Current options in the management of gastrointestinal cancer

Bioactive Peptides: Potential Impact on the Treatment of Gastrointestinal Cancers

We have reviewed the potential use of bioactive peptides in the treatment of gastrointestinal (GI) malignancies, which are a significant cause of morbidity and mortality globally. Conventional therapies, such as surgery, chemotherapy, and radiotherapy, are associated with numerous side effects that may lead to longterm complications. Bioactive peptides are short-chain amino acids that can be extracted from natural sources or synthesized, and they have various potential health benefits, including anti-inflammatory, anti-hypertensive, antioxidant, antimicrobial, and anti-cancer properties. Bioactive peptides can be acquired from animal or plant sources, and can be classified based on their function, such as ACE-inhibiting, antimicrobial, and electrolyte- regulating peptides. Recent studies have demonstrated the promising role of bioactive peptides in tumor suppression, especially when combined with conventional therapies. In this study, we have reviewed the beneficial properties of bioactive peptides and their role in suppressing tumor activity. The mechanisms of bioactive peptides in tumor suppression are discussed. We have further reviewed the findings of preclinical and clinical studies that have investigated the application of bioactive peptides in the treatment of GI cancers. This review highlights the potential use of bioactive peptides as a promising treatment method for GI malignancies to increase the quality of life of GI cancer patients.

The role of oxaliplatin in the adjuvant setting of different Lauren's type of gastric adenocarcinoma after D2 gastrectomy: a real-world study

BACKGROUND

To compare the efficacy of oxaliplatin-based and oxaliplatin-free adjuvant chemotherapies in patients with different Lauren type gastric cancers after D2 gastrectomy.

METHODS

From our established gastric cancer database, patients with pathological stage II and III gastric cancer who received adjuvant chemotherapy after D2 gastrectomy at Zhongshan Hospital of Fudan University were analyzed. Patients who received different adjuvant chemotherapy regimens were divided into two subgroups: oxaliplatin-based and oxaliplatin-free subgroup. Clinical outcomes were analyzed according to pathological stage and different Lauren types.

RESULTS

From Jan 2010 to June 2017, a total of 580 patients met all the eligibility criteria and were enrolled. The median DFS for all the patients was 24.37 months and the median OS was 56.70 months. In patients with intestinal type gastric cancer, the median DFS of the oxaliplatin-based subgroup was significantly longer than that of oxaliplatin-free subgroup (48.73 vs. 18.33 months, P < 0.001). The median OS was not reached in the oxaliplatin-based subgroup and 54.33 months in the oxaliplatin-free subgroup (P = 0.006). In patients with diffuse type gastric cancer, neither DFS nor OS differed significantly between two subgroups. In multivariate analysis, oxaliplatin-based adjuvant chemotherapy was independent positive predictor of DFS (HR 0.40; 95% CI 0.28-0.59; P < 0.001) and OS (HR 0.35; 95% CI 0.20-0.62; P < 0.001) in patients with intestinal type gastric cancer.

CONCLUSIONS

The results of our study suggested that oxaliplatin-based adjuvant chemotherapy was more effective in patients with intestinal type gastric cancer after D2 gastrectomy but showed no more survival benefit in patients with diffuse type.

Oleanolic acid induces apoptosis of MKN28 cells via AKT and JNK signaling pathways

CONTEXT

Oleanolic acid (OA) belongs to the triterpenoid compound group existing widely in food, medicinal herbs and other plants. Its effects on gastric cancer cells and the mechanisms involved have not been investigated.

OBJECTIVE

This study aimed to substantiate whether OA induces apoptosis of gastric cancer cell line (MKN28) and to elucidate the molecular mechanism involved.

MATERIALS AND METHODS

Cell viability was assessed by MTT assay within the range of 0-160 μg/mL. The effects of OA (5, 10 and 20 μg/mL) on apoptosis of MKN28 cells were evaluated by flow cytometry, DNA fragmentation and mitochondrial membrane potential assays. Western blot and FQRT-PCR assays were used to investigate the mechanism of cell apoptosis induced by OA (5 and 10 μg/mL).

