Genomic analysis of exceptional responder to regorafenib in treatment-refractory metastatic rectal cancer: a case report and review of the literature

Case report: Unique FLT4 variants associated with differential response to anlotinib in angiosarcoma

Angiosarcoma (AS) is a rare, clinically aggressive tumor with limited treatment options and a poor prognosis. Mutations involving the angiogenesis-related genesTP53, PTPRB, PLCG1, KDR as well as FLT4 amplification have been observed in AS. There is a potential therapeutic value of inhibition of the VEGF pathway against angiosarcoma. Our case first described a patient with two sites of cutaneous angiosarcomas (cASs) that responded differently to anlotinib. And genetic analysis revealed that those two sites had different FLT4 variants, suggesting that FLT4 amplification could be the cause of anlotinib non-response.

Prolonged clinical response with regorafenib administered as second-line therapy in an elderly patient suffering from peritoneal carcinomatosis of colon cancer

Peritoneal carcinomatosis from colorectal cancer (CRC) has a poor prognosis with median survival and clinical responses that are worse than for other metastatic sites, and even more so in pretreated patients proposed for regorafenib therapy. Thus, patients with these characteristics are a therapeutic challange. The present study reports the case of an 83-year-old woman with diffuse peritoneal carcinomatosis from CRC, RAS-mutated, and treated with second-line therapy with the off-label administration of regorafenib at full dose (160 mg once daily, for the first 21 days of each 4-week cycle), refusing conventional chemotherapy. The patient reported an unexpected clinical response, reduced toxicity, excellent adherence to therapy and remained progression-free for 30 months from the start of treatment. In clinical practice, an earlier use of regorafenib and a different selection of patients could be the subject of future studies.

Clinical and molecular distinctions in patients with refractory colon cancer who benefit from regorafenib treatment

Regorafenib (Stivarga, BAY 73-4506; Bayer Pharma AG, Berlin, Germany) is a novel oral multikinase inhibitor that blocks the activity of several protein kinases. However, few guidelines exist for novel biomarkers to select patients who will likely benefit from regorafenib treatment. Metastatic colorectal cancer (mCRC) patients treated with regorafenib were evaluated in this study. Tumor tissues of these patients were subjected to next-generation sequencing-based cancer panel tests. The relationship between molecular profiling and efficacy of regorafenib was analyzed. Among the 76 mCRC patients, the median age was 58 years (range 22–79 years), and 73.7% received regorafenib as a third-line therapy. The primary tumor locations were the right side (n = 15, 19.8%) and the left side (n = 61, 80.2%). Most patients (97.4%) had received prior anti-angiogenetic agents, and a prior anti-Epidermal Growth Factor Receptor (EGFR) agent had been administered to 32.9%. Of these 76 patients, 65 were evaluated to determine the efficacy of treatment. We observed zero complete responses, seven confirmed partial responses (PR 9.2%), 26 stable disease states (34.2%), and 32 disease progressions (42.1%). The overall confirmed response rate and the disease control rate were 9.2% and 43.4%, respectively. Genomic analysis revealed that APC mutations were significant in patients who demonstrated a tumor response to regorafenib (p < 0.05). Interestingly, FGFR1 amplification was detected in only three of 76 patients (3.9%), and these three patients achieved a PR to regorafenib. The median progression-free survival time was 2.8 months (95% Confidence Interval [CI] 1.6–4.0). Patients with BRAF mutation and/or SMAD4 mutation had significantly worse progression-free survival (PFS) than those without such a mutation. On pathway analysis, Tumor Growth Factor (TGF)-beta pathways were significantly associated with worse PFS. We found that efficacy of regorafenib might be correlated with specific genetic aberrations, such as APC mutation and FGFR1 amplification. In addition, SMAD4 mutation and TGF-beta pathway were associated with worse PFS after regorafenib. We found that efficacy of regorafenib might be correlated with specific genetic aberrations, such as APC mutation and FGFR1 amplification. In addition, SMAD4 mutation and the TGF-beta pathway were associated with worse PFS after regorafenib.

Recommendations for the use of next-generation sequencing (NGS) for patients with metastatic cancers: a report from the ESMO Precision Medicine Working Group

Next-generation sequencing (NGS) allows sequencing of a high number of nucleotides in a short time frame at an affordable cost. While this technology has been widely implemented, there are no recommendations from scientific societies about its use in oncology practice. The European Society for Medical Oncology (ESMO) is proposing three levels of recommendations for the use of NGS. Based on the current evidence, ESMO recommends routine use of NGS on tumour samples in advanced non-squamous non-small-cell lung cancer (NSCLC), prostate cancers, ovarian cancers and cholangiocarcinoma. In these tumours, large multigene panels could be used if they add acceptable extra cost compared with small panels. In colon cancers, NGS could be an alternative to PCR. In addition, based on the KN158 trial and considering that patients with endometrial and small-cell lung cancers should have broad access to anti-programmed cell death 1 (anti-PD1) antibodies, it is recommended to test tumour mutational burden (TMB) in cervical cancers, well- and moderately-differentiated neuroendocrine tumours, salivary cancers, thyroid cancers and vulvar cancers, as TMB-high predicted response to pembrolizumab in these cancers. Outside the indications of multigene panels, and considering that the use of large panels of genes could lead to few clinically meaningful responders, ESMO acknowledges that a patient and a doctor could decide together to order a large panel of genes, pending no extra cost for the public health care system and if the patient is informed about the low likelihood of benefit. ESMO recommends that the use of off-label drugs matched to genomics is done only if an access programme and a procedure of decision has been developed at the national or regional level. Finally, ESMO recommends that clinical research centres develop multigene sequencing as a tool to screen patients eligible for clinical trials and to accelerate drug development, and prospectively capture the data that could further inform how to optimise the use of this technology.

Long-term survival of an advanced colorectal cancer patient treated with Regorafenib: Case report and literature review

Two phase 3 trials reported a prolonged survival in the third-line setting of colorectal cancer patients treated with regorafenib with the longest duration of treatment of 16 months. Herein, we reported a unique case of a patient refractory to conventional chemotherapy who showed a prolonged stable disease with regorafenib.

Signet ring cell colorectal cancer: genomic insights into a rare subpopulation of colorectal adenocarcinoma

Background

Signet ring cell carcinoma (SRCC) is a rare subtype of colorectal cancer (CRC). The aim of this study was to characterise the genomic alterations and outcomes of SRCC.

Methods

Medical records of metastatic CRC (mCRC) patients whose tumours were evaluated by NGS analysis were reviewed. SC-mCRC were classified into two groups: SRCC (>50% signet ring cells) and adenocarcinoma (AC) with SC component (≤50% signet ring cells).

Results

Six hundred and sixty-five mCRC patients were included. Of the 93 mCRC cases with SC features, 63 had slides for review. Of those 63 cases, 35 were confirmed SRCC, and 28 were AC with SC component. Compared with AC group, KRAS and PIK3CA mutations (mts) were found in only 11% (OR: 0.13) and 3% (OR: 0.15) of SRCC cases, respectively. In contrast to the 44% rate of APC mts in AC group, only 3% of SRCC patients had APC mts (OR = 0.04).

Conclusions

SRCC has distinct molecular features, including low rates of KRAS, PIK3CA and APC mts. Further study to identify activation pathways and potential therapeutic targets are needed.

Back to the Colorectal Cancer Consensus Molecular Subtype Future

PURPOSE OF REVIEW

This review seeks to provide an informed prospective on the advances in molecular profiling and analysis of colorectal cancer (CRC). The goal is to provide a historical context and current summary on how advances in gene and protein sequencing technology along with computer capabilities led to our current bioinformatic advances in the field.

RECENT FINDINGS

An explosion of knowledge has occurred regarding genetic, epigenetic, and biochemical alterations associated with the evolution of colorectal cancer. This has led to the realization that CRC is a heterogeneous disease with molecular alterations often dictating natural history, response to treatment, and outcome. The consensus molecular subtypes (CMS) classification classifies CRC into four molecular subtypes with distinct biological characteristics, which may form the basis for clinical stratification and subtype-based targeted intervention. This review summarizes new developments of a field moving "Back to the Future." CRC molecular subtyping will better identify key subtype specific therapeutic targets and responses to therapy.

VEGF-C is positively associated with lymphangiogenesis and lymphatic metastasis in rectal cancer

Rectal cancer is a common malignancywith a less than 5-year postoperative survival rate. Although it often metastasizes via the lymph and blood, the detailed mechanism of this process remains unclear. This study investigated the relationship between vascular endothelial growth factor-C (VEGF-C) expression and lymphangiogenesis, as well as its relation to lymphatic metastasis of rectal cancer. To address this question, VEGF-C expression in rectal cancer and normal tissue adjacent to tumor was assessed by immunohistochemistry. The lymphatic endothelial cell-specific marker D2-40 was used to label lymphatic endothelial cells and the lymphatic vessel density (LVD) was subsequently quantified. As expected, the expression of VEGF-C in rectal cancer (75%) was significantly higher than in normal adjacent tissue (25%), and this level correlated with differentiation, Dukes stage, and lymph node metastasis, though not with sex or age. The LVD was higher in VEGF-C positive rectal cancer than in VEGF-C negative rectal cancer, and was also higher in lymphatic metastases than in non-lymphatic metastases. These results indicate that expression of VEGF-C may impact the prognosis of rectal cancer via its effect on the formation of new lymphatic vessels. This represents a significant advance in the study of the genesis and development of rectal cancer, and may have value in clinical care.