Phase II study of trastuzumab in combination with S-1 and cisplatin in the first-line treatment of human epidermal growth factor receptor HER2-positive advanced gastric cancer

Recent Trends and Advancements in the Diagnosis and Management of Gastric Cancer

Gastric cancer is an enigmatic malignancy that has recently been shown to be increasing in incidence globally. There has been recent progress in emerging technologies for the diagnosis and treatment of the disease. Improvements in non-invasive diagnostic techniques with serological tests and biomarkers have led to decreased use of invasive procedures such as endoscopy. A multidisciplinary approach is used to treat gastric cancer, with recent significant advancements in systemic therapies used in combination with cytotoxic chemotherapies. New therapeutic targets have been identified and clinical trials are taking place to assess their efficacy and safety. In this review, we provide an overview of the current and emerging treatment strategies and diagnostic techniques for gastric cancer.

Trastuzumab combined chemotherapy for the treatment of HER2-positive advanced gastric cancer: A systematic review and meta-analysis of randomized controlled trial

BACKGROUND

This systematic review and meta-analysis aimed to assess the efficacy of trastuzumab combined with chemotherapy for the treatment in HER2-positive advanced gastric cancer (HER2-PAGC).

METHODS

This systematic review and meta-analysis was designed using randomized controlled trials that compared trastuzumab in combination with chemotherapy and chemotherapy alone. A comprehensive search was conducted in the following databases from their inception onwards: PubMed, EMBASE, Cochrane Library, WANGFANG, and CNKI. We also searched other literature sources to avoid missing relevant studies. Two reviewers independently performed all record selection, data collection, and methodological assessments. Any confusion was resolved by discussion or referral to a third reviewer. If there were ample data from eligible studies, we performed a fixed-effects meta-analysis. Whenever this was not possible, we conducted a narrative synthesis.

RESULTS

Meta-analysis results showed that trastuzumab in combination with chemotherapy achieved better outcomes on response rate (trastuzumab plus CFC vs CFC: odds ratio [OR] = 1.56, 95% confidence interval [CI] [1.17-2.09], I2 = 0%, P < .003; trastuzumab plus OT vs OT: OR = 2.97, 95% CI [1.74-5.09], I2 = 0%, P < .0001; and trastuzumab plus CC vs CC: OR = 2.62, 95% CI [1.84-3.73], I2 = 0%, P < .0001), and disease control rate (trastuzumab plus CFC vs CFC: OR = 1.61, 95% CI [1.17-2.21], I2 = 0%, P = .004; trastuzumab plus OT vs OT: OR = 4.29, 95% CI [2.33-7.90], I2 = 0%, P < .0001; and trastuzumab plus CC vs CC: OR = 2.99, 95% CI [1.99-4.48], I2 = 0%, P < .0001). However, there were no significant differences in the adverse events.

CONCLUSIONS

The results of this study revealed that the efficacy of trastuzumab combined with chemotherapy was superior to that of chemotherapy alone for the treatment of HER2-PAGC. The 2 modalities showed similar safety profiles.

Trastuzumab ± Capecitabine Maintenance After the First-Line Treatment of HER2-Positive Advanced Gastric Cancer: Retrospective Observational Real-Life Data of Turkish Oncology Group

PURPOSE

In the ToGA trial for HER2-positive advanced gastric cancer, cisplatin plus fluoropyrimidine was given for 6 cycles; trastuzumab was given until disease progression. However, there is a lack of real-life data about trastuzumab maintenance after 6 cycle chemotherapy. This study aims to present real-life data of trastuzumab ± capecitabine maintenance after 6 cycles of platinum, fluoropyrimidine, and trastuzumab in non-progressive patients.

METHODS

This is a retrospective multicenter study of the Turkish Oncology Group. A total of 35 HER2-positive, inoperable locally advanced, recurrent, or metastatic gastric adenocarcinoma patients being non-progressive at the end of 6 cycle chemotherapy and being given trastuzumab ± capecitabine as maintenance treatment were included from sixteen oncology centers. Baseline characteristics, objective tumor responses, progression free and overall survival data, and toxicities were determined.

RESULTS

About 68% of the patients were given CF, and 32% were given FOLFOX with trastuzumab as the first-line treatment. The best response in 6 cycle chemotherapy was complete 8 (22%), partial 24 (68%), and stable disease 3 (8%). All patients had trastuzumab maintenance (median cycle 13; range 7-51), and 49% of the patients had capecitabine with trastuzumab (median capecitabine cycle 6; range 2-30). The median PFS of the patients was 12.0 months (95% CI 10.3-13.7), and median OS was 17.4 months (95% CI 15.2-19.5). There were 2 patients with grade 1 cardiotoxicity.

CONCLUSION

Trastuzumab maintenance ± capecitabine after 6 cycles of trastuzumab plus combined chemotherapy treatment revealed efficacy and safety in non-progressive HER2-positive advanced gastric cancer.

