Immune adjuvant efficacy of CpG oligonucleotide in cancer treatment is founded specifically upon TLR9 function in plasmacytoid dendritic cells

The differences in function, location, and migratory pattern of conventional dendritic cells (cDC) and plasmacytoid DCs (pDC) not only point to specialized roles in immune responses but also signify additive and interdependent relationships required to clear pathogens. We studied the in vivo requirement of cross-talk between cDCs and pDCs for eliciting antitumor immunity against in situ released tumor antigens in the absence or presence of the Toll-like receptor (TLR) 9 agonist CpG. Previous data indicated that CpG boosted tumor-specific T-cell responses after in vivo tumor destruction and increased survival after tumor rechallenges. The present study shows that cDCs are indispensable for cross-presentation of ablation-released tumor antigens and for the induction of long-term antitumor immunity. Depletion of pDCs or applying this model in type I IFN receptor-deficient mice abrogated CpG-mediated responses. CD8α(+) cDCs and the recently identified merocytic cDCs were dependent on pDCs for CpG-induced upregulation of CD80. Moreover, DC transfer studies revealed that merocytic cDCs and CD8α(+) cDCs were most susceptible to pDC help and subsequently promoted tumor-free survival in a therapeutic setting. By transferring wild-type pDCs into TLR9-deficient mice, we finally showed that TLR9 expression in pDCs is sufficient to benefit from CpG as an adjuvant. These studies indicate that the efficacy of CpG in cancer immunotherapy is dependent on cross-talk between pDCs and specific subsets of cDCs.

A novel iterative method for lesion delineation and volumetric quantification with FDG PET

OBJECTIVES

The determination of lesion boundaries on FDG PET is difficult due to the point-spread blurring and unknown uptake of activity within a lesion. Standard threshold-based methods for volumetric quantification on PET usually neglect any size dependence and are biased by dependence on the signal-to-background ratio (SBR). A novel, model-based method is hypothesized to provide threshold levels independent f the SBR and to allow accurate measurement of volumes down to the resolution of the PET scanner.

METHODS

A background-subtracted relative-threshold level (RTL) method was derived, based on a convolution of the point-spread function and a sphere with diameter D. Validation of the RTL method was performed using PET imaging of a Jaszczak phantom with seven hollow spheres (D=10-60 mm). Activity concentrations for the background and spheres (signal) were varied to obtain SBRs of 1.5-10. An iterative procedure was introduced for volumetric quantification, as the optimal RTL depends on a priori knowledge of the volume. The feasibility of the RTL method was tested in two patients with liver metastases and compared to a standard method using a fixed percentage of the signal.

RESULTS

Phantom data validated that the theoretically optimal RTL depends on the sphere size, but not on the SBR. Typically, RTL=40% (D=15-60 mm), and RTL>50% for small spheres (D<12 mm). The RTL method is better applicable to patient data than the standard method.

CONCLUSIONS

Based on an iterative procedure, the RTL method has been shown to provide optimal threshold levels independent of the SBR and to be applicable in phantom and in patient studies. It is a promising tool for lesion delineation and volumetric quantification of PET lesions.

Profiling the humoral immune response in colon cancer patients: diagnostic antigens from Streptococcus bovis

The human bowel contains a large and dynamic bacterial population that is not only essential for intestinal health, but also critical for the development of diseases such as cancer. In this respect, the Gram-positive bacterium Streptococcus bovis has been associated with colon cancer for many years. To investigate the clinical importance of this association, an immunocapture mass spectrometry assay was developed that can generate infection-related protein profiles. The composition of these profiles is governed by the capture of specific antigens by serum antibodies from colon cancer patients. This assay showed that S. bovis antigen profiles could distinguish 11 out of 12 colon cancer patients from 8 control subjects, whereas antigen profiles derived from the gut bacterium Escherichia coli were not diagnostic for colon cancer. Moreover, S. bovis antigen profiles were also detected in polyp patients, indicating that infection with this bacterium does occur early during carcinogenesis. Highly accurate tandem mass spectrometry was used to identify one of the diagnostic antigens as a surface-exposed heparin-binding protein, which might be involved in attachment of S. bovis to tumor cells. Together, these findings corroborate the hypothesis that colonic lesions provide a specific niche for S. bovis, resulting in tumor-associated "silent" infections. These infections, however, only become apparent in colon cancer patients with a compromised immune system (bacteremia) or coincidental cardiac valve lesions (endocarditis). This makes profiling of the humoral immune response against "silent" S. bovis infections a promising diagnostic tool for the early detection of human colon cancer, which is crucial for the effective treatment of this disease.

Vaccination of colorectal cancer patients with CEA-loaded dendritic cells: antigen-specific T cell responses in DTH skin tests

BACKGROUND

Dendritic cells (DCs) are the professional antigen-presenting cells of the immune system. As such they are currently used in clinical vaccination protocols in cancer patients.

PATIENTS AND METHODS

We evaluated the ability of mature DCs pulsed with carcinoembryonic antigen (CEA)-peptide to induce CEA-specific T cell responses in patients with resectable liver metastases from colorectal cancer. CEA-specific T cell reactivity was monitored in peripheral blood, biopsies of vaccination sites and post-treatment DTH skin tests, and when available also in resected abdominal lymph nodes and tumor tissue.

RESULTS

Ten patients were vaccinated intradermally and intravenously with CEA-peptide pulsed mature DCs three times prior to resection of liver metastases. High numbers of CEA-specific T cells were detected in post-treatment DTH biopsies in seven out of 10 patients, which produced high amounts of interferon (IFN)-gamma upon stimulation with CEA-loaded target cells. These responses were not found in biopsies of first vaccination sites, indicating a de novo T cell induction or at least a strong potentiation by the vaccine. In addition, CEA-specific T cells were detected in a resected lymph node in one patient, but not in peripheral blood or tumor tissue.

