Martin H. Poleski

Efficacy, Safety, and Biomarkers of Neoadjuvant Bevacizumab, Radiation Therapy, and Fluorouracil in Rectal Cancer: A Multidisciplinary Phase II Study

PURPOSE To assess the safety and efficacy of neoadjuvant bevacizumab with standard chemoradiotherapy in locally advanced rectal cancer and explore biomarkers for response. PATIENTS AND METHODS In a phase I/II study, 32 patients received four cycles of therapy consisting of: bevacizumab infusion (5 or 10 mg/kg) on day 1 of each cycle; fluorouracil infusion (225 mg/m(2)/24 hours) during cycles 2 to 4; external-beam irradiation (50.4 Gy in 28 fractions over 5.5 weeks); and surgery 7 to 10 weeks after completion of all therapies. We measured molecular, cellular, and physiologic biomarkers before treatment, during bevacizumab monotherapy, and during and after combination therapy. RESULTS Tumors regressed from a mass with mean size of 5 cm (range, 3 to 12 cm) to an ulcer/scar with mean size of 2.4 cm (range, 0.7 to 6.0 cm) in all 32 patients. Histologic examination revealed either no cancer or varying numbers of scattered cancer cells in a bed of fibrosis at the primary site. This treatment resulted in an actuarial 5-year local control and overall survival of 100%. Actuarial 5-year disease-free survival was 75% and five patients developed metastases postsurgery. Bevacizumab with chemoradiotherapy showed acceptable toxicity. Bevacizumab decreased tumor interstitial fluid pressure and blood flow. Baseline plasma soluble vascular endothelial growth factor receptor 1 (sVEGFR1), plasma vascular endothelial growth factor (VEGF), placental-derived growth factor (PlGF), and interleukin 6 (IL-6) during treatment, and circulating endothelial cells (CECs) after treatment showed significant correlations with outcome. CONCLUSION Bevacizumab with chemoradiotherapy appears safe and active and yields promising survival results in locally advanced rectal cancer. Plasma VEGF, PlGF, sVEGFR1, and IL-6 and CECs should be further evaluated as candidate biomarkers of response for this regimen.

A randomized, placebo-controlled, double-blind trial of mesalamine in the maintenance of remission of Crohn's disease. The Canadian Mesalamine for Remission of Crohn's Disease Study Group

BACKGROUND & AIMS The efficacy of mesalamine for the maintenance of remission in patients with Crohns disease is controversial. The aim of this study was to conduct a double-blind, placebo-controlled study of mesalamine (750 mg four times a day for 48 weeks) in maintaining remission in 293 patients with Crohns disease. Patients were stratified according to the method of induction of remission (medical or surgical). METHODS Patients were assessed at weeks 4, 12, 24, 36, and 48. Relapse was defined as a Crohns Disease Activity Index of >150 (+60 points over baseline). RESULTS Of the 293 patients, 246 (84%) returned for at least 4 weeks of follow-up and were included in the final analysis. Thirty of the 118 (25%) who received mesalamine had a relapse compared with 47 of 128 (36%) receiving placebo (P = 0.056). Among those with relapse, the time to relapse was 119 days for the mesalamine-treated patients compared with 109 days for placebo-treated patients (P = NS). However, 25% of mesalamine-treated patients had relapsed by 249 days of follow-up compared with 154 days for placebo-treated patients. Subgroup analysis showed that patients with ileocecal-colonic disease or patients who were women had fewer relapses on mesalamine therapy than placebo-treated patients (21% vs. 41%, P = 0.018; and 19% vs. 41%, P = 0.003, respectively). CONCLUSIONS Mesalamine treatment reduced relapse compared with placebo treatment, although conventional statistical significance was not achieved.

Direct Evidence that Bevacizumab, an Anti-VEGF Antibody, Up-regulates SDF1α, CXCR4, CXCL6, and Neuropilin 1 in Tumors from Patients with Rectal Cancer

Clinical studies converge on the observation that circulating cytokines are elevated in most cancer patients by anti-vascular endothelial growth factor (VEGF) therapy. However, the source of these molecules and their relevance in tumor escape remain unknown. We examined the gene expression profiles of cancer cells and tumor-associated macrophages in tumor biopsies before and 12 days after monotherapy with the anti-VEGF antibody bevacizumab in patients with rectal carcinoma. Bevacizumab up-regulated stromal cell-derived factor 1alpha (SDF1alpha), its receptor CXCR4, and CXCL6, and down-regulated PlGF, Ang1, and Ang2 in cancer cells. In addition, bevacizumab decreased Ang1 and induced neuropilin 1 (NRP1) expression in tumor-associated macrophages. Higher SDF1alpha plasma levels during bevacizumab treatment significantly associated with distant metastasis at three years. These data show that VEGF blockade up-regulates inflammatory pathways and NRP1, which should be evaluated as potential targets for improving anti-VEGF therapy.

