Aggressive Fibromatosis of the Left Mesocolon Mimicking a Gastrointestinal Stromal Tumor: A Case Report

Mesenteric fibromatosis (MF) is a proliferative fibroblastic lesion of the intestinal mesentery. It constitutes 8% of all desmoid tumors, representing 0.03% of all neoplasms. It is benign histologically, although it could infiltrate locally and recur following excision; however, it is free from the potential to metastasize. It is spontaneous or associated with familial adenomatous polyposis (FAP]) mutation as a part of Gardner's syndrome. This case report discusses the radiological, intraoperative, and histopathological findings from a 45-year-old male patient who presented with abdominal pain and a palpable mass in the left hemiabdomen. The pain was dull and aching, extending to the back and unrelated to any other gastrointestinal symptoms. There was no history of severe weight reduction. Furthermore, he is not a smoker. There were no comorbidities, severe medical diseases, or prior surgical procedures. Computerized tomography revealed a well-defined, lobulated, heterogeneously enhancing altered signal intensity mass at the mesocolon. Ultrasonography of the abdomen showed an intra-abdominal mass. Macroscopic mass characteristics include a well-defined mass measuring 22 × 14 × 11 cm connected to a small intestine segment measuring 21 × 2 × 2 cm. Histopathological and immunohistochemical examinations of the resected tumor, including positive nuclear immunostaining for beta-catenin, confirmed a postoperative diagnosis of desmoid-type fibromatosis. Based on its clinical presentation and computed tomography results, this case demonstrated how desmoid-type fibromatosis of the colon might mimic gastrointestinal stromal tumors (GISTs). Due to the varied therapies and follow-up methods used for these lesions, the differential diagnosis between desmoid-type fibromatosis and GIST is clinically significant.

Dose reduction and discontinuation of standard-dose regorafenib associated with adverse drug events in cancer patients: a systematic review and meta-analysis

Background

Regorafenib (REG) is an oral multikinase inhibitor used in colorectal cancer, gastrointestinal stromal tumour and hepatocellular carcinoma. Several adverse events (AEs) are commonly reported during REG administration, and strategies for managing AEs in everyday clinical practice include supportive care, dose modifications and, when necessary, treatment withdrawal. We performed a systematic review and meta-analysis to assess the schedule treatment modifications of REG associated with AEs across randomized controlled clinical trials (RCTs).

Methods

Eligible studies included RCTs assessing standard dose REG versus placebo. Outcomes of interest included: AE-related permanent discontinuation, dose interruptions and dose reductions.

Results

We retrieved all the relevant RCTs through PubMed/Med, Cochrane library and EMBASE: 7 eligible studies involving a total of 2099 patients (Regorafenib: 1362; placebo: 737) were included in our analysis. The use of REG was associated with higher incidence and risk of all outcomes of interest when compared with placebo. The incidences of permanent discontinuation, dose interruptions and dose reductions in patients receiving REG were 9.7%, 57.2% and 47%, respectively, versus 3.3%, 16.7% and 7.7% of placebo group; compared with placebo, the summary relative risks (RRs) of permanent discontinuation, dose interruptions and dose reductions in REG arm were 2.80 (95% CI 1.85-4.22), 3.21 (95% CI 2.59-3.99) and 6.02 (95% CI 3.28-11.03), respectively.

Conclusions

Treatment with REG at the standard dose of 160 mg is associated with a significant increase in AE-related permanent discontinuation, dose interruptions and dose reductions. Prompt identification and management of AEs seem mandatory to obtain maximal benefit from REG treatment. In the current landscape, dose personalization of REG may have the potential to improve quality of life, minimize treatment discontinuation and maximize patient outcomes.

The use of regorafenib for patients with refractory metastatic colorectal cancer in clinical practice

Aim

Patients in clinical practice are relatively vulnerable compared to those enrolled in clinical trials. We focused on analyzing the pattern of regorafenib use in routine clinical practice, which included initial starting dose and follow-up schedule. We also evaluated the efficacy and safety according to clinical regimen.

Methods

We retrospectively reviewed the medical records of 134 Korean heavily pretreated metastatic colorectal cancer (mCRC) patients who had received regorafenib monotherapy as salvage treatment in routine clinical practice between January 2014 and January 2018.

