Regorafenib treatment for advanced, refractory gastrointestinal stromal tumor: a report of the UK managed access program

Background

Tyrosine kinase inhibitors (TKI) have revolutionized the treatment of gastrointestinal

stromal tumors (GIST) although most patients develop resistance to first and second-line therapies.

Regorafenib, an oral multi-targeted TKI, has demonstrated benefit in previously treated GIST patients.

Methods

We assessed safety and activity of regorafenib in patients treated within the Managed Access Program (MAP). All consecutive patients with advanced GIST who had progressed on or were intolerant to imatinib and sunitinib were recruited from the Royal Marsden and University College Hospitals. We retrospectively reviewed the data for response, toxicity, treatment duration and survival. Response was assessed by RECIST and Choi criteria. Toxicity was graded according to CTCAE v4.0 criteria.

Results

20 patients were included in the MAP in the UK between 3/2013 and 9/2013. Median age was 68 (range 45–87), 65% of patients were male. Performance Status was 0–1 for 18 patients (90%), 2 for 2 patients (10%). The median treatment duration was 9.25 months (range 0.1-15.33). 18 patients were assessable for response and all patients attained a best response of at least stable disease. At a median follow-up of 12.6 months, there were 2 partial responses (11%) by RECIST and 7 partial responses (39%) according to Choi criteria. 7 patients remain on regorafenib. 3 patients discontinued treatment due to unacceptable adverse events; fistulation, myalgia and fatigue. 10 (50%) patients had grade 3 toxicities and 11 (55%) patients required a dose reduction. Median PFS was 9.4 months (95% Cl: 6.2-not calculable) and median OS was 12.2 months (95% Cl: 10.5-not calculable). Notably, prolonged stable disease was seen in 1 patient with exon 9 mutation and 1 patient with PDGFR D842V mutation.

Conclusions

These data demonstrate encouraging activity and tolerability of regorafenib in routine clinical practice. The documented adverse events are in line with previous trial data.

Regorafenib as Salvage Treatment in Korean Patients with Refractory Metastatic Colorectal Cancer

Purpose

Regorafenib, an oral multi-targeted tyrosine kinase inhibitor, is considered the new standard of care in patients with chemotherapy-refractory colorectal cancers (CRCs). However, there are no data on this drug in Korean patients.

Materials and Methods

We evaluated patients who received oral regorafenib 160 mg once daily during the first 3 weeks of each 4-week cycle between August 2013 and September 2013. All patients had previously progressed fluorouracil, irinotecan, and oxaliplatin with or without biologic agents such as cetuximab or bevacizumab.

Results

Thirty-two patients were enrolled (median age, 57 years; male:female ratio, 20:12; Eastern Cooperative Oncology Group performance status [0-1:2], 31:1; colon:rectum, 21:11). The overall response rate was 3.1% and the disease control rate was 50.0% (95% confidence interval [CI]) with one partial response and 15 patients with stable disease. The median progression-free survival was 4.2 months (95% CI, 3.1 to 5.2 months) and the median overall survival has not yet been reached. The most common adverse events of grade two or higher related to regorafenib were hand-foot skin reaction (25%), mucositis (19%), abdominal pain (9%), and liver function test (LFT) abnormalities (9%). Grade 3 or 4 toxicities included LFT abnormalities (9%), abdominal pain (9%), rash (6%), anemia (3%), leukopenia (3%), neutropenic fever (3%), and fatigue (3%). There was no treatment-related death.

Conclusion

Regorafenib appears to have promising activity and tolerable toxicity profiles in Korean patients with refractory CRC, consistent with the CORRECT trial findings.

Taking aim at Alzheimer's disease through the mammalian target of rapamycin

A significant portion of the world's population suffers from sporadic Alzheimer's disease (AD) with available present therapies limited to symptomatic care that does not alter disease progression. Over the next decade, advancing age of the global population will dramatically increase the incidence of AD and severely impact health care resources, necessitating novel, safe, and efficacious strategies for AD. The mammalian target of rapamycin (mTOR) and its protein complexes mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2) offer exciting and unique avenues of intervention for AD through the oversight of programmed cell death pathways of apoptosis, autophagy, and necroptosis. mTOR modulates multi-faceted signal transduction pathways that involve phosphoinositide 3-kinase (PI 3-K), protein kinase B (Akt), hamartin (tuberous sclerosis 1)/ tuberin (tuberous sclerosis 2) (TSC1/TSC2) complex, proline-rich Akt substrate 40 kDa (PRAS40), and p70 ribosomal S6 kinase (p70S6K) and can interface with the neuroprotective pathways of growth factors, sirtuins, wingless, forkhead transcription factors, and glycogen synthase kinase-3β. With the ability of mTOR to broadly impact cellular function, clinical strategies for AD that implement mTOR must achieve parallel objectives of protecting neuronal, vascular, and immune cell survival in conjunction with preserving networks that determine memory and cognitive function.

Everolimus and lung atypical carcinoid: case report

SUMMARY 

Atypical bronchopulmonary carcinoid is a rare disease with poor prognosis. The low number of patients and their dispersion in different centers makes it difficult to draw clinical trials. The right treatment is still controversial. This study reports the clinical case of a patient with bronchopulmonary carcinoid, who showed stable disease with everolimus (an mTOR inhibitor) plus somatostatin analog after the failure of two lines of chemotherapy plus somatostatin analog. Although in literature the overall survival for metastatic bronchopulmonary carcinoid  patients is 16 months, our patient reported a progression-free survival of 18 months with everolimus as third-line. Our case report underlines the importance to use new drugs that may change the disease course.