History and emerging trends in chemotherapy for gastric cancer

Chemotherapy is indispensable for gastric cancer. For unresectable and/or recurrent gastric cancer, first-line chemotherapy consists of multidrug regimens including oral 5-FU agents such as S1/Xeloda and platinum preparations, as well as Trastuzumab, which is effective in HER2-positive cases. Second- and third-line chemotherapy regimens include taxanes, Ramucirumab (R-mab), and Nivolumab (N-mab), which have different mechanisms of action from first-line chemotherapy. R-mab is molecularly targeted to vascular endothelial growth factor receptor 2 in the host cells, but its indication is not conditional. For resectable gastric cancer, in Eastern countries, postoperative adjuvant chemotherapy has been successful, including S1, Docetaxel/S1 (DS), and Xeloda/Oxaliplatin (Xelox) regimens, whereas, in Western countries, the 5-FU/Leucovorin/Oxaliplatin/Docetaxel (FLOT) regimen was recently shown to be effective in the perioperative chemotherapy setting. Most recently, however, in Eastern countries, perioperative SOX was demonstrated to be effective in specific advanced gastric cancer. For stage IV gastric cancer, new therapeutic strategies have been proposed such as neoadjuvant chemotherapy and conversion surgery, and cures can be conditionally obtained. Recent genomic understanding of gastric cancer proposed a diversity of molecular targets by molecular profiling. Such optimized chemotherapy regimens, according to the specific clinical situations, have been rigorously established for the best survival of advanced gastric cancer.

Maintenance in gastric cancer: New life for an old issue?

The interest in maintenance therapy for patients with advanced cancers has been rapidly growing. Maintenance therapy is a useful strategy that may strengthen results of induction therapy thus extending survival and preserving the quality of life (QoL) with less toxicity. Maintenance also represents a suitable setting to investigate novel agents. The value of maintenance therapy after first-line chemotherapy has been well established in several solid tumours, such as colorectal, lung, breast, and ovarian cancer in which it is largely adopted. To date, there is no established role for maintenance therapy following first-line chemotherapy for advanced gastric cancer (GC). This review summarizes the current knowledge regarding maintenance strategies in advanced GC exploring cytotoxic agents, biologic agents and immunotherapy. We also critically review new issues to optimize randomized clinical trials for maintenance therapies and suggest clinical consideration to guide a personalized approach in daily clinical practice for this setting.

Response Rates and Durations of Response for Biomarker-Based Cancer Drugs in Nonrandomized Versus Randomized Trials

BACKGROUND

Many new targeted cancer drugs have received FDA approval based on durable responses in nonrandomized controlled trials (non-RCTs). The goal of this study was to evaluate whether the response rates (RRs) and durations of response (DoRs) of targeted cancer drugs observed in non-RCTs are consistent when these drugs are tested in RCTs.

METHODS

We used the FDA's Table of Pharmacogenomic Biomarkers in Drug Labeling to identify cancer drugs that were approved based on changes in biomarker endpoints through December 2017. We then identified the non-RCTs and RCTs for these drugs for the given indications and extracted the RRs and DoRs. We compared the RRs and median DoR in non-RCTs versus RCTs using the ratio of RRs and the ratio of DoRs, defined as the RRs (or DoRs) in non-RCTs divided by the RRs (or DoRs) in RCTs. The ratio of RRs or DoRs was pooled across the trial pairs using random-effects meta-analysis.

RESULTS

Of the 21 drug-indication pairs selected, both non-RCTs and RCTs were available for 19. The RRs and DoRs in non-RCTs were greater than those in RCTs in 63% and 87% of cases, respectively. The pooled ratio of RRs was 1.06 (95% CI, 0.95-1.20), and the pooled ratio of DoRs was 1.17 (95% CI, 1.03-1.33). RRs and DoRs derived from non-RCTs were also poor surrogates for overall survival derived from RCTs.

CONCLUSIONS

The RRs were not different between non-RCTs and RCTs of cancer drugs approved based on changes to a biomarker, but the DoRs in non-RCTs were significantly higher than in RCTs. Caution must be exercised when approving or prescribing targeted drugs based on data on durable responses derived from non-RCTs, because the responses could be overestimates and poor predictors of survival benefit.

Survival Outcomes Following Combination of First-Line Platinum-Based Chemotherapy with S-1 in Patients with Advanced Gastric Cancer

The efficacy of S-1 combined with a platinum agent in the first-line setting and in patients with advanced gastric adenocarcinoma has been previously demonstrated in randomized clinical trials. However, real-world data regarding S-1 efficacy in European patients remains limited. In the present study, we reviewed the data of a European cohort of patients with advanced gastric cancer treated with first-line therapy consisting of S-1 in combination with a platinum agent. Forty-eight patients (29 with locally advanced/inoperable and 19 with metastatic disease) were treated with S-1 plus oxaliplatin (33 patients) or S1 plus cisplatin (15 patients). The Cox regression analysis, adjusted with propensity score, indicated that the use of cisplatin as compared to oxaliplatin was associated with increased risk of death (HR 9.634, p = 0.000). Four SAEs (serious adverse events) GIII were recorded (1 fatigue, 1 neutropenia, 1 anemia, 1 diarrhea) in 3 patients. S-1 combination with a platinum agent in the first-line setting in European patients with advanced gastric cancer results to similar survival outcomes and toxicity with previously reported data from Asian populations. S-1 combination with oxaliplatin seems to be associated with superior efficacy as compared to cisplatin.

