrence at 4 months post-surgery. To the best of our knowledge, this is only the second case of a gastric cancer patient achieving a pCR by S-1 monotherapy reported in the English literature and indicates the potential adoption of curative resection after S-1 chemotherapy as a treatment strategy for advanced gastric cancer.

Successful treatment of liver metastases arising from early gastric cancer achieved clinical complete response by nivolumab

BACKGROUND

Although a recent randomized clinical trial has demonstrated that the objective response rate to nivolumab for metastatic gastric cancer was 11.2%, there was no patients confirmed complete response. Herein, we report on a case of liver metastasis arising from early gastric cancer in which a complete clinical response was achieved to nivolumab as third-line therapy.

CASE PRESENTATION

A 77-year-old man was referred to Kochi Medical School Hospital for the treatment of liver metastases from gastric cancer. The patient had undergone laparoscopic total gastrectomy with regional lymph node dissection 30 months prior for early gastric cancer, with a final diagnosis of T1N0M0, stage IA. The patient developed solitary splenic metastasis measuring 42 mm 28 months later and underwent splenectomy because there was no evidence of further metastatic lesions in any other organ. The patient was treated with S-1 plus oxaliplatin based on negative immunohistochemical staining of the resected specimens for human epidermal growth factor receptor 2 (HER2). Four months after the splenectomy, the patient developed multiple liver metastases and was treated with ramucirumab plus paclitaxel. Because of disease progression, the patient was administered 3 mg/kg, i.v., nivolumab every 2 weeks. After 4 cycles of systemic treatment using nivolumab, abdominal computed tomography revealed marked shrinkage of the liver metastases. After 12 cycles of nivolumab, the liver metastases had disappeared completely. The patient did not develop any adverse reactions, including immune-reactive adverse events, during treatment. The patient continues to receive nivolumab, and there is no evidence of disease recurrence in the 8-month period since starting nivolumab.

CONCLUSIONS

To the best of our knowledge, this is the first case report in the English literature of a gastric cancer patient achieving a complete clinical response to nivolumab, and highlights the potential for successful treatment of metastatic gastric cancer using nivolumab.

Medicinal mushrooms as an attractive new source of natural compounds for future cancer therapy

Medicinal mushrooms have been used throughout the history of mankind for treatment of various diseases including cancer. Nowadays they have been intensively studied in order to reveal the chemical nature and mechanisms of action of their biomedical capacity. Targeted treatment of cancer, non-harmful for healthy tissues, has become a desired goal in recent decades and compounds of fungal origin provide a vast reservoir of potential innovational drugs. Here, on example of four mushrooms common for use in Asian and Far Eastern folk medicine we demonstrate the complex and multilevel nature of their anticancer potential, basing upon different groups of compounds that can simultaneously target diverse biological processes relevant for cancer treatment, focusing on targeted approaches specific to malignant tissues. We show that some aspects of fungotherapy of tumors are studied relatively well, while others are still waiting to be fully unraveled. We also pay attention to the cancer types that are especially susceptible to the fungal treatments.

Rhizopus nigricans polysaccharide activated macrophages and suppressed tumor growth in CT26 tumor-bearing mice

In this study, a homogeneous polysaccharide (RPS-1) was extracted from liquid-cultured mycelia of Rhizopus nigricans. The weight-average molecular weight of RPS-1 was 1.617 × 10⁷ g/mol and structural characterization indicated that RPS-1 was a non-starch glucan which consisted of a backbone structure of (1→4)-linked α-d-glucopyranosyl residues substituted at the O-6 position with α-d-glucopyranosyl branches. RPS-1 stimulated the production of nitric oxide and tumor necrosis factor-α by triggering phosphorylation of mitogen-activated protein kinases and nuclear translocation of nuclear factor kappa B p65 in RAW 264.7 macrophage cells. Moreover, intragastric administration of RPS-1 improved the immune function of CT26 tumor-bearing mice and significantly inhibited the growth of transplanted tumor. In combination with 5-FU, RPS-1 enhanced antitumor activity of 5-FU and alleviated its toxicity on immune system. These findings suggested that RPS-1 has the potential for the development of functional foods and dietary supplements.