Regorafenib-induced transverse myelopathy after stereotactic body radiation therapy

Stereotactic body radiation therapy (SBRT) delivers large doses of radiation with great accuracy, but is known to have deleterious effects on the vascular compartment of irradiated tissues. Combining SBRT with targeted anti-angiogenesis agents, while able to increase therapeutic efficacy, may unexpectedly precipitate vascular-based toxicities. In this report, we describe a patient with colon cancer who developed transverse myelopathy from regorafenib 2 years after receiving SBRT for three metastatic liver lesions. Regorafenib (Stivarga), formerly BAY 73-4506, (Bayer HealthCare Pharmaceuticals, Montville, NJ) is a multiple receptor tyrosine kinase inhibitor with anti-angiogenic effects used in metastatic colon cancer. Its most common side effects are fatigue, diarrhea and hypertension. However, severe neurologic toxicity has not been previously recognized. Here, we illustrate a case in which the patient developed hyperalgesia and radicular pain 2 weeks after starting regorafenib. Several studies report an increased neurological toxicity when angiogenesis inhibitors are given after radiation therapy, and we postulate that the angioinhibitory effects of regorafenib accelerated subclinical microvascular injury from SBRT. This unexpected toxicity may be clinically relevant when giving targeted angiogenesis inhibitors after SBRT.

Therapeutic biomarkers in lung neuroendocrine neoplasia

The well-known classification of neuroendocrine neoplasms of the lung into four major subtypes (including typical and atypical carcinoids and small- and large-cell neuroendocrine carcinomas) has a proven prognostic validity but only partially helps to predict the response to specific therapies. Therapeutic biomarkers are incompletely known and include morphological, immunophenotypic, and molecular markers. Morphology alone has no specific predictive role, nor has any immunophenotypic marker been proven to bear predictive implications. Ki67 is a relevant prognostic marker and can indirectly predict response to chemotherapy, when levels are extremely high in high-grade neuroendocrine (NE) carcinomas. The expression of somatostatin receptors, especially of the type 2A, has been shown to predict response to somatostatin analog treatments, paralleling the information derived from octreotide scintigraphy. mTOR pathway is targeted by specific inhibitors, but the exact cellular molecules predicting response are still to be defined. It seems that high levels of phosphorylated forms of mTOR and of its downstream factor S6K are associated to a better response to rapalogs in experimental models. Data from gene expression profiling and mutational analyses are currently emerging, providing a more detailed map of different molecular activation pathways, potentially leading to a more accurate molecular classification of lung NE tumors as well as to the discovery of new therapeutic targets. The combination of mutational profiles with those of upregulated or downregulated genes also by gene gains or losses may ultimately provide a better characterization of NE tumor histological types in terms of response to specific chemotherapy or biotherapy.

Primary small-bowel malignancy: update in tumor biology, markers, and management strategies

PURPOSE

Primary small-bowel malignancies (SBM) are rare tumors but their incidence is rising. An estimated 9160 new cases and 1210 deaths due to SBM may occur in the USA in 2014. We review advances made in tumor biology, immunohistochemistry, and discuss treatment strategies for these malignancies.

METHODS

Relevant articles from PubMed/Medline and Embase searches were collected using the phrases "small-bowel adenocarcinoma, gastrointestinal carcinoids, gastrointestinal stromal tumors, small-bowel leiomyosarcoma, and small-bowel lymphoma".

RESULTS

Advances in imaging techniques such as wireless capsule endoscopy, CT and MRI enterography, and endoscopy (balloon enteroscopy) along with discovery of molecular markers such as c-kit and PDGFRA for GIST tumors have improved our ability to diagnose, localize, and treat these patients. Early detection and surgical resection offers the best chance for long-term survival in all tumors except bowel lymphoma where chemotherapy plays the main role. Adjuvant therapy with imatinib has improved overall survival for GIST tumors, somatostatin analogs have improved symptoms and also inhibited tumor growth and stabilized metastatic disease in carcinoid disease, but chemotherapy has not improved survival for adenocarcinoma.

CONCLUSIONS

Recent advances in molecular characterization holds promise in novel targeted therapies. Currently ongoing trials are exploring efficacy of targeted therapies and role of adjuvant therapy for adenocarcinoma and results are awaited. Early detection and aggressive surgical therapy for all localized tumors and lymph node sampling particularly for adenocarcinoma remains the main treatment modality.

Gemcitabine plus capecitabine (Gem-Cape) biweekly in chemorefractory metastatic colorectal cancer

Purpose

A proportion of patients with metastatic colorectal cancer (mCRC) are still able to continue with active therapy after their progression to fluoropyrimidines, oxaliplatin, and irinotecan regimens. Studies suggest that gemcitabine and fluoropyrimidines are synergic antimetabolites. The purpose was to evaluate gemcitabine–capecitabine (Gem–Cape) in heavily pretreated mCRC and to thus assess possible predictive factors for progression-free survival (PFS) and overall survival (OS).

Patients and methods

This analysis was performed on 119 evaluable patients pretreated with fluoropyrimidines, oxaliplatin, irinotecan, and biological agents between June 2001 and July 2011. Patients received gemcitabine 1,000 mg/m² day 1 and capecitabine 1,000 mg/m²bid for 7 days every 2 weeks.

Results

The general characteristics were ECOG 0–1, 89 %; male, 68 %, and median age 63 years. In total, 61 % had received two chemotherapy lines, while 39 % had received three or more. Objective response rates and stable disease rates at 3 months were 6.72 and 37.81 %, equalling a clinical benefit of 44.53 %. The median PFS and OS were 2.87 months [95 % confidence interval (CI) 2.53–3.17 months] and 6.53 months (95 % CI 5.33–8.77), respectively. The most frequent toxicities were grades 1–2, anemia (22 %), thrombocytopenia (10 %), and hand–foot syndrome (9 %); grade ≥3, diarrhea (2 %), with no treatment-related discontinuations. No treatment-related deaths were reported. Statistical significance was obtained by subgroups, assessing clinical benefits and objective responses for PFS and OS. Moreover, patients under 65 tended to have a better PFS.

Conclusion

These data suggest that Gem–Cape is a tolerable and feasible regimen, associated with clinical benefit in non-selected, heavily pretreated, mCRC patients.