Neoadjuvant therapy strategies for advanced gastric cancer: Current innovations and future challenges

Gastric cancer, which has a high incidence and poor prognosis, remains a therapeutic challenge. Recently, neoadjuvant therapy has attracted increasing attention due to high recurrence rate and low survival rate after resection in most patients with advanced stage. Clinical trials show that neoadjuvant approaches confer a significant survival advantage for resectable locally advanced gastric cancer. The specific advantages of chemoradiotherapy compared with chemotherapy have not been clarified; optimal regimens and cycles, particularly in the preoperative setting, should be studied further; and trials aimed at determining the role of targeted and immunological therapies should be conducted.

Precision medicine in gastric cancer

Gastric cancer (GC) is a complex disease linked to a series of environmental factors and unhealthy lifestyle habits, and especially to genetic alterations. GC represents the second leading cause of cancer-related deaths worldwide. Its onset is subtle, and the majority of patients are diagnosed once the cancer is already advanced. In recent years, there have been innovations in the management of advanced GC including the introduction of new classifications based on its molecular characteristics. Thanks to new technologies such as next-generation sequencing and microarray, the Cancer Genome Atlas and Asian Cancer Research Group classifications have also paved the way for precision medicine in GC, making it possible to integrate diagnostic and therapeutic methods. Among the objectives of the subdivision of GC into subtypes is to select patients in whom molecular targeted drugs can achieve the best results; many lines of research have been initiated to this end. After phase III clinical trials, trastuzumab, anti-Erb-B2 receptor tyrosine kinase 2 (commonly known as ERBB2) and ramucirumab, anti-vascular endothelial growth factor receptor 2 (commonly known as VEGFR2) monoclonal antibodies, were approved and introduced into first- and second-line therapies for patients with advanced/metastatic GC. However, the heterogeneity of this neoplasia makes the practical application of such approaches difficult. Unfortunately, scientific progress has not been matched by progress in clinical practice in terms of significant improvements in prognosis. Survival continues to be low in contrast to the reduction in deaths from many common cancers such as colorectal, lung, breast, and prostate cancers. Although several target molecules have been identified on which targeted drugs can act and novel products have been introduced into experimental therapeutic protocols, the overall approach to treating advanced stage GC has not substantially changed. Currently, surgical resection with adjuvant or neoadjuvant radiotherapy and chemotherapy are the most effective treatments for this disease. Future research should not underestimate the heterogeneity of GC when developing diagnostic and therapeutic strategies aimed toward improving patient survival.

The promising role of monoclonal antibodies for gastric cancer treatment

Gastric cancer (GC) is the second leading cause of cancer-related death world-wide. Despite improvements in prevention, early detection and various therapeutic options, the prognosis is still poor. GC is often diagnosed at an advanced stage with survivals less than 1 year. Chemotherapy as the mainstay of treatment in advanced stage is not of notable advantages, underlining the need for novel more effective therapeutic options. Based on current knowledge of molecular and cellular mechanisms, a number of novel biologic approaches such as monoclonal antibodies have been recently introduced for cancer treatment that mainly affect the immune system or target signaling pathways playing role in cancer and metastasis development. In this review, various monoclonal antibodies for GC therapy were explained.

Evolving Treatment Strategies and Outcomes in Advanced Gastric Cancer with Peritoneal Metastasis

Gastric cancer (GC) has a predilection to metastasize to the peritoneum, denoting a poor prognosis. Treatment strategies available for advanced GC have significantly evolved over time and can be categorized into systemic, regional, and surgical. Although systemic therapies have been the mainstay for the treatment of advanced GC, their ability in achieving long-term survival in patients with peritoneal involvement is modest at best. This article describes advances in combined modality treatment of peritoneal metastases, specifically with an emphasis on peritoneal-directed therapies.