CONCLUSIONS

Vaccination with CEA-peptide loaded mature DCs induced potent CEA-specific T cell responses in advanced colorectal cancer patients. In this study, antigen-specific T cell responses were readily detected in DTH skin tests, much less in abdominal lymph nodes, and not in peripheral blood and tumor tissue.

[More hereditary intestinal cancer can be detected if patients with colorectal carcinoma that are selected by the pathologist are examined for microsatellite instability]

OBJECTIVE

To determine whether an investigation of microsatellite instability (MSI) in patients with colorectal carcinoma that have been selected by the pathologist could increase the number of detected families with hereditary non-polyposis colorectal carcinoma (HNPCC).

DESIGN

Prospective inventory.

METHOD

Pathologists selected patients with a newly diagnosed colorectal carcinoma for MSI analysis of their tumour tissue if they met one of the following four criteria: (a) colorectal carcinoma diagnosed below 50 years of age; (b) a second colorectal carcinoma; (c) a combination of colorectal carcinoma and another HNPCC-related cancer; (d) colorectal adenoma with high-grade dysplasia diagnosed below 40 years of age. Patients with a positive MSI-test were referred to a clinical geneticist. The new strategy was introduced and explored in 5 hospitals for a period of to months.

RESULTS

The new strategy was adopted and implemented successfully by pathologists and surgeons and accepted with satisfaction by the patients. Of the 55 patients included, 10 had a positive MSI-test. In 8/10 patients, DNA-mutation analysis was started by the clinical geneticist and 3 germline mutations in the MSH2-gene were detected. In 2 of 3 families with a pathogenic mutation, the family history alone did not fulfil the clinical criteria for HNPCC.

CONCLUSION

Selection by the pathologist for MSI investigation was feasible in daily practice and identified more HNPCC patients than selection based on family history alone.

Decrease in circulating anti-angiogenic factors (angiostatin and endostatin) after surgical removal of primary colorectal carcinoma coincides with increased metabolic activity of liver metastases

Removal of a primary colorectal tumor resulted in an increase in metabolic activity in its liver metastasis. Concomitantly, levels of angiostatin and endostatin in urine and plasma, respectively, dropped. This finding indicates that the primary tumor suppressed angiogenesis in its distant metastasis, and that removal of the primary lesion caused a flare-up in vessel neoformation and, thus, enhanced metabolic activity in its liver metastasis.

Cost effectiveness of a new strategy to identify HNPCC patients

BACKGROUND

Distinguishing hereditary non-polyposis colorectal cancer (HNPCC) from non-hereditary colorectal cancer (CRC) can increase the life expectancy of HNPCC patients and their close relatives.

AIM

To determine the effectiveness, efficiency, and feasibility of a new strategy for the detection of HNPCC, using simple criteria for microsatellite instability (MSI) analysis of newly detected tumours that can be applied by pathologists. Criteria for MSI analysis are: (1) CRC before age 50 years; (2) second CRC; (3) CRC and HNPCC associated cancer; or (4) adenoma before age 40 years.

METHODS

The efficacy and cost effectiveness of the new strategy was evaluated against current practice. Decision analytic models were constructed to estimate the number of extra HNPCC mutation carriers and the costs of this strategy. The incremental costs and gain in life expectancy for a HNPCC mutation carrier were evaluated by Markov modelling. Feasibility was explored in five hospitals.

RESULTS

Using the new strategy, 2.2 times more HNPCC patients can be identified among a CRC population compared with current practice. This new strategy was found to be cost effective with an expected cost effectiveness ratio of 3801 per life year gained. When including the group of siblings and children, the cost effectiveness ratio became 2184 per life year gained. Sensitivity analysis showed these findings to be robust.

CONCLUSIONS

MSI testing in a selection of newly diagnosed CRC patients was shown to be cost effective and a feasible method to identify patients at risk for HNPCC who are not recognised by family history.

Method for quantitation of dynamic MRI contrast agent uptake in colorectal liver metastases

PURPOSE

To investigate the reproducibility of dynamic contrast-enhanced MRI (DCE-MRI) in colorectal liver metastases using a vascular normalization function (VNF) from pixels in the spleen and to compare this with a technique using an arterial input function (AIF) from pixels in the aorta.

MATERIALS AND METHODS

DCE-MRI with gadolinium-DTPA (Gd-DTPA) was performed in patients with colorectal liver metastases. The VNF and AIF were determined using an automated algorithm. The average Gd-DTPA uptake rate (k(ep)) was calculated for the metastases using a physiological pharmacokinetic model. The protocol was repeated on a second day to calculate the repeatability coefficient of the measurements of k(ep).

RESULTS

Using the VNF from the spleen the overall mean k(ep) of the two sessions for 11 patients was 0.033 per second and the repeatability coefficient was 0.009 per second. Using the AIF from the aorta these values were 0.031 per second and 0.028 per second, respectively.

CONCLUSION

The mean Gd-DTPA uptake rate using a VNF taken from the spleen can be determined with adequate reproducibility in colorectal liver metastases. The use of a VNF from pixels in the spleen is better than an AIF from pixels in the aorta in terms of reproducibility, and is recommended when this DCE-MRI technique is used for prediction and monitoring of therapy outcome in colorectal liver metastases.

Effective migration of antigen-pulsed dendritic cells to lymph nodes in melanoma patients is determined by their maturation state

Dendritic cells are the professional antigen-presenting cells of the immune system. To induce an effective immune response, these cells should not only express high levels of MHC and costimulatory molecules but also migrate into the lymph nodes to interact with naïve T cells. Here, we demonstrate that in vitro-generated mature, but not immature dendritic cells, efficiently migrate into the T-cell areas of lymph nodes of melanoma patients. This difference is confirmed by in vitro studies, in which immature dendritic cells are strongly adherent, whereas mature dendritic cells remain highly motile. Our present findings demonstrate that the ability of dendritic cells to mount a proper immune response correlates with their ability to migrate both in vitro and in vivo.

