Tumor heterogeneity of fibroblast growth factor receptor 3 (FGFR3) mutations in invasive bladder cancer: implications for perioperative anti-FGFR3 treatment.

BACKGROUND: Fibroblast growth factor receptor 3 (FGFR3) is an actionable target in bladder cancer. Preclinical studies show that anti-FGFR3 treatment slows down tumor growth, suggesting that this tyrosine kinase receptor is a candidate for personalized bladder cancer treatment, particularly in patients with mutated FGFR3. We addressed tumor heterogeneity in a large multicenter, multi-laboratory study, as this may have significant impact on therapeutic response. PATIENTS AND METHODS: We evaluated possible FGFR3 heterogeneity by the PCR-SNaPshot method in the superficial and deep compartments of tumors obtained by transurethral resection (TUR, n = 61) and in radical cystectomy (RC, n = 614) specimens and corresponding cancer-positive lymph nodes (LN+, n = 201). RESULTS: We found FGFR3 mutations in 13/34 (38%) T1 and 8/27 (30%) ≥T2-TUR samples, with 100% concordance between superficial and deeper parts in T1-TUR samples. Of eight FGFR3 mutant ≥T2-TUR samples, only 4 (50%) displayed the mutation in the deeper part. We found 67/614 (11%) FGFR3 mutations in RC specimens. FGFR3 mutation was associated with pN0 (P < 0.001) at RC. In 10/201 (5%) LN+, an FGFR3 mutation was found, all concordant with the corresponding RC specimen. In the remaining 191 cases, RC and LN+ were both wild type. CONCLUSIONS: FGFR3 mutation status seems promising to guide decision-making on adjuvant anti-FGFR3 therapy as it appeared homogeneous in RC and LN+. Based on the results of TUR, the deep part of the tumor needs to be assessed if neoadjuvant anti-FGFR3 treatment is considered. We conclude that studies on the heterogeneity of actionable molecular targets should precede clinical trials with these drugs in the perioperative setting.

Expression of NRG1 and its receptors in human bladder cancer.

BACKGROUND: Therapies targeting ERBB2 have shown success in the clinic. However, response is not determined solely by expression of ERBB2. Levels of ERBB3, its preferred heterodimerisation partner and ERBB ligands may also have a role. METHODS: We measured NRG1 expression by real-time quantitative RT-PCR and ERBB receptors by western blotting and immunohistochemistry in bladder tumours and cell lines. RESULTS: NRG1α and NRG1ß showed significant coordinate expression. NRG1ß was upregulated in 78% of cell lines. In tumours, there was a greater range of expression with a trend towards increased NRG1α with higher stage and grade. Increased expression of ERBB proteins was detected in 15% (EGFR), 20% (ERBB2), 41% (ERBB3) and 0% (ERBB4) of cell lines. High EGFR expression was detected in 28% of tumours, associated with grade and stage (P=0.05; P=0.04). Moderate or high expression of ERBB2 was detected in 22% and was associated with stage (P=0.025). Cytoplasmic ERBB3 was associated with high tumour grade (P=0.01) and with ERBB2 positivity. In cell lines, NRG1ß expression was significantly inversely related to ERBB3, but this was not confirmed in tumours. CONCLUSION: There is a wide spectrum of NRG1 and ERBB receptor expression in bladder cancer. In advanced tumours, EGFR, ERBB2 and ERBB3 upregulation is common and there is a relationship between expression of ERBB2 and ERBB3 but not the NRG1 ligand.

Improving the accuracy of pre-operative survival prediction in renal cell carcinoma with C-reactive protein.

BACKGROUND: Validated objective biomarkers are needed for patients with renal cell carcinoma (RCC) to guide patient management and define high-risk populations for follow-up or for therapeutic purposes. METHODS: Patients undergoing nephrectomy for RCC (n=286 all stages, 84% with conventional clear cell type) were included with a median duration follow-up of 5 years. The prognostic significance of pre-operative haematological and biochemical variables, including C-reactive protein (CRP) values were examined and whether they added additional information to a recently published pre-operative scoring system was determined. RESULTS: C-reactive protein was the most significant predictor of overall survival (OS; χ(2)=50.9, P<0.001). Five-year OS for patients with CRP ≤ 15 mg l(-1) vs >15 mg l(-1) was 72% (95% CI 65-78%) and 33% (95% CI 23-44%), respectively. Similar results were seen for cancer-specific survival (CSS) and disease-free survival. On multivariate analysis, CRP remained highly significant for CSS (χ(2)=17.3, P<0.0001) and OS (χ(2)=9.8, P<0.002), in addition to other pre-operative variables including log of neutrophil/lymphocyte ratio, red blood cell count and white cell count. C-reactive protein was significant in addition to the pre-operative nomogram score (χ(2)=12.5, P=0.0004 for OS, χ(2)=16.2, P=0.0001 for CSS and χ(2)=8.6, P=0.003 for DFS) and was still significant when other pre-operative variables were included. CONCLUSION: C-reactive protein and other haematological and biochemical variables have independent prognostic significance in RCC and may enhance pre-operative scoring systems.

