Stephan Störkel

Immunohistochemical detection of EGFR in paraffin-embedded tumor tissues: Variation in staining intensity due to choice of fixative and storage time of tissue sections

The epidermal growth factor receptor (EGFR) is highly expressed in a variety of solid malignant tumors and its expression has been correlated with disease progression and poor survival. With the advent of targeted therapies, especially IMC-C225 (Cetuximab), a monoclonal antibody (MAb) directed against the EGFR, there is an increasing interest in immunohistochemistry (IHC)-based EGFR screening methods using paraffin-embedded tumor specimens to select cancer patients eligible for treatment with Cetuximab. With the EGFRpharmDX kit, a complete assay for demonstration of EGFR is now available. Because no information about the preservation of the EGFR under various conditions of fixation is available, we performed a prospective study on a panel of commonly used fixatives to determine optimal tissue preservation protocols. The stability of the epitope on cut tissue sections stored for a period up to 24 month was also tested using material originating from patients with head and neck cancer, non-small-cell lung carcinomas, and colorectal adeno-carcinomas. Depending on the fixative used and the time of storage of cut tissue sections, a variation in the determined level of EGFR expression was demonstrated compared with the most optimal fixation procedure. (J Histochem Cytochem 52:893–901, 2004)

Adjuvant Radiotherapy Versus Wait-and-See After Radical Prostatectomy: 10-year Follow-up of the ARO 96–02/AUO AP 09/95 Trial

BACKGROUND Local failure after radical prostatectomy (RP) is common in patients with cancer extending beyond the capsule. Three prospectively randomized trials demonstrated an advantage for adjuvant radiotherapy (ART) compared with a wait-and-see (WS) policy. OBJECTIVE To determine the efficiency of ART after a 10-yr follow-up in the ARO 96-02 study. DESIGN, SETTING, AND PARTICIPANTS After RP, 388 patients with pT3 pN0 prostate cancer (PCa) were randomized to WS or three-dimensional conformal ART with 60 Gy. The present analysis focuses on intent-to-treat patients who achieved an undetectable prostate-specific antigen after RP (ITT2 population)--that is, 159 WS plus 148 ART men. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The primary end point of the study was progression-free survival (PFS) (events: biochemical recurrence, clinical recurrence, or death). Outcomes were compared by log-rank test. Cox regression analysis served to identify variables influencing the course of disease. RESULTS AND LIMITATIONS The median follow-up was 111 mo for ART and 113 mo for WS. At 10 yr, PFS was 56% for ART and 35% for WS (p<0.0001). In pT3b and R1 patients, the rates for WS even dropped to 28% and 27%, respectively. Of all 307 ITT2 patients, 15 died from PCa, and 28 died for other or unknown reasons. Neither metastasis-free survival nor overall survival was significantly improved by ART. However, the study was underpowered for these end points. The worst late sequelae in the ART cohort were one grade 3 and three grade 2 cases of bladder toxicity and two grade 2 cases of rectum toxicity. No grade 4 events occurred. CONCLUSIONS Compared with WS, ART reduced the risk of (biochemical) progression with a hazard ratio of 0.51 in pT3 PCa. With only one grade 3 case of late toxicity, ART was safe. PATIENT SUMMARY Precautionary radiotherapy counteracts relapse after surgery for prostate cancer with specific risk factors.

Prognostic accuracy of individual uropathologists in noninvasive urinary bladder carcinoma: a multicentre study comparing the 1973 and 2004 World Health Organisation classifications.