Results

Among the 134 mCRC patients, the median age was 55 years (range, 22–80 years), and 51% had previously received four or more chemotherapy treatments. Thirty-eight (28.3%) patients had more than three metastatic lesions. As an initial starting dose, 120 mg regorafenib was mostly frequently used (n=65, 48.5%), followed by 80 mg (32.8%) and 160 mg (18.7%). The first follow-up after regorafenib initiation was most frequently at 28 days (45.5%), followed by 14 days (29.9%), 7 days (13.4%), and 21 days (11.2%). There was no significant difference in response rate according to initial dose of regorafenib (80 mg vs 120 mg vs 160 mg, 4.5% vs 1.5% vs 4.0%, P=0.596) or disease control rate (80 mg vs 120 mg vs 160 mg, 38.6% vs 29.2% vs 31.6%, P=0.299). Progression-free survival did not differ according to initial dose (80 mg vs 120 mg vs 160 mg, 2.8 months [95% CI 2.1–3.5] vs 2.2 months [95% CI 1.7–2.8] vs 1.9 months [95% CI 1.3–2.4], P=0.076). Grade 3/4 adverse events occurred in 17 (12.7%) patients and were not related to initial dose of regorafenib (P=0.126).

Conclusion

Here, we present efficacy and safety data according to different initial doses of regorafenib in clinical practice. These data may provide useful information when using regorafenib for refractory mCRC in clinical practice.

Research progress on common adverse events caused by targeted therapy for colorectal cancer

As targeted drug therapy is increasingly applied in the treatment of colon cancer, understanding and managing the adverse reactions of patients is becoming increasingly important. The present review examines the mechanisms of and adverse reactions to the most commonly used targeted drugs for colon cancer, and discusses methods of coping with these adverse reactions. Approved targeted drugs for metastatic colon cancer include monoclonal antibodies targeting vascular endothelial growth factor (VEGF), including bevacizumab, ziv-aflibercept and regorafenib, and monoclonal antibodies targeting epithelial growth factor receptor (EGFR), including cetuximab and panitumumab. The present review assesses the major adverse effects of these drugs and methods of dealing with reactions to them. VEGF inhibitors primarily result in cardiovascular and kidney problems. Meanwhile, EGFR receptor inhibitors are frequently reported to cause rashes, diarrhea and hypertension, and are reviewed from the point of view of resulting electrolyte disturbances.

Heterogeneous expression of A33 in colorectal cancer: possible explanation for A33 antibody treatment failure

The A33 protein, expressed in colorectal tumors, is a target for improving treatment of patients with colorectal cancer. Over the last decade, studies have tested anti-A33 antibody as a therapeutic agent for these patients. Preclinical results were promising, but clinical trials did not confirm positive results. Here, immunohistochemistry in colorectal cancer tissue showed that samples from well-differentiated tumors presented a strong A33 membrane staining, whereas poorly differentiated tumors and mucinous adenocarcinomas showed weak cytoplasmic and nuclear staining. Moderately differentiated tumors presented variable staining. We suggest that in future clinical trials, patients should be selected on the basis of membrane expression of A33.

DW10075, a novel selective and small-molecule inhibitor of VEGFR, exhibits antitumor activities both in vitro and in vivo

AIM

Targeting the VEGF/VEGF receptor (VEGFR) pathway has proved to be an effective antiangiogenic approach for cancer treatment. Here, we identified 6-((2-((3-acetamidophenyl)amino)pyrimidin-4-yl)oxy)-N-phenyl-1-naphthamide (designated herein as DW10075) as a novel and highly selective inhibitor of VEGFRs.

METHODS

In vitro tyrosine kinase activity was measured using ELISA, and intracellular signaling pathway proteins were detected by Western blot analysis. Endothelial cell proliferation was examined with CCK-8 assays, and tumor cell proliferation was determined with SRB assays. Cell migration, tube formation and rat aortic ring assays were used to detect antiangiogenic activity. Antitumor efficacy was further evaluated in U87-MG human glioblastoma xenograft tumors in nude mice receiving DW10075 (500 mg · kg(-1) · d(-1), po) for two weeks.

RESULTS

Among a panel of 21 kinases tested, DW10075 selectively inhibited VEGFR-1, VEGFR-2 and VEGFR-3 (the IC50 values were 6.4, 0.69 and 5.5 nmol/L, respectively), but did not affect 18 other kinases including FGFR and PDGFR at 10 μmol/L. DW10075 significantly blocked VEGF-induced activation of VEGFR and its downstream signaling transduction in primary human umbilical vein endothelial cells (HUVECs), thus inhibited VEGF-induced HUVEC proliferation. DW10075 (1-100 nmol/L) dose-dependently inhibited VEGF-induced HUVEC migration and tube formation and suppressed angiogenesis in both the rat aortic ring model and the chicken chorioallantoic membrane model. Furthermore, DW10075 exhibited anti-proliferative activity against 22 different human cancer cell lines with IC50 values ranging from 2.2 μmol/L (for U87-MG human glioblastoma cells) to 22.2 μmol/L (for A375 melanoma cells). In U87-MG xenograft tumors in nude mice, oral administration of DW10075 significantly suppressed tumor growth, and reduced the expression of CD31 and Ki67 in the tumor tissues.

CONCLUSION

DW10075 is a potent and highly selective inhibitor of VEGFR that deserves further development.