Clinical use of trastuzumab combined with different chemotherapy regimens in multi-line treatment of advanced human epidermal growth factor receptor 2-positive gastric cancer: A case report

It is generally acknowledged that gastric cancer requires comprehensive treatment approaches to be adopted. For patients with human epidermal growth factor receptor-2 (HER2)-overexpressing gastric cancer, targeting HER2 with trastuzumab in first-line therapy combined with standard chemotherapy significantly improves the prognosis. However, there is a lack of international guidance for second-line treatment if a patient experiences disease progression. There is also no accepted conclusion regarding the efficiency of cross-line therapy with trastuzumab. The present study reports the case of a 55-year-old male with gastric cancer who underwent radical gastrectomy. Immunohistochemistry indicated that samples were EGFR(+) and HER-2(3+), with Ki-67 (20%). From abdominal computed tomography scanning and contrast-enhanced ultrasound following surgery, hepatic metastasis was identified and the patient was administered microwave thermocoagulation therapy. Since December 2012, the patient received multi-line chemotherapy regimens as follows: i) Oxaliplatin, tegafur/gimeracil/oteracil and trastuzumab; ii) paclitaxel liposome and S-1 plus trastuzumab; iii) apatinib; iv) epirubicin/oxaliplatin/xeloda; and v) irinotecan plus trastuzumab. During the course of therapy, the trastuzumab served an important function in multi-line therapy and the patient benefited from the combined therapy. The application of trastuzumab in the multi-line treatment of a patient with HER2-positive advanced gastric cancer may be worthy of investigation for use in the clinic.

New therapeutic options opened by the molecular classification of gastric cancer

Gastric cancer (GC) is one of the most lethal and aggressive cancers, being the third cause of cancer related death worldwide. Even with radical gastrectomy and the latest generation of molecular chemotherapeutics, the numbers of recurrence and mortality remains high. This is due to its biological heterogeneity based on the interaction between multiple factors, from genomic to environmental factors, diet or infections with various pathogens. Therefore, understanding the molecular characteristics at a genomic level is critical to develop new treatment strategies. Recent advances in GC molecular classification provide the unique opportunity to improve GC therapy by exploiting the biomarkers and developing novel targeted therapy specific to each subtype. This article highlights the molecular characteristics of each subtype of gastric cancer that could be considered in shaping a therapeutic decision, and also presents the completed and ongoing clinical trials addressed to those targets. The implementation of the novel molecular classification system will allow a preliminary patient selection for clinical trials, a mandatory issue if it is desired to test the efficacy of a certain inhibitor to the given target. This will represent a substantial advance as well as a powerful tool for targeted therapy. Nevertheless, translating the scientific results into new personalized treatment opportunities is needed in order to improve clinical care, the survival and quality of life of patients with GC.

Docetaxel, oxaliplatin, 5FU, and trastuzumab as first-line therapy in patients with human epidermal receptor 2-positive advanced gastric or gastroesophageal junction cancer: Preliminary results of a phase II study

The aim of this study is to report first preliminary results of patients enrolled in a phase II study that will investigate the activity and safety of docetaxel, oxaliplatin, and 5-fluorouracil (DOF) in combination with trastuzumab in human epidermal receptor-2 (HER-2) positive patients with advanced gastric or gastroesophageal junction (GEJ) cancer.Treatment consisted of docetaxel 70 mg/m combined with oxaliplatin 130 mg/m on day 1, and continuous infusion 5-fluorouracil mg/m days 1-5 plus trastuzumab at the standard dose on day 1, every 3 weeks for a maximum of 8 cycles.Fifteen patients were enrolled. The overall response rate was 60%. The median progression-free survival was 9.2 months (95% confidence interval [CI], 4.4-10.1 months) and the median overall survival was 19.4 months (95% CI, 8.9-21.1 months). Grade 3 neutropenia was observed in 3 patients (20%).The DOF plus trastuzumab seems active in HER-2 positive advanced gastric or GEJ cancer, final results of the phase II study are awaited.

Comparing cytotoxic backbones for first-line trastuzumab-containing regimens in human epidermal growth factor receptor 2-positive advanced oesophagogastric cancer: A meta-analysis

According to the Trastuzumab for Gastric Cancer (ToGA) study, trastuzumab plus cisplatin and capecitabine/5-fluorouracil (5-FU) is standard first-line treatment for human epidermal growth factor receptor 2 (HER2)-positive advanced oesophagogastric cancer. We examined the relative efficacy and safety of alternative trastuzumab-based cytotoxic backbone regimens compared to the standard ToGA regimen using meta-analysis. We searched Medline, EMBASE, CENTRAL and ASCO and ESMO up to March 2017 for studies investigating alternative first-line trastuzumab-based regimens for HER2-positive oesophagogastric cancer, defined as high protein expression IHC3+ or IHC2+ and gene amplification by in situ hybridisation. We compared primary outcome overall survival (OS) of alternative trastuzumab-based regimens to the ToGA regimen. Hazard ratios (HRs) and 95% confidence intervals (95%CI) were calculated by extraction of the published Kaplan-Meier curves. Incidence counts and toxicity sample-sizes were extracted for adverse events and compared using single-arm proportion meta-analysis in R. Fifteen studies (N = 557 patients) were included. OS was significantly longer with regimen trastuzumab plus doublet oxaliplatin and capecitabine/5-FU (median OS = 20.7 months) versus ToGA (16.0 months, HR = 0.75, 95% CI = 0.59-0.99) and was less toxic. Trastuzumab plus doublet cisplatin and S-1 showed no OS difference versus ToGA, but showed a different toxicity profile, including less hand-foot syndrome. Trastuzumab plus cisplatin or capecitabine as singlet backbone showed significantly worse survival and more toxicity versus ToGA regimen. Trastuzumab with triplet cytotoxic backbones or with bevacizumab and doublet cytotoxic backbone showed no survival benefit and more toxicity. In conclusion, trastuzumab plus doublet cytotoxic backbone containing oxaliplatin is preferable over the ToGA regimen with cisplatin. S-1 can substitute capecitabine or 5-FU when specific toxicities are encountered.