Quality of life as an outcome measure in surgical oncology

Background

There is a growing interest in assessing the impact of a disease and the effect of a treatment on a patient's life, expressed as health-related quality of life (HRQoL). HRQoL assessment can provide essential outcome information for cancer surgery.

Methods

The core of this review is derived from a literature search of the Medline database.

Results

Three types of HRQoL instrument can be distinguished: generic, disease specific and symptom specific. There are criteria against which HRQoL instruments may be evaluated. The instrument chosen must be reliable, valid and sensitive to change.

Conclusion

HRQoL measurement may be useful in identifying the optimal surgical procedure. It may also be of help in deciding whether surgery in patients with limited life expectancy should still be considered. No HRQoL instrument fits all the recommended conditions or is suitable in all clinical situations. Using the appropriate instrument is essential to arrive at valid and clinically meaningful outcome measures.

Extranodal extension of axillary metastasis of invasive breast carcinoma as a possible predictor for the total number of positive lymph nodes

INTRODUCTION

By the implementation of the sentinel node procedure in the treatment of breast carcinoma routine axillary lymph node, dissection can be abandoned in patients with a tumour-negative sentinel node. When the sentinel node is positive there are two options; an axillary dissection or radiotherapy of the axilla. In the latter case one is not informed about the total number of positive lymph nodes which can be of importance for the choice of adjuvant chemotherapy. In this paper we analyse whether it is possible to use histological parameters of a lymph-node metastasis to predict the number of tumour-cell-containing nodes.

METHODS

Four hundred and ninety-eight patients treated for invasive breast cancer at our department from 1991 to 1996 were investigated to see whether extranodal extension of axillary metastases had a significant predictive value for the number of positive lymph nodes. Extranodal extension was scored as: no extranodal extension (NEE) and extranodal extension (EE); the latter was subdivided in minimal extranodal extension (MEE) or extensive extranodal extension (EEE).

RESULTS

Of 498 patients, 230 patients had axillary involvement. NEE was seen in 83 (36.1%) patients and 147 (63.9%) had EE. Subdivision of this latter group revealed 77 patients with MEE (52%), 65 patients with EEE (45%) and five patients not further specified (3%). The number of positive nodes for the EE-group (6.9+/-0.5) was significant higher compared with the NEE-group (2.1+/-0.2) (P<0.001). The number of positive nodes was also significantly higher for the EEE-group compared to the MEE-group, 10.6+/-0.8 vs 4.0+/-0.4 (P<0.001). The predictive value for > or =4 positive axillary lymph nodes was 84.6% for EEE, 58.5% for EE and only 14.5% for NEE. These differences were significant (P<0.001).

CONCLUSIONS

The presence of extranodal extension in axillary lymph-node metastases can be a good predictor for the expected number of positive nodes. This histological parameter could be of value to determine the kind of adjuvant chemotherapy after a positive sentinel-node biopsy with only radiotherapy of the axilla and no further axillary lymph-node dissection.

Micro-metastases in axillary lymph nodes: an increasing classification and treatment dilemma in breast cancer due to the introduction of the sentinel lymph node procedure

BACKGROUND

Sentinel lymph node (SN) biopsy will increasingly replace axillary lymph node dissection (ALND) for staging in breast cancer. For daily practice, examination of the SN by serial sectioning (SS) and/or immunohistochemistry (IHC) is being promoted. Use of these techniques may result into stage migration due to the increased detection of micro-metastases. The consequence may be overshooting of patients with adjuvant therapy, as the prognostic relevance of (small) micro-metastases and isolated tumor cells is unclear.

METHODS

The prognostic impact of micro-metastases is determined by reviewing ALND studies with a follow up of at least 5 years, including more than 100 patients, before the SN era. Furthermore, studies in which conventionally haematoxylin-eosin (H&E) negative SNs are investigated for occult metastases by SS and/or IHC are reviewed.

RESULTS

In only one of eight studies, occult metastases were an independent risk factor for reduced survival. The outcome is dependent on the size of the nodal metastasis. IHC and SS as used in the SN procedure indeed induce a shift from pNO to pN1a (according to TNM).

CONCLUSION

By the thorough pathologic examination of the SN, isolated tumor cells and micro-metastases are more frequently detected. We propose to classify small micro-metastases (<0.5 mm) in a separate pN1a(min) category (min for minimal) to prevent stage migration. As the prognostic relevance of isolated tumor cells and (small) micrometastases has not been proven, the value of adjuvant therapy can be questioned for patients with otherwise good prognostic factors.

Periodic follow-up after breast cancer and the effect on survival

OBJECTIVE

To assess the role of routine follow-up in current management of breast cancer.

DESIGN

Retrospective review.

SETTING

Teaching hospital, The Netherlands.

SUBJECTS

270 patients who presented with recurrent breast cancer, 1974-90.

MAIN OUTCOME MEASURE

Recurrence was coded as asymptomatic or symptomatic and related to survival.

RESULTS

170 (63%) of the recurrences were detected when they were symptomatic and 100 (37%) when they were not. The groups differed significantly according to the site of recurrence; 45/100 recurrences were local in the asymptomatic group compared with 23/170 (14%) in the symptomatic group. There was no significant difference in disease-free survival between the two groups. Overall 5-year survival after primary treatment for all recurrences (locoregional and distant) was significantly better (p=0.0003) in the asymptomatic group (62/100) than in the symptomatic group 79/170 (46%). However, when locoregional and distant recurrences were analysed separately no significant differences were found between both groups in overall survival after primary treatment or survival after detection of recurrence. The 5-year overall survival after primary treatment for distant recurrence was 26/47 (55%) in the asymptomatic group compared with 62/134 (46%) in the symptomatic group (p=0.13). For locoregional recurrence these figures were 35/45 (78%) and 14/23 (61%), respectively (p=0.34). Routine follow-up hardly affected the course of locoregional recurrence. Only five of 75 patients with local recurrence (7%) developed uncontrolled local disease, 2 of whom were initially detected during routine follow-up.

