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Query: UMLS:C0009402 (colorectal cancer)
 53,228 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The treatment of colorectal cancer has undergone enormous changes in the past decade. From a disease with a single treatment option (ie, fluorouracil, a modestly effective drug), the treatment options have evolved to include at least five new classes of antineoplastic agents. Among the considerable number of recently approved drugs, two are monoclonal antibodies and are the testing ground for our rapidly emerging knowledge about cancer cell biology. Cetuximab (Erbitux) targets the epidermal growth factor receptor, an important molecule involved with cell cycling, survival, invasion, and metastasis. Bevacizumab (Avastin) neutralizes the vascular endothelial growth factor, blocking its ability to activate its receptor on the endothelial cells. The development of both antibodies resulted from decades of research in molecular and cell biology, as well as preclinical and clinical studies, and signals a new paradigm where the tumor cells' own unique features are exploited in a rational way.
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PMID:Monoclonal antibodies: the foundation of therapy for colorectal cancer in the 21st century? 1521 93

Monoclonal antibodies (mAbs) against growth factors or their receptors have been revealed to be effective therapeutic agents for solid tumors. Trastuzumab (humanized anti-HER2 mAb) is the first mAb approved for the treatment of a solid tumor, metastatic breast cancer. Large-scale phase III clinical trials are now ongoing to further evaluate the additive effects on chemotherapy and the efficacy as a maintenance monotherapy. Another anti-HER2 mAb CH401 that we developed also seems to have good potential. This chimeric mAb completely suppressed the growth of established human tumor xenografts in SCID mice after a single injection. Furthermore, CH401 characteristically showed much stronger induction of apoptosis in HER2-overexpressing gastric cancer cells compared to trastuzumab. Additional targets now being intensively evaluated are epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF). Both cetuximab (chimeric anti-EGFR mAb) and bevacizumab (humanized anti-VEGF mAb) have recently been shown to be of clinical value for metastatic colorectal cancer. Anti-idiotype mAbs are unique as active immunotherapeutic agents, and survival benefits have been observed in clinical trials for solid tumors.
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PMID:Monoclonal antibodies as effective therapeutic agents for solid tumors. 1529 22

Two of the most promising new targets in the treatment of colorectal cancer are the epithelial growth factor receptor (EGFR) and the vascular endothelial growth factor (VEGF). Agents that inhibit the EGFR or bind to VEGF have demonstrated clinical activity as single agents and in combination with chemotherapy in phase II and phase III clinical trials. The most promising of these agents are cetuximab, which blocks the binding of EGF and transforming growth factor alpha (TGF-alpha) to EGFR, and bevacizumab, which binds free VEGF. Cetuximab and irinotecan have been evaluated in two clinical studies in the USA (IMCL CP02-0141 and IMCL CP02-9923). Study IMCL CP02-0141 evaluated the antitumor activity of single-agent cetuximab in patients with irinotecan-refractory, EGFR-positive metastatic colorectal carcinoma. There were 6 partial responses in 57 treated patients, for a response rate of 10.5%. Study IMCL CP02-9923 evaluated the combination of cetuximab and irinotecan in a total of 139 patients enrolled at 27 study sites. In this trial 22.5% of patients with progressive disease on irinotecan achieved an objective response (19% by investigator assessment) showing that the combination of cetuximab and irinotecan has antitumor activity in this population. A large randomized phase II trial evaluating similar study populations in Europe confirmed these findings, demonstrating response rates for cetuximab/irinotecan and cetuximab alone of 22.9% and 10.8%, respectively. The other promising agent bevacizumab is a humanized variant of the anti-VEGF monoclonal antibody. VEGF is produced by healthy and neoplastic cells. Its activities are mediated by two receptor tyrosine kinases. VEGF signaling is often a rate-limiting step in physiologic and pathologic angiogenesis. Bevacizumab has been studied as an antiangiogenic cancer therapeutic as a single agent and in combination with chemotherapy in patients with stage III and IV colon cancer. In addition to its direct antiangiogenic effects, bevacizumab may allow more efficient delivery of chemotherapy by altering tumor vasculature and decreasing the elevated interstitial pressure common in tumors. In this regard, some of the most robust phase II data using bevacizumab are from a randomized study of chemotherapy [fluorouracil (5-FU) and leucovorin (LV)] with or without bevacizumab in metastatic colorectal cancer. In this study, treatment with bevacizumab plus 5-FU/LV resulted in higher response rates, longer median time to disease progression, and longer median survival. Recently, a phase III, multicenter, double-blind, randomized, placebo-controlled trial was designed to investigate the addition of bevacizumab to first-line irinotecan, 5-FU, and LV chemotherapy (IFL). The trial showed a higher response rate, longer time to tumor progression, and prolonged overall survival in patients with metastatic colorectal cancer. It was the first large, randomized, phase III survival trial to assess the importance of targeting VEGF and tumor angiogenesis for the treatment of human cancer. Integration of novel agents targeting VEGF and EGFR with irinotecan-based chemotherapy has shown clinical activity in patients with metastatic colorectal cancer. The goal in the future will be to predict which specific chemotherapy and targeted agent combination will most likely benefit individual patients.
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PMID:Integration of novel agents in the treatment of colorectal cancer. 1530 12

