Arne Bakka

Comprehensive geriatric assessment can predict complications in elderly patients after elective surgery for colorectal cancer: A prospective observational cohort study

OBJECTIVE To examine the association between the outcomes of a pre-operative comprehensive geriatric assessment (CGA) and the risk of severe post-operative complications in elderly patients electively operated for colorectal cancer. METHODS One hundred seventy-eight consecutive patients ≥ 70 years electively operated for all stages of colorectal cancer were prospectively examined. A pre-operative CGA was performed, and patients were categorized as fit, intermediate, or frail. The main outcome measure was severe complications within 30 days of surgery. RESULTS Twenty-one patients (12%) were categorized as fit, 81 (46%) as intermediate, and 76 (43%) as frail. Eighty-three patients experienced severe complications, including three deaths; 7/21 (33%) of fit patients, 29/81 (36%) of intermediate patients and 47/76 (62%) of frail patients (p=0.002). Increasing age and ASA classification were not associated with complications in this series. CONCLUSION CGA can identify frail patients who have a significantly increased risk of severe complications after elective surgery for colorectal cancer.

Female fecundity before and after operation for familial adenomatous polyposis

Knowledge about the fertility of women suffering from familial adenomatous polyposis (FAP) is scarce and inconclusive. The purpose of this study was to investigate the fecundity of women with FAP before and after operation, and to compare the findings with those of a general population database and women with ulcerative colitis.

Cytokine profiles differ in newly recruited and resident subsets of mucosal macrophages from inflammatory bowel disease

BACKGROUND & AIMS Most macrophages in the normal intestinal mucosa have a mature phenotype. In inflammatory bowel disease (IBD), a monocyte-like subset (CD14+ L1+) accumulates. The aim of this study was to characterize its potential with regard to cytokines. METHODS Lamina propria mononuclear cells were adherence-separated, with or without depletion of CD14+ cells, and production of cytokines was investigated by bioassay, enzyme-linked immunosorbent assay, or immunocytochemistry. RESULTS Tumor necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta), and IL-1 receptor antagonist were found mainly in cells positive for myelomonocytic L1. In undepleted IBD cultures, TNF-alpha, IL-1alpha and beta, and IL-10 were markedly up-regulated by pokeweed mitogen stimulation; IL-1alpha and beta and IL-10 were also up-regulated by stimulation of interferon gamma and lipopolysaccharide in combination. The latter stimulation had no effect on normal control or CD14-depleted IBD cultures. Indomethacin caused a marked increase of TNF-alpha, particularly in undepleted IBD cultures, whereas IL-10 and IL-4 decreased TNF-alpha and IL-1beta in both CD14+ and CD14 macrophages. CONCLUSIONS In IBD mucosa, macrophages with a monocyte-like phenotype are primed for production of TNF-alpha and IL-1alpha/beta and may therefore be of significant pathogenic importance [corrected]. However, this CD14+ subset, as well as the mucosal resident macrophages, have preserved responsiveness to several down-regulatory factors such as the macrophage deactivators IL-10 and IL-4.

Intradermal ras peptide vaccination with granulocyte‐macrophage colony‐stimulating factor as adjuvant: Clinical and immunological responses in patients with pancreatic adenocarcinoma

K‐RAS mutations are frequently found in adenocarcinomas of the pancreas, and induction of immunity against mutant ras can therefore be of possible clinical benefit in patients with pancreatic cancer. We present data from a clinical phase I/II trial involving patients with adenocarcinoma of the pancreas vaccinated by i.d. injection of synthetic mutant ras peptides in combination with granulocyte‐macrophage colony‐stimulating factor. Forty‐eight patients (10 surgically resected and 38 with advanced disease) were treated on an outpatient basis. Peptide‐specific immunity was induced in 25 of 43 (58%) evaluable patients, indicating that the protocol used is very potent and capable of eliciting immune responses even in patients with end‐stage disease. Patients followed‐up for longer periods showed evidence of induction of long‐lived immunological memory against the ras mutations. CD4+ T cells reactive with an Arg12 mutation also present in the tumor could be isolated from a tumor biopsy, demonstrating that activated, ras‐specific T cells were able to selectively accumulate in the tumor. Vaccination was well tolerated in all patients. Patients with advanced cancer demonstrating an immune response to the peptide vaccine showed prolonged survival from the start of treatment compared to non‐responders (median survival 148 days vs. 61 days, respectively; p = 0.0002). Although a limited number of patients were included in our study, the association between prolonged survival and an immune response against the vaccine suggests that a clinical benefit of ras peptide vaccination may be obtained for this group of patients.