CONCLUSIONS

We conclude that in the current management of breast cancer the medical impact of follow-up is low, so follow-up visits after treatment for breast cancer are hardly warranted.

Long-term results of treating hepatic colorectal metastases with cryosurgery

BACKGROUND

The purpose of this study was to determine the long-term efficacy of cryosurgery as an adjunct to hepatic resection in patients with colorectal liver metastases not amenable to resection alone.

METHODS

Thirty patients met the following inclusion criteria: metastases confined to the liver and judged irresectable, ten or fewer metastases, cryosurgery alone or in combination with hepatic resection allowed tumour clearance.

RESULTS

Median follow-up was 26 (range 9--73) months. Overall 1- and 2-year survival rates were 76 and 61 per cent respectively. Median survival was 32 months. Disease-free survival at 1 year was 35 per cent, at 2 years 7 per cent. Six patients developed recurrence at the site of cryosurgery; given that the total number of cryosurgery-treated lesions was 69 the local recurrence rate was 9 per cent.

CONCLUSION

In patients with colorectal liver metastases, local ablative techniques can be used as an effective adjunct to hepatic resection to obtain tumour clearance.

Cryosurgery as treatment modality for colorectal liver metastases

Liver metastases occur in more than 40% of the patients with colorectal cancer. The best prospect of cure is achieved by resection of the metastases. Only 10-15% of the patients with colorectal metastases are candidates for resection. When resection is impossible, other treatment options are limited. Response rates to chemotherapy are around 40%, but survival benefit is generally limited to a few months. Recently, cryosurgery has provided a new therapeutic approach for unresectable colorectal liver metastases. The metastases are localized by ultrasonography and are subsequently frozen with the aid of cryosurgical equipment. The treatment results in necrosis of the tumor and is characterized by low mortality and acceptable morbidity. Experience with cryosurgery is limited, but the results are promising. Various studies report a 1-year survival of more than 70% and a 2-year survival of > 50%. Disease-free survival after 2 years varies between 20-29%. Recurrences in the liver are usually other lesions than those treated with cryosurgery. Cryosurgery in combination with resection or as sole treatment, can result in radical treatment for patients formerly considered unresectable. Resection of liver metastases, however, remains the gold standard in the treatment of liver metastases. The main indication for cryosurgery may be as a complement to hepatic resection in those patients in whom liver resection can not achieve complete tumor clearance.

In vivo destruction of tumor tissue by cryoablation can induce inhibition of secondary tumor growth: an experimental study

BACKGROUND

Cryoablation has been used successfully for the local treatment of several cancers. Besides local destruction, a systemic antitumor response has been postulated after cryoablation of tumor tissue. In this study we evaluate the possible systemic antitumor response induced by cryodestruction of tumor tissue in two mouse tumor models.

METHODS

Mice received two subcutaneously placed tumor implants (thigh and flank) of the nonimmunogenic mouse colon tumor cell line, colon 26-B. After 7 days, the thigh implant was treated by cryoablation or excision and the effect on secondary tumor growth was determined by volume measurement of the nontreated flank tumor. Cytokine (IL-1alpha and TNF-alpha) levels in plasma were measured after treatment. Similar experiments were performed in nude mice using a human melanoma cell line (MV3). Moreover, in this model the effect of cryoablation on development of spontaneous lung metastases was evaluated.

RESULTS

In the colon 26-B tumor model treatment of primary tumor implants by cryoablation resulted in a significant inhibition of secondary tumor growth compared to animals treated by surgical excision (P < 0.01). Six hours after treatment, plasma levels of IL-1alpha and TNF-alpha were higher after cryoablation than after excision (P < 0.01). Also in the nude mice model cryoablation resulted in inhibition of secondary tumor growth, though not significant. Mice treated by cryoablation showed significantly less lung metastases compared to those treated by excision (P = 0.03).

CONCLUSIONS

Cryoablation of tumor tissue can result in inhibition of secondary and metastatic tumor growth. A cytokine response induced by cryoablation of tumor tissue may attribute to this feature.

Detection of breast cancer after biopsy for false-positive screening mammography. An increased risk?

INTRODUCTION

After false-positive screening for breast cancer, women are still at risk of developing breast cancer. In this study the incidence of breast cancer in a group of women who had a false-positive outcome is compared with the expected breast cancer incidence.

METHODS

Follow-up data of 188 women (mean age 58 years) with a false-positive screening result were collected and analysed for breast cancer development. The mean length of follow-up in the study was 7.4 years. The occurrence of breast cancer was compared to the expected incidence of breast cancer in an age-matched control population using figures from the local cancer registration.

RESULTS

The occurrence of breast cancer in the study population (n=7) was not significantly different from the expected incidence of breast cancer in the age-matched control group (n=5).

CONCLUSION

There is no relationship between false-positive findings during breast cancer screening and later development of breast cancer. Patients who do not have an increased risk of developing breast cancer (due to family history) should not be followed-up clinically, but should be returned to the screening programme.

[Summary of the guideline 'Sentinel node biopsy in breast cancer.' Dutch Work Group 'Sentinel Node Biopsy for Breast Cancer']

The team Sentinel Node Biopsy Breast Cancer issued guidelines for the performance of the sentinel node procedure. The team took into account the problems resulting from the introduction of the technique. The eligible group consists mainly of women with demonstrated breast cancer with a diameter of < or = 2 cm without palpable axillary nodes. Contraindications include presence of more than one tumour, pathological nodes in the ipsilateral axilla and previous treatment of breast or axilla. After injection of a radioactive substance, the sentinel node is detected during the operation using a gamma probe. The tracer is injected 2 to 24 hours before the operation in or near the tumour. Shortly before the incision, patent blue is injected as well, improving the detectability of the sentinel node. One or several sentinel nodes are examined histologically. The pathology report meets minimal requirements. In the planning and introduction of the technique in a hospital a locally responsible radiation expert should be involved. The procedure should be performed a number of times and evaluated with reference to a histopathological result before it is decided to draw clinical conclusions from the procedure. For the necessary evaluations of the procedure central registration is an absolute condition.