Hepatotoxicity with vascular endothelial growth factor receptor tyrosine kinase inhibitors: A meta-analysis of randomized clinical trials

A meta-analysis of randomized controlled trials (RCT) was conducted to determine the relative risk (RR) of hepatotoxicity with vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKI). Citations from PubMed/Medline, abstracts from major conferences, clinicaltrials.gov and package inserts were reviewed to include RCTs comparing arms with or without a VEGFR TKI. The RRs of all-grade ALT, AST, ALP and bilirubin elevation in 18,282 patients from 52 trials were 1.57 (95% CI 1.38-1.79, p<0.001), 1.57 (95% CI 1.36-1.81, p<0.001), 1.20 (95% CI 1.09-1.83, p<0.001) and 1.55 (95% CI 1.21-1.97, p<0.001) respectively, and high-grade elevations were 1.66 (95% CI 1.25-2.20, p=0.001), 1.61 (95% CI 1.21-2.14, p=0.001), 1.02 (95% CI 0.70-1.47, p=0.932) and 1.34 (95% CI 1.0-1.81, p=0.054) respectively compared to those in the non-TKI group. The incidence of hepatic failure with VEGFR TKIs was 0.8%.

FOLFIRI and regorafenib combination therapy with dose escalation of irinotecan as fourth-line treatment for patients with metastatic colon cancer according to UGT1A1 genotyping

Here we report a case of metastatic colon cancer treated with 5-fluorouracil, leucovorin, and escalated doses of irinotecan (FOLFIRI) combined with regorafenib in the fourth-line setting after uridine diphosphate glucuronosyltransferase (UGT)1A1 genotyping analysis. A 66-year-old male was initially diagnosed with Union Internationale Contre le Cancer stage III descending colon cancer and underwent curative surgery. He received postoperative adjuvant chemotherapy; however, liver metastasis developed and a partial hepatectomy was performed thereafter. Unfortunately, pulmonary metastases and recurrent liver tumors were found despite a series of systemic treatments with multiple combinations of cytotoxic and biologic agents. Recently, a novel multikinase inhibitor, regorafenib, was approved for the treatment of metastatic colorectal cancer refractory to other therapeutic modalities. As further treatment, we combined regorafenib with FOLFIRI, which included dose escalations of irinotecan, after UGT1A1 genotyping analysis. The therapeutic results were promising, with the improvement in liver and pulmonary metastases being classified as stable disease and partial response, respectively. Moreover, the progression-free survival was over 6 months. FOLFIRI, with dose escalation of irinotecan according to UGT1A1 genotyping plus regorafenib appears to be a promising salvage therapy for patients with refractory metastatic colorectal cancer.

E7080 (lenvatinib), a multi-targeted tyrosine kinase inhibitor, demonstrates antitumor activities against colorectal cancer xenografts

Clinical prognosis of metastasized colorectal carcinoma (CRC) is still not at desired levels and novel drugs are needed. Here, we focused on the multi-tyrosine kinase inhibitor E7080 (Lenvatinib) and assessed its therapeutic efficacy against human CRC cell lines in vitro and human CRC xenografts in vivo. The effect of E7080 on cell viability was examined on 10 human CRC cell lines and human endothelial cells (HUVEC). The inhibitory effect of E7080 on VEGF-induced angiogenesis was studied in an ex vivo mouse aortic ring angiogenesis assay. In addition, the efficacy of E7080 against xenografts derived from CRC cell lines and CRC patient resection specimens with mutated KRAS was investigated in vivo. A relatively low cytotoxic effect of E7080 on CRC cell viability was observed in vitro. Endothelial cells (HUVEC) were more susceptible to the incubation with E7080. This is in line with the observation that E7080 demonstrated an anti-angiogenic effect in a three-dimensional ex vivo mouse aortic ring angiogenesis assay. E7080 effectively disrupted CRC cell-mediated VEGF-stimulated growth of HUVEC in vitro. Daily in vivo treatment with E7080 (5 mg/kg) significantly delayed the growth of KRAS mutated CRC xenografts with decreased density of tumor-associated vessel formations and without tumor regression. This observation is in line with results that E7080 did not significantly reduce the number of Ki67-positive cells in CRC xenografts. The results suggest antiangiogenic activity of E7080 at a dosage that was well tolerated by nude mice. E7080 may provide therapeutic benefits in the treatment of CRC with mutated KRAS.

The targeted therapy revolution in neuroendocrine tumors: in search of biomarkers for patient selection and response evaluation

The molecular events of tumorigenesis in neuroendocrine tumors are poorly understood. Understanding of the molecular alterations will lead to the identification of molecular markers, providing new targets for therapeutics. The purpose of this review was to critically analyze the genetic abnormalities in neuroendocrine tumors, with the aim of identifying biomarkers that indicate a response to agents developed against these targets and to serve as an understanding for the combinations of different active compounds. Human epidermal growth factor receptor 1/2 (EGFR and HER2), vascular endothelial growth factor receptors, hepatocyte growth factor receptor (c-Met), platelet-derived growth factor receptor, insulin-like growth factor, phosphatidylinositol 3-kinase-Akt-mammalian target of rapamycin pathway, and heat shock proteins are all interesting candidate biomarkers with involvement in carcinogenesis and tumor evolution of several neoplasms, including neuroendocrine tumors. Some of them have already been evaluated both as targets and also as biomarkers in clinical trials conducted in advanced neuroendocrine tumor settings, and others should encourage further investigations into innovative therapeutic opportunities.

The use of EGFR inhibitors in colorectal cancer: is it clinically efficacious and cost-effective?

Cetuximab (Erbitux) and panitumumab (Vectibix) are monoclonal antibodies to the EGFR. They are used as monotherapy or in combination with cytotoxic chemotherapy and increase both progression-free survival and overall survival in patients with wild-type RAS metastatic colorectal cancer. The most common side effects of therapy are dermatological, including skin (acneiform) rash, pruritus and hair changes. Despite their clinical activity, cost-effectiveness of the two drugs should be addressed in a discussion of their usage in everyday care. This study provides an up-to-date review of the clinical efficacy and cost-effectiveness of anti-EGFR inhibitors.

Efficacy and safety of raltitrexed combinations with uracil- tegafur or mitomycin C as salvage treatment in advanced colorectal cancer patients: a multicenter study of Anatolian Society of Medical Oncology (ASMO)

BACKGROUND

There is no standard treatment for patients with colorectal cancer (CRC) progressing after irinotecan and oxaliplatin treatment. Here we aimed to retrospectively evaluate the efficacy and tolerability of raltitrexed in combination with oral 5-fluoropyrimidine (uracil tegafur-UFT) or mitomycin C as salvage therapy in mCRC patients.