Management of adverse events associated with idelalisib treatment: expert panel opinion

Idelalisib is a first-in-class selective, oral, phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor approved for the treatment of several types of blood cancer. Idelalisib has demonstrated significant efficacy and a tolerable safety profile in clinical trials. However, the US prescribing information contains a black box warning for fatal and/or severe diarrhea or colitis, hepatotoxicity, pneumonitis and intestinal perforation. An expert panel was convened to review the pathology of these treatment-emergent adverse events (TEAEs) to propose key management tools for patients receiving idelalisib therapy. This article provides an overview of idelalisib TEAEs reported in clinical trials, and a summary of the panels recommendations for identification and management of idelalisib treatment-emergent diarrhea or colitis as well as a discussion of transaminitis and pneumonitis. For idelalisib-related diarrhea or colitis (including unresolved grade 2 and grade ≥ 3), after exclusion of infectious causes, the panel recommends individualized treatment with budesonide or oral or intravenous steroid therapy.

The value of diagnostic aids in detecting pancreas cancer.

By contract with the National Cancer Institute, the accuracy of diagnostic techniques was assessed in 184 patients suspected of having pancreas cancer. Of 138 patients who were operated upon, 89 were found to have pancreas duct cancer, 30 had cancer of a different site of origin in the head of the pancreas region and in 19 there was no evidence of cancer at operation. All of the 46 patients who were not operated upon, 13 proven to have cancer and 33 patients discharged as free of cancer, were followed in our clinic. The majority of our patients presented with signs and symptoms of biliary obstruction. Computerized transaxial tomography (CTT) gave a “correct” diagnosis in 31 of 33 patients (94%) with proven cancer, there were 2 patients with a false negative report and a false positive diagnosis occurred in 8 of 20 patients (40%) without cancer. Celiac angiography (CA) gave a correct diagnosis in 78 of 94 patients (83%) with cancer, a false negative in 17%, and a false positive in 32%. 75Sele‐nomethionine pancreas scan correctly diagnosed 27 of 36 patients (75%) with cancer, gave a false negative in 25% and a false positive in 31%. Ultrasonog‐raphy gave a correct diagnosis in 18 of 27 patients with cancer (67%), a false negative in 33% and a false positive in 28%. Endoscopic retrograde cholangio‐pancreatography diagnosed correctly 8 of 11 cases (73%) of cancer, there were false negative diagnoses in 3 cases (27%) and false positives in 3 of 14 patients (21%). Duodenal aspiration techniques gave a very low percentage of correct diagnoses. Chronic pancreatitis most commonly gave rise to a false positive diagnosis. Serum alkaline phosphatase was elevated in 82% of patients, gave 18% false negatives and 33% false positives. Carcinoembryonic antigen (CEA) was elevated (> 2.5 ng/ml) in most of the pancreas cancer patients but also in patients with other cancers and with non‐cancerous diseases. In our hands, CTT, CA, alkaline phosphatase, 75Se‐methionine and ultrasonography, in descending order, have given the highest percentage of correct diagnoses but false positive and false negative diagnoses prevented any single test from being conclusive.

Complete pathological response to bevacizumab and chemoradiation in advanced rectal cancer

Background Localized rectal cancer responds well to 5-fluorouracil and radiation-based regimens. A phase I–II trial is currently testing the efficacy of adding bevacizumab, a VEGF-specific antibody, to standard chemoradiotherapy. The case presented here is a complete pathological response seen in a patient with extensive and locally invasive carcinoma after receiving this combined treatment.Investigations Physical examination, rectal ultrasound, PET–CT scan, laboratory tests, proctoscopic examination, chest radiograph, rectal forcep biopsies with immunohistochemistry, and protein and flow cytometric analyses.Diagnosis Large, invasive, ultrasound stage T4 carcinoma of the rectum, which was positive for survivin.Management One 2-week cycle of bevacizumab alone, followed by 3 cycles of bevacizumab with continuous 5-fluorouracil infusion, and external-beam radiation therapy given 5 days per week to the pelvis, abdominoperineal resection with posterior vaginectomy, hysterectomy and bilateral salpingo-oophorectomy.