Quantitative measurement of telomerase reverse transcriptase (hTERT) mRNA in urothelial cell carcinomas

Telomerase reverse transcriptase (hTERT) messenger RNA has been detected in 95% of bladder tumors using RT-PCR. In this study, we quantified the expression of hTERT in 35 bladder urothelial cell carcinomas and in 6 normal bladder epithelia using a real-time quantitative PCR assay. hTERT expression was detected in all 35 urothelial cell carcinomas of varying grade and stage, but not in normal tissue samples. An increase in both pathological grade and clinical stage as prognostic parameters correlated with increased hTERT expression. Using different cutoff values for grades and stages, normalized hTERT expression values could discriminate among low, medium, and high grade tumors and between superficial and muscle-invasive tumors. We conclude that standardized real-time measurement of hTERT expression can be used for early tumor detection and may be used for determination of prognosis in urothelial cell carcinomas of the bladder.

Clinical value of bile for the detection of mutant K-ras from colorectal liver metastases

In 25% of patients diagnosed with colorectal cancer, hepatic metastases are not detected at presentation of the colorectal primary but develop during follow-up. Early detection of these metastases may improve the chance of cure by surgical resection. We hypothesised that in patients with occult hepatic metastases, tumour DNA might be detected in bile which could be collected during resection of the colorectal primary. To test this hypothesis, bile from the gall bladder was collected from 17 patients scheduled for resection of evident hepatic metastases (> 2 cm3) from a previously resected colorectal primary. Mutation analysis of the metastases identified five patients (34%) with a K-ras gene mutation in the tumour tissue. These cases were selected for bile analysis for mutant K-ras. Non-mutated DNA could be amplified from all the bile samples, but mutant K-ras could only be detected in bile from one patient. False negative results due to technical deficits could be ruled out by control experiments showing a high DNA isolation efficiency and high sensitivity of the mutation detection method. It is concluded that hepatic metastases, in contrast to pancreatic cancers, do not (regularly) shed mutated DNA into the bile. Hence, molecular screening of bile seems of only limited clinical value for the detection of occult liver metastases.

Real-time quantification of human telomerase reverse transcriptase mRNA in tumors and healthy tissues

BACKGROUND

Expression of the hTERT gene, which codes for the catalytic subunit of telomerase, is associated with malignancy. We recently developed a real-time reverse transcription-PCR assay, based on TaqMan technology, for accurate and reproducible determination of hTERT mRNA expression (Lab Investig 1999;79:911-2). This method may be of interest for molecular tumor diagnostics in tissues and corresponding body fluids, washings, or brushes.

METHODS

In this study, we measured hTERT expression in a subset of healthy tissues and tumors to select those tumor types with the best potential for quantification of hTERT in corresponding body fluids. To demonstrate the use of the method in body fluids, we quantified hTERT expression in voided urine of patients with bladder cancer and controls.

RESULTS

Real-time measurement of hTERT expression could discriminate between all healthy and malignant tissue samples from pancreas, lung, esophagus, and bladder, but not for colon tissues. Moreover, in five of nine (55%) urine samples, hTERT could be quantified.

CONCLUSIONS

The present study demonstrates that accurate quantitative measurement of hTERT expression has high potential for discrimination between healthy and tumor cells in tissues and urine and supports future measurements in pancreatic fluid, bronchoalveolar lavage fluid, esophageal brushings, and urine or bladder washings.

Screen-detected breast cancers have a lower mitotic activity index

We know that screening for breast cancer leads to detection of smaller tumours with less lymph node metastases. Could it be possible that the decrease in mortality after screening is not only caused by this earlier stage, but also by a different mitotic activity index (MAI) of the tumours that are detected by screening? Is MAI a prognostic factor for recurrence-free survival? A retrospective study was carried out of 387 patients with breast cancer, treated at the University Hospital Nijmegen between January 1992 and September 1997. Ninety patients had screen-detected breast cancer, 297 patients had breast cancers detected outside the screening programme. The MAI, other prognostic factors and recurrence-free survival were determined. In non-screen-detected tumours the MAI is twice as high as in screen-detected tumours, even after correction for age took place. The MAI correlated well with other tumour characteristics. The MAI in itself is a prognostic factor for recurrence-free survival. Favourable outcome in screen detected breast cancer is not entirely caused by detecting cancer in early stages: quantitative features such as the MAI indicate a less malignant character of screen detected breast cancer. The MAI is an independent prognostic factor for recurrence-free survival.

The use of X-ray for lymph node determination in the axillary dissection specimen

A new and simple method by X-ray is described for lymph node determination in the axillary specimen of breast cancer patients. X-rays were performed of the axillary specimens of 49 women with breast cancer. The number of lymph nodes visible on the X-rays were assessed by two radiologists (A and B). The number of nodes identified in the axillary specimens was reported by the pathologist independently. The method described shows a clear correlation between the mean numbers of nodes counted on the X-rays of the specimens (radiologist A 18.3, B 16.1 nodes) and the mean numbers of nodes recovered by the pathologist (18.4). No intra-observer variation was observed and only a small inter-observer variation (2.2 nodes). This method of X-ray determination of lymph nodes can be used in auditing the surgeon's accuracy in performing complete axillary dissection as well as in auditing the number of lymph nodes found by the pathologist.

Intraoperative lymphatic mapping and the sentinel node concept in colorectal carcinoma

BACKGROUND

Orderly progression of nodal metastases has been described for melanoma and breast cancer. The first draining lymph node, the sentinel node, is also the first to contain metastases and accurately predicts nodal status. The aim of this study was to assess the feasibility of lymphatic mapping and sentinel node biopsy in colorectal cancer.

