fur gene expression as a discriminating marker for small cell and nonsmall cell lung carcinomas.

The recently discovered fur gene encodes a membrane-associated protein with a recognition function. To further characterize the gene, we studied its expression by Northern blot analysis using poly(A)-selected RNA from a variety of organs of African green monkey and rat. The fur gene appeared to be differentially expressed, relatively high levels of fur mRNA being present in specimens of liver and kidney, low levels in brain, spleen, and thymus, and very low levels in heart muscle, lung, and testis. mRNA levels in specimens of human lung tissue without neoplastic lesions were also very low. Similar analyses of primary human lung carcinomas of different histopathological types revealed a highly selective and strong elevation of fur expression in nonsmall cell lung carcinomas, but not in small cell lung carcinomas. These results indicate that fur expression can be used to discriminate between these two types of human lung cancer.

Precision surgery and genitourinary cancers.

The landscape of the surgical management of urologic malignancies has dramatically changed over the past 20 years. On one side, better diagnostic and prognostic tools allowed better patient selection and more reliable surgical planning. On the other hand, the implementation of minimally invasive techniques and technologies, such as robot-assisted laparoscopy surgery and image-guided surgery, allowed minimizing surgical morbidity. Ultimately, these advances have translated into a more tailored approach to the management of urologic cancer patients. Following the paradigm of "precision medicine", contemporary urologic surgery has entered a technology-driven era of "precision surgery", which entails a range of surgical procedures tailored to combine maximal treatment efficacy with minimal impact on patient function and health related quality of life. Aim of this non-systematic review is to provide a critical analysis of the most recent advances in the field of surgical uro-oncology, and to define the current and future role of "precision surgery" in the management of genitourinary cancers.

Decreased E-cadherin immunoreactivity correlates with poor survival in patients with bladder tumors.

E-cadherin, an intercellular adhesion molecule, has been shown to behave like an invasion suppressor gene in vitro. This may explain the inverse relation between expression of E-cadherin and tumor grade that was found in certain cancers. We therefore examined E-cadherin expression in bladder cancer samples from patients with known clinical follow-up. Forty-nine snap-frozen specimens (24 superficial and 25 invasive tumors) and 4 samples of normal urothelium were retrospectively analyzed with anti-E-cadherin monoclonal antibodies. In normal urothelium E-cadherin is expressed homogeneously with a typical membranous staining at cell-cell borders. Decreased expression is found in 5 of 24 superficial tumors and in 19 of 25 invasive cancers. Completely negative tumors are infrequent (4 cases). Most of the time a heterogeneous staining, which may correspond to an unstable E-cadherin expression during tumor development, is seen. Decreased E-cadherin expression correlates with both increased grade and stage (chi 2 = 9.5, P < 0.01, and chi 2 = 14.9, P < 0.005, respectively). More importantly, abnormal E-cadherin expression correlates with shorter survival (log rank test: chi 2 = 16.5, P < 0.001). In keeping with its in vitro invasion suppressor function, decreased E-cadherin expression correlates with the clinical aggressiveness of bladder tumors. This is the first report of E-cadherin as a marker with prognostic value. This parameter must now be tested in a large prospective study to assess its precise clinical relevance.

Identification of high mobility group protein I(Y) as potential progression marker for prostate cancer by differential hybridization analysis.

One of the major problems in the diagnosis of localized prostatic tumors is to predict the aggressiveness of an individual tumor, which is presumably associated with chance to progression. In an attempt to find molecular markers that are specific for aggressive prostatic cancer cells, we compared steady-state mRNA levels of progressionally related prostatic tumors. The Dunning R-3327-H subline, a relatively benign rat prostatic tumor, was compared to the therefrom derived highly aggressive MatLyLu tumor by differential hybridization analysis. The differential screening revealed 26 complementary DNA clones that detected transcripts overexpressed in MatLyLu. Upon further screening on the entire panel of Dunning R-3327 sublines, it appeared that three clones (pBUS1, pBUS19, and pBUS30), detected transcripts specifically expressed in metastatic rat prostatic tumors. The expression pattern of pBUS19 and pBUS30 suggested a relation between these complementary DNAs. Nucleotide sequence analysis, however, could not yet substantiate this. Computer-assisted comparison of the DNA sequences revealed the presence of rat long terminal repeat-like repetitive elements in pBUS19. The differential expression of repetitive elements in progressionally related tumors is interesting, yet similar findings have not been reported in human malignancies. Nucleotide sequence analysis of pBUS1 indicated that this clone is identical or related to high mobility group protein I(Y), a non-histone nuclear protein. From recent studies it appeared that this protein might be implicated in replication and/or transcription processes and is induced in fast proliferating/undifferentiated cells. The overexpression of high mobility group protein I(Y) correlates rather with metastatic ability than with growth rate; hence it may serve as a valuable marker to identify progressionally advanced prostate cancer cells.