MATERIALS AND METHODS

A total of 62 patients who had received raltitrexed combined with UFT or mitomycin C were identified between December 2008 and June 2013. They were given raltitrexed 2.6 mg/m2 (max 5 mg) i.v. on day 1 in combination with either oral UFT 500 mg/day on days 1-14 every 3 weeks (group A) or mitomycin C 6 mg/m2 i.v. on day every 3 weeks (group B).

RESULTS

Forty-two patients (67.7%) were in group A and 20 (32.2%) in group B. In 15 patients (24%) grade 3/4 toxicity was observed, resulting in dose reduction, and in 13 patients (20.9%) dose delay was necessary. The median progression free survival (PFS) was 3 months (95%CI 2.65-3.34) and median overall survival (OS) was 6 months (95%CI 2.09-9.90) in the whole group. Median PFS was 3 months (95%CI 2.60-3.39) in group A vs 3 months (95%CI 1.64-4.35) in group B (p=0.90). Median OS was 6 months (95%CI 2.47-9.53) in group A vs 12 months (95%CI 2.83-21.1) in group B (p=0.46).

CONCLUSIONS

The combination of raltitrexed with UFT or mitomycin C seem to be a salvage therapy option due to safety profile and moderate clinical activity in heavily-pretreated mCRC patients.

The development of anti-angiogenic heparan sulfate oligosaccharides

Angiogenesis has emerged as a novel target for anti-cancer therapies through randomized clinical trials that tested the benefit of adding vascular endothelial growth factor (VEGF) inhibitors to conventional cytotoxic therapies. However, despite improvements in the progression-free survival, the benefit in overall survival is modest. Tumour angiogenesis is regulated by a number of angiogenic cytokines. Thus innate or acquired resistance to VEGF inhibitors can be caused, at least in part, through expression of other angiogenic cytokines, including fibroblast growth factor 2 (FGF2), interleukin 8 (IL-8) and stromal-cell-derived factor 1α (SDF-1α), which make tumours insensitive to VEGF signalling pathway inhibition. The majority of angiogenic cytokines, including VEGF-A, FGF2, IL-8 and SDF-1α, manifest an obligate dependence on heparan sulfate (HS) for their biological activity. This mandatory requirement of angiogenic cytokines for HS identifies HS as a potential target for novel anti-angiogenic therapy. Targeting multiple angiogenic cytokines with HS mimetics may represent an opportunity to inhibit tumour angiogenesis more efficiently. Our published studies and unpublished work have demonstrated the feasibility of generating synthetic HS fragments of defined structure with biological activity against a number of angiogenic cytokines.

Genomic landscape of metastatic colorectal cancer

Response to drug therapy in individual colorectal cancer (CRC) patients is associated with tumour biology. Here we describe the genomic landscape of tumour samples of a homogeneous well-annotated series of patients with metastatic CRC (mCRC) of two phase III clinical trials, CAIRO and CAIRO2. DNA copy number aberrations of 349 patients are determined. Within three treatment arms, 194 chromosomal subregions are associated with progression-free survival (PFS; uncorrected single-test P-values <0.005). These subregions are filtered for effect on messenger RNA expression, using an independent data set from The Cancer Genome Atlas which returned 171 genes. Three chromosomal regions are associated with a significant difference in PFS between treatment arms with or without irinotecan. One of these regions, 6q16.1–q21, correlates in vitro with sensitivity to SN-38, the active metabolite of irinotecan. This genomic landscape of mCRC reveals a number of DNA copy number aberrations associated with response to drug therapy.

Response to drug therapy in colorectal cancer (CRC) patients has been associated with tumour heterogeneity. Here the authors analyse DNA copy number aberrations in primary tumours from CRC patients and identify genetic variants that influence drug response.

A nomogram to predict overall survival and disease-free survival after curative resection of gastric adenocarcinoma

BACKGROUND

The American Cancer Society projects there will be over 22,000 new cases, resulting in nearly 11,000 deaths, related to gastric adenocarcinoma in the US in 2014. The aim of the current study was to find clinicopathologic variables associated with disease-free survival (DFS) and overall survival (OS) following curative resection of gastric adenocarcinoma, and create a nomogram for individual risk prediction.

METHODS

A nomogram to predict DFS and OS following surgical resection of gastric adenocarcinoma was constructed using a multi-institutional cohort of patients who underwent surgery for primary gastric adenocarcinoma at seven major institutions in the US between January 2000 and August 2013. Discrimination and calibration of the nomogram were tested by C-statistic, Kaplan-Meier curves, and calibration plots.

RESULTS

A total of 719 patients who underwent surgery for primary gastric adenocarcinoma were included in the study. Using the backward selection of clinically relevant variables with Akaike information criteria, age, sex, tumor site, depth of invasion, and lymph node ratio (LNR) were selected as factors predictive of OS, while age, tumor site, depth of invasion, and LNR were incorporated in the prediction of DFS. A nomogram was constructed to predict OS and DFS using these variables. Discrimination and calibration of the nomogram revealed good predictive abilities (C-index, DFS 0.711; OS 0.702).

CONCLUSION

Independent predictors of recurrence and death following surgery for primary gastric adenocarcinoma were used to create a nomogram to predict DFS and OS. The nomogram was able to stratify patients into prognostic groups, and performed well on internal validation.

Antiangiogenesis strategies revisited: from starving tumors to alleviating hypoxia

Ten antiangiogenic drugs targeting VEGF or its receptors are approved for cancer treatment. However, these agents, intended to block tumors' blood supply, may cause hypoxia, which may fuel tumor progression and treatment resistance. Emerging clinical data suggest that patients whose tumor perfusion or oxygenation increases in response to these agents may actually survive longer. Hence, strategies aimed at alleviating tumor hypoxia while improving perfusion may enhance the outcome of radiotherapy, chemotherapy, and immunotherapy. Here I summarize lessons learned from preclinical and clinical studies over the past decade and propose strategies for improving antiangiogenic therapy outcomes for malignant and nonmalignant diseases.