Inflammatory bowel disease following solid organ transplantation

Inflammatory bowel disease (IBD) is a T cell driven inflammatory condition of the gut. Following solid organ transplantation (SOT), de novo IBD has been reported despite anti-T cell therapy for the prevention of organ rejection. This paradox is illustrated with a case report, highlighting the difficult diagnostic criteria, the potential role of Damage or Pathogen Associated Molecular Pattern Molecules [DAMPs and PAMPs] that drives aspects of ongoing inflammation within the transplanted organ as well as the intestine, and the therapeutic strategies applied. Recurrent IBD is more common than de novo IBD following transplantation, with cumulative risks ten years after orthotopic liver transplantation of 70% and 30%, respectively. Furthermore, the annual incidence of de novo IBD following solid organ transplantation has been estimated to be 206 cases/100,000 or ten times the expected incidence of IBD in the general population (approximately 20 cases/100,000). The association of IBD with other autoimmune conditions such as primary sclerosing cholangitis and autoimmune hepatitis, both common indications for liver transplantation, may play a contributory role, particularly in view of the observation that IBD is more common following liver transplant than other solid organ transplants. Recurrent IBD following transplant appears to run a more aggressive course than de novo IBD, with a higher proportion requiring colectomy for medically refractory disease. Risk factors that have been associated with development of post-transplant IBD include acute CMV infection and the use of tacrolimus.

A Safety and Survival Analysis of Neoadjuvant Bevacizumab with Standard Chemoradiation in a Phase I/II Study Compared with Standard Chemoradiation in Locally Advanced Rectal Cancer

INTRODUCTION Bevacizumab is increasingly being tested with neoadjuvant regimens in patients with localized cancer, but its effects on metastasis and survival remain unknown. This study examines the long-term outcome of clinical stage II/III rectal cancer patients treated in a prospective phase II study of bevacizumab with chemoradiation and surgery. As a benchmark, we used data from an analysis of 42 patients with locally advanced rectal cancer treated with a contemporary approach of preoperative fluoropyrimidine-based radiation therapy. MATERIALS AND METHODS Outcome analyses were performed on 32 patients treated prospectively with neoadjuvant bevacizumab, 5-fluorouracil, radiation therapy, and surgery as well as 42 patients treated with standard fluoropyrimidine-based chemoradiation. RESULTS Overall survival, disease-free survival, and local control showed favorable trends in patients treated with bevacizumab with chemoradiation followed by surgery. Acute and postoperative toxicity appeared acceptable. CONCLUSIONS Neoadjuvant bevacizumab with standard chemoradiation and surgery shows promising long-term efficacy and safety profiles in locally advanced rectal cancer patients.

Using capsule endoscopy to identify GI tract lesions in cirrhotic patients with portal hypertension and chronic anemia.

Goals We aimed to evaluate the ability of capsule endoscopy (CE) to detect small intestine (SI) lesions, especially SI varices, in patients with intrahepatic cirrhosis, portal hypertension (PHTN), and chronic anemia. Background Gastroesophageal variceal bleeding is a well-recognized complication of cirrhosis and PHTN, yet methods of identifying lesions in the SI that may contribute to covert bleeding and anemia, such as small bowel enteroscopy and angiography, are invasive and may be inadequate. Study In this observational pilot study, 19 consecutive patients presenting to a tertiary care, liver transplantation referral center with cirrhosis, PHTN, and chronic anemia after obliterative esophageal variceal therapy were evaluated with wireless CE using the GIVEN Pillcam SB M2A capsule. Two independent and blinded examiners reviewed the CE examinations. Results SI varices were identified in 15.8% (3/19) of patients. Other PHTN-related findings included portal hypertensive gastropathy (13/19, 68.4%), portal hypertensive enteropathy (12/19, 63.1%), and portal hypertensive colopathy (3/19, 15.8%). Two patients had nonbleeding esophageal varices (2/19, 10.5%). A potential source of gastrointestinal blood loss was identified in 89.5% (17/19) of patients. Active bleeding sites were identified in 15.8% (3/19). Conclusions CE can identify potential bleeding sources and could have diagnostic utility in patients with end-stage liver disease and chronic anemia after obliterative esophageal variceal therapy.

Effects of Pirenzepine on Acute Mucosal Erosions, Gastric Acid and Mucosal Blood Flow in the Spinal Rat Stomach

The aim of this study was to examine the effects of varying doses of pirenzepine, a selective muscarinic subtype M1 antagonist, on the prevention of acute gastric mucosal lesions in male Sprague-Dawley rats subjected to spinal cord section at the C7 level. It was also intended to evaluate the effects of the drug on gastric acid output and gastric mucosal blood flow. Pirenzepine 1, 2.5 and 5 mg/kg every 2 h all caused a significant reduction in mean total ulcer length (p less than 0.01) compared to controls. This was associated with a significant decrease in acid output (p less than 0.05). There was no significant effect on gastric mucosa blood flow as measured by hydrogen gas clearance. These results indicate that the protective effects of pirenzepine on gastric mucosa, in the spinal rat model, are associated with the acid-inhibitory action of the drug and not on mucosal blood flow effects.