BACKGROUND Grading of noninvasive papillary urinary bladder carcinoma (PUC) is routinely performed in clinical oncologic practice; however, reports regarding diagnostic and prognostic accuracy are contradictory. OBJECTIVE To compare the 1973 and 2004 World Health Organisation (WHO) classifications in terms of interobserver variability and prognostic implications. DESIGN, SETTING, AND PARTICIPANTS Two hundred PUC were retrospectively reviewed by four independent expert genitourinary pathologists blinded with respect to patient identity and clinical outcome. Tumour grading was assigned according to the 1973 and 2004 WHO classifications. Surveying a mean postsurgical follow-up of 71.8 mo (range: 18-163 mo), clinical outcome in terms of recurrence-free and progression-free survival was recorded for all patients. INTERVENTION All of the patients underwent transurethral resection of the bladder. MEASUREMENTS The generalised κ (kappa statistic) for interobserver variability was calculated, and Kaplan-Meier analysis as well as univariate regression analysis were performed to evaluate prognostic implications in terms of recurrence and progression rates. RESULTS AND LIMITATIONS During the follow-up, a total of 84 (42%) patients experienced recurrence, whereas another 18 (9%) patients featured disease progression. Owing to the rare presence of papillary urothelial neoplasms of low malignant potential (PUNLMP) in our cohort (0-3.5%), the 2004 WHO classification approached a two-tier system (low and high grade), which showed less interobserver variability than the 1973 classification (κ: 0.30-0.52 vs 0-0.37, respectively). In comparing the power of both classifications to separate indolent from aggressive PUC, striking pathologist-dependent differences became apparent. CONCLUSIONS Both WHO classifications for grading of PUC suffer from substantial interobserver variability, with the 2004 WHO classification showing less interobserver variability. Stark differences in the prognostic power of the individual grading approaches were also found. These significant differences in the individual interpretation of the WHO grading schemes for noninvasive PUC highlight the necessity of better-defined criteria for conventional tumour grading; otherwise, the subdivision into prognostically different groups by conventional histomorphology might remain of limited value.

MORPHOLOGICAL CLASSIFICATION OF RENAL-CANCER

SummaryThe current classification of renal-cell adenomas (RCAs) and carcinomas (RCCs) is based on eight basic cell and tumor types (entities) with characteristic morphologic features: (1) RCCs of clear-cell type, (2) RCAs/RCCs of chromophilic-cell type, (3) RCAs/RCCs of chromophobic-cell type, (4) RCCs of duct Bellini type, (5) RCCs of transitional-cell type, (6) RCCs of neuroendocrine type, (7) RCAs of oncocytic type, and (8) RCAs of metanephroid type. Tumors with a proposed histogenesis from the proximal tubule (clear-cell and chromophilic tumors) amount to 85% of renal cancers, whereas tumors with a proposed histogenesis from the connecting tubule/collecting duct (chromophobic-, oncocytic-, and duct Bellini-type tumors) amount to only 11%. The remaining tumor types represent rare entities (less than 1% each). Tumor cytogenetics data confirm the proposed eight morphologic subtypes and give further indications for type-specific tumor development and progression.

MHC class I antigen processing pathway defects, ras mutations and disease stage in colorectal carcinoma

Colorectal tumorigenesis has been associated with the progressive acquisition of a variety of genetic alterations. These include mutations of the Ki‐ras proto‐oncogene in codons 12 and 13, which account for 85% of genetic changes in colorectal cancer. In murine in vitro models of oncogenic transformation, an association between ras‐mediated transformation and downregulation of different components of the MHC class I antigen processing machinery (APM) has been described. In order to investigate whether this association also exists in human tumors, 10 cases of high‐grade intraepithelial neoplasia (HIN), as well as primary tumors and autologous lymph node metastases from 42 patients with colorectal carcinoma, were monitored by allele‐specific restriction analysis for Ki‐ras mutations. In parallel, APM component expression and tumor cell proliferation were analyzed by immunohistochemistry. In comparison to autologous colorectal mucosa, TAP1, LMP2 and tapasin loss was found in 68%, 67% and 80% of HIN, respectively. In contrast, impaired TAP1, LMP2 and tapasin expression was found in 42%, 42% and 63% of primary adenocarcinomas of stage III disease and in 63%, 47% and 79% of the matched lymph node metastases, respectively. More than 60% of colorectal tumor lesions with TAP1, LMP2 and/or tapasin defects displayed Ki‐ras mutations. The frequency of TAP1, LMP2 and tapasin loss varied between 33% of primary adenocarcinomas, 40% of HIN to approximately 