Vaccination with mutant ras peptides and induction of T-cell responsiveness in pancreatic carcinoma patients carrying the corresponding RAS mutation

Mutations in codon 12 of K-RAS are frequently found in pancreatic adenocarcinomas. T-cell responses specific for individual RAS mutations can be elicited in vitro by stimulation of peripheral blood mononuclear cells with synthetic peptides. Mutant ras peptides are therefore a candidate vaccine for specific immunotherapy in pancreatic carcinoma patients. When vaccinated with a synthetic ras peptide representing the K-RAS mutation in their tumours, a transient ras-specific T-cell response was induced in two of five patients treated. The vaccination protocol involved multiple infusions of large amounts of peptide-pulsed antigen-presenting-cells obtained by leucapheresis. These results indicate that specific T-cell responses against mutations uniquely harboured in tumour cells can be induced in cancer patients by vaccination.

Differential distribution of B7.1 (CD80) and B7.2 (CD86) costimulatory molecules on mucosal macrophage subsets in human inflammatory bowel disease (IBD)

The molecules B7.1 and B7.2 deliver costimulatory signals of critical importance to naive T cells, and may thus be involved in abrogation of oral tolerance in IBD. Functional disparity apparently exists among antigen‐presenting cells in vivo. We wanted to examine if differential B7 expression occurs on mucosal macrophage subsets. Cryosections of bowel specimens from patients with IBD and normal controls were subjected to immunofluorescence and immunoperoxidase staining. In normal mucosa, selective subepithelial accumulation of B7.2+ cells was found. In inflamed IBD mucosa, however, subsets appeared consisting of both B7.2hi and B7.1hi cells as well as CD14hi macrophages. Notably, outside lymphoid aggregates the prominent fraction of recently recruited CD14hi macrophages comprised most (≈ 80%) of the B7.1hi cells, whereas most (≈ 70%) B7.2hi cells were identified as resident mucosal macrophages (CD14lo or CD14−). Differential expression of B7.1 and B7.2 on two functionally different subsets of intestinal macrophages implies separate immunoregulatory roles for the two molecules. This finding is in keeping with recent experimental data demonstrating that monocyte‐derived cells are crucial for immune responses at mucosal surfaces. Preferential B7.1 up‐regulation might be critical in breaking the immunological tolerance to luminal antigens in IBD, but it cannot be excluded that it is a secondary pathogenic event.

Respiratory burst of intestinal macrophages in inflammatory bowel disease is mainly caused by CD14+L1+ monocyte derived cells.

Macrophages play a crucial role in intestinal mucosal defence, forming dense subepithelial aggregates, particularly in the colon. One of their important bactericidal mechanisms is production of oxygen radicals but this may damage the intestinal epithelium, perhaps as an early step in inflammatory bowel disease (IBD). The potential for release of oxygen radicals from mucosal macrophages in IBD was measured and whether a difference exists between newly arrived (CD14+L1+) monocyte-like cells and resident macrophages (CD14(-)L1-), without or with additional priming in vitro, was investigated. Lamina propria mononuclear cells from six patients with IBD and five with a normal intestine were isolated with an ethylenediaminetetra acetic acid/collagenase/dispase technique and cultured for three days. The cells were tested with or without interferon gamma (200 U/ml) priming in the presence or absence of lipopolysaccharide (1 microgram/ml) for the last 48 hours in cultures. Samples from inflamed IBD mucosa depleted of CD14+ cells by immunomagnetic beads were compared with their undepleted counterparts and with samples from virtually normal mucosa from the same patients. The production of oxygen radicals was measured as the amount of reduced cytochrome C 2.5 hours after triggering with phorbol 12-myristate 13-acetate. The oxygen radical production in macrophages from moderately or severely inflamed mucosa was reduced by median 69% (range 22%-79%, p < 0.027) after depletion of CD14+ cells, reaching a level similar to that found for virtually normal samples from the same IBD patients. Furthermore, this production did not increase significantly in mucosal macrophages from normal reference mucosa and from virtually normal or inflamed IBD mucosa after priming with interferon gamma with or without addition of lipopolysaccharide. Upregulation of a respiratory burst in subepithelial resident macrophages os not a likely pathogenetic step in IBD. The increased oxygen radical production shown by macrophages from IBD lesions can, however, be ascribed to recently extravasated CD14+L1+ monocyte-like cells. Inhibition of extravasation of these reactive cells may form part of a therapeutic approach in the future.