METHODS

In 50 patients with colorectal cancer patent blue dye was injected around the tumour. After resection of the tumour the specimen was examined to identify blue-stained lymph nodes. Routine histopathological examination was performed on all nodes and the blue, haematoxylin and eosin-stained tumour-negative nodes were tested immunohistochemically.

RESULTS

Lymphatic mapping was possible in 35 of 50 patients (70 per cent). Pathological examination with haematoxylin and eosin staining showed lymph node metastases in 20 of 35 patients. In eight of these 20 patients the blue nodes showed tumour, while in 12 the blue nodes were not involved. This represents a false-negative rate of 60 per cent.

CONCLUSION

Lymphatic mapping using patent blue dye is feasible in colorectal cancer. The blue-stained nodes do not predict nodal status of the remaining lymph nodes in the resected specimen. The concept of lymphatic mapping and sentinel node identification is not valid for colorectal cancer.

[A role for cryosurgery in the treatment of non-resectable liver metastases of colorectal neoplasms]

Liver metastases occur in over 40% of patients with colorectal carcinomas. The best prospect of cure is achieved by resection of the metastases. However, only 10-15% of the patients with hepatic metastases are estimated to be candidates for resection. When curative resection cannot be performed the options for treatment are limited. Response rates to chemotherapy are around 40% and even then survival benefit is generally limited to a few months. Hepatic cryosurgery recently provided a new therapeutic approach for unresectable liver metastases. For cryosurgery tumour tissue is located by ultrasonography and then cooled by liquid nitrogen to a temperature of -196 degrees C, which results in necrosis of tumour tissue. In a limited number of series encouraging results of cryosurgery have been reported. One year and two year survival rates of respectively 70% and 50% were reported after cryosurgery for hepatic metastases. Disease free survival rate after 2 years varies from 20% to 28%. If recurrence of the disease occurred in the liver it was generally outside the areas treated by cryosurgery. Benefit in survival is only achieved when all tumour tissue is treated adequately. Hepatic cryosurgery is appropriate in those patients with unresectable metastatic disease in whom cryosurgery alone or in combination with resection is able to eradicate all metastatic disease in the liver.

[The sentinel node biopsy in patients with breast cancer: recommendations for the introduction of this procedure. Dutch Working Group Sentinel Node Biopsy in Breast Cancer]

Sentinel node biopsy may be useful in the staging of breast cancer. In experienced hands presence or absence of metastasis in the sentinel node accurately predicts the nodal status and in patients with a negative sentinel node biopsy axillary dissection may be avoided. The technique, however, shows a clear learning curve and hasty introduction may lead to an unacceptable rate of false negative biopsies. Moreover, the introduction of the technique in general practice should be well coordinated in order to prevent large differences between hospitals in the staging and treatment of breast cancer patients. On the initiative of NABON (Nationaal Borstkanker Overleg Nederland; 'national breast cancer consultation') and the Nederlandse Vereniging voor Chirurgische Oncologie (Netherlands Association for Surgical Oncology) a study group was formed to co-ordinate the introduction of the sentinel node biopsy in breast cancer patients in the Netherlands. Important topics are central registration of all procedures in order to evaluate its applicability and technical variations, the performance in each centre of at least 50 procedures together with axillary node dissection to evaluate the results before clinical application is considered, and nationwide co-ordination to find the best therapy for patients with positive sentinel nodes.

Detection of tumour DNA in serum of colorectal cancer patients

Circulating tumour DNA has previously been detected in serum and plasma of patients with lung cancer and head and neck cancer. These observations could potentially lead to new, specific and non-invasive tools for diagnosis, prognosis and follow-up in neoplastic disease, if found to be a more general phenomenon. To test if tumour DNA is also present in serum of patients with colorectal cancer, we selected 14 colorectal cancer patients with advanced disease. In seven patients, K-ras mutations were detected in the primary tumour, using mutant-specific primers for point mutations in codon 12 or 13 of the K-ras gene. All patients were analysed for mutant DNA in serum. Tumour-specific point mutations, corresponding to the K-ras mutations found in the primary tumour were detected in the serum of all patients but one. No mutant K-ras could be detected in the serum of seven patients without K-ras mutations in the primary tumour. These results may be useful in assessing tumour burden in patients with neoplastic disease. Moreover, consecutive testing of serum tumour DNA after surgery or chemotherapy may be used as a tumour marker for recurrent disease.

[Transanal resection of large sessile rectal polyps]

OBJECTIVE

To assess the safety and effectiveness of transanal resection of large rectal adenomas.

DESIGN

Retrospective.

SETTING

Department of Surgery, University Hospital Maastricht, the Netherlands.

METHOD

35 patients underwent transanal resection of large rectal polyps. These cases were analysed as to the accuracy of preoperative biopsies, complication rate, recurrence rate and value of endoscopic follow-up.

RESULTS

Preoperative biopsies proved to be unreliable: in 49% of the cases histology of the whole specimen matched with the result of the biopsy. Five patients showed adenocarcinoma in the definite specimen, they were treated successfully by low anterior resection or rectum extirpation following the transanal resection. Six patients developed complications. In 1 patient this resulted in a colostomy. The average follow-up was 45 months. Sixty per cent of the patients in whom an adenoma or a carcinoma in situ was removed developed a recurrent adenoma. Recurrent adenomas were all treated by endoscopic polypectomy.

CONCLUSION

Transanal resection of large rectal adenomas is a safe and effective method of treatment. However, the high recurrence requires frequent endoscopy.