Increased expression of high mobility group protein I(Y) in high grade prostatic cancer determined by in situ hybridization.

In a previous study using the Dunning rat prostate cancer model, we found high mobility group protein I-(Y) [HMG-I(Y)] to be overexpressed in metastatic tumor lines when compared to nonmetastatic lines. Hence, overexpression of this 12-kDa non-histone chromosomal protein may be associated with tumor progression. Firstly, by Northern analysis we showed that HMG-I(Y) expression increases in high grade prostate tumors. These studies, however, required fresh material, and clinical follow-up was limited. To overcome this problem paraffin-embedded material must be made amenable for determination of HMG-I(Y) expression in retrospective studies. RNA in situ hybridization enables the evaluation of mRNA levels in such material. We studied tumors from 71 patients with prostate cancer. The microscopic analysis of each sample included: (a) hybridization on sections with sense HMG-I(Y) and (b) 28S rRNA probes (nonspecific signal); (c) hybridization with antisense 28S rRNA (RNA preservation); (d) hybridization with an antisense HMG-I(Y) probe [quantification of HMG-I(Y) mRNA in the expressing areas]. Data were quantified using an image analysis system. High expression of HMG-I(Y) was observed in regions with high Gleason grade (4 and 5); whereas in lesions of Gleason grade 3, both weak and no expression was observed. In areas of grade 1 and 2, as well as in normal glands, low or no expression was found. We conclude that HMG-I(Y) expression assessed by RNA in situ hybridization is related to tumor differentiation in prostate cancer. These findings indicate that HMG-I(Y) expression may be a marker in prostate cancer diagnosis, and the possible clinical implication of expression of this gene in malignancy is discussed in this report.

Synergistic antitumor effects of rat gamma-interferon and human tumor necrosis factor alpha against androgen-dependent and -independent rat prostatic tumors.

We have examined the antitumor effects of rat gamma-interferon (IFN-gamma) and human tumor necrosis factor alpha (TNF) against androgen-dependent and -independent Dunning rat prostatic tumors. In vitro studies, using the double layer soft agar assay, showed a very limited antiproliferative activity of the drugs in the dose range tested (1-1000 units IFN-gamma and/or 1-1000 ng TNF/dish). For in vivo studies IFN-gamma and TNF were administered s.c., peritumorally. IFN-gamma was given 3 times/week, 8,000 or 80,000 units/rat, and TNF 5 times/week, 10 or 100 micrograms/rat. IFN-gamma and TNF monotherapy were not significantly effective in inhibiting tumor growth, except for IFN-gamma against the androgen-independent MatLyLu tumor. Combinations of IFN-gamma and TNF had synergistic antiproliferative effects against all four tumor lines tested; however, complete growth inhibitions could not be achieved. Survival studies showed significant increase in survival of tumor-bearing rats.

Decreased expression of E-cadherin in the progression of rat prostatic cancer.