RESULTS

OA evidently inhibited cell viability with IC50 of 44.8 and 15.9 μg/mL at 12 and 24 h, respectively. Furthermore, OA increased JNK phosphorylation, decreased AKT phosphorylation, but did not affect p38 and ERK phosphorylation in MKN28 cells. In contrast, OA also significantly enhanced the mRNA expression levels of caspase 3, caspase 9 and Apaf-1 in MKN28 cells.

CONCLUSION

OA induces apoptosis of MKN28 cells via the mitochondrial pathway regulated by AKT and JNK signaling pathways.

Neoadjuvant treatment for gastric cancer

Surgery is still considered to be the mainstay for the treatment of localized gastric cancer with negative margins (R0-resection) and an adequate lymph-node-dissection (D2-lymphadenectomy). Unfortunately, most cases of gastric cancer are only diagnosed at an advanced stage due to frequent recurrences after primary resection in curative intent. In order to improve prognosis after curative resection, in the recent past, patients with locally advanced tumors were subjected to a pre-, peri-, or postoperative treatment. Interestingly, postoperative chemotherapy has significantly improved survival after gastric resection in Asia, adjuvant radiochemotherapy is favored in North America and perioperative chemotherapy is considered as a treatment of choice in Europe indicating region specific approach towards the treatment. Recently there has also been growing evidence of positive outcomes of neoadjuvant radiochemotherapy on patient survival. In the present article, we discuss the concepts of neoadjuvant treatment approach and provide recommendations to surgeons based on current evidence.

Neoadjuvant treatment for gastric cancer

Surgery is still considered to be the mainstay for the treatment of localized gastric cancer with negative margins (R0-resection) and an adequate lymph-node-dissection (D2-lymphadenectomy). Unfortunately, most cases of gastric cancer are only diagnosed at an advanced stage due to frequent recurrences after primary resection in curative intent. In order to improve prognosis after curative resection, in the recent past, patients with locally advanced tumors were subjected to a pre-, peri-, or postoperative treatment. Interestingly, postoperative chemotherapy has significantly improved survival after gastric resection in Asia, adjuvant radiochemotherapy is favored in North America and perioperative chemotherapy is considered as a treatment of choice in Europe indicating region specific approach towards the treatment. Recently there has also been growing evidence of positive outcomes of neoadjuvant radiochemotherapy on patient survival. In the present article, we discuss the concepts of neoadjuvant treatment approach and provide recommendations to surgeons based on current evidence.

Suppression of myeloid cell leukemia-1 (Mcl-1) enhances chemotherapy-associated apoptosis in gastric cancer cells

BACKGROUND

Myeloid cell leukemia-1 (Mcl-1) is an anti-apoptotic protein that regulates apoptosis sensitivity in a variety of cell types. Here we evaluate the roles of Mcl-1 in chemotherapy-associated apoptosis in gastric cancer cells. In addition, our study examined whether Mcl-1 contributed to apoptosis resistance in so-called cancer stem cell (CSC)-like populations in gastric cancer.

METHODS

Seven gastric cancer cell lines were used. The expression of Mcl-1 was assessed by either real-time polymerase chain reaction or Western blot analysis. Apoptosis was quantitated by morphological observation and caspase activity measurement. Adenovirus-mediated RNA interference (RNAi) technology was used to knockdown the expression of Mcl-1. The release of cytochrome c was evaluated by subcellular fractionation and immunoblot analysis. To identify and isolate the CSC-like populations, we used the CSC-associated cell surface marker CD44 and flow cytometry.

RESULTS

Six out of the 7 gastric cancer cell lines overexpressed Mcl-1 protein. These Mcl-1-expressing cell lines were relatively resistant to chemotherapeutic agents such as 5-fluorouracil (5-FU) and cisplatin (CDDP). Depletion of Mcl-1 protein by RNAi technology effectively sensitized the cells to anticancer drug-induced mitochondrial cytochrome c release, caspase activation, and apoptosis. In addition, vast amounts of Mcl-1 mRNA were expressed in CD44-positive CSC-like cells. Mcl-1 suppression enhanced the apoptosis in CD44-positive cells to a level equivalent to that in CD44-negative cells, suggesting that Mcl-1 mediates chemotherapy resistance in CSC-like populations.