Antitumor Efficacy of Combination Therapy Consisting of S-1, Leucovorin, and Oxaliplatin against Human Gastric Cancer Xenografts

BACKGROUND/AIM

A phase 3 trial of S-1, leucovorin (LV), and oxaliplatin for treating gastric cancer is now underway. However, the antitumor efficacy of the combination has not yet been examined in an in vivo preclinical study. This study examined the antitumor efficacy of combination therapy consisting of S-1, LV, and oxaliplatin against 4 human gastric cancer xenografts: NUGC-4, St-40, SC-2, and SC-4.

METHODS

The antitumor efficacy was evaluated using human gastric cancer xenograft-bearing nude mice. S-1 and LV were administered orally once daily on days 1-7 at doses of 6.9 and 10 mg/kg, respectively. Oxaliplatin was administered intravenously at a dose of 8.3 mg/kg on day 1. The tumor volume was measured on day 15, and the relative tumor volume (RTV) was calculated.

RESULTS

In all 4 xenograft models, S-1 alone and oxaliplatin alone, but not LV alone, had significant antitumor activities (p < 0.001). Combination therapy consisting of S-1 and LV resulted in a significantly smaller RTV than S-1 alone (p < 0.001). Combination therapy consisting of S-1 and oxaliplatin also resulted in a significantly smaller RTV than either S-1 alone (p < 0.001) or oxaliplatin alone (p < 0.001). Furthermore, combination therapy consisting of S-1, LV, and oxaliplatin resulted in the highest antitumor activity in these models (p < 0.001 vs. S-1 + LV; p < 0.001 or p = 0.003 vs. S-1 + oxaliplatin).

CONCLUSION

Combination therapy consisting of S-1, LV, and oxaliplatin administered according to a 1-week-on/1-week-off schedule may be useful for the treatment of patients with gastric cancer.

Current therapeutic landscape for advanced gastroesophageal cancers

Treatment of advanced gastroesophageal cancers remains challenging for clinicians, patients, and caregivers alike. Despite considerable research, the therapeutic armamentarium is restricted and hardly personalized. In the first-line setting, trastuzumab with a fluoropyrimidine and platinum agent is the standard-of-care in patients with HER2-positive tumor. For the others, a platinum-based doublet (preferably with oxaliplatin) is recommended. Three-drug cytotoxic regimens should be reserved for exceptional cases where patients have good performance status. Triple combinations produce higher toxicity and provide marginal advantage. In the second line setting, the combination of paclitaxel and ramucirumab is preferred over all others. Currently, nothing is approved in the 3rd or later line. Nivolumab has resulted in an improved benefit in an Asian trial. Early trials of TAS-102, STAT3 inhibitors, anti-claudin 18.2 and other immune checkpoint inhibitors (alone or in combination) are ongoing. However, development of reproducible biomarkers for patient enrichment is critical for future progress.

A multi-institution phase II study of docetaxel and S-1 in combination with trastuzumab for HER2-positive advanced gastric cancer (DASH study)

BACKGROUND

Trastuzumab when combined with fluoropyrimidine and cisplatin was proven to improve survival in patients with human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC) in the ToGA study. The safety and efficacy of trastuzumab in combination with docetaxel and S-1 have not yet been evaluated.

METHODS

This study was a multicenter, phase II study. Patients with chemotherapy-naïve HER2-positive advanced or metastatic GC were eligible. Trastuzumab was administered intravenously on day 1 of the first cycle at 8 and 6 mg/kg in subsequent cycles. Docetaxel was administered intravenously at 40 mg/m² on day 1 of each cycle. S-1 was administered at a dosage based on body surface area for 14 days in a 3-weekly cycle. The primary endpoint was progression-free survival (PFS).

RESULTS

A total of 23 patients were enrolled. Median PFS was 6.7 months (95% CI 4.1-10.1). The response rate (RR) was 39.1%. Median overall survival (OS) and time to treatment failure (TTF) were 17.5 and 4.4 months, respectively. Major grade 3-4 adverse events were neutropenia (39.1%), leukopenia (30.4%), and febrile neutropenia (8.7%).