Pretreatment neutrophil-to-lymphocyte ratio is associated with outcome of advanced-stage cancer patients treated with immunotherapy: a meta-analysis

BACKGROUND

To investigate the association between pretreatment blood neutrophil-to-lymphocyte ratio (NLR) and clinical outcomes for advanced-stage cancer patients treated with immunotherapy.

METHODS

We conducted a comprehensive literature search to assess the relationship between pretreatment blood NLR and overall survival (OS) or progression-free survival (PFS) in advanced-stage cancer patients treated with immunotherapy. Published data including hazard ratios (HRs) and related 95% confidence interval (CI) were extracted. Pooled estimates of treatment outcomes were calculated using RevMan 5.3.5.

RESULTS

Twenty-seven studies with 4647 patients were included in the current study. The pooled results suggested that high pretreatment blood NLR was correlated with significant shorter OS (HR = 1.98, 95% CI 1.66-2.36, P < 0.001) and PFS (HR = 1.78, 95% CI 1.48-2.15, P < 0.001). Subgroup analysis stratified by study targets revealed that anti-VEGF/VEGFR therapy (HR = 2.04, 95% CI 1.61-2.60, P < 0.001) and immune checkpoints blockade (HR = 2.16, 95% CI 1.86-2.51, P < 0.001) were significantly associated with inferior OS while other targets (HR = 1.63, 95% CI 0.89-2.99, P = 0.120) were not associated with OS. There was no correlation between distinct NLR cutoff values and OS ([Formula: see text] = 0.218, P = 0.329) or PFS benefit ([Formula: see text] = - 0.386, P = 0.140). Of note, HRs of PFS showed significant correlation with HRs of OS ([Formula: see text] = 0.656, P = 0.015).

CONCLUSION

Elevated pretreatment blood NLR was a promising prognostic and predictive biomarker for advanced-stage cancer patients treated with immunotherapy.

Conversion surgery after S-1 plus oxaliplatin combination chemotherapy for advanced gastric cancer with multiple liver metastases

Conversion therapy for gastric cancer is a new therapeutic concept. We report a case of a patient with advanced gastric cancer who underwent conversion surgery due to a remarkable regression of multiple liver metastases following chemotherapy. A 71-year-old man was referred to our hospital with gastric cancer. Esophagogastroduodenoscopy (EGD) revealed an irregular, nodular, ulcerated lesion in the lower third of the stomach. Analysis of biopsy specimens revealed a poorly differentiated adenocarcinoma. Abdominal contrast-enhanced computed tomography (CT) showed multiple liver mass lesions. The patient was clinically diagnosed with advanced gastric cancer with liver metastases and received S-1 plus oxaliplatin chemotherapy. After 6 cycles of chemotherapy, CT and magnetic resonance imaging showed complete resolution of the liver metastases, and EGD detected mucosal irregularities only. Since there was no evidence of further metastatic lesions in other organs, the patient underwent distal gastrectomy with D2 lymphadenectomy. The gross appearance of the surgically resected specimen showed a slightly elevated tumor measuring 4.5 × 3.5 cm. Pathological examination confirmed the diagnosis of a moderately differentiated gastric adenocarcinoma invading the muscularis propria with no lymph node metastases. The postoperative course was uneventful. The patient has continued to receive S-1 and oxaliplatin chemotherapy, and there has been no evidence of recurrence for 3 months following the operation. We propose that conversion therapy might be an effective treatment for patients with advanced gastric cancer; however, further studies and assessments are needed to confirm and establish this treatment strategy.