Cadherins represent a family of Ca(2+)-dependent cell adhesion molecules involved in homotypic, homophilic cell-cell interactions. Recent studies have shown that the cadherins can play a role in invasive and metastatic behavior. Using the established Dunning R-3327 model system of serially transplantable rat prostate cancers, the expression of E- and P-cadherin in rat prostatic cancer was studied. Analysis within this system demonstrated that whereas E-cadherin was expressed in the normal rat prostate and the well- or moderately differentiated, noninvasive Dunning tumors, no expression, either at the mRNA or at the protein level, could be detected in the invasive sublines. Since not all invasive Dunning tumors studied have metastatic ability, these results suggest that a decreased expression of E-cadherin is correlated with invasive behavior rather than with metastatic ability. Recently, genetic instability occurred in an animal bearing the well differentiated, androgen-responsive, slow growing, nonmetastatic Dunning R-3327-H rat prostate cancer resulting in the progression to an anaplastic, androgen-independent, fast growing, highly metastatic state. This spontaneously arising tumor, termed the AT6 subline, in its original host was heterogeneously composed of both a well differentiated and an anaplastic population of cancer cells in which areas of squamous cell differentiation were occasionally observed. The original animal bearing this heterogeneous AT6 cancer developed multiple metastases, the lung metastases being heterogeneously composed of anaplastic and squamous cell populations. Cytogenetic analysis demonstrated that the lung metastases were derived from a specific subpopulation of cancer cells present in the original AT6 primary tumor. Immunohistochemical studies demonstrated that only the area of lung metastases displaying squamous morphology were positive for E-cadherin. In contrast, the anaplastic areas of the lung metastases and the metastases in other organs were E-cadherin negative. By the first passage of the AT6 tumor only the anaplastic cells were present and no detectable E-cadherin mRNA or protein was found in the primary tumor and metastatic deposits. These results suggest that a decreased expression of E-cadherin is associated with the progression of prostatic cancer.

Expression of the cellular adhesion molecule E-cadherin is reduced or absent in high-grade prostate cancer.

E-cadherin is a Ca(2+)-dependent cell adhesion molecule which plays an important role in normal growth and development via mediation of homotypic, homophilic cell-cell interaction. Recent studies suggest that E-cadherin may be important in neoplastic progression as well, particularly as a suppressor of invasion. We have previously demonstrated that the invasive phenotype of rat prostate cancer cells is associated with the decreased expression of E-cadherin (M. J. G. Bussemakers, R. J. A. Van Moorselaar, L. A. Giroldi, T. Ichikawa, J. T. Isaacs, F. M. J. Debruyne, and J. A. Schalken, Cancer Res., 52:2916-2922, 1992). This is of particular interest, since the locus to which the human E-cadherin gene is mapped is frequently involved in allelic loss in prostate cancer (B. S. Carter, C. M. Ewing, W. S. Ward, B. F. Treiger, T. W. Aalders, J. A. Schalken, J. I. Epstein, and W. B. Isaacs, Proc. Natl. Acad. Sci. USA, 87:8751-8755, 1990; U. S. Bergerheim, K. Kunimi, V. P. Collins, and P. Ekman, Genes, Chromosomes Cancer, 3: 215-220, 1991). Impaired E-cadherin function is likely to be associated with aberrant expression of the protein. We therefore analyzed E-cadherin expression in situ by immunohistochemistry in nonmalignant and malignant specimens of human prostatic tissue. Of 92 tumor samples of either primary or metastatic deposits of prostate cancer, 46 had reduced or absent E-cadherin staining when compared to nomalignant prostate, which uniformly stained strongly positive. There was a statistically significant correlation between the decreased expression of E-cadherin and loss of tumor differentiation. Additionally, certain tumors within a histologically similar group could be distinguished by the presence of mixed populations of E-cadherin-negative and -positive cells. The percentage of tumors with aberrant E-cadherin staining increased when clinically localized tumors were compared to either tumors with extensive local progression or metastatic deposits of prostate cancer, suggesting a correlation between loss of E-cadherin and tumor progression. Taken together, these findings suggest that further exploration of E-cadherin as a candidate invasion suppressor molecule in human prostate cancer is warranted.

Colocalization of basal and luminal cell-type cytokeratins in human prostate cancer.

