Tumor Response and Symptom Palliation from RAINBOW,a Phase III Trial of Ramucirumab Plus Paclitaxel in Previously Treated Advanced Gastric Cancer

BackgroundIn the intent‐to‐treat (ITT) population of the RAINBOW study, objective response rate (ORR) was 28% and 16% in the ramucirumab and control arms, respectively. To further characterize tumor response, we present details on timing and extent of tumor shrinkage, as well as associations with symptom palliation.Materials and MethodsTumor response was assessed with RECIST v1.1, and quality of life (QoL) was assessed with the European Organization for Research and Treatment of Cancer Quality‐of‐Life Questionnaire‐Core 30 (EORTC QLQ‐C30) v3.0. Prespecified and post hoc analyses were conducted in the ITT population, patients with measurable disease, or responders, and included best overall response (BOR), ORR, disease control rate (DCR), duration of response, time to response (TtR), change in tumor size, and associations of QoL with tumor shrinkage and BOR.ResultsIn both treatment arms, median TtR was 1.5 months. Responses were more durable in the ramucirumab versus control arm (median 4.4 vs. 2.8 months). In patients with measurable disease (78% of ITT), ORR was 36% versus 20%; DCR was 81% versus 61% in the ramucirumab versus control arms. Waterfall plots demonstrated more tumor shrinkage in the ramucirumab versus control arm. Regardless of treatment, tumor response and stable disease were associated with improved or stable QoL, with more tumor shrinkage associated with greater symptom palliation.ConclusionTreatment with ramucirumab plus paclitaxel yielded the highest ORR reported to date for patients with previously treated advanced gastric or gastroesophageal junction adenocarcinoma. Additional details demonstrate robustness of tumor response results. The extent of tumor shrinkage is directly associated with symptom palliation and should be considered when evaluating patient needs and treatment selection. Clinical trial identification number. {"type":"clinical-trial","attrs":{"text":"NCT01170663","term_id":"NCT01170663"}}NCT01170663.Implications for PracticeRamucirumab plus paclitaxel is a recognized standard of care as it improves survival for patients with advanced gastric or gastroesophageal junction adenocarcinoma who have been previously treated with recommended first‐line therapy. These additional data on tumor response demonstrate a positive association between tumor shrinkage and symptom palliation in a patient population that is often symptomatic. These observations included patients with nonmeasurable disease, a group of patients often underrepresented in clinical trials. This knowledge can inform treatment decisions, which align individual patient characteristics and needs with demonstrated benefits.     

Microsatellite instable vs stable colon carcinomas: analysis of tumour heterogeneity,inflammation and angiogenesis

Background:

Microsatellite instability (MSI) accounts for 15% of all colorectal tumours. Several specific clinicopathologicals (e.g., preference for the proximal colon over the distal colon, improved prognosis and altered response to chemotherapeutics) are described for this subset of tumours. This study aimed to analyse morphological, inflammatory and angiogenic features of MSI vs microsatellite stable (MSS) tumours.

Methods:

Twenty-seven MSS and 29 MSI, TNM stage matched, colorectal tumours were selected from the archive of the Department of Pathology, UZ Leuven. Morphology was analysed on haematoxylin–eosin sections. Immunohistochemistry for CD3, CD4, CD8, CD20 and CD68 was used to map tumour infiltration in both a digital and traditional microscope-based manner for all distinct morphological components of the tumour. CD31 immunostains were performed to assess angiogenesis.

Results:

Morphological tumour heterogeneity was a marked feature of MSI tumours, occurring in 53% of the cases as compared with 11% of the MSS tumours (P<0.001). Digital immune quantification showed an increased number of tumour-infiltrating cytotoxic T-lymphocytes (CD8+) in MSI compared with MSS tumours for both the tumour (P=0.02) and peritumoural area (P=0.03). Traditional microscope-based quantification confirmed these results (P<0.001 for both) and, in addition, revealed large numbers of CD68+ macrophages in the peritumoural area of MSI cancers (P=0.001). Moreover, traditional microscope-based analysis was able to distinguish between lymphocytes directly infiltrating the tumoural glands (intra-epithelial) and those infiltrating only the neoplastic stroma around the glands (intratumoural). Quantification showed high numbers of intra-epithelial CD3+, CD4+, CD8+, CD20+ and CD68+ cells in MSI compared with MSS cancers (P<0.001, P=0.01, P<0.001, P<0.001 and P=0.006, respectively). Higher microvessel density (MVD) was observed in MSI tumours compared with their MSS counterpart.

Conclusions:

Mixed morphology, reflecting tumour heterogeneity, is an important feature of MSI tumours and may have both diagnostic and therapeutic impact. The inflammatory reaction also presented with significant differences in MSI vs MSS colorectal tumours. MSI cancers showed mainly infiltration by cytotoxic T-cells in both the tumour and the close border around the tumour, as well as increased intra-epithelial infiltration in contrast to MSS tumours. The type of immune cell and the compartment it resides in (intratumoural or intra-epithelial) depend both on MSI status and morphology. Finally, MSI tumours showed a higher angiogenic capacity represented by an increased MVD, hinting for possible therapeutic consequences.     

Analysis of HER2 expression and gene amplification in adenocarcinoma of the stomach and the gastro-oesophageal junction: rationale for the Belgian way of working

The Human Epidermal growth factor Receptor 2 (HER2) has been established as a key player in the development of certain human tumors. ToGA trial has demonstrated that the addition of the monoclonal antibody blocking HER2 receptor, trastuzumab (Herceptin?), to chemotherapy significantly improves overall survival of patients with HER2-positive advanced or metastatic adenocarcinoma of the stomach or gastro-oesophageal junction. Therefore, it is essential that pathologists guarantee an accurate testing of HER2 status in these tumours. Following the international recommendations and the Belgian criteria for reimbursement of trastuzumab, a consortium of expert pathologists (Belgian Working Group Molecular Pathology) proposes an adaptation of the international guidelines in order to develop strategies for optimal performance, interpretation and reporting assays.     

Report on the Belgian consensus meeting on colorectal cancer screening

Screening and prevention of colorectal cancer must be a public health priority. It is the most frequent malignancy in Europe, the second leading cause of cancer death, including Belgium where more than 6000 new cases occur per year. Various screening modalities, from non invasive to invasive are available and currently in use and they are all cost-effective in comparison with no screening. The decision as to which screening test to use should be made by the patient and clinician. Consensus documents prepared by the Belgian scientific community appear in this issue of Acta Gastroenterologica Belgica, summarizing the scientific evidence in favour as well as the limitations of fecal occult blood tests, flexible sigmoidoscopy, videocolonoscopy and virtual colonoscopy.     

Genetic variability of VEGF pathway genes in six randomized phase III trials assessing the addition of bevacizumab to standard therapy

Background

Despite extensive translational research, no validated biomarkers predictive of bevacizumab treatment outcome have been identified.

Methods

We performed a meta-analysis of individual patient data from six randomized phase III trials in colorectal, pancreatic, lung, renal, breast, and gastric cancer to explore the potential relationships between 195 common genetic variants in the vascular endothelial growth factor (VEGF) pathway and bevacizumab treatment outcome.

Results

The analysis included 1,402 patients (716 bevacizumab-treated and 686 placebo-treated). Twenty variants were associated (P < 0.05) with progression-free survival (PFS) in bevacizumab-treated patients. Of these, 4 variants in EPAS1 survived correction for multiple testing (q < 0.05). Genotype-by-treatment interaction tests revealed that, across these 20 variants, 3 variants in VEGF-C (rs12510099), EPAS1 (rs4953344), and IL8RA (rs2234671) were potentially predictive (P < 0.05), but not resistant to multiple testing (q > 0.05). A weak genotype-by-treatment interaction effect was also observed for rs699946 in VEGF-A, whereas Bayesian genewise analysis revealed that genetic variability in VHL was associated with PFS in the bevacizumab arm (q < 0.05). Variants in VEGF-A, EPAS1, and VHL were located in expression quantitative loci derived from lymphoblastoid cell lines, indicating that they affect the expression levels of their respective gene.

Conclusions

This large genetic analysis suggests that variants in VEGF-A, EPAS1, IL8RA, VHL, and VEGF-C have potential value in predicting bevacizumab treatment outcome across tumor types. Although these associations did not survive correction for multiple testing in a genotype-by-interaction analysis, they are among the strongest predictive effects reported to date for genetic variants and bevacizumab efficacy.     

Risk factors which determine the long term outcome of Neodymium-YAG laser palliation of colorectal carcinoma

We have analysed the long term results of YAG laser palliation for incurable colorectal carcinoma in 88 patients. Although initial palliation was achieved in 82%, good palliation could only be maintained in 51% and 41% of patients surviving 6 months and 12 months respectively. The relative inefficacy of YAG laser therapy for palliation of rectal cancer is due to the failure to control extraluminal tumour growth, complications of YAG laser therapy and the poor general condition of these elderly patients. Factors influencing the efficacy of palliation, besides life expectancy, included T classification, and length of the neoplastic stricture. Treatment-related mortality due to perforation was 2.3%. YAG laser therapy, applied as the sole therapeutic modality, is effective for short term palliation of incurable colorectal carcinoma, but is not adequate for long term palliation in most patients. Trials should be conducted to study the effect of combined treatment (e.g. laser+radiotherapy) on palliation.