Serum carbohydrate antigen 125 is a significant prognostic marker in patients with unresectable advanced or recurrent gastric cancer

PURPOSE

We evaluated the diagnostic and prognostic value of three tumor markers: carcino-embryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 125 (CA125), in the pretreatment serum of patients with unresectable advanced or recurrent gastric cancer.

METHODS

The subjects of this retrospective analysis were 245 patients with unresectable advanced or recurrent gastric cancer diagnosed at Kochi Medical School between 2007 and 2015. We ascertained the sensitivity of CEA, CA19-9, and CA125 to identify a certain survival time and then evaluated the relative prognosis of the patients.

RESULTS

The overall positive rates for each tumor marker in the study group were as follows: 57.6% (141/245) for CEA, 38.4% (94/245) for CA19-9, and 34.3% (84/245) for CA125; the sensitivity of these three biomarkers in combination was 73.1% (179/245). The median survival time of the CA125-positive patients was 4.5 months, which was significantly shorter than that of a normal range group (18.3 months, P < 0.001). Multivariate survival analysis identified that high CA125 was independently associated with a worse prognosis (HR 3.941; 95% CI 2.544-6.106; P < 0.001).

CONCLUSIONS

Pretreatment serum CA125 is a useful prognostic biomarker in patients with unresectable advanced or recurrent gastric cancer. Evaluating a panel of serum tumor biomarkers is a useful diagnostic tool as elevated values might be associated with poor survival.

Administration of polysaccharide from Panax notoginseng prolonged the survival of H22 tumor-bearing mice

BACKGROUND

Polysaccharides from various sources are being considered potential sources for the treatment of liver cancer. The aim of this study was to investigate the impact of polysaccharide isolated from Panax notoginseng (PPN) on the proliferation of H22 liver cancer cells and the survival of the tumor-bearing mice transplanted with H22 cells.

MATERIALS AND METHODS

Polysaccharide from PPN was added to the culture medium of mouse hepatoma H22 cells at different doses. Cell proliferation was assayed with a standard MTT assay. Survival rates of tumor-bearing mice were recorded. Peripheral blood lymphocytes were assayed by flow cytometry. Serum interleukin-2 levels in peripheral blood were measured by enzyme-linked immunosorbent assay.

RESULTS

Polysaccharide from PPN inhibited the growth of H22 cells and significantly prolonged the survival of tumor-bearing mice. The increase in activated CD4(+) T-cells and the elevation of serum interleukin-2 may contribute to the antitumor activity of PPN.

CONCLUSION

PPN has potential antitumor activity for the treatment of liver cancer.

Prognostic Value of the Preoperative Neutrophil to Lymphocyte Ratio in Resectable Gastric Cancer

This study aimed to investigate the prognostic value of the preoperative neutrophil to lymphocyte ratio (NLR) in resectable gastric cancer (GC). This was a retrospective review of 1030 patients with resectable GC managed between 2005 and 2011. Patients were stratified into 2 groups, those with a preoperative NLR >3.44 and those with a preoperative NLR ≤ 3.44. Clinicopathological data affecting patient prognosis were collected prospectively and analyzed. The high NLR (> 3.44) group had a higher proportion of a platelet to lymphocyte ratio > 132, tumor size > 4.8 cm, T4 lesions, metastatic tumors, a ratio of metastatic to examined lymph nodes >0.18, positive resection margins, and presence of vascular or lymphatic invasion than the low NLR (≤ 3.44) group. Patients with a high preoperative NLR had significantly lower 3- and 5-year overall survival rates than those with a low preoperative NLR (55.1% vs 71.0% and 47.2% vs 64.1%, respectively; P < 0.001). Preoperative NLR was a prognostic factor for resectable GC in multivariate analysis. More aggressive tumor behavior was observed in patients with resectable GC with a high preoperative NLR than in those with a low preoperative NLR. High preoperative NLR was an independent unfavorable prognostic factor. Measurement of this ratio may serve as a clinically accessible and useful biomarker for patient outcomes.