CONCLUSION

These results suggest that Mcl-1 mediates the resistance to apoptosis in gastric cancer cells by blocking the mitochondrial pathway of cell death. Mcl-1 depletion appears to be an attractive strategy to overcome chemotherapy resistance in gastric cancer cells.

Neoadjuvant or adjuvant therapy for resectable gastric cancer: a systematic review and practice guideline for North America

BACKGROUND

Gastric cancer is a global health problem accounting for 10% of all new cancer cases and 12% of all cancer deaths worldwide. Many clinical trials and meta-analyses have explored the value of neoadjuvant or adjuvant chemotherapy and radiation therapy in gastric cancer; however, these studies have produced conflicting results. The purpose of this guidance document was to determine whether patients with resectable gastric cancer should receive neoadjuvant or adjuvant therapy in addition to surgery. Outcomes of interest were overall survival, disease-free survival, and adverse events.

METHODS

A systematic review was undertaken to inform recommendations regarding neoadjuvant and adjuvant therapy in resectable gastric cancer in Ontario, Canada. MEDLINE and EMBASE databases, as well as American Society of Clinical Oncology (ASCO) annual meeting proceedings and American Society for Therapeutic Radiology and Oncology (ASTRO) proceedings were systematically searched from 2002 to 2010. Oral fluoropyrimidine trials were excluded owing to the unavailability of these agents in North America.

RESULTS

Overall, 22 randomized controlled trials (RCTs), 13 meta-analyses, and two secondary analyses were included. The systematic review informed the development of a clinical practice guideline with the following recommendations. Postoperative 5-fluorouracil-based chemoradiotherapy based on the Macdonald approach or perioperative ECF (epirubicin, cisplatin, fluorouracil) chemotherapy based on the Cunningham/MAGIC (Medical Research Council Adjuvant Gastric Infusional Chemotherapy) approach are both acceptable standards of care in North America. Choice of treatment should be made on a case-by-case basis. Adjuvant chemotherapy is a reasonable option for those patients for whom the Macdonald and MAGIC protocols are contraindicated. All patients with resectable gastric cancer should undergo a pretreatment multidisciplinary assessment to determine the best plan of care.

CONCLUSIONS

Overall survival in patients with resectable gastric cancer is significantly improved with the use of either postoperative chemoradiation (Macdonald approach) or perioperative ECF (MAGIC protocol).

Chemoradiation therapy in the management of gastrointestinal malignancies

Concurrent administration of chemotherapy and radiotherapy has been increasingly used in cancer treatment, leading to improvements in survival as well as quality of life. Currently, it is a feasible preference, often regarded as the standard therapeutic option, for many locally confined solid tumors, including anal, bladder, cervical, esophageal, gastric, head and neck, lung, pancreatic and rectal cancers. In patients with these tumors, combined modality therapy improves local tumor control and survival while, in some instances, obviating the need for surgical removal of the organ of origin. The scientific rationale for the use of chemoradiation derives from the preclinical and clinical observations of synergistic interactions between radiotherapy and chemotherapy. When chemotherapy and radiotherapy are administered together, the chemotherapeutic agents can sensitize the cancer cells to the effects of ionizing radiation, leading to increased tumor-killing effects within the radiotherapy field. This, in turn, can improve local control of the primary tumor and, in some cancers, render surgical resection unnecessary. In other cases, patients with tumors that were initially considered unresectable are able to undergo curative interventions after completing chemoradiation. The chemotherapy component can address any potential micrometastatic disease that, without therapy, leads to an increased risk of distant recurrence. A large body of evidence exists that supports the use of chemoradiotherapy in gastrointestinal cancers. In fact, one of the first tumor types in which the superior efficacy of chemoradiation was described was anal cancer. Since then, chemoradiotherapy has been explored in other gastrointestinal malignancies with superior outcomes when compared with either radiation or chemotherapy alone. This article aims to recapitulate the clinical evidence supporting the use of chemoradiotherapy in a variety of gastrointestinal tumor types.