CONCLUSION

Trastuzumab in combination with docetaxel and S-1 showed effective antitumor activity and manageable toxicities as first-line treatment for patients with HER2-positive GC.

Comparative effectiveness and safety between oxaliplatin-based and cisplatin-based therapy in advanced gastric cancer: A meta-analysis of randomized controlled trials

Background & Aims

Platinum-based drugs are the most significant chemotherapy for advanced gastric cancer. The study aims to compare the efficacy and safety of oxaliplatin-based therapy versus cisplatin-based therapy in patients with advanced gastric cancer.

Materials and Methods

An adequate literature search in EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, American Society of Clinical Oncology (ASCO) and European Society of Medical Oncology (ESMO) was conducted. Phase II or III randomized controlled trials (RCTs) that compared effectiveness and safety between oxaliplatin-based and cisplatin-based therapy in patients with advanced gastric cancer were eligible. The primary endpoint was overall response rate (ORR), progression free survival (PFS) and overall survival (OS). The second endpoint was the adverse events.

Results

Five phase II or III RCTs involving a total of 2,046 patients were identified. The results showed that there were no significant difference in ORR (OR = 1.17, 95% CI = 0.98–1.40, p = 0.08, I² = 0%), PFS (HR = 0.92, 95% CI = 0.84–1.01, p = 0.09, I² = 0%) and OS (HR = 0.91, 95% CI = 0.82–1.01, p = 0.07, I² = 0%) between oxaliplatin-based therapy and cisplatin-based therapy. In addition, oxaliplatin-based therapy had lower risk of neutropenia, anemia, nausea, alopecia, thromboembolism, stomatitis and creatinine increased at all grades, and neutropenia, anemia, leukopenia and alopecia at 3–4 grades than cisplatin-based therapy. However, oxaliplatin-based therapy was associated with increased risk of neurosensory toxicity and thrombocytopenia.

Conclusions

Our meta-analysis showed that there were no significant difference in ORR, PFS and OS between oxaliplatin-based therapy and cisplatin-based therapy. The oxaliplatin-based therapy could generally decrease the risk of adverse effects except neurosensory toxicity and thrombocytopenia.

Cardiotoxicity of trastuzumab in patients with HER2-positive gastric cancer

Trastuzumab-induced cardiotoxicity (TIC) is the primary adverse event that limits the use of trastuzumab in HER2-positive breast cancer patients. However, the incidence and risk factors of TIC in HER2-positive gastric cancer are not known. Therefore, we evaluated the incidence and predictive factors of TIC in gastric cancer patients treated with trastuzumab in clinical practice. We reviewed cardiac dysfunction in HER2-positive gastric cancer patients between December 2005 and April 2015 in a prospectively-collected database that included prospective clinical trials at Yonsei Cancer Center, Republic of Korea. TIC was defined as an absolute decline in left ventricular ejection fraction (LVEF) of at least 10 percentage points from the baseline to a value less than 55%, as identified by a multiple-gated acquisition scan or an echocardiogram. Among the 115 patients, 70 patients (60.9%) received trastuzumab combined with chemotherapy, and 45 patients (39.1%) received chemotherapy alone as a first-line therapy. Symptomatic heart failure was not observed in either group, but a significant asymptomatic drop in LVEF was noted in five (7.1%) of the trastuzumab combined-group patients and in one (2.2%) chemotherapy-only group patient [hazard ratio (HR), 3.47; 95% confidence interval (CI), 0.40-29.8; P=0.257]. TIC was observed more frequently in elderly patients than in younger patients (HR, per age in year, 1.16; 95% CI, 1.02-1.31; P=0.019). Similar to prior observations in breast cancer, TIC in gastric cancer patients is not frequent or reversible. However, the asymptomatic drop in LVEF should be monitored continually in HER2-positive gastric cancer patients treated with trastuzumab, especially in elderly patients.

High expression of EGFR predicts poor survival in patients with resected T3 stage gastric adenocarcinoma and promotes cancer cell survival

Epidermal growth factor receptor (EGFR) is an essential regulator and biomarker of several types of cancer. However, the association between its expression and prognosis in patients with resected T3 stage gastric adenocarcinoma (RT3-GA) remains to be determined. In total, 683 patients with resectable T3-GA who underwent surgery were retrospectively included in the present study, and their immunohistochemical data for EGFR expression were collected. The associations between the patients' clinicopathologic characteristics and EGFR immunohistochemistry data were analyzed by multiple statistical methods. Annexin V apoptosis and MTT cell viability assays were performed to explore the effect of EGFR on AGS gastric adenocarcinoma cell survival. EGFR expression levels were categorized into two groups: low (406 cases) and high (277 cases). High EGFR was demonstrated to be significantly associated with distant metastasis (P=0.043) and severely decreased median overall survival time (MOST) and recurrence-free survival time (MRFST). MOST and MRFST in the low EGFR group were 39 and 37 months, respectively; whereas in the high EGFR group these values were only 18 and 13 months (P=3.10×10^-9 and P=6.74×10^-8, respectively). Multivariate analysis confirmed that high EGFR expression levels were associated with poor survival, which was associated with significantly increased recurrence risk and ~2-fold elevation in mortality risk [hazard ratio (HR), 1.73; 95% confidence interval (CI), 1.43-2.10; P=2.37×10^-8 and HR, 1.80; 95% CI, 1.50-2.17; P=3.80×10^-10]. Inhibiting EGFR with AG1478 suppressed its effect on promoting AGS cell survival. These results suggest that high EGFR expression indicates poor survival in patients with RT3-GA, which may be correlated with EGFR promoting GA cell survival.