In the epithelium of secretory acini of the prostate two different cell types can be discriminated on the basis of localization, morphology, and degree of differentiation, the luminal and basal cells. The possibility of a developmental relationship between basal and luminal cells has been a subject of interest in several studies. According to the stem cell model at least three cell types, i.e., stem, amplifying, and transit cells, can be discriminated in the epithelium of prostate secretory acini. We previously reported that in the process of degeneration and regeneration in normal rat prostate a population of cells could be identified as candidates for the amplifying cells. These cells showed a keratin expression profile intermediate between those of basal and luminal cells. We now show, by using keratin antibodies, that also in normal human prostate at least three subpopulations of cells can be identified, one of them putatively representing amplifying cells as defined in the stem cell model. Furthermore, these antibodies were used to obtain a better insight into the different cell types involved in the etiology and progression of prostatic carcinoma. Both primary and hormone-independent prostatic tumors were investigated. Our results indicated that the candidate stem cell population was absent in prostatic carcinoma. Unlike earlier reports on the unique presence of cells with luminal characteristics in prostatic carcinoma, we identified also a population of cells coexpressing basal and luminal cell-type cytokeratins in primary and hormone-independent prostatic carcinoma. Since amplifying cells are defined in the stem cell model as precursors of transit (luminal) cells in the hierarchical pathway of prostatic epithelium differentiation, we postulate that on the basis of the keratin expression profile this subpopulation is most likely the target for neoplastic transformation.

Prognostic value of cadherin-associated molecules (alpha-, beta-, and gamma-catenins and p120cas) in bladder tumors.

Loss of E-cadherin-mediated adhesion is an important step in the progression of many carcinomas. In model systems, it has been shown that cadherin function requires not only proper E-cadherin expression but also its linkage to the cytoskeleton through catenins. Hence, defects in catenins may cause defective E-cadherin function, and catenins as well as E-cadherin might constitute prognostic indicators. Here, we extend our previous study on E-cadherin in bladder cancer (Cancer Res., 53: 3241-3245, 1993). We have evaluated the expression of E-cadherin-associated cytoplasmic molecules (alpha-, beta-, and gamma-catenins and p120cas) to clarify whether or not the pattern of their expression could provide additional prognostic information beyond that from E-cadherin alone. Forty-eight frozen bladder tumor specimens and 9 samples of normal urothelium were studied by immunohistochemistry. A discrepancy between the E-cadherin and catenin expression pattern was seen in 20.8% of cases. Abnormal expression of each molecule is significantly correlated with tumor grade (P < 0.01) and stage (P < 0.01). Reduced expression of all of the molecules correlates with poor survival (P < 0.01 for each variable). Proportional hazard regression analysis showed that beta-catenin, E-cadherin, and alpha-catenin have strong predictive value, whereas plakoglobin and p120cas have a somewhat lower predictive value. Within patients with invasive tumors, those with a normal staining for either E-cadherin, alpha-catenin, or beta-catenin show a trend toward better survival. However, the difference in survival is significant only for E-cadherin (P < 0.05). Thus, beta-catenin, E-cadherin, and alpha-catenin have similar prognostic values. Therefore, from a practical point of view, the expression of any of these proteins can be of prognostic value for patients with bladder cancer.

Decreased E-cadherin expression is associated with poor prognosis in patients with prostate cancer.

Decreased levels of the cell-cell adhesion molecule E-cadherin are associated with loss of differentiation in a number of human carcinomas. However, the value of E-cadherin as a prognostic marker in these cancers is largely undetermined. A previous study of E-cadherin levels in prostate cancer revealed that almost 50% of tumors examined had reduced or absent levels of this protein (Umbas et al., Cancer Res., 52: 5104-5109, 1992). To determine the potential prognostic significance of this finding, prostate cancer specimens from 89 patients were evaluated immunohistochemically for E-cadherin expression, and the results were related to histopathological grade, tumor stage, presence of metastases, and survival. As previously observed, a significant inverse correlation was found between E-cadherin expression and tumor grade. Importantly, we also found significant correlations between E-cadherin expression and tumor stage and overall survival. Sixty-three percent of the tumors that extended beyond the prostate capsule (T3-4) versus 33% of the tumors confined to the prostate (T1-2) had aberrant expression (chi 2 = 8.1, P < 0.005). Seventy-six percent of the primary tumors from patients that presented with metastases showed aberrant staining compared to 32% from patients without metastases (chi 2 = 14.9; P < 0.001). The life table analysis showed a significantly higher survival rate for patients with normal staining compared to patients with aberrant expression (chi 2 = 20.4, P < 0.001 by log rank test). Moreover, abnormal expression of E-cadherin correlated significantly with progression after radical prostatectomy (P < 0.005). These results suggest that E-cadherin expression can serve as a prognostic indicator for the biological potential of prostate cancer.

DD3: a new prostate-specific gene, highly overexpressed in prostate cancer.