Management of colorectal cancer

Colorectal cancer is one of the most frequent solid tumors in the Western world. Treatment options are dependent on the stage of the disease, the performance status of the patient, and increasingly the molecular makeup of the tumor. In countries with surveillance programs, the incidence rate as well as the mortality rate has gone down because of the earlier stages at which the tumors are detected. For rectal cancer, standard of care differs from that of colon cancer with regard to perioperative treatment. In the metastatic setting, treatment options are uniform for colorectal cancer. Over the years, treatment options have emerged from single-agent 5-fluorouracil (5-FU) treatment to combination regimens using 5-FU and oxaliplatin or irinotecan or both. Treatment efficacy in the metastatic setting has been increased with the introduction of targeted substances. These include (a) the anti-vascular endothelial growth factor-A (anti-VEGF-A) antibody bevacizumab, (b) the anti-epidermal growth factor receptor (anti-EGFR) antibodies cetuximab and panitumumab, (c) the anti-angiogenic multi-kinase inhibitor regorafenib, and (d) the anti-angiogenic compound aflibercept. Anti-EGFR antibodies have shown efficacy only in the subpopulations of tumors that do not have any mutation in KRAS and NRAS exon 2, 3, 4. Physicians have the choice in the first line to use anti-EGFR or anti-VEGF inhibitors in combination with chemotherapy based on treatment goals and patient performance. In recent years, tumor location has been shown to be prognostic and predictive for clinical outcome. Right-sided sporadic colon cancers differ significantly in molecular characteristics and, with the exception of microsatellite instability (MSI-H) tumors, are associated with poor prognosis. Tumors based on hereditary non-polyposis colorectal cancer, on the other hand, have excellent prognosis in stage II and III disease. Recent efforts have focused on the molecular classification of colorectal cancer with the purpose of establishing molecularly defined subgroups.

The clinicopathologic importance of serum lactic dehydrogenase in patients with gastric cancer

Background. To explore possible correlation between serum lactate dehydrogenase (SLDH) levels and gastric cancer. Materials and Methods. We retrospectively reviewed 365 patients with gastric cancer. The correlation of SLDH levels with clinicopathologic features and survival rate was studied. Results. SLDH levels were closely associated with the pathological (p) T stage (P = 0.011), metastasis (P = 0.012), pTNM stage (P = 0.001), and recurrence (P = 0.012). Moreover, we found a significant SLDH level difference among Borrmann type (P = 0.027), pT stage (P = 0.004), lymph node metastasis (P = 0.027), metastasis (P < 0.001), pTNM stage (P = 0.006), and recurrence (P = 0.002). In addition, we detected a significant SLDH level difference between alive and dead subgroups (P = 0.001). In addition, both univariate analysis and multivariate analysis showed that high SLDH levels were independent prognostic factor. For the subgroup with normal LDH (median point of 157.0 U/L), we detected that the subset with SLDH levels ≥157 U/L (158–245 U/L) showed poorer OS (P = 0.005) and DFS (P = 0.01) than that of ≤157 subgroup. Conclusions. Our results suggest that high SLDH level could be an independent poor prognostic biomarker. Gastric cancer patients with relative high SLDH level (158–245 U/L) were prone to develop a shorter OS and DFS.

Regorafenib in metastatic colorectal cancer

Regorafenib is an oral multikinase inhibitor that blocks the activity of protein kinases involved in the regulation of tumor angiogenesis (VEGFR1, 2, 3; angiopoietin-1 receptor), oncogenesis (stem cell growth factor receptor; RET; BRAF including BRAFV600E), and tumor microenvironment (PDGFR-β and FGFR). Based on data from the Phase III CORRECT study, regorafenib stands as a further option for patient affected by metastatic colorectal cancer who have exhausted previous available therapies. Its multi-targeted effect might explain activity in advanced lines of treatment, when cancer cells have been heavily challenged with previous lines of therapy and potentially developed multiple mechanisms of resistance, but also makes difficult to identify predictive biomarkers. In this article we examine preclinical as well as clinical data of regorafenib in the therapy of metastatic colorectal cancer, challenges for potential markers of efficacy and its role in the treatment algorithm.

Clinical management of regorafenib in the treatment of patients with advanced colorectal cancer

Colorectal cancer is one of the most common tumors worldwide and at least 50 % of patients with this disease develop metastases. In this setting, additional treatment options are needed for patients presenting disease progression after exhausting all standard therapies. Regorafenib is an orally administered multikinase inhibitor which has been shown to provide survival benefits to patients with metastatic colorectal cancer (mCRC). Although most adverse events (AEs) associated with regorafenib may resolve within the first 8 weeks of treatment, some of them may require dose reduction or treatment interruption. Overall, while remaining aware of the safety profile of regorafenib and how to manage the most common toxicities related to its use, this drug should be considered a new standard of care for patients with pretreated mCRC. This review addresses practical aspects of its use, such as dosing, patient monitoring, and management of the most common regorafenib-related AEs.

The role of targeted therapy for gastrointestinal tumors

Many targeted drugs have been studied to target the molecular pathways involved in the development of gastrointestinal cancers. Anti-VEGF, anti-EGFR agents, and recently also multi-kinase inhibitor regorafenib, have already been available for the treatment of metastatic colorectal cancer patients. To date, Her-2 positive, gastric cancer patients, are also treated with trastuzumab, while the multi-targeted inhibitor, sorafenib, represents the standard treatment for hepatocellular carcinoma patients. Finally, sunitinib and everolimus, have been approved for the treatment of the neuroendocrine gastroenteropancreatic tumors. Actually a great number of further drugs are under preclinical and clinical development. The aim of this review is to provide a comprehensive overview of the state of art, focusing on the new emerging strategies in the personalized treatment of gastrointestinal tumors.

Current clinical trials of targeted agents for well-differentiated neuroendocrine tumors

Neuroendocrine tumors (NETs) are a group of tumors originating in various locations, including the gastrointestinal tract, lung, and pancreas. Clinical trial design and disease management of these tumors pose a significant challenge because of the heterogeneous clinical presentations and varying degrees of aggressiveness. The recent completion of several phase II and III trials demonstrates that rigorous investigation of novel agents can lead to practice-changing outcomes. Furthermore, the molecular and genetic understanding of NETs has dramatically improved during the last few years; as a result, investigators have shifted clinical trial design to focus on targeted therapies. Most of these trials have targeted the somatostatin, vascular endothelial growth factor, and mammalian target of rapamycin pathways. This review will discuss the NET treatment landscape and trials of targeted agents currently offered.