Laparoscopic cholecystectomy: a new trend in the management of gallstone disease

The results of the first 100 consecutive patients who underwent laparoscopic cholecystectomy in our hospital are described. The procedure was completed in 93 cases, and 7 cases (7%) were converted to open cholecystectomy. Of these conversions six were elective because of extensive adhesions, and one conversion was enforced because of instrument failure. The mortality in the series was 0%, and the morbidity rate was 5%: two wound infections, one haematoma of the wound, one intraabdominal bleeding, and one patient with a retained stone. The median anaesthesia time was 150 min. Recovery after the operation was remarkably fast; the median hospital stay was 4 days, and 80% of the patients had left the hospital on day 5 after admission. Laparoscopic cholecystectomy seems a safe procedure with significant advantages to the patient, such as a short hospital stay, a rapid recovery, and a satisfactory cosmetic result.

Cellular proliferation at the site of organ allografts and the influence of immunosuppressive therapy

In this study we investigated cellular proliferation of T cells and macrophages at the site of rat cardiac allografts and determined the influence of immunosuppressive therapy on the proliferative characteristics of these cell types. A bromodeoxyuridine-labeling technique was used that allowed both the accurate detection of proliferative activity and the phenotypic characterization of cellular infiltrates within grafted tissues. In untreated recipients (BN----Lewis), T cytotoxic/suppressor cells as well as T helper cells showed proliferative activity at the site of the graft. The percentage of OX8-positive cells within the graft that showed proliferation ranged from 15% to 37%. The percentage of W3/25-positive cells within the graft that showed proliferation ranged from 25% to 30%. In contrast, macrophages hardly showed proliferative activity within the graft; only 1-4% of the macrophages stained positive for bromodeoxyuridine. From these observations it is concluded that the graft serves as a nonlymphoid tissue site, wherein lymphocytes can freely proliferate and expand. To study the influence of immunosuppressive therapy on cellular proliferation, the steroid budesonide, 120 micrograms/kg/day, was administered for 13 days (MST, 20 days). During effective immunosuppressive therapy, still a remarkable amount of infiltrating cells was present within the grafts. Moreover, immunosuppressive treatment did not primarily appear to affect the proliferative capacity of the individual cell types. OX8-positive cells as well as W3/25-positive cells clearly showed proliferative activity within the treated grafts. However, despite the presence of these proliferative cells, signs of graft destruction were absent during immunosuppressive therapy. This finding may shed new light on the effect of steroids at the site of the graft and their role in the prevention of tissue destruction.

Inhibitory effect of corticosteroids on the secretion of tumour necrosis factor (TNF) by monocytes is dependent on the stimulus inducing TNF synthesis

The cytokine tumour necrosis factor (TNF) is believed to be involved in the pathophysiology of several human disease states, both septic and non-septic. Different pathways of induction are involved in the generation ofTNF in these disease states. We therefore used four different stimulatory agents, lipopolysaccharide, phorbol myristate acetate, silica quartz, and anti-human IgG antibody to study the influence of the corticosteroids prednisolone and budesonide on the secretion of TNF by human monocytes. Both prednisolone and budesonide inhibited TNF secretion induced by these four stimulating agents in a different degree. Inhibition was strong when TNF secretion was induced by lipopolysaccharide or anti-human IgG antibody. A weaker inhibitory effect was observed when TNF secretion was induced by silica quartz. Only minimal inhibition of phorbol myristate acetate induced TNF secretion was observed. Furthermore, it is shown that inhibition is dependent on the dose of corticosteroid, but not or only minimally on the dose of stimulating agent, indicating that inhibition cannot be overcome by increasing the cell-activating stimulus. Finally, optimal inhibition of TNF secretion by corticosteroids is shown to be dependent on the presence of corticosteroids during the phase of cell stimulation.

The effect of steroids on the regulation of major histocompatibility complex-class II expression on nonlymphoid tissue

The induction of MHC-class II antigens on human nonlymphoid tissues plays an essential role during the inhibition and augmentation of the immune response. Steroids have long been shown to possess strong immunosuppressive properties and successful steroid treatment has been associated with the absence of MHC-class II antigens on grated tissues. In this study we more specifically investigated the effect of steroids on the regulation of MHC-class II expression on nonlymphoid tissue. First, the influence of prednisolone on the induction process of the MHC-class II antigens on nonlymphoid tissue was determined. For this purpose vascular endothelial cells, kidney epithelial cells, fibroblasts, and a human colon tumor cell line were incubated with rIFN-gamma or primary MLC supernatant in the absence or presence of different concentrations of prednisolone. It was demonstrated that the induction process of MHC-class II antigens on these cell types was not affected by the drug at the different concentrations tested (1, 10, and 100 micrograms/ml). Next, the effect of prednisolone on the production of MHC-class II inducing factors was investigated. The drug was added at initiation of culture to primary MLC and the MHC-class II-inducing capacity of the supernatants was determined on day 7. Prednisolone at concentrations of 0.5-100 micrograms/ml clearly inhibited the overall production of factors responsible for MHC-class II induction on nonimmunological cells. The drug inhibited the production of IFN-gamma as well as non-IFN-gamma MHC-class II-inducing mediators. At a concentration of 1 microgram/ml the production of IFN-gamma and non-IFN-gamma MHC-class II-inducing mediators was reduced by, respectively, 85 per cent and 75 per cent. At a concentration of 10 micrograms/ml the production of both IFN-gamma and non-IFN-gamma mediators was almost completely inhibited. It is concluded that steroids downregulate the expression of MHC-class II antigens on nonlymphoid tissue by the inhibition of the production of MHC-class II-inducing mediators. However, once these mediators are present, the induction process itself is not affected by the drug.

