Pheochromocytoma and the normal adrenal medulla: improved visualization with I-123 MIBG scintigraphy

The radiopharmaceutical iodine 131 metaiodobenzylguanidine (I-131 MIBG) has been shown to locate pheochromocytomas scintigraphically with a false-negative rate of approximately 13%. To improve image quality and reduce the false-negative rate, I-123 was examined as a radioactive label for MIBG, as it has many advantages over I-131, including superior dosimetry and better detection efficiency. Diagnostic doses of 0.5 mCi (18.5 MBq) I-131 MIBG and 10.0 mCi (370.0 MBq) I-123 MIBG with nearly equivalent radiation dosimetries were compared in 18 patients with known or suspected pheochromocytomas. Images of superior quality were obtained with I-123 MIBG in 18 of 18 patients, and in eight cases lesions not visualized on I-131 MIBG scintigraphy were portrayed. A further advantage of I-123 MIBG is that it permits single photon emission computed tomography (SPECT). This was performed in six cases and provided additional information in three cases. The adrenal medullae were definitely visualized using I-123 scintigraphy in eight of 14 patients still possessing adrenal glands, whereas I-131 MIBG images portrayed the adrenal medulla in only one of 14 cases. Five remaining patients had multiple abdominal tumor deposits that were difficult to differentiate from normal adrenal medullae.     

Application of image-guided surface coil P-31 MR spectroscopy to human liver, heart, and kidney

Localized phosphorus-31 magnetic resonance (MR) spectroscopy in humans has previously been accomplished with surface coils by means of depth-resolved surface coil spectroscopy or rotating frame experiments, in which the extent of tissue sampled critically depends on surface coil placement. The authors' goal was to modify the surface coil image-selected in vivo spectroscopy (ISIS) experiment to accomplish three-dimensional volume selection through application of selective pulses in the presence of B0 gradients. Advantages of ISIS include the ability to use proton images to define the volume of interest (VOI) and reduced dependence on exact positioning of the surface coil. However, rapid replication of the surface coil ISIS experiment can cause spectral contamination from signals originating outside the VOI. A modified version of the ISIS experiment was developed to alleviate contamination under conditions of rapid replication. Applications of localized P-31 MR spectroscopy for observation of high-energy phosphorus metabolites are presented in human liver, heart, and transplanted and normal kidney.     

Correlation of reversion-inducing cysteine-rich protein with kazal motifs (RECK) and extracellular matrix metalloproteinase inducer (EMMPRIN), with MMP-2, MMP-9, and survival in colorectal cancer

mRNA, and latent and active levels MMP-2 and -9 were higher in tumor tissue compared to normal tissue from 63 patients with colorectal cancer, whereas RECK and EMMPRIN levels were lower. Correlations between mRNA, latent, and active MMP were particular high for MMP-2 in tumor tissue (R(s)=0.6-0.8, P<0.001). For active MMP-2, but not for MMP-9, a significant negative partial correlation (R(p)=-0.440, P<0.001) for RECK was found in tumor tissue, which was confirmed by linear regression analysis. In exploratory survival analyses we found that in patients with localized disease the RECK level in normal or tumor tissue had a significant (P=0.017) association with overall survival.     

Hypoxia in relation to vasculature and proliferation in liver metastases in patients with colorectal cancer

PURPOSE: To investigate hypoxia measured by pimonidazole binding, glucose transporter 1 (GLUT1) and carbonic anhydrase IX (CA-IX) expression, proliferation, and vascularity in liver metastases of colorectal cancer and to compare GLUT1 and CA-IX expression in corresponding primary tumors. METHODS AND MATERIALS: Twenty-five patients with liver metastases of colorectal cancer, planned for metastasectomy, were included. The hypoxia marker pimonidazole and proliferation marker iododeoxyuridine were administered before surgery. After immunofluorescent staining of the frozen metastases, pimonidazole binding, vascularity, and proliferation were analyzed quantitatively. Thirteen paraffin-embedded primary tumors were stained immunohistochemically for GLUT1 and CA-IX expression, which was analyzed semiquantitatively in primary tumors and corresponding liver metastases. RESULTS: In liver metastases, pimonidazole binding showed a pattern consistent with diffusion-limited hypoxia. The mean pimonidazole-positive fraction was 0.146; the mean distance from vessels to pimonidazole-positive areas was 80 microm. When expressed, often co-localization was observed between pimonidazole binding and GLUT1 or CA-IX expression, but microregional areas of mismatch were also observed. No correlation between the level of pimonidazole binding and GLUT1 or CA-IX expression was observed. In some patients, a large fraction (up to 30%) of proliferating cells was present in pimonidazole-stained areas. Expression of CA-IX in primary tumors and metastases showed a significant correlation, which was absent for GLUT1 expression. CONCLUSIONS: Compared with other tumor types, liver metastases of colorectal cancer contain large amounts of hypoxic cells. The lack of correlation with pimonidazole binding brings into question the value of GLUT1 and CA-IX as endogenous markers of hypoxia.     

Outgrowth of human liver metastases after resection of the primary colorectal tumor: a shift in the balance between apoptosis and proliferation

Rapid outgrowth of metastases after removal of the primary tumor has been described in several mouse models. Loss of primary tumor-induced inhibition of angiogenesis in the metastases has been suggested as the underlying cause. Accordingly, we recently demonstrated that vascular density in human colorectal liver metastases increases after primary tumor resection. Here, we investigate whether this increase in vascular density has, in its turn, effects on the tumor growth of the liver metastases. We analyzed tumor growth in synchronous liver metastases from patients with the primary tumor in place, in synchronous metastases from patients with the primary tumor resected and in metachronous metastases. Tumor growth was studied by assessing the percentage of cells undergoing apoptosis by activated caspase-3 staining, and the percentage of proliferating cells by Ki-67 staining. While the percentage of proliferating cells within the metastases showed a modest increase after primary tumor resection, a significant decrease in the percentage of apoptotic cells was observed. Taken together, an increased net tumor growth of the metastases occurred after primary tumor resection. This acceleration of tumor growth could be confirmed by studying biopsies taken from the same patient before and after tumor resection. Our data show that in human cancer patients, a primary tumor may inhibit the growth of its liver metastases.     

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.     

Quality of life after surgical treatment of colorectal liver metastases

BACKGROUND: The surgical approach to colorectal liver metastases is becoming increasingly aggressive. The aim of this prospective study was to evaluate the impact of surgery on health-related quality of life (HRQoL) of patients with colorectal liver metastases. METHODS: HRQoL data from 97 patients with colorectal liver metastases were analysed. Sixty patients (group 1) had surgical treatment of the liver metastases. Seventeen patients (group 2) were shown to have inoperable disease at laparotomy. Twenty outpatients with inoperable disease were included as a control group (group 3). Two validated HRQoL instruments, the European Organization for Research and Treatment of Cancer Core questionnaire (QLQ C-30) and the EuroQol-5D, were applied. RESULTS: By 2 weeks after operation patients in group 1 showed a clear overall deterioration in HRQoL, but after 3 months most HRQoL scores had returned to baseline levels. At 2 weeks after surgery there was clear deterioration in almost all HRQoL domains in group 2, and several symptoms were still being reported at 3 months. Patients in group 3 showed hardly any deterioration in HRQoL over the 3 months. CONCLUSION: The fast recovery of HRQoL, generally within 3 months, justifies an aggressive surgical approach to colorectal liver metastases. However, careful preoperative evaluation is crucial to avoid needless laparotomy, considering the ongoing deteriorated HRQoL of group 2.