Targeted therapies in metastatic colorectal cancer: a systematic review and assessment of currently available data

BACKGROUND

Survival of patients with metastatic colorectal cancer (mCRC) has been significantly improved with the introduction of the monoclonal antibodies targeting the vascular endothelial growth factor (VEGF) and the epidermal growth factor receptor (EGFR). Novel molecular-targeted agents such as aflibercept and regorafenib have recently been approved. The aim of this review is to summarize and assess the effects of molecular agents in mCRC based on the available phase II and III trials, pooled analyses, and meta-analyses/systematic reviews.

METHODS

A systematic literature search was conducted using the meta-database of the German Institute of Medical Documentation and Information. Criteria of the Scottish Intercollegiate Guidelines Network were used to assess the quality of the controlled trials and systematic reviews/meta-analyses.

RESULTS

Of the 806 retrieved records, 40 publications were included. For bevacizumab, efficacy in combination with fluoropyrimidine-based chemotherapy in first- and subsequent-line settings has been shown. The benefit of continued VEGF targeting has also been demonstrated with aflibercept and regorafenib. Cetuximab is effective with fluoropyrimidine, leucovorin, and irinotecan (FOLFIRI) in first-line settings and as a single agent in last-line settings. Efficacy for panitumumab has been shown with oxaliplatin with fluoropyrimidine in first-line settings, with FOLFIRI in second-line settings, and as monotherapy in last-line settings. Treatment of anti-EGFR antibodies is restricted to patients with tumors that do not harbor mutations in Kirsten rat sarcoma and in neuroblastoma RAS.

CONCLUSION

Among various therapeutic options, the future challenge will be a better selection of the population that will benefit the most from specific anti-VEGF or anti- EGFR treatment and a careful consideration of therapy sequence.

Bevacizumab combined with 5-FU/streptozocin in patients with progressive metastatic well-differentiated pancreatic endocrine tumours (BETTER trial)--a phase II non-randomised trial

AIM OF THE STUDY

Neuroendocrine tumours are highly vascular neoplasms known to overexpress vascular endothelial growth factor (VEGF) and its receptor. Bevacizumab, an inhibitor of VEGF, was assessed in combination with chemotherapy in pancreatic neuroendocrine tumour (P-NET).

PATIENTS AND METHODS

BETTER was a multicentre, open-label, non-randomised, two-group phase II trial. Patients with progressive metastatic, well-differentiated P-NET received a minimum of 6 month treatment of bevacizumab at 7.5 mg/kg IV on d1 q3w with 5-FU at 400 mg/m2/day and streptozocin at 500 mg/m2/day IV from d1 to d5 every 42 days. The primary end-point was progression-free survival (PFS); secondary end-points were overall survival (OS), overall response rate, safety and quality of life.

RESULTS

A total of 34 patients were included. Median age was 55 years, 65% of patients were men, 97% had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 and 97% had a Ki-67 proliferative index of <15%. After a maximum of 24 month follow-up per patient, the median PFS assessed by investigators was 23.7 months [95% confidence interval (CI): 13.1; not reached], 19 (56%) patients had a partial response and 15 (44%) had stable disease as best response. OS rate at 24 months was 88%. The most frequently reported grade 3-4 adverse events were hypertension (21% patients), abdominal pain (12%) and thromboembolic events (9%).

CONCLUSION

Bevacizumab with 5-FU/streptozocin in the treatment of pancreatic NETs seems to be feasible with a PFS of 23.7 months, which deserves further attention. No unexpected toxicity was observed.

Regorafenib in gastrointestinal stromal tumors: clinical evidence and place in therapy

Gastrointestinal stromal tumors (GISTs) are rare malignancies, and historically had a poor prognosis, with little benefit from traditional anticancer therapies. The management of GISTs has undergone a paradigm change in recent years with the detection of activating mutations in the majority of these tumors. This knowledge has led to the development of targeted treatments which have dramatically improved benefit rates and survival. The tyrosine kinase inhibitor, imatinib, has become the standard of care for both those with high-risk resected GIST, and as first-line therapy in metastatic GIST. However, some patients demonstrate innate resistance to imatinib or, for many, resistance develops despite an initial response. Other tyrosine kinase inhibitors with a broader spectrum of action, such as sunitinib and sorafenib, have been investigated and show some benefit after the use of imatinib. Regorafenib, an orally available multitargeted tyrosine kinase inhibitor with antiangiogenic activity, has also demonstrated preclinical evidence of activity against a number of solid tumors and further studies have proven it to be effective in GISTs following failure of standard therapy, with manageable toxicity profile. It has now received licensing approval in a number of countries both for the treatment of GISTs and for colorectal cancer, and further research is ongoing. With a number of potential agents now available to treat this disease, clinicians must now consider questions of timing and sequencing to maximize the benefit from these treatments, and the role that new agents such as regorafenib could play in further advancing changes.

Systemic therapy, clinical outcomes, and overall survival in locally advanced or metastatic pulmonary carcinoid: a brief report

BACKGROUND

Data to guide the management of advanced pulmonary carcinoid (APC) come from retrospective reports and subgroup analyses of trials that included mainly extrapulmonary carcinoid tumors. We report the largest series to date of 49 patients with locally advanced or metastatic pulmonary carcinoid.

METHODS

The Johns Hopkins Pathology Database was reviewed for APC patients treated between January 1992 and December 2012. Data on time to recurrence, progression-free survival, and overall survival were estimated by using the Kaplan-Meier method.

RESULTS

Forty-nine patients were treated for APC in the specified time period. Median time to recurrence after surgical resection was 2.5 years (atypical carcinoid [AC] versus typical carcinoid [TC], 2.5 versus 6.3 years; p = 0.063). Median survival with advanced disease was 7.1 years and significantly longer for TC compared with AC (10.2 versus 4 years; p = 0.009). Among the diverse systemic therapies used, responses occurred in four of 17 patients (23.5%) who received platinum/etoposide with a median progression-free survival of 7 months.