Sensitivity of graft rejection in rats to local immunosuppressive therapy

In this study we investigated whether allograft rejection is sensitive to local immunosuppressive therapy. In rats, cardiac transplantations (BN----Lewis) were performed with venous return on the portal vein of the recipient. For local treatment the topical steroid budesonide was infused with an osmotic minipump directly into the carotid artery of the transplant. Budesonide is rapidly cleared by the liver, and cardiac tissue binding of the drug is high. Hence, local budesonide administration, 120 micrograms/kg/day, resulted in high drug levels within the graft (29.6 ng/mg) and low systemic drug levels (0.34 ng/ml). Systemic drug levels were so low that systemic biological effects of the drug during local administration were not measurable. In contrast systemic drug delivery, via the jugular vein of recipient, resulted in similar drug levels within the graft (31.0 ng/mg), but with high systemic drug levels within the graft (31.0 ng/mg), but with high systemic drug levels (1.65 ng/ml) and important systemic side effects. Both local and systemic administration of budesonide, 120 micrograms/kg/day for 13 days, resulted in significant prolongation of graft survival; median graft survival time was respectively 19.5 days and 20.0 days, compared with 7 days in controls. These results demonstrate that allograft rejection can be treated locally without significant systemic immunosuppression.

Immunohistological observations in rat kidney allografts after local steroid administration

In this report we investigated local regulatory mechanisms in graft rejection and their response to local immunosuppressive therapy. For this purpose local immunosuppression was induced in rat kidney allografts by intrarenal infusion of prednisolone. Intrarenal drug delivery resulted in high drug levels within the graft and low systemic drug levels. Systemic drug levels were by themselves not sufficiently immunosuppressive to induce graft survival, and local prednisolone levels within the graft proved to be responsible for prolongation of graft survival. During intrarenal drug delivery, systemic responsiveness to the renal allograft proved normal, since intrarenally treated grafts were infiltrated by MHC class II-positive host cells and, except for a somewhat lower percentage of macrophages, cellular infiltration in intrarenal treated grafts was comparable to untreated grafts. However, T cells and macrophages present in intrarenally treated grafts were not able to destroy the grafted tissue. Local immunosuppressive therapy resulted in inhibition of IL-2-R expression, absence of IFN-gamma, and prevention of MHC class II induction on grafted tissue. These observations strongly indicate the presence of local regulatory mechanisms in graft rejection. The experimental model described can be used for further analysis of these intragraft events. Moreover, the results demonstrate that local immunosuppressive therapy can contribute to effective inhibition of cellular immune response in graft rejection.

2'Deoxycoformycin and deoxyadenosine affect IL 2 production and IL 2 receptor expression of human T cells

Congenital deficiency of the enzyme adenosine deaminase (ADA) leads to severe combined immunodeficiency. 2'Deoxycoformycin (dCF), a tightly binding inhibitor of ADA, can induce the metabolic state of ADA deficiency. In vivo, the drug causes specific impairment of lymphocyte function and shows strong immunosuppressive properties. However, to decide whether inhibition of the enzyme ADA offers an attractive approach for immunosuppressive therapy, more information is needed about the immunologic mechanisms affected. In human T cells, we investigated the effect of dCF and deoxyadenosine (AdR) on cell activation, interleukin 2 (IL 2) production, and IL 2 receptor induction after allogeneic and lectin-induced stimulation. After allogeneic stimulation, dCF and AdR affected several events in T cellular immune response. Early events in T cell activation showed to be most sensitive to the drugs. Primary MLC was completely inhibited by concentrations as low as 1 microM dCF and 1 microM AdR. The addition of human recombinant IL 2 (rIL 2) could not abrogate the inhibitory effect of the drugs. Apart from activation of T cells, the drugs interfered with proliferation of activated T cells. Two events in activated T cells were affected: IL 2 production and IL 2 receptor expression. In secondary MLC, IL 2 production was markedly reduced in the presence of 9 microM dCF and 60 microM AdR. These concentrations appeared also to affect IL 2 receptor expression in 12-day primary MLC cells stimulated with rIL 2. Lectin stimulation was also affected by the drugs. In phytohemagglutinin (PHA)-stimulated cultures, 9 microM dCF and 60 microM AdR resulted in inhibition of proliferation and IL 2 receptor expression, whereas IL 2 production was normal. It is concluded that dCF and AdR interfere with several events in T cellular immune response such as cell activation, IL 2 production, and IL 2 receptor expression. According to these results, inhibition of the enzyme ADA seems an attractive approach to immunosuppressive therapy.

2'Deoxycoformycin and deoxyadenosine affect IL 2 production and IL 2 receptor expression of human T cells

Congenital deficiency of the enzyme adenosine deaminase (ADA) leads to severe combined immunodeficiency. 2'Deoxycoformycin (dCF), a tightly binding inhibitor of ADA, can induce the metabolic state of ADA deficiency. In vivo, the drug causes specific impairment of lymphocyte function and shows strong immunosuppressive properties. However, to decide whether inhibition of the enzyme ADA offers an attractive approach for immunosuppressive therapy, more information is needed about the immunologic mechanisms affected. In human T cells, we investigated the effect of dCF and deoxyadenosine (AdR) on cell activation, interleukin 2 (IL 2) production, and IL 2 receptor induction after allogeneic and lectin-induced stimulation. After allogeneic stimulation, dCF and AdR affected several events in T cellular immune response. Early events in T cell activation showed to be most sensitive to the drugs. Primary MLC was completely inhibited by concentrations as low as 1 microM dCF and 1 microM AdR. The addition of human recombinant IL 2 (rIL 2) could not abrogate the inhibitory effect of the drugs. Apart from activation of T cells, the drugs interfered with proliferation of activated T cells. Two events in activated T cells were affected: IL 2 production and IL 2 receptor expression. In secondary MLC, IL 2 production was markedly reduced in the presence of 9 microM dCF and 60 microM AdR. These concentrations appeared also to affect IL 2 receptor expression in 12-day primary MLC cells stimulated with rIL 2. Lectin stimulation was also affected by the drugs. In phytohemagglutinin (PHA)-stimulated cultures, 9 microM dCF and 60 microM AdR resulted in inhibition of proliferation and IL 2 receptor expression, whereas IL 2 production was normal. It is concluded that dCF and AdR interfere with several events in T cellular immune response such as cell activation, IL 2 production, and IL 2 receptor expression. According to these results, inhibition of the enzyme ADA seems an attractive approach to immunosuppressive therapy.