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Preliminary results of a phase II study of cyclooxygenase-2 (COX-2) inhibition in rectal cancer
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I. J. Radiation Oncology
● Biology ● Physics
Volume 60, Number 1, Supplement, 2004
and inhibition of sublethal damage repair by ZD6474 were determined using a clonogenic assay. For in vivo studies, 5 ⫻ 105 lung adenocarcinoma cells were injected into the left lung of nude mice. The mice were then randomized to treatment with vehicle (p.o. daily), ZD6474 (15mg/kg orally once daily), radiation (4 Gy fractions 3 times weekly to a total dose of 20Gy), ZD6474 and radiation, paclitaxel (200g weekly i.p.), or paclitaxel and radiation. Therapy was initiated on day 8 and mice were sacrificed on day 24 –26 after tumor injection, when control mice showed signs of disease-associated morbidity. Tumor burden was assessed by lung and tumor weight, pleural effusion volume, and total weight of disseminated thoracic lesions. Tumor and adjacent lung tissues were then subjected to immunohistochemical analyses. Results: In the MTT assay, marked repopulation of the H441 cells was observed 72–96h after 4Gy irradiation. Cell proliferation was inhibited by 55 ⫾ 4.7% (p ⫽ 0.007) of control by 2.5M ZD6474 treatment for 4 h before and 72 h after irradiation. Radioresponse in the clonogenic assay was enhanced by a factor of 1.37. Sublethal damage repair was completely inhibited by incubation with 5M ZD6474 for 4h split time. Recovery ratios between 4Gy single dose and 2 ⫹ 2Gy split dose were 1.34 in untreated control and 1.04 in ZD6474 treated group. In vivo, the suppression of both tumor growth and metastasis in the orthotopic lung model was greatest in mice treated with combined radiation and ZD6474 compared with radiation with paclitaxel or monotherapy with each modality. The lung weight of control, radiation, ZD6474, radiation with paclitaxel, and radiation with ZD6474 treated mice increased by 330%, 200%, 155%, and 147%, and 110%, respectively, as compared with normal lung weight and the total weight of disseminated lesions was 197 ⫾ 38.1, 160 ⫾ 49.7, 53.9 ⫾ 14.5, 47.5 ⫾ 16.6, and 17.2 ⫾ 8.00, respectively. Radiation therapy had no effect on the formation of pleural effusion (565 ⫾ 99.4l) as compared with control (745 ⫾ 112l). Combined therapy with ZD6474 and radiation blocked pleural effusion (14.2 ⫾ 4.84l) more effectively than radiation and paclitaxel (246 ⫾ 69.4l). By immunohistochemical analysis, tumor cell apoptosis in the lung primary tumors was substantially increased in mice treated with combined radiation and ZD6474. Microvessel density of lung primary tumors was 55 ⫾ 3.3, 52 ⫾ 7.3, 13 ⫾ 3.3, 42 ⫾ 4.6, 31 ⫾ 3.5, and 16 ⫾ 1.9 in control, radiation, ZD6474, paclitaxel, radiation with paclitaxel, and radiation with ZD6474 treated groups, respectively. Conclusions: When radiation therapy is combined with ZD6474 as targeted therapy against VEGFR and EGFR a significant enhancement of antiangiogenic, anti-vascular and anti-tumor effects are seen in an orthotopic model of lung cancer. These data provide support for clinical trials combining biologically targeted therapies and conventional therapies in human lung cancer.
36
Preliminary Results of a Phase II Study of Cyclooxygenase-2 (COX-2) Inhibition in Rectal Cancer
B. Chakravarthy,1 C. Schmidt,2 N. Merchant,2 J. Berlin,3 J. Morrow,5 A. Herline,2 K. Wyman,3 S. Pearson,2 M. K. Washington,4 C. Gilmore,2 R. Coffey,3 R.D. Beauchamp2 1 Radiation Oncology, Vanderbilt University, Nashville, TN, 2Surgery, VUMC, Nashville, TN, 3Oncology, VUMC, Nashville, TN, 4Pathology, VUMC, Nashville, TN, 5Pharmacology, VUMC, Nashville, TN
Purpose/Objective: COX-2 promotes tumor growth through the production of prostaglandin E2 (PGE2) and the induction of vascular endothelial growth factor (VEGF). Preclinical studies have shown that selective inhibitors of COX-2 can enhance the effect of radiation therapy as well as chemotherapy. This phase II study examines the biological effects of COX-2 inhibition alone and in combination with standard chemoradiation. Materials/Methods: Patients with histologically confirmed, clinically resectable, primary adenocarcinoma of the rectum located at or below the peritoneal reflection were enrolled. Eligibility criteria included adequate renal, hepatic and bone marrow function; no history of allergy to celecoxib, NSAIDs, or sulfonamides. Patients with stage I rectal cancer received 5 days of celecoxib prior to surgical resection. Patients with stage II/III disease completed preoperative continuous infusion 5FU 225-mg/m2/day, 7 days/week and concurrent radiation (5040cGy/ 28 fractions) prior to surgical resection. Patients with Stage I rectal cancer had samples pre-treatment and post 5 days of celecoxib. Patients with Stage II/III rectal cancer had specimens obtained from the tumor and surrounding normal tissue at the following intervals: (1) pre-treatment (2) after 5 days of celecoxib (3) after 7 days of 5FU/radiation/celcoxib (4) and at time of surgical resection. These samples are being evaluated for the following: gene expression by microarray, MALDI-TOF mass spectroscopy, 2D gel proteomics, and immunostaining