CONCLUSION

Although systemic chemotherapy has moderate activity for APC, novel approaches are required. TC and AC, although both classified as pulmonary carcinoid, are clearly different clinical and molecular entities and require separate treatment paradigms in the advanced/metastatic setting.

Bevacizumab plus capecitabine in patients with progressive advanced well-differentiated neuroendocrine tumors of the gastro-intestinal (GI-NETs) tract (BETTER trial)--a phase II non-randomised trial

AIM OF THE STUDY

Gastro-intestinal neuroendocrine tumours (GI-NETs) are chemotherapy-resistant tumours. Bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF), has shown promising results in several phase II trials of gastro-entero-pancreatic-NETs. We assessed bevacizumab combined with capecitabine, specifically in GI-NET patients.

PATIENTS AND METHODS

BEvacizumab in The Treament of neuroEndocrine tumoRs (BETTER) was a multicentre, open-label, non-randomised, two-group phase II trial. Here we present the group of patients with progressive, metastatic, well-differentiated GI-NETs. Patients Eastern Cooperative Oncology Group-performance status (ECOG-PS)⩽2, Ki-67 proliferation rate <15% and no prior systemic chemotherapy were treated with bevacizumab (7.5 mg/kg/q3w) and capecitabine (1000 mg/m2 twice daily, orally d1-14, resumed on d22) for 6-24 months. The primary end-point was progression-free survival (PFS); secondary end-points included overall survival (OS), response rate, safety and quality of life.

RESULTS

Of the 49 patients included, 53% were men, median age was 60 years (41-82), primary tumour site was ileal in 82% patients and Ki-67 was <15% in 48 patients and not available for one patient. After a maximum of 24 month follow-up per patient, the median PFS by investigator assessment was 23.4 months [95% confidence interval (CI): 13.2; not reached] and the overall disease control rate was 88% (18% partial response, 70% stable disease). The 2-year survival rate was 85%. Median OS was not reached. The most frequent grade 3-4 adverse events were hypertension (31%), diarrhoea (14%) and hand-foot syndrome (10%).

CONCLUSION

The combination of bevacizumab and capecitabine showed clinical activity and a manageable safety profile in the treatment of GI-NETs that warrant confirmation in a randomised phase III trial.

A tale of two tumors: treating pancreatic and extrapancreatic neuroendocrine tumors

Despite their perceived rarity, gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rising in incidence and prevalence. The biology, natural history, and therapeutic options for GEP-NETs are heterogeneous: NETs arising in the pancreas can be distinguished from those arising elsewhere in the gastrointestinal tract, and therapy is dichotomized between these two groups. Somatostatin analogues are the mainstay of oncologic management of bowel NETs; everolimus, streptozocin, and sunitinib are approved to treat pancreatic NETs. There are significant differences in molecular genetics between pancreatic and extrapancreatic NETs, and studies are evaluating whether additional NET patients may benefit from targeted agents. We discuss the distinguishing features of these two groups of tumors, as well as the therapeutic implications of the distinction. We also examine the evolving therapeutic landscape and discuss the likelihood that treatment will be developed independently for pancreatic and extrapancreatic gastrointestinal NETs, with novel therapeutics effective for newly identified pathologically or molecularly defined subgroups.

[Chemotherapy of metastatic colorectal cancer]

Increasing numbers of therapeutic options are becoming available for the systemic treatment of metastasized colorectal cancer (mCRC) which emphasizes the need for strategic decision making and planning across multiple lines of treatment. The choice of first-line therapy is influenced by clinical and molecular characteristics of patients and tumors, such as (K-)RAS gene mutations with respect to therapy guidance of epidermal growth factor receptor (EGFR) antibodies. First-line therapy is the major determinant of subsequent treatment regimens and can therefore be considered as the key decision in patients with mCRC. The German standard for first-line therapy in the majority of patients includes chemotherapy in combination with biological agents, with antibodies targeting EGFR possibly being the preferable option in patients with (K-)RAS wild-type tumors. The development of effective therapeutic strategies in patients with (K-)RAS mutant mCRC tumors must be promoted in the future and requires intensive research because the therapy options for this group of patients are very limited.

The bromodomain and extra-terminal inhibitor CPI203 enhances the antiproliferative effects of rapamycin on human neuroendocrine tumors

Endogenous c-MYC (MYC) has been reported to be a potential pharmacological target to trigger ubiquitous tumor regression of pancreatic neuroendocrine tumors (PanNETs) and lung tumors. Recently inhibitors of bromodomain and extra-terminal (BET) family proteins have shown antitumor effects through the suppression of MYC in leukemia and lymphoma. In this paper, we investigated the antitumor activity of a BET protein bromodomain inhibitor (BETi) CPI203 as a single agent and in combination with rapamycin in human PanNETs. We found that exposure of human PanNET cell lines to CPI203 led to downregulation of MYC expression, G1 cell cycle arrest and nearly complete inhibition of cell proliferation. In addition, overexpression of MYC suppressed the growth inhibition caused by CPI203 and knockdown of MYC phenocopied the effects of CPI203 treatment. These findings indicate that suppression of MYC contributed to the antiproliferative effects of BETi inhibition in human PanNET cells. Importantly, CPI203 treatment enhanced the antitumor effects of rapamycin in PanNET cells grown in monolayer and in three-dimensional cell cultures, as well as in a human PanNET xenograft model in vivo. Furthermore, the combination treatment attenuated rapamycin-induced AKT activation, a major limitation of rapamycin therapy. Collectively, our data suggest that targeting MYC with a BETi may increase the therapeutic benefits of rapalogs in human PanNET patients. This provides a novel clinical strategy for PanNETs, and possibly for other tumors as well.

Conditional survival after surgical resection of gastric cancer: a multi-institutional analysis of the us gastric cancer collaborative

BACKGROUND

Survival estimates following surgical resection of gastric adenocarcinoma are traditionally reported as survival from the date of surgery. Conditional survival (CS) estimates, however, may be more clinically relevant by accounting for time already survived. We assessed CS following surgical resection for gastric adenocarcinoma.