Evaluation of dose coverage to target volume and normal tissue sparing in the adjuvant radiotherapy of gastric cancers: 3D-CRT compared with dynamic IMRT

Purpose:

To assess the potential advantage of intensity-modulated radiotherapy (IMRT) over 3D-conformal radiotherapy (3D-CRT) planning in postoperative adjuvant radiotherapy for patients with gastric carcinoma.

Methods and materials:

In a retrospective study, for plan comparison, dose distribution was recalculated in 15 patients treated with 3D-CRT on the contoured structures of same CT images using an IMRT technique. 3D-conformal plans with three fields and four-fields were compared with seven-field dynamic IMRT plans. The different plans were compared by analyzing the dose coverage of planning target volume using TV₉₅, D_mean, uniformity index, conformity index and homogeneity index parameters. To assess critical organ sparing, D_mean, D_max, dose to one-third and two-third volumes of the OARs and percentage of volumes receiving more than their tolerance doses were compared.

Results:

The average dose coverage values of PTV with 3F-CRT and 4F-CRT plans were comparable, where as IMRT plans achieved better target coverage(p<0.001) with higher conformity index value of 0.81±0.07 compared to both the 3D-CRT plans. The doses to the liver and bowel reduced significantly (p<0.001) with IMRT plans compared to other 3D-CRT plans. For all OARs the percentage of volumes receiving more than their tolerance doses were reduced with the IMRT plans.

Conclusion:

This study showed that a better target coverage and significant dose reduction to OARs could be achieved with the IMRT plans. The IMRT can be preferred with caution for organ motion. The authors are currently studying organ motion in the upper abdomen to use IMRT for patient treatment.

Adjuvant chemo-radiation for gastric adenocarcinoma: an institutional experience

BACKGROUND

Studies have shown that surgery alone is less than satisfactory in the management of early gastric cancer, with cure rates approaching 40%. The role of adjuvant therapy was indefinite until three large, randomized controlled trials showed the survival benefit of adjuvant therapy over surgery alone. Chemoradiation therapy has been criticized for its high toxicity.

METHODS

24 patients diagnosed between September 2001 and July 2007 were treated with adjuvant chemoradiation. 18 patients had the classical MacDonald regimen of 4500 cGy of XRT and chemotherapy with 5-fluorouracil (5FU) and leucovorin, while chemotherapy consisted of 5FU/Cisplatin for 6 patients.

RESULTS

This series consisted of non-metastatic patients, 17 females and 7 males with a median age of 62.5 years. 23 patients (96%) had a performance status of 0 or 1. The full course of radiation therapy (4500 cGy) was completed by 22 patients (91.7%). Only 7 patients (36.8%) completed the total planned courses of chemotherapy. 2 local relapses (10%), 2 regional relapses (10%) and 2 distant relapses (10%) were recorded. Time to progression has not been reached. 9 patients (37.5%) died during follow-up with a median overall survival of 75 months. Patients lost a mean of 4 Kgs during radiation therapy. We recorded 6 episodes of febrile neutropenia and the most frequent toxicity was gastro-intestinal in 17 patients (70.8%) with 9 (36%) patients suffering grade 3 or 4 toxicity and 5 patients (20%) suffering from grade 3 or 4 neutropenia. 4 (17%) patients required total parenteral nutrition for a mean duration of 20 days. 4 patients suffered septic shock (17%) and 1 patient developed a deep venous thrombosis and a pulmonary embolus.

CONCLUSIONS

Adjuvant chemo-radiation for gastric cancer is a standard at our institution and has resulted in few relapses and an interesting median survival. Toxicity rates were serious and this remains a harsh regimen with only 36.8% of patients completing the full planned courses of chemotherapy. This is due to hematological toxicity, mainly febrile neutropenia. This should prompt us to review the subsequent chemotherapy protocol and make it more tolerable.