for COX-2 and CD-31 (an endothelial marker for angiogenesis), serum VEGF levels and a urinary prostaglandin E2 metabolite (PGE-M). Results: Twenty-seven patients with rectal cancer have enrolled. Eight patients with Stage I disease have completed the planned 5 days of celecoxib without difficulty. Of the 19 patients with Stage II/III rectal cancer, two are still undergoing chemoradiation. One patient suffered grade 2 hypokalemia, nausea, dehydration, and fatigue. A second patient experienced grade 2 thrombocytopenia. A third patient required an emergent exploratory laparotomy for small bowel perforation (outside the radiation field) during the course of neoadjuvant chemoradiation therapy. There were two unexpected deaths. One patient died at home one month following completion of therapy of probable myocardial infarction. A second patient was recovering from severe diarrhea and died of probable pulmonary embolus. The remaining 14 patients tolerated the treatment well. Of the 12 patients who have completed surgical resection, 3 had no tumor at time of surgery. Treatment with celecoxib 400 mg orally twice per day for five days was associated with a significant decrease in urine PGE-M. Mean PGE-M levels decreased from 20.670 to 10.790 pg/mg Cr, p ⫽ .015. Serum and plasma VEGF levels are highly variable, and pre-treatment VEGF levels did not correlate with clinical tumor stage. COX-2 inhibition decreased VEGF levels in patients with high pre-treatment levels. Laboratory correlates: gene expression by microarray, MALDI-TOF mass spectroscopy, 2D gel proteomics, and immunostaining for COX-2 and CD-31 will be presented. Conclusions: Preliminary analysis shows that five days of celecoxib results in a measurable decrease in urinary PGE-M (a major urinary metabolite of PGE2). Therefore, urinary PGE-M may prove to be a useful non-invasive biomarker to measure response to treatment with COX-2 inhibitors. The addition of celecoxib to 5FU-based neoadjuvant chemoradiation was well tolerated and has led to acceptable rates of pathologic complete responses. Grant support: NIH grants GI SPORE 50CA 95103– 02 & Pfizer Pharmaceuticals. Celecoxib was provided by Pfizer.
I. J. Radiation Oncology
● Biology ● Physics
Volume 60, Number 1, Supplement, 2004
and inhibition of sublethal damage repair by ZD6474 were determined using a clonogenic assay. For in vivo studies, 5 ⫻ 105 lung adenocarcinoma cells were injected into the left lung of nude mice. The mice were then randomized to treatment with vehicle (p.o. daily), ZD6474 (15mg/kg orally once daily), radiation (4 Gy fractions 3 times weekly to a total dose of 20Gy), ZD6474 and radiation, paclitaxel (200g weekly i.p.), or paclitaxel and radiation. Therapy was initiated on day 8 and mice were sacrificed on day 24 –26 after tumor injection, when control mice showed signs of disease-associated morbidity. Tumor burden was assessed by lung and tumor weight, pleural effusion volume, and total weight of disseminated thoracic lesions. Tumor and adjacent lung tissues were then subjected to immunohistochemical analyses. Results: In the MTT assay, marked repopulation of the H441 cells was observed 72–96h after 4Gy irradiation. Cell proliferation was inhibited by 55 ⫾ 4.7% (p ⫽ 0.007) of control by 2.5M ZD6474 treatment for 4 h before and 72 h after irradiation. Radioresponse in the clonogenic assay was enhanced by a factor of 1.37. Sublethal damage repair was completely inhibited by incubation with 5M ZD6474 for 4h split time. Recovery ratios between 4Gy single dose and 2 ⫹ 2Gy split dose were 1.34 in untreated control and 1.04 in ZD6474 treated group. In vivo, the suppression of both tumor growth and metastasis in the orthotopic lung model was greatest in mice treated with combined radiation and ZD6474 compared with radiation with paclitaxel or monotherapy with each modality. The lung weight of control, radiation, ZD6474, radiation with paclitaxel, and radiation with ZD6474 treated mice increased by 330%, 200%, 155%, and 147%, and 110%, respectively, as compared with normal lung weight and the total weight of disseminated lesions was 197 ⫾ 38.1, 160 ⫾ 49.7, 53.9 ⫾ 14.5, 47.5 ⫾ 16.6, and 17.2 ⫾ 8.00, respectively. Radiation therapy had no effect on the formation of pleural effusion (565 ⫾ 99.4l) as compared with control (745 ⫾ 112l). Combined therapy with ZD6474 and radiation blocked pleural effusion (14.2 ⫾ 4.84l) more effectively than radiation and paclitaxel (246 ⫾ 69.4l). By immunohistochemical analysis, tumor cell apoptosis in the lung primary tumors was substantially increased in mice treated with combined radiation and ZD6474. Microvessel density of lung primary tumors was 55 ⫾ 3.3, 52 ⫾ 7.3, 13 ⫾ 3.3, 42 ⫾ 4.6, 31 ⫾ 3.5, and 16 ⫾ 1.9 in control, radiation, ZD6474, paclitaxel, radiation with paclitaxel, and radiation with ZD6474 treated groups, respectively. Conclusions: When radiation therapy is combined with ZD6474 as targeted therapy against VEGFR and EGFR a significant enhancement of antiangiogenic, anti-vascular and anti-tumor effects are seen in an orthotopic model of lung cancer. These data provide support for clinical trials combining biologically targeted therapies and conventional therapies in human lung cancer.