Prognostic factors for renal cell carcinoma.

Renal cell carcinoma is a relatively uncommon tumour with a widely varying prognosis depending on several tumour and clinical factors. This review discusses these factors and critically appraises their value both as individual markers and when they are incorporated into scoring systems/models or algorithms. Disease stage (assessed pathologically and/or clinically) and performance status have the strongest evidence as helpful individual prognostic markers but a better discrimination is obtained by combining these and adding in various other indices. Prospective validation of such integrated prognostic models will be essential.

Prostatic pathology reporting in the UK: development of a national external quality assurance scheme.

AIMS: To develop a baseline picture of prostatic pathology reporting in the UK, identify areas of particular difficulty and assess the feasibility of a national external quality assurance scheme based on prostatic biopsy specimens using the same format as the National Health Service breast pathology scheme, as recommended by the National Institute for Clinical Excellence. METHODS AND RESULTS: Eight expert uropathologists and 32 randomly selected pathologists participated in four circulations each of 12 cases of prostatic biopsy specimens. A fixed text proforma was developed and responses were analysed for interobserver agreement using kappa statistics. Consistency of reporting the main diagnostic categories of benign and invasive carcinoma was good (kappa values 0.77 and 0.88, respectively), but only after excluding 19% of cases for which the experts did not reach 75% agreement. Areas of difficulty included the diagnosis of high-grade prostatic intraepithelial neoplasia and small foci of cancer. Prognostic factor reporting was more variable, with lower overall kappas for the assessment of Gleason grading (experts 0.55, others 0.50), perineural invasion (experts 0.64, others 0.50) and number of positive cores (experts 0.74, others 0.61). CONCLUSIONS: Given the difficulties in diagnosis of prostatic biopsy specimens and the assessment of prognostic factors, the expansion of the scheme could deliver important educational benefits.

Identification of genes involved in human urothelial cell-matrix interactions: implications for the progression pathways of malignant urothelium.

Interactions between epithelial cells and the extracellular matrix are central to tissue homeostasis and have a dynamic role in tissue remodeling and repair. Regulation of these pathways is balanced by positive and negative feedback elements, many of which have been implicated in the pathways of malignant progression. We have used differential display to identify genes that are up-regulated in normal human urothelial cells in response to exposure to extracellular matrix proteins (Matrigel) in vitro. This approach has identified genes that have key roles in cell-cell and cell-matrix interactions and that have been implicated in the progression of carcinomas of urothelial or other epithelial cell origins. One confirmed but unknown differentially expressed sequence was used to isolate a full-length gene, MIG-C4, from a human urothelial cDNA library. This gene was found to encode a novel urokinase plasminogen-activator receptor-like member of the Ly-6 family of glycosyl-phosphatidylinositol-anchored glycoproteins, and was identified as the human homologue of the rat metastasis-associated C4.4A gene. By in situ hybridization, MIG-C4 was expressed variably in normal urothelium and intensely in the tumor component of some noninvasive superficial lesions and in invasive and metastatic urothelial cancers. Thus, our approach has identified previously nonimplicated gene products involved in normal urothelium-matrix interactions that could be tumor-invasion or suppressor-gene targets in the development of invasive and metastatic tumor phenotypes.

Increased incidence of renal parenchymal carcinoma in the Northern and Yorkshire region of England, 1978-1997.

Kidney cancer remains relatively rare, but incidence and mortality rates are reported to be rising steadily across the world. To determine if such increases were occurring in the UK, we examined the rates of incidence and mortality in different histological subtypes of kidney cancer in the Northern and Yorkshire region of England. Details of all 8741 cases diagnosed between 1978 and 1997 were extracted from the population-based Northern and Yorkshire Cancer Registry. For all types of tumour, both incidence and mortality rates increased over the study period. Overall age-standardised incidence rates increased by 86% for renal parenchymal carcinoma (RPC) (80% for males, 90% for females) from 2.8 to 5.2 cases per 100000 (3.8-6.8 male, 2.0-3.8 female). There were incidence increases in all age groups, all Carstairs index groups and in both urban and rural populations. Although increased incidental detection of kidney tumours by improved investigational techniques may account for some of this rise, we believe it unlikely that it accounts for all of the increase observed. Potential aetiological causes for the increased rates include hypertension, smoking, a diet lacking fruit and vegetables, analgesic use and, particularly, obesity.

Cytokeratin expression patterns in normal and malignant urothelium: a review of the biological and diagnostic implications.