In colorectal cancer, cyclooxygenase-2 (COX-2) overexpression in stromal cells induces angiogenesis through EP2 prostaglandin E2 receptor signaling. Cytoplasmic phospholipase A2 (PLA2) alpha preferentially hydrolyses arachidonic acid, which is the limiting substrate for prostaglandin production, from membrane phospholipids. We therefore investigated a possible relationship between cytoplasmic PLA2 and COX-2 overexpression in stromal cells, angiogenesis and microsatellite instability in 48 human colorectal adenocarcinomas. Cytoplasmic PLA2 and COX-2 expression in stromal cells and vascular endothelial growth factor (VEGF) expression in tumor cells were evaluated by immunohistochemistry. Microvessel density was assessed in 10 x 400 fields after CD31 staining. Microsatellite instability was evaluated by PCR and immunohistochemistry. A total of 16 tumors had microsatellite instability. We found an overexpression of cytoplasmic PLA2 in superficial stromal cells. These cells corresponded to fibroblasts and myofibroblasts. There was an association between the number of cytoplasmic PLA2 and COX-2-expressing cells (P=0.006). Cytoplasmic PLA2-positive stromal cells usually also expressed COX-2. A high number of cytoplasmic PLA2-positive stromal cells was correlated with a high microvessel density (P=0.002), a strong VEGF (P=0.01) and the absence of microsatellite instability (P=0.001). The coordinate overexpression of cytoplasmic PLA2 and COX-2 in stromal cells could lead to an important prostaglandin production. These results suggest that cytoplasmic PLA2 overexpression in these cells regulates COX-induced angiogenesis probably by providing arachidonic acid, which is the limiting factor for prostaglandin production. The lower number of cytoplasmic PLA2-positive stromal cells in carcinomas with microsatellite instability could be related to their lower microvessel density and VEGF expression.
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PMID:Cytoplasmic phospholipase A2 alpha overexpression in stromal cells is correlated with angiogenesis in human colorectal cancer. 1547 36