Prostate cancer is the most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in the Western male population. Despite the tremendous efforts that have been made to improve the early detection of this disease and to design new treatment modalities, there is still an urgent need for new markers and therapeutic targets for the management of prostate cancer patients. Using differential display analysis to compare the mRNA expression patterns of normal versus tumor tissue of the human prostate, we identified a cDNA, DD3, which is highly overexpressed in 53 of 56 prostatic tumors in comparison to nonneoplastic prostatic tissue of the same patients. Reverse transcription-PCR analysis using DD3-specific primers indicated that the expression of DD3 is very prostate specific because no product could be amplified in 18 different normal human tissues studied. Also, in a sampling of other tumor types and a large number of cell lines, no expression of DD3 could be detected. Molecular characterization of the DD3 transcription unit revealed that alternative splicing and alternative polyadenylation occur. The fact that no extensive open reading frame could be found suggests that DD3 may function as a noncoding RNA. The DD3 gene was mapped to chromosome 9q21-22, and no homology of DD3 to any gene present in the computer databases was found. Our data indicate that DD3 is one of the most prostate cancer-specific genes yet described, and this makes DD3 a promising marker for the early diagnosis of prostate cancer and provides a powerful tool for the development of new treatment strategies for prostate cancer patients.

Intratumoral distribution of two consecutive injections of chimeric antibody G250 in primary renal cell carcinoma: implications for fractionated dose radioimmunotherapy.

Tumor uptake of the chimeric G250 (cG250) monoclonal antibody (mAb) in patients with primary renal cell carcinoma (RCC) is among the highest reported in solid tumors. However, as observed in other tumor types, the intratumoral distribution of the antibody is highly heterogeneous, which may limit the efficacy of radioimmunotherapy. A number of highly dynamic physiological factors have been postulated that may contribute to heterogeneous tumor uptake of antibodies. Their impact on tumor uptake of antibodies may vary from one tumor region to another as well as from one day to the next. Here, we report on a clinical study that was designed to investigate whether the pattern of mAb cG250 uptake within RCC tumors is altered with subsequent injections. Ten patients with a clinical diagnosis of primary RCC were studied. Nine days before surgery, patients received 125I-cG250 (5 mg of cG250, 50 microCi of 125I), followed by a second injection of 131I-cG250 (5 mg of cG250, 3.5 mCi of 131I) 4 days later. Postsurgery, the tumor was cut into (1-cm) thick slices. Slices were imaged on a gamma camera, and the slice with the most pronounced heterogeneity in 131I-cG250 distribution was selected and cut into 1-cm3 cubes. Each cube was analyzed for 121I-cG250 and 131I-cG250 uptake, and the 131I/125I ratio was determined. For each tumor slice, the distribution patterns of both isotopes were reconstructed and compared with each other. All tumors analyzed showed a heterogeneous distribution of both isotopes throughout the tumor slice; focal uptake in some areas of a tumor reached very high levels (up to 0.19% injected dose/g), whereas other tumorous areas of the same slice showed much lower uptake (as low as 0.0047% injected dose/g). Remarkably, in all tumors, the distribution pattern of both injections was identical: without exception, in all samples analyzed (n = 692), the uptake of 125I-cG250 was similar to 131I-cG250 uptake. Overall, the 131I/125I ratio was 1.64+/-0.31 (mean+/-SD). The constant 131I/125I ratios, observed in all tumor samples investigated, indicate that the tumor parameters governing cG250 mAb uptake were not altered significantly within the time period studied. In addition, the results of this study suggest that multiple radiolabeled antibody injections, administered within short time periods, will target the same areas within a tumor and, thus, will not solve the problem of heterogeneous tumor uptake of antibody.

Differential expression of ferritin heavy chain in a rat transitional cell carcinoma progression model.

To identify molecular markers with predictive value for the progression of superficial bladder cancer we used the differential hybridization analysis approach. Since primary tumor material is heterogeneously composed of subpopulations that are poorly characterized, we used in this study a rat progression model system that phenotypically and cytogenetically resembles human superficial bladder cancer. In the differential hybridization analysis we compared the mRNA populations of low and high metastatic tumor lines. We observed an overexpression of ferritin Heavy chain (ferritin H) in the tumor line with the lower metastatic capacity and better differentiated phenotype. The exact clinical relevance for the differential expression of ferritin H in human bladder cancer remains to be determined.