METHODS

We analyzed 807 patients who underwent resection for gastric adenocarcinoma from 2000 to 2012 at seven participating institutions in the U.S. Gastric Cancer Collaborative. Cox proportional hazards models were used to evaluate factors associated with overall survival. Three-year CS estimates at "x" year after surgery were calculated as follows: CS3 = S(x+3)/S(x).

RESULTS

Overall 1-, 3-, and 5-year overall survival rates after gastric resection were 42, 34, and 30 %, respectively. Using CS estimates, the probability of surviving an additional 3 years given that the patient had survived at 1, 3, and 5 years were 56, 71, and 82 %, respectively. Patients with higher risk at baseline (i.e., stage III or IV disease, lymphovascular invasion) demonstrated the greatest increase in CS over time.

CONCLUSIONS

Survival estimates following surgical resection of gastric adenocarcinoma is dynamic; the probability of survival increases with time already survived. Patients with worse prognostic features at the time of surgery had the greatest increases in CS over time. Conditional survival estimates provide important information about the changing probability of survival over time and should be used among patients with resected gastric adenocarcinoma to guide subsequent follow-up strategies.

Colorectal cancer in Chinese patients: current and emerging treatment options

Colorectal cancer is the second most common cancer in Hong Kong and its incidence is rising in economically developed Chinese cities, including Hong Kong and Shanghai. Several studies conducted in the People's Republic of China have characterized the unique molecular epidemiology of familial colorectal cancer syndromes and molecular biomarkers such as microsatellite instability and genetic mutations (eg, KRAS, NRAS, BRAF, PIK3CA, ERCC1) in Chinese populations. Interethnic differences in anticancer drug response and toxicity have been well described in many cancers, and this review examined the literature with regard to the tolerance of Chinese patients to commonly used chemotherapeutic regimens and targeted therapies for metastatic colorectal cancer. Studies on the pharmacogenomic differences in drug metabolizing and DNA repair enzymes between Chinese, North Asians, and Caucasian patients were also reviewed.

Colorectal cancer in Chinese patients: current and emerging treatment options

Colorectal cancer is the second most common cancer in Hong Kong and its incidence is rising in economically developed Chinese cities, including Hong Kong and Shanghai. Several studies conducted in the People's Republic of China have characterized the unique molecular epidemiology of familial colorectal cancer syndromes and molecular biomarkers such as microsatellite instability and genetic mutations (eg, KRAS, NRAS, BRAF, PIK3CA, ERCC1) in Chinese populations. Interethnic differences in anticancer drug response and toxicity have been well described in many cancers, and this review examined the literature with regard to the tolerance of Chinese patients to commonly used chemotherapeutic regimens and targeted therapies for metastatic colorectal cancer. Studies on the pharmacogenomic differences in drug metabolizing and DNA repair enzymes between Chinese, North Asians, and Caucasian patients were also reviewed.

Treatment-related fatigue with everolimus and temsirolimus in patients with cancer-a meta-analysis of clinical trials

Mammalian target of rapamycin (mTOR) inhibitors, everolimus and temsirolimus, are approved for the treatment of a variety of malignancies. Fatigue has been described with these agents as a common side effect, although the overall incidence and risk remain unclear. We performed a meta-analysis to calculate the overall incidence of fatigue in cancer patients treated with everolimus and temsirolimus and to compare the differences in incidence with placebo. The electronic databases PubMed, Embase, Web of Science, and Cochrane databases were searched for studies to include in the meta-analysis. Eligible studies were phase II and III prospective clinical trials of cancer patients treated with single drug everolimus or temsirolimus with toxicity data on fatigue. Overall incidence rates, relative risk (RR), and 95% confidence intervals (CI) were calculated employing fixed or random effects models depending on the heterogeneity of the included studies. A total of 9,760 patients with a variety of malignancies from 56 prospective clinical trials were included for the meta-analysis. The overall incidences of all-grade and high-grade fatigue in cancer patients treated with mTOR inhibitor (everolimus or temsirolimus) were 45.4% (95% CI 36.9-55.8%) and 8.7% (95% CI 7.2-10.4%), respectively. The relative risks of fatigue of mTOR inhibitor compared to placebo were increased for all-grade (RR = 1.22, 95% CI 1.08-1.38, P = 0.002) and high-grade (RR = 1.82, 95% CI 1.24-2.69, P = 0.002) fatigue. The incidence of all-grade fatigue of patients treated with everolimus was higher than those with temsirolimus (RR = 1.85, 95% CI 1.71-2.01, P < 0.001). No significant difference was detected with between everolimus and temsirolimus in terms of high-grade fatigue (RR = 1.15, 95% CI 0.94-1.41, P = 0.18). Treatment with mTOR inhibitor, everolimus and temsirolimus, is associated with an increased incidence of fatigue in patients with cancer. Early detection and management of fatigue is needed.

Nordic guidelines 2014 for diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms

BACKGROUND

The diagnostic work-up and treatment of patients with neuroendocrine neoplasms (NENs) has undergone major recent advances and new methods are currently introduced into the clinic. An update of the WHO classification has resulted in a new nomenclature dividing NENs into neuroendocrine tumours (NETs) including G1 (Ki67 index ≤ 2%) and G2 (Ki67 index 3-20%) tumours and neuroendocrine carcinomas (NECs) with Ki67 index > 20%, G3. Aim. These Nordic guidelines summarise the Nordic Neuroendocrine Tumour Group's current view on how to diagnose and treat NEN-patients and are meant to be useful in the daily practice for clinicians handling these patients.

Multitarget inhibitors derived from crosstalk mechanism involving VEGFR2

Seven VEGFR small-molecule inhibitors have been approved by the US FDA as anticancer drugs, which confirms the therapeutic value of angiogenesis inhibitors. However, much more evidence indicates that VEGFR inhibition alone is usually not sufficient to block the tumor progress. The potential of some agents targeting VEGFR owes partially to the simultaneous inhibition of additional targets in other signaling pathways. In this review, the crosstalk between VEGFR2 and the additional targets in other signaling pathways, such as EGFR, MET, FGFR, PDGFR, c-Kit, Raf, PI3K and HDAC, and the synergistic effects derived from multitarget activities against these crosstalks are discussed. We also briefly describe the multitarget inhibitors in clinical trials or reported in the literature and patents under the different multitarget categories involving VEGFR2.