Randomized phase II trial of the clinical and biological effects of two dose levels of gefitinib in patients with recurrent colorectal adenocarcinoma.
ABSTRACT The clinical objective of this trial was to evaluate gefitinib in patients with metastatic colorectal cancer that had progressed despite prior treatment. Serial tumor biopsies were performed when possible and analyzed for activation of the epidermal growth factor receptor (EGFR) signaling pathway. Serial serum samples were measured for amphiregulin and transforming growth factor-alpha (TGFalpha).
One hundred fifteen patients were randomly assigned to receive gefitinib 250 or 500 mg orally once a day. One hundred ten patients were assessable for clinical efficacy. Biologic evaluation was performed on paired tumor samples from 28 patients and correlated with clinical outcome.
Median progression-free survival was 1.9 months (95% CI, 1.8 to 2.1 months) and 4-month progression-free survival rate was 13% +/- 5%. One patient achieved a radiographic partial response (RR = 1%; 95% CI, 0.01% to 5%). Median survival was 6.3 months (95% CI, 5.1 to 8.2 months). The most common adverse events were skin rash, diarrhea, and fatigue. In the biopsy cohort, expression of total or activated EGFR, activated Akt, activated MAP-kinase, or Ki67 did not decrease following 1 week of gefitinib. However, a trend toward decreased post-treatment levels of activated Akt and Ki67 was observed in patients with a PFS higher than the median, although these did not reach the .05 level of significance.
Gefitinib is inactive as a single agent in patients with previously treated colorectal cancer. In tumor samples, gefitinib did not inhibit activation of its proximal target, EGFR. Trends were observed for inhibition of downstream regulators of cellular survival and proliferation in patients achieving longer progression-free survival.
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ABSTRACT: This pilot, open-label study examined the safety and tolerability (primary objective) and efficacy (secondary objective) of gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in combination with celecoxib, a cyclooxygenase-2 (COX-2) inhibitor, in patients with advanced or refractory gastrointestinal (GI) tumors of epithelial origin. Patients were administered gefitinib (250 mg/day) plus celecoxib (400 mg twice daily). In the event of toxicity, dose interruptions were permitted and a single celecoxib dose reduction was allowed. Thirty patients (median age 60 years) with primary colorectal (25 patients), pancreatic (3 patients), esophageal (1 patient), or gall bladder (1 patient) tumors were recruited, 29 of whom had received prior chemotherapy. Adverse events (AEs) were generally mild and consisted mainly of acne, diarrhea, and nausea. Few severe AEs were noted. There were no withdrawals or deaths due to AEs. Dose reductions for celecoxib were reported for five patients, in three cases due to toxicity. Stable disease was confirmed in 12 patients (40%), with progressive disease in 18 patients (60%). After study completion, safety issues relating to the long-term use of COX-2 inhibitors have been raised. However, in this pilot study, the combination of gefitinib and celecoxib was generally well tolerated in patients with advanced GI cancer.Journal of gastrointestinal oncology 02/2014; 5(1):57-66.
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ABSTRACT: This review discusses the role of molecular analysis in the diagnosis and treatment of gastrointestinal (GI) neoplasms. It is divided into 3 sections. The first section describes clinical applications of 11 immunohistochemical stains (p53, HER2, KIT, SDHB, SMAD4, beta-catenin, L-FABP, MLH1, PMS2, MSH2, and MSH6), the results of which directly reflect underlying genetic or epigenetic events. These applications are mainly diagnostic but in a few instances are predictive. Germline mutation testing is a diagnostic cornerstone in the hereditary cancer predisposition syndromes (HCPSs). Section two will describe the genotype and phenotype of 8 HCPSs presenting in the GI tract. Where available, guidelines based on evidence and/or expert opinion as to whom to test are presented. With our ever-expanding knowledge of the molecular genetic basis of cancer and an increasingly "biologic-oriented" therapeutic armamentarium, pathologists play a vital role in directing molecular-based predictive testing. The final section will discuss the 4 most mature examples in the GI tract: (1) HER2 testing to select patients with advanced gastroesophageal adenocarcinoma for anti-HER2 therapy, (2) KIT and PDGFRA mutation analysis to direct tyrosine kinase inhibitor therapy in gastrointestinal stromal tumor, (3) DNA mismatch repair function testing to determine the applicability of adjuvant chemotherapy in patients with stage II colorectal cancer (CRC), and (4) KRAS mutation analysis and related testing to determine the appropriateness of anti-EGFR monoclonal antibody therapy in patients with metastatic CRC.Seminars in Diagnostic Pathology 11/2013; 30(4):329-61. · 1.62 Impact Factor