The cytokeratins are the intermediate filament proteins characteristic of epithelial cells. In human cells, some 20 different cytokeratin isotypes have been identified. Epithelial cells express between two and ten cytokeratin isotypes and the consequent profile which reflects both epithelial type and differentiation status may be useful in tumour diagnosis. The transitional epithelium or urothelium of the urinary tract shows alterations in the expression and configuration of cytokeratin isotypes related to stratification and differentiation. In transitional cell carcinoma, changes in cytokeratin profile may provide information of potential diagnostic and prognostic significance. The intensification of immunolabelling with some CK8 and CK18 antibodies may underly an active role in tumour invasion and foci of CK17-positive cells may represent proliferating populations. Loss of CK13 is a marker of grade and stage and de novo expression of CK14 is indicative of squamous differentiation and an unfavourable prognosis. However, perhaps the most important recent finding is the demonstration that a normal CK20 expression pattern is predictive of tumour non-recurrence and can be used to make an objective differential diagnosis between transitional cell papilloma and carcinoma. This review will consider cytokeratin expression in urothelium and discuss the application of cytokeratin typing to the diagnosis and prognosis of patients with TCC.

Cytokeratin 14 as a marker of squamous differentiation in transitional cell carcinomas.

The presence of squamous differentiation in transitional cell carcinomas has been variably related to prognosis and response to radiotherapy. This study sought to establish whether cytokeratin (CK) 14, normally expressed in the basal cells of squamous epithelium, could be used as a reliable marker of the emergence of a squamous phenotype in transitional cell carcinomas. In a series of 42 tumours, CK14 was expressed in areas of squamous morphology, whereas CK20 identified continuing urothelial differentiation. Furthermore, focal positivity for CK14 was present in a proportion of tumours with no morphological evidence of squamous differentiation, suggesting that it is a more sensitive marker of phenotypic switch. Investigation of CK subtypes may be more powerful than morphology alone in clinical studies of transitional cell carcinomas as CK expression profiles have been related to treatment response in other tumour types.

Association of anticardiolipin antibodies with intraglomerular thrombi and renal dysfunction in lupus nephritis.

We studied positivity for anti-cardiolipin antibody, intraglomerular capillary thrombi on renal biopsy, and the progression of renal disease in 51 patients (10 male and 41 female), mean age 37 years (range 17-65 years), with a diagnosis of systemic lupus erythematosis and clinically evident nephritis confirmed by renal biopsy. Serum creatinine, serum indicators of disease activity and biopsies were analysed in subgroups according to thrombi and anticardiolipin status. End-points were death or chronic dialysis requirement and survival. Degree of sclerosis, crescent formation and necrosed glomeruli were all greater in those specimens positive for thrombi and in those specimens of patients who were serum ACA-positive, suggesting a relationship to disease activity/severity at presentation. The increase in serum anti-DNA antibodies and ANA and the reduction in C3 and C4 were significant in ACA-positive patients, with a strong relationship to disease activity when compared with changes in the ACA-negative patients (p < 0.05 in all cases). There was no significant difference when patients were separated according to the presence or absence of thrombi. Renal function at presentation was worse in patients with intracapillary thrombi and ACA positivity (p = 0.085 and p = 0.042, respectively). All patients progressed, but only those with intracapillary thrombi or anti-cardiolipin antibody positivity had a significant deterioration in renal function. Twenty-one thrombotic episodes occurred in 14 patients, of whom 13 were ACA-positive. Anticardiolipin antibody is a strong predictor of the presence of intraglomerular thrombi in SLE patients with renal involvement. The presence of thrombi and/or anticardiolipin antibodies indicate a worse long-term renal outcome. Anti-cardiolipin antibody positivity is a strong predictor of systemic vascular thrombotic complications.

Muscle hypertrophy in Duchenne muscular dystrophy. A pathological and morphometric study.

In order to investigate the pathological basis of muscle hypertrophy in Duchenne dystrophy, 9 biopsy specimens of the lateral gastrocnemius and 7 of the vastus lateralis were compared. All patients had calf hypertrophy and normal strength in gastrocnemius-soleus, whereas the quadriceps biopsied were all atrophied and weak. The patients' ages ranged from 4 to 11 years. The pathological and histochemical changes were assessed semi-quantitatively. Comparison of the gastrocnemius and quadriceps groups showed that the number of hypercontracted fibres, the degree of endomysial fibrosis and the degree of fat infiltration were significantly higher in the quadriceps. The fibre type differentiation was better in the gastrocnemius group. The mean fibre diameter was above normal in all gastrocnemius biopsies and showed no increase with age. In the quadriceps, fibre hypertrophy was found early in the disease but had changed into fibre atrophy in the three oldest patients. When present, fibre hypertrophy involved both fibre types. The amount of fat-fibrosis per unit area was increased in both groups, but more severely so in the quadriceps. These results indicate that there is no true muscle hypertrophy in the gastrocnemius, in which the fat-fibrosis component was increased in all patients and that the dystrophic process is more active in the quadriceps. The finding of persistent fibre hypertrophy in the gastrocnemius is discussed with respect to the postural abnormalities observed in the lower limbs in Duchenne dystrophy.