36
Preliminary Results of a Phase II Study of Cyclooxygenase-2 (COX-2) Inhibition in Rectal Cancer
B. Chakravarthy,1 C. Schmidt,2 N. Merchant,2 J. Berlin,3 J. Morrow,5 A. Herline,2 K. Wyman,3 S. Pearson,2 M. K. Washington,4 C. Gilmore,2 R. Coffey,3 R.D. Beauchamp2 1 Radiation Oncology, Vanderbilt University, Nashville, TN, 2Surgery, VUMC, Nashville, TN, 3Oncology, VUMC, Nashville, TN, 4Pathology, VUMC, Nashville, TN, 5Pharmacology, VUMC, Nashville, TN
Purpose/Objective: COX-2 promotes tumor growth through the production of prostaglandin E2 (PGE2) and the induction of vascular endothelial growth factor (VEGF). Preclinical studies have shown that selective inhibitors of COX-2 can enhance the effect of radiation therapy as well as chemotherapy. This phase II study examines the biological effects of COX-2 inhibition alone and in combination with standard chemoradiation. Materials/Methods: Patients with histologically confirmed, clinically resectable, primary adenocarcinoma of the rectum located at or below the peritoneal reflection were enrolled. Eligibility criteria included adequate renal, hepatic and bone marrow function; no history of allergy to celecoxib, NSAIDs, or sulfonamides. Patients with stage I rectal cancer received 5 days of celecoxib prior to surgical resection. Patients with stage II/III disease completed preoperative continuous infusion 5FU 225-mg/m2/day, 7 days/week and concurrent radiation (5040cGy/ 28 fractions) prior to surgical resection. Patients with Stage I rectal cancer had samples pre-treatment and post 5 days of celecoxib. Patients with Stage II/III rectal cancer had specimens obtained from the tumor and surrounding normal tissue at the following intervals: (1) pre-treatment (2) after 5 days of celecoxib (3) after 7 days of 5FU/radiation/celcoxib (4) and at time of surgical resection. These samples are being evaluated for the following: gene expression by microarray, MALDI-TOF mass spectroscopy, 2D gel proteomics, and immunostaining for COX-2 and CD-31 (an endothelial marker for angiogenesis), serum VEGF levels and a urinary prostaglandin E2 metabolite (PGE-M). Results: Twenty-seven patients with rectal cancer have enrolled. Eight patients with Stage I disease have completed the planned 5 days of celecoxib without difficulty. Of the 19 patients with Stage II/III rectal cancer, two are still undergoing chemoradiation. One patient suffered grade 2 hypokalemia, nausea, dehydration, and fatigue. A second patient experienced grade 2 thrombocytopenia. A third patient required an emergent exploratory laparotomy for small bowel perforation (outside the radiation field) during the course of neoadjuvant chemoradiation therapy. There were two unexpected deaths. One patient died at home one month following completion of therapy of probable myocardial infarction. A second patient was recovering from severe diarrhea and died of probable pulmonary embolus. The remaining 14 patients tolerated the treatment well. Of the 12 patients who have completed surgical resection, 3 had no tumor at time of surgery. Treatment with celecoxib 400 mg orally twice per day for five days was associated with a significant decrease in urine PGE-M. Mean PGE-M levels decreased from 20.670 to 10.790 pg/mg Cr, p ⫽ .015. Serum and plasma VEGF levels are highly variable, and pre-treatment VEGF levels did not correlate with clinical tumor stage. COX-2 inhibition decreased VEGF levels in patients with high pre-treatment levels. Laboratory correlates: gene expression by microarray, MALDI-TOF mass spectroscopy, 2D gel proteomics, and immunostaining for COX-2 and CD-31 will be presented. Conclusions: Preliminary analysis shows that five days of celecoxib results in a measurable decrease in urinary PGE-M (a major urinary metabolite of PGE2). Therefore, urinary PGE-M may prove to be a useful non-invasive biomarker to measure response to treatment with COX-2 inhibitors. The addition of celecoxib to 5FU-based neoadjuvant chemoradiation was well tolerated and has led to acceptable rates of pathologic complete responses. Grant support: NIH grants GI SPORE 50CA 95103– 02 & Pfizer Pharmaceuticals. Celecoxib was provided by Pfizer.