Recent advances in the treatment of colorectal cancer (CRC) include the incorporation of new drugs to treat a disease where only one drug was known to be active. Oxaliplatin and irinotecan have been incorporated into 5-fluorouracil (5-FU)-based regimens where they have increased response rates and survival. Targeted therapies against the epidermal growth factor pathway and the vascular endothelial growth factor (VEGF) pathway are also on the forefront of oncology research, and are beginning to play a role in the treatment of CRC. Current research efforts are trying to optimize the integration of targeted therapies into chemotherapy regimens such as IFL (irinotecan/bolus 5-FU/leucovorin [LV]), FOLFIRI (irinotecan/infusional 5-FU/LV), and FOLFOX (oxaliplatin/infusional 5-FU/LV). In this article, the incorporation of the monoclonal antibody bevacizumab into the IFL regimen will be reviewed in detail. Bevacizumab targets VEGF-A, an important angiogenesis signaling factor commonly expressed in metastatic CRC. The addition of bevacizumab to the IFL regimen significantly increased response rates, median time to progression, and overall survival in patients receiving first-line treatment for CRC, thus leading the Food and Drug Administration to approve bevacizumab for the treatment of CRC in combination with 5-FU-based regimens. Bevacizumab treatment is associated with an increased rate of hypertension. In addition, there may be slight (1%-2%) but relevant increased risks related to gastrointestinal perforations and cardiovascular events. A modest increased risk of wound healing complications was observed in patients who underwent surgery while still receiving, or shortly after receiving, bevacizumab. Bevacizumab plus 5-FU is also a highly active first-line regimen. The role of bevacizumab with other first-line combination regimens, as well as its activity in the second-line setting, is now being determined by ongoing clinical trials.
Clin Colorectal Cancer 2004 Oct
PMID:Integrating the anti-VEGF-A humanized monoclonal antibody bevacizumab with chemotherapy in advanced colorectal cancer. 1547 81

Two closely related diaryl acylsulfonamides were recently reported as potent antitumor agents against a broad spectrum of human tumor xenografts (colon, lung, breast, ovary, and prostate) in nude mice. Especially intriguing was their activity against colorectal cancer xenografts. In this paper, rapid parallel synthesis along with traditional medicinal chemistry techniques were used to quickly delineate the structure-activity relationships of the substitution patterns in both phenyl rings of the acylsufonamide anti-proliferative scaffold. Although the molecular target of the compounds remains unclear, we determined that the vascular endothelial growth factor-dependent human umbilical vein endothelial cells assay in combination with a soft agar disk diffusion assay allowed for optimization of potency in the series. The pharmacokinetic properties and in vivo activity in an HCT116 xenograft model are reported for representative compounds.
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PMID:Acyl sulfonamide anti-proliferatives: benzene substituent structure-activity relationships for a novel class of antitumor agents. 1548 75

Colorectal carcinoma is one of the most common malignancies in the world, and its incidence has increased in recent years. We have reported that expression of hypoxia-inducible factor (HIF)-1alpha correlates with expression of vascular endothelial growth factor (VEGF), tumor stage, lymphatic invasion, venous invasion, and liver metastasis. It has also been reported that a single nucleotide polymorphism (SNP) in exon 12 of HIF-1alpha gene is present in renal cell carcinoma and head and neck squamous cell carcinoma patients. We investigated the C1772T polymorphism in colorectal cancer patients and healthy control subjects to clarify the mechanism of HIF-1alpha activation in colorectal carcinoma. The exon 12 genotype was not associated with sex or age. The distribution of HIF-1alpha genotypes in controls was 89 C/C (89%), 11 C/T (11%), and 0 T/T (0%). The distribution of HIF-1alpha genotypes in colorectal cancer patients was 100 C/C (100%), 0 C/T (0%), and 0 T/T (0%). The difference in genotype distribution between patients and control subjects was significant (p<0.0005). These results suggest that the C1772T polymorphism in HIF-1alpha is not involved in progression or metastasis of colorectal carcinoma.
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PMID:Single nucleotide polymorphism in the hypoxia-inducible factor-1alpha gene in colorectal carcinoma. 1549 89