Aflibercept a new target therapy in cancer treatment: a review

Angiogenesis is the process through which new blood vessels are formed from pre-existing vessels and is essential for the growth of all solid tumors. Vascular endothelial growth factor (VEGF) is a regulator of angiogenesis, which is crucial for tumor growth and metastasis. Its inhibition with antiangiogenic drugs is thought to improve delivery of chemotherapy through vascular normalization and disruption of tumor vasculature. Aflibercept is a recombinant fusion protein of the VEGF receptor (VEGFR)1 and VEGFR2 extracellular domains that binds to VEGF-A, VEGF-B, placental growth factor (PlGF) 1 and 2. Aflibercept has demonstrated preclinical efficacy in different tumor types and exerts its antiangiogenic effects through regression of tumor vasculature, remolding of vasculature, and inhibition of new tumor vessel growth. This review examines the effects of aflibercept on tumor vasculature and on different types of solid tumors, and explores the preclinical and clinical benefits of inclusion aflibercept into anticancer treatment strategies.

[FGF/FGFR signalling: Implication in oncogenesis and perspectives]

Deregulation of FGF (fibroblast growth factor)/FGFR (fibroblast growth factor receptor) signalling leads to the promotion of several oncogenic mechanisms: proliferation, epithelial-mesenchymal transition, cytoskeleton modifications, migration and angiogenesis. Deregulation of this pathway is reported in various cancers at early stages, and can therefore be responsible for the emergence of the hallmarks of cancer. It is necessary to precise downstream pathways of FGFR signalling to understand its oncogenic potential. We will then describe its implications in different cancer types. Oncogenic mechanisms will be studied through the example of melanoma, in which deregulation of FGF/FGFR pathway is considered as a driver event and occurs in nearly 90% of cases. The FGF/FGFR signalling pathway is a putative therapeutic target. Numerous agents are in active development, operating through a selective or multi-targeted approach. Recent studies have shown rather disappointing results in non-selected patients, but promising results in patients with FGF/FGFR pathway alterations. A careful screening of patients is the key to a valuable evaluation of these new targeted molecular therapies.

Phase 1/2 study of KRN330, a fully human anti-A33 monoclonal antibody, plus irinotecan as second-line treatment for patients with metastatic colorectal cancer

KRN330 is a recombinant, fully-human monoclonal antibody directed against A33, a surface differentiation antigen that is uniformly expressed in 95 % of colorectal cancers. A previous Phase 1 study of single-agent KRN330 identified a maximum tolerated dose (MTD) of 3 mg/kg q2w and preliminary evidence of clinical activity among patients with advanced and metastatic colorectal cancer (mCRC). This Phase 1/2 trial sought to assess the safety and activity of second-line KRN330 plus irinotecan in patients with mCRC. Patients with mCRC who showed disease progression after FOLFOX/CapOx received intravenous doses of KRN330 (0.5 or 1.0 mg/kg qw or q2w) plus irinotecan (180 mg/m(2)) in a standard 3 + 3 dose escalation. The MTD of KRN330 with irinotecan in 19 patients was 0.5 mg/kg qw in the Phase 1 study with gastrointestinal effects and neutropenia being the predominant dose-limiting toxicities. In the Phase 2 study, the most frequent treatment-related Grade ≥3 toxicities in 44 patients were fatigue (15.9 %), neutropenia (13.6 %), leukopenia (6.8 %), diarrhea (4.5 %), and dehydration (4.5 %). Objective response rate (ORR) was 4.5 % and disease control rate was 45.5 % for the intent-to-treat population. Median progression-free survival was 87 days (95 % CI, 43-136 days). The prespecified ORR of KRN330 plus irinotecan was not met. Further investigation of KRN330 plus other agents may be warranted.

Antiangiogenesis therapy: an update after the first decade

Angiogenesis is a complex biological phenomenon that forms new blood vessels from the pre-existing vasculature. Aberrant angiogenesis has been implicated in a variety of diseases such as cancer, atherosclerosis, arthritis, obesity, pulmonary hypertension, diabetic retinopathy, and age-related macular degeneration. These conditions collectively affect nearly 10% of the global population. Much effort has focused on identifying new therapeutic agents that inhibit pathological angiogenesis since 1971, when Judah Folkman published the hypothesis that tumor growth is angiogenesis-dependent and that its inhibition may be therapeutic. In 2004, the U.S. Food and Drug Administration approved the first antiangiogenic drug for the treatment of metastatic colon cancer, bevacizumab (Avastin, Genentech). This drug is a humanized monoclonal antibody that neutralizes the vascular endothelial growth factor. It is used in combination with chemotherapy, and its use began the era of antiangiogenesis therapy. Several new therapeutic agents have been added to the list of approved drugs, and clinical trials of new therapeutic options and antiangiogenic agents are ongoing. This review describes the progress made in the first decade of antiangiogenesis therapy, and addresses both validated and possible targets for future drug development.