Unravelling the pharmacologic opportunities and future directions for targeted therapies in gastro-intestinal cancers Part 1: GI carcinomas

Until the 1990s, cytotoxic chemotherapy has been the cornerstone of medical therapy for gastrointestinal (GI) cancers. Better understanding of the molecular biology of cancer cell has led to the therapeutic revolution of targeted therapies, i.e. monoclonal antibodies or small molecule inhibitors directed against proteins that are specifically overexpressed or mutated in cancer cells. These agents being more specific to cancer cells were expected to be less toxic than cytotoxic agents. Targeted agents have provided clinical benefit in many GI cancer types. For example, antiangiogenics and anti-EGFR therapies have significantly improved survival of patients affected by metastatic colorectal cancer and have deeply changed the therapeutic strategy in this disease. However, their effects have sometimes been disappointing, due to intrinsic or acquired resistance mechanisms (e.g., RAS mutation for anti-EGFR therapies), or to an activity restricted to some tumour settings (e.g., lack of activity in other cancer types, or on the microscopic residual disease in adjuvant setting). Many studies are negative in overall population but positive in some specific patient subgroups (e.g., trastuzumab in HER2-positive gastric cancer), illustrating the importance of patient selection and early identification of predictive biomarkers of response to these therapies. We propose a comprehensive two-part review providing a panoramic approach of the successes and failures of targeted agents in GI cancers to unravel the pharmacologic opportunities and future directions for these agents in GI oncology. In this first part, we will focus on adenocarcinomas and squamous cell carcinomas, for which targeted therapies are mostly used in combination with chemotherapy.

Evaluation of a trastuzumab-containing treatment regimen for patients with unresectable advanced or recurrent gastric cancer

The present study aimed to evaluate the efficacy and safety of trastuzumab plus chemotherapy for patients with unresectable advanced or recurrent gastric cancer. A retrospective analysis of 213 patients with unresectable advanced or recurrent gastric cancer who received systemic chemotherapy, including 15 patients who were also administered trastuzumab, at Kochi Medical School between 2007 and 2013 was performed. The overall survival was compared between patients who received trastuzumab plus chemotherapy and patients who received chemotherapy alone, and the safety and efficacy of the trastuzumab-containing regimen was evaluated. Human epidermal growth factor receptor (HER)2 status was examined in 86 patients, of whom 15 (17.4%) exhibited strong positive HER2 expression. The rate of strong positive HER2 expression was significantly higher for intestinal type tumors compared with diffuse type tumors [23.6 (13/55) vs. 6.5% (2/31); P=0.044]. The median overall survival of the patients treated with trastuzumab was significantly longer compared with that for patients who were not treated with trastuzumab (22.9 vs. 11.6 months; P=0.014). The objective response rate and disease control rate for trastuzumab plus chemotherapy were 46.7 and 86.7%, respectively. Frequently encountered grade 3-4 toxicities included neutropenia (26.7%; 4/15), anemia (13.3%; 2/15) and fatigue (13.3%; 2/15). Trastuzumab plus chemotherapy is effective for patients with HER2-positive advanced or recurrent gastric cancer, and the frequencies of hematological and non-hematological toxicities experienced by patients in the present study indicated that it can be safely administered clinically.

Individualized molecular targeted therapy for gastric cancer based on human epidermal growth factor receptor 2 gene detection

Compared with traditional chemotherapy drugs, molecular targeted drugs have the advantages of high specificity and fewer side effects. Human epidermal growth factor receptor 2 (HER2) has been a focus of research in recent years, although the relationship between HER2 and prognosis of gastric cancer remains controversial. With the advent of trastuzumab, lapatinib, pertuzumab and other anti-HER2 drugs, many clinical studies have achieved good results; however, there are still some patients with unsatisfactory results due to the occurrence of drug resistance. Finding solutions to overcome drug resistance can increase the efficacy, and individualized molecular targeted therapy can better benefit gastric cancer patients.