Outcome of four weeks’ intervention with probiotics on symptoms and endoscopic appearance after surgical reconstruction with a J-configurated ileal-pouch-anal-anastomosis in ulcerative colitis

Objective Pouchitis is a common and troublesome condition in patients operated on with ileal-pouch-anal-anastomosis (IPAA). A disturbed microecology in the pouch has been suggested as one possible explanation. In a previous double-blind, randomized, controlled study we demonstrated clinical improvement of symptoms in patients with ulcerative colitis (UC) operated on with IPAA, during intervention with live probiotic microbes Lactobacilli and Bifidobacteriae. The aim of the present study was to confirm our previous results in a much larger material, including clinical symptoms, faecal flora and endoscopic evaluation, and to compare the results in UC/IPAA patients with those of patients with familial adenomatous polyposis (FAP) with IPAA and UC patients with ileorectal anastomosis (IRA). Material and methods Five hundred millilitres of a fermented milk product (Cultura) containing live lactobacilli (La-5) and bifidobacteriae (Bb-12) was given daily for 4 weeks to 51 UC patients and 10 patients with FAP, operated on with IPAA, and six UC patients operated on for IRA. Stool samples were cultured for examination of lactobacilli, bifidobacteriae, fungi and pH before, during and after intervention. Before, during and after intervention, endoscopic evaluation was performed. Categorized symptomatology was examined prospectively using diary cards in addition to an interview, before and on the last day of intervention. Results The number of lactobacilli and bifidobacteriae increased significantly during intervention in the UC patients operated on with IPAA and remained significantly increased one week after intervention. Involuntary defecation, leakage, abdominal cramps and the need for napkins (category I), faecal number and consistency (category II) and mucus and urge to evacuate stools (category III) were significantly decreased during intervention in the UC/IPAA group. In the FAP group there was a significant decrease in faecal leakage, abdominal cramps and use of napkins (category I) during intervention. The median endoscopic score of inflammation was significantly decreased during intervention in the UC/IPAA patients. Blood tests, faecal fungi and faecal pH did not change significantly during intervention. Conclusions Results of this extended study, showing an effect of probiotics on symptoms and endoscopic inflammation in UC patients operated on with IPAA confirm our previously reported effect of probiotics on clinical symptoms and endoscopic score in a smaller, double-blind, randomized, controlled study. The significantly higher response to probiotics in families with increased risk of IBD will have to be repeated in future studies.

Ex vivo ras peptide vaccination in patients with advanced pancreatic cancer: Results of a phase I/II study

In a pilot phase I/II study we have tested synthetic ras peptides used as a cancer vaccine in 5 patients with advanced pancreatic carcinoma. The treatment principle used was based on loading professional antigen‐presenting cells (APCs) from peripheral blood with a synthetic ras peptide corresponding to the ras mutation found in tumour tissue from the patient. Peptide loading was performed ex vivo and the next day APCs were re‐injected into the patients after washing to remove unbound peptide. Patients were vaccinated in the first and second week and thereafter every 4–6 weeks. In 2 of the 5 patients treated, an immune response against the immunising ras peptide could be induced. None of the patients showed evidence of a T‐cell response against any of the ras peptides before vaccination. The treatment was well tolerated and could be repeated multiple times in the same patient. Side effects were not observed even if an immunological response against the ras peptide was evident. We conclude that ras peptide vaccination according to the present protocol is safe and may result in a potentially beneficial immune response even in patients with advanced malignant disease.

DNA sequence profiles of the colorectal cancer critical gene set KRAS-BRAF-PIK3CA-PTEN-TP53 related to age at disease onset.

The incidence of colorectal cancer (CRC) increases with age and early onset indicates an increased likelihood for genetic predisposition for this disease. The somatic genetics of tumor development in relation to patient age remains mostly unknown. We have examined the mutation status of five known cancer critical genes in relation to age at diagnosis, and compared the genomic complexity of tumors from young patients without known CRC syndromes with those from elderly patients. Among 181 CRC patients, stratified by microsatellite instability status, DNA sequence changes were identified in KRAS (32%), BRAF (16%), PIK3CA (4%), PTEN (14%) and TP53 (51%). In patients younger than 50 years (n = 45), PIK3CA mutations were not observed and TP53 mutations were more frequent than in the older age groups. The total gene mutation index was lowest in tumors from the youngest patients. In contrast, the genome complexity, assessed as copy number aberrations, was highest in tumors from the youngest patients. A comparable number of tumors from young (<50 years) and old patients (>70 years) was quadruple negative for the four predictive gene markers (KRAS-BRAF-PIK3CA-PTEN); however, 16% of young versus only 1% of the old patients had tumor mutations in PTEN/PIK3CA exclusively. This implies that mutation testing for prediction of EGFR treatment response may be restricted to KRAS and BRAF in elderly (>70 years) patients. Distinct genetic differences found in tumors from young and elderly patients, whom are comparable for known clinical and pathological variables, indicate that young patients have a different genetic risk profile for CRC development than older patients.