This article reviews the available data regarding the acticity of postoperative adjuvant systemic therapy for colorectal cancer as first and second-line treatment in metastatic disease. The efficacy of adjuvant treatment of patients with stage III colorectal cancer is well established. 5-fluorouracil (5-FU) and folic acid over 6 months (still) represent todays standard and should serve as comparison in randomized studies. The risk of relapse is low in stage II colon carcinoma and consequently the efficacy is relatively small compared to stage III. New investigation indicate, Capecitabene has the potential to replace 5-FU/FS as standard treatment for patients with colon cancer. Efficacy results are expected to be available in 2004. In metastatic disease combination of 5-FU/folic acid plus CPT-11 or OXA are treatment of choice for the first-line therapy of metastatic colorectal carcinoma. FOLFOX is high-dose intensity oxaliplatin added to the simplified bimonthly leucovorin and 5-fluorouracil regimen as second- line therapy for metastatic colorectal cancer. It resulted in prolongation of the median progress free survival from 6,8 to 8,8 months and increased the survival for 4,5 months. New perspectives are novel chemotherapeutic and targeted agents in metastatic colorectal cancer: For the first time, there has been a targeted therapy shown convincingly to prolong survival for patients with unresectable metastatic colorectal cancer in a well-performed Phase III trial. This agent is bevacizumab, a humanised monoclonal antibody targeting the circulating proangiogenic growth factor vascular endothelial growth factor. Results with bevacizumab should lead to rapid expansion of the number of strategies targeting tumour neovasculature. Additionally, an antibody against the epidermal growth factor, cetuximab, has been shown to have both single-agent activity and the potential ability to partially reverse resistance to a chemotherapy drug. These advancements, as well as data on other novel treatment agents that have been studied specifically in patients with colorectal neoplasms, are discussed in detail.
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PMID:[Adjuvant and palliative anticancer treatment of colon carcinoma in 2004]. 1549 53

Monoclonal antibody-directed therapy has been used as an effective treatment for some cancers that overexpress HER2/neu and vascular endothelial growth factor (VEGF). Overexpression of the HER2/neu oncogene and VEGF has been reported to occur in adenocarcinomas of the colon. Assessing whether HER2/neu and VEGF overexpression could serve as prognostic indicators for stage II colon cancer may provide insight into optimal treatment following surgery. Demographic and tumor characteristics from 109 patients diagnosed with stage II colon cancer between 1991 and 1996 were assessed for HER2/neu and VEGF expression using immunohistochemical staining techniques. Of the 109 cases, 107 (98%) were histologically classified as adenocarcinomas, 105 (96%) were grades 2/3, and 105 (96%) were stage T3. Only 12 cases (11%) exhibited HER2/neu overexpression and 72 cases (66%) exhibited VEGF expression. There was no significant difference in overall survival or in time to recurrence between the groups with and without HER2/neu overexpression. There was a trend toward decreased overall survival with VEGF expression (P = 0.07), but no difference in time to recurrence (P = 0.63). There were 18 patients who received adjuvant chemotherapy, but removal of these patients from the analysis did not change the results. There was no association between HER2/neu and VEGF expression and patient demographics or tumor characteristics, with the exception of VEGF expression and mucinous histology (P < 0.01). Our results do not support an association between HER2/neu or VEGF expression and overall survival or time to recurrence in stage II colon cancer. With further investigation, a significant correlation may be found between VEGF expression and prognosis, and thus direct therapy with a monoclonal antibody.
Clin Colorectal Cancer 2004 Nov
PMID:Expression of vascular endothelial growth factor and HER2/neu in stage II colon cancer and correlation with survival. 1555 9

In Westernised countries, colorectal cancer (CRC) is second only to lung cancer as a cause of death from malignancy, with only 60% of patients alive at 5 years. In Stage II/III CRC, where the standard treatment is 5-fluorouracil (5-FU)/leucovorin, a recent clinical trial has shown that with the addition of oxaliplatin, fewer patients have relapsed or died at 40 months follow-up. The benefit was more pronounced in patients with Stage III than II CRC, and the addition of oxaliplatin to 5-FU/leucovorin should be considered in Stage III CRC. In metastatic CRC, where the standard treatment is 5-FU/leucovorin/irinotecan, a recent clinical trial has shown that the addition of bevacizumab, a mAb, to vascular endothelial growth factor, prolonged progression-free and overall survival. Bevacizumab is likely to become part of the standard therapy for metastatic CRC.
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PMID:Which drug combination for colorectal cancer? 1557 79


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