Gastric carcinoma

Although gastric cancer is still a worldwide major public health concern, it remains relatively uncommon in the Western countries. Despite improvement in surgical morbidity and mortality, as well as significant advancement of chemotherapy and radiotherapy options, the survival for gastric cancer has not significantly improved over the past decades. In the United States, standard of care for localized resectable gastric cancer is with adjuvant chemoradiotherapy. In this article, we summarize salient randomized and phase II and III clinical trials representing current treatment for gastric cancer.

Updates on esophageal and gastric cancers

Esophageal and gastric cancers are both common and deadly. Patients present most often after disease progression and survival is therefore poor. Due to demographic variability and recent changes in disease incidence, much emphasis has been placed on studying risk factors for both esophageal and gastric cancers. However, with increasing understanding of these diseases, low survival rates persist and continued intensive studies are necessary to optimize treatment plans. This review article discusses updates in the evolving epidemiology, clinical presentation, risk factors, and diagnostic and treatment modalities of esophageal and gastric cancers.

Evaluation of an inflammation-based prognostic score in patients with inoperable gastro-oesophageal cancer

There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor outcome in patients with advanced cancer. The aim of the present study was to examine whether an inflammation-based prognostic score (Glasgow Prognostic score, GPS) was associated with survival, in patients with inoperable gastro-oesophageal cancer. Patients diagnosed with inoperable gastro-oesophageal carcinoma and who had measurement of albumin and C-reactive protein concentrations, at the time of diagnosis, were studied (n=258). Clinical information was obtained from a gastro-oesophageal cancer database and analysis of the case notes. Patients with both an elevated C-reactive protein (>10 mg l(-1)) and hypoalbuminaemia (<35 g l(-1)) were allocated a GPS score of 2. Patients in whom only one of these biochemical abnormalities was present were allocated a GPS score of 1, and patients with a normal C-reactive protein and albumin were allocated a score of 0. On multivariate survival analysis, age (hazard ratio (HR) 1.22, 95% CI 1.02-1.46, P<0.05), stage (HR 1.55, 95% CI 1.30-1.83, P<0.001), the GPS (HR 1.51, 95% CI 1.22-1.86, P<0.001) and treatment (HR 2.53, 95% CI 1.80-3.56, P<0.001) were significant independent predictors of cancer survival. A 12-month cancer-specific survival in patients with stage I/II disease receiving active treatment was 67 and 60% for a GPS of 0 and 1, respectively. For stage III/IV disease, 12 months cancer-specific survival was 57, 25 and 12% for a GPS of 0, 1 and 2, respectively. In the present study, the GPS predicted cancer-specific survival, independent of stage and treatment received, in patients with inoperable gastro-oesophageal cancer. Moreover, the GPS may be used in combination with conventional staging techniques to improve the prediction of survival in patients with inoperable gastro-oesophageal cancer.

Gastric adenocarcinoma: review and considerations for future directions

OBJECTIVE

This update reviews the epidemiology and surgical management, and the controversies of gastric adenocarcinoma. We provide the relevance of outcome data to surgical decision-making and discuss the application of gene-expression analysis to clinical practice.

SUMMARY BACKGROUND DATA

Gastric cancer mortality rates have remained relatively unchanged over the past 30 years, and gastric cancer continues to be one of the leading causes of cancer-related death. Well-conducted studies have stimulated changes to surgical decision-making and technique. Microarray studies linked to predictive outcome models are poised to advance our understanding of the biologic behavior of gastric cancer and improve surgical management and outcome.

METHODS

We performed a review of the English gastric adenocarcinoma medical literature (1980-2003). This review included epidemiology, pathology and staging, surgical management, issues and controversies in management, prognostic variables, and the application of outcome models to gastric cancer. The results of DNA microarray analysis in various cancers and its predictive abilities in gastric cancer are considered.

RESULTS

Prognostic studies have provided valuable data to better the understanding of gastric cancer. These studies have contributed to improved surgical technique, more accurate pathologic characterization, and the identification of clinically useful prognostic markers. The application of microarray analysis linked to predictive models will provide a molecular understanding of the biology driving gastric cancer.

CONCLUSIONS

Predictive models generate important information allowing a logical evolution in the surgical and pathologic understanding and therapy for gastric cancer. However, a greater understanding of the molecular changes associated with gastric cancer is needed to guide surgical and medical therapy.

A phase III randomized trial of 5-fluorouracil, doxorubicin, and mitomycin C versus 5-fluorouracil and mitomycin C versus 5-fluorouracil alone in curatively resected gastric cancer

BACKGROUND

A phase III single-center randomized trial was performed in order to determine whether the addition of mitomycin C (MMC) and/or doxorubicin to 5-fluorouracil (5-FU) as adjuvant chemotherapy could influence survival in patients with curatively resected gastric cancer.

PATIENTS AND METHODS

A total of 416 patients who had undergone curative resection for stage IB-IIIB gastric adenocarcinoma were stratified according to the stage and type of surgery, and then randomized to receive one of the three chemotherapy regimens, 5-FU alone (F) or 5-FU and MMC (FM) or 5-FU, doxorubicin and MMC (FAM) within 5 weeks after surgery.

RESULTS

Of 416 patients registered, 395 (133 in F, 131 in FM and 131 in FAM) were assessable. Median follow-up duration was 91 months. Five-year overall survival rates were 67.2% for F, 67.0% for FM and 66.7% for FAM (P = 0.97). Five-year disease-free survival rates were 62.1% for F, 63.3% for FM and 62.5% for FAM (P = 0.83). Hematological toxicities were more frequent in the FM and FAM groups, whereas stomatitis was more common in the F group.

CONCLUSIONS

Compared with adjuvant 5-FU alone, the addition of MMC and/or doxorubicin to 5-FU did not influence survival in patients with resected gastric cancer.

Adjuvant chemotherapy after curative resection for gastric cancer in non-Asian patients: revisiting a meta-analysis of randomised trials

The aim of this study was to assess whether adjuvant chemotherapy after curative resection of gastric cancer increases survival rates.

DATA SOURCES

MEDLINE (1966-1999), CancerLit (1983-1999), bibliographies, personal reprint files, and review articles were searched for relevant articles. Studies had to be randomised controlled trials of adjuvant chemotherapy versus observation following curative resection of stomach cancer that took place in non-Asian countries. Two reviewers independently evaluated the trials for eligibility, quality assessment and data abstraction, 13 trials met the eligibility criteria. The odds ratio for death in the treated group was 0.80 (95% confidence interval (CI) 0.66-0.97), corresponding to a relative risk of 0.94 (95% CI 0.89-1.00). Subgroup analyses showed a trend towards a larger magnitude of the effect when analysis was restricted to trials in which at least 2/3 of patients had node-positive disease. Our results suggest that adjuvant chemotherapy may produce a small survival benefit of borderline statistical significance in patients with curatively resected gastric carcinoma. Continued trials to find and confirm an effective adjuvant strategy are warranted.

Survival and treatment for colorectal cancer Medicare patients in two group/staff health maintenance organizations and the fee-for-service setting

The current study compares treatment use and long-term survival in colorectal cancer patients between Medicare beneficiaries enrolled in two large prepaid group/staff health maintenance organizations (HMOs) and the fee-for-service (FFS) setting. The study is based on 15,352 colorectal cancer cases diagnosed between 1985 and 1992 and followed through 1995. Survival differences between the HMO and FFS cases were assessed using Cox regression. Treatment differences were evaluated using logistic regression. HMO cases had a lower overall mortality than did FFS cases but not a significantly lower colorectal cancer-specific mortality. Use of surgical resection was similar between HMO and FFS cases. However, rectal cancer cases in the HMOs were more likely to receive postsurgical radiation therapy than FFS cases. Superior overall survival in the HMOs may be the result of increased colorectal cancer screening, greater use of adjuvant therapies, and selection of healthier individuals.