Targeting of renal cell carcinoma with iodine-131-labeled chimeric monoclonal antibody G250.

PURPOSE: Pharmacokinetics, biodistribution, immunogenicity, and imaging characteristics of iodine 131 (131I)-labeled chimeric monoclonal antibody (mAb) G250 (cG250) were studied in patients with renal cell carcinoma (RCC) to determine the therapeutic potential of this antibody. PATIENTS AND METHODS: Sixteen patients with RCC received a single intravenous (IV) infusion of 6 mCi 131I-labeled cG250. Five protein dose levels were investigated (2 to 50 mg). Planar scintigraphic images were acquired, and normal tissue biopsies and tumor samples were obtained of surgery (7 days postinjection). The immunogenicity of cG250 was investigated using a sandwich enzyme-linked immunosorbent assay (ELISA) and dosimetric analysis was performed. RESULTS: In all patients with antigen-positive tumors (n = 13), the primary tumors and all known metastases were clearly visualized. Overall uptake, expressed as the percentage of the injected dose (%ID), in the primary tumors ranged from 2.4 to 9.0. Focally, 131I-cG250 uptake as high as 0.52% ID/g was observed. However, intratumoral uptake was highly heterogeneous. 131I-cG250 uptake in nontumorous tissues remained low. Dosimetric analysis showed that up to .48 Gy/mCi was guided to the primary tumors. Selected "hot areas" within these tumors received up to .72 Gy/mCi. A bone metastasis received .23 Gy/mCi and regional lymph node metastases received .20 Gy/mCi. Minimal human antichimeric antibody (HACA) levels were detected in two of 16 patients. CONCLUSION: 131I-cG250 tumor uptake is among the highest reported in clinical studies with antitumor antibodies in solid tumors. Since tumor-sterilizing levels may be guided to the tumor when high doses 131I-cG250 are administered (> 100 mCi) and cG250 appears to be immunosilent, cG250 is a promising vehicle for radioimmunotherapy in RCC.

Expression of cadherin-6 as a novel diagnostic tool to predict prognosis of patients with E-cadherin-absent renal cell carcinoma.

In many carcinomas, E-cadherin is considered to be a prognostic marker for patient survivals, and its decreased expression is associated with metastatic disease. Among renal cell carcinomas (RCCs), however, only 20% of tumors express E-cadherin, whereas a much higher percentage express other cadherins, e.g., N-cadherin and cadherin-6 (T. Shimazui et al, Cancer Res., 56: 3234-3237, 1996). Among these cadherins expressed in RCCs, cadherin-6 has been identified as a major cadherin in the renal proximal tubules and in the tumors themselves. Hence, we have investigated the relationship between prognosis and cadherin-6 expression in tumor cells in 43 patients with RCC. Expression of cadherin-6, E-cadherin, and alpha-catenin was detected immunohistochemically and evaluated microscopically as normal, heterogeneous, or absent. Normal, heterogeneous, and absent expression of cadherin-6 were observed in 19, 16, and 8 of 43 cases, respectively. Coexpression of E-cadherin and cadherin-6 was detected in only 10 cases. Among 30 tumors in which E-cadherin expression was absent, 24 expressed cadherin-6. In addition, the expression pattern of alpha-catenin correlated more highly with that of cadherin-6 than it did with E-cadherin (P = 0.0003 versus 0.025). In survival analyses, aberrant expression of cadherin-6 correlated with poor survivals both among all patients (P = 0.0009) and in those with E-cadherin-absent RCC (P = 0.0008). These results suggest that cadherin-6 is a major cadherin playing an essential role in cell-cell adhesion in E-cadherin-absent RCC.

Predictive value of p53 mutations analyzed in bladder washings for progression of high-risk superficial bladder cancer.

To assess the value of p53 mutations in predicting the progression of superficial bladder cancer [transitional cell carcinoma (TCC)] and to define exactly when p53 mutations occur in the process of tumor progression, 80 consecutive bladder washings from 26 high-risk (indicated by quantitative karyometric analysis) superficial TCC patients were examined by single-strand conformation polymorphism. Six of 13 patients who experienced clinical progression (progression to T2 or higher) were found to have a p53 mutation in one or more of their bladder washings. In the control group (no progression to invasive disease), only 1 of 13 patients had a p53 mutation. For these high-risk superficial TCC patients, the occurrence of a p53 mutation has a positive predictive value of 86% for the progression of disease. A negative predictive value of 63% was observed. Moreover, because p53 mutations were found in samples prior to progression (mean, 8 months), they could identify patients who need changes in their treatment strategies to prevent progression to invasive disease. Despite these promising results, it is obvious that to increase not only the positive predictive value but especially the negative predictive value of this procedure to predict progression, additional prognostic markers are still needed.

Phase I radioimmunotherapy of metastatic renal cell carcinoma with 131I-labeled chimeric monoclonal antibody G250.

Clinical tumor targeting studies with chimeric monoclonal antibody G250 (cG250) in renal cell carcinoma (RCC) patients indicated the potential use of this antibody for radioimmunotherapy. Here we report on a phase I activity dose escalation study to determine the safety, the maximum tolerable dose (MTD), and the possible therapeutic potential of 131I-labeled cG250 in patients with progressive metastatic RCC. All patients (n = 12) received a diagnostic i.v. infusion of 5 mg of cG250 labeled with 222 MBq of 131I. If accumulation of the antibody in metastatic lesions was observed, patients were hospitalized and a second, therapeutic, i.v. infusion of 5 mg of cG250 labeled with a high dose of 131I was administered (n = 8). Three patients per dose level were entered, starting at 1665 MBq/m2. If no dose-limiting toxicity occurred, the study continued at the next dose level (555 MBq/m2 increase). Most patients experienced mild nausea without vomiting. No other complaints were reported during hospitalization. In two of two patients who received a dose of 2775 MBq/m2, grade IV hematological toxicity was observed, which was defined as dose limiting. Thus, the MTD was set at 2220 MBq/m2. In one patient (2220 MBq/m2), stable disease (lasting 3-6 months) was achieved, whereas another patient (2220 MBq/m2) showed a partial response that is ongoing (>9 months). The minor responses observed in this phase I trial in patients with an advanced stage of RCC are encouraging and warrant further study in a phase II setting at the MTD to determine the efficacy of radioimmunotherapy for metastatic RCC.

Recurrent pancreatitis after trimethoprim-sulfamethoxazole rechallenge.

We report a female patient who repeatedly developed pancreatitis after trimethoprim-sulfamethoxazole (TMP/SMX) use. During childhood she had undergone an ureterosigmoidostomy after which she had been on TMP/SMX 480 mg daily as prophylaxis for pyelonephritis for many years. The patient presented with abdominal pain caused by acute pancreatitis. No other cause, except for TMP/SMX use, could be identified. A causal relationship was confirmed by relapse of the pancreatitis after rechallenge. Our case is unique in demonstrating that acute pancreatitis related to the use of TMP/SMX may occur even after long-term treatment. We advise that the medication is discontinued immediately if a causal relationship with pancreatitis is suspected.

Dysplasia in normal-looking urothelium increases the risk of tumour progression in primary superficial bladder cancer.

Random urothelium biopsies were taken at initial endoscopic surgery from 1001 patients with primary superficial bladder cancer. The clinical course of all the patients was assessed prospectively. Actuarial risks of recurrence and disease progression were determined for prognostic characteristics and comparisons were made using log-rank tests. The independent prognostic significance of concomitant intra-aurothelial dysplastic changes was examined with Cox's regression analyses. The 3-year risk of recurrence in patients with dysplasia and carcinoma in situ (CIS) in macroscopically normal-looking urothelium was only slightly higher than the risk in patients without dysplastic changes (56, 58 and 51%, respectively; P = 0.25). Concomitant dysplasia or CIS significantly increased the 3-year risk of disease progression (17 and 31%, respectively, versus 7%; P < 0.001). After adjustment for the effects of age, tumour stage, grade, size and multicentricity, the result of random biopsies had no prognostic significance regarding the risk of recurrence, but the detection of dysplasia or CIS increased the risk of progression by approximately 80%. This result suggests that random urothelium biopsies may be useful as an additional guide in defining therapy in primary superficial bladder cancer.