Targeted therapy for gastric cancer: Current status and future directions (Review)

According to the 2012 statistics of the International Agency for Research on Cancer (IARC), gastric cancer is the fifth most common malignancy, and the third leading cause of cancer-related deaths worldwide. Conventional chemotherapy and radiation have shown limited efficacy for advanced gastric cancer, showing an overall survival (OS) rate of ~10 months. Trastuzumab, a monoclonal antibody against human epidermal growth factor receptor 2 (HER2), is the first approved molecularly targeted agent for HER2-overexpressing gastric cancer, which was found to prolong the OS and the progression-free survival (PFS) of patients. However, HER2 overexpression is present only in a minority of patients with gastric cancer. Hence, other targeted agents are urgently needed. Ramucirumab, a novel human IgG1 monoclonal antibody that selectively targets the extracellular domain of VEGF receptor 2 (VEGFR2), is regarded as a new standard second-line treatment for patients with advanced gastric cancer. The combination of two or more targeted agents directed against two different molecular targets may improve the survival of patients with advanced gastric cancer. Although great efforts have been made, the effect of targeted therapy for gastric cancer is limited. One key reason is that participants in clinical trials for new targeted agents were not selected by detection of the targeted molecule. Here, we review clinical trials related to molecular targets such as anti-epidermal growth factor receptor signaling including anti-HER2 and anti-EGFR1, anti-VEGF signaling, anti-mammalian target of rapamycin (mTOR), tyrosine kinase inhibitors (TKIs) and anti-MET.

Advanced gastric cancer: Current treatment landscape and future perspectives

Gastric cancer currently ranks fourth in cancer-related mortality worldwide. In the western world, it is most often diagnosed at an advanced stage, after becoming metastatic at distant sites. Patients with advanced disease (locally advanced or metastatic) have a somber prognosis, with a median overall survival of 10-12 mo, and palliative chemotherapy is the mainstay of treatment. In recent years, novel approaches using inhibition of human epidermal growth factor receptor 2 (HER2) have demonstrated significant improvements in progression-free and overall survival, compared with chemotherapy alone, in first-line treatment of patients with overexpression of HER2. In addition, both second-line chemotherapy and treatment with the vascular endothelial growth factor receptor-inhibitor ramucirumab demonstrated significant benefits in terms of overall survival, compared with best supportive care, in randomized studies. Moreover, ramucirumab in combination with chemotherapy demonstrated further significant benefits in terms of progression-free and overall survival, compared with chemotherapy alone, in second-line treatment for patients with metastatic gastric cancer. A recently published molecular classification of gastric cancer is expected to improve patient stratification and selection for clinical trials and provide a roadmap for future drug development. Nevertheless, despite these developments the prognosis of patients with advanced gastric cancer remains poor. In this review we discuss current standards of care and outline major topics of drug development in gastric cancer.

Akt inhibitor MK-2206 enhances the effect of cisplatin in gastric cancer cells

The phosphoinositide 3-kinase/Akt pathway activation commonly occurs in various types of human cancer and has an important role in chemoresistance. Combination of traditional chemotherapy drugs and molecular-targeted agents is a promising strategy for cancer therapy, which has shown enhanced cytotoxicity and lower drug resistance. The present study found that the Akt inhibitor, MK-2206, can increase the effect of cisplatin in the gastric cancer cell line AGS, which has higher Akt phosphorylation, but exhibited a poor combination effect in MKN-45 and MGC-803 cells, which have limited Akt activation. The MTT assay demonstrated that sequential treatment of cisplatin, followed by the Akt inhibitor, MK-2206, caused a synergistic effect of proliferation inhibition, and the apoptosis assay by propidium iodide/fluorescein isothiocyanate staining also showed that combination treatment induced more apoptosis compared to the monotherapy groups. Using western blot analysis, MK-2206 was shown to significantly suppress the phosphorylation of Akt (Ser473), however, the expression of total Akt remained the same, and the combination treatment also increased the expression of cleaved poly adenosine diphosphate ribose polymerase, which contributed to apoptosis.

Immunohistochemical Markers of Soft Tissue Tumors: Pathologic Diagnosis, Genetic Contributions, and Therapeutic Options

After ~30 years of widespread usage, immunohistochemistry (IHC) has become a standard method of diagnosis for surgical pathology. Because of the plethora of diagnoses and often subtle nature of diagnostic criteria, IHC finds particular utility in soft tissue tumors. The use of progressively small amounts of tissue for diagnosis highlights the importance of this method. The sensitivity and crispness of IHC stains have progressively improved with the advent of new techniques. Traditionally, IHC detects cell-typic markers that characterize cell phenotypes, such as chromogranin for neuroectodermal tissue, myogenin for skeletal muscle, and cytokeratin for epithelium. However, the advent of genetic discoveries have led to IHC testing for detection of fusion gene products or overexpressed oncogenes associated with deletions and mutations. Proliferation-based markers such as Ki-67 can also be used for prognosis and grading, but more standardization is needed. Development of monoclonal antibody-based pharmaceuticals, such as imatinib or crizotinib, holds the promise of tailored anticancer therapy. IHC thus has assumed importance not only for diagnosis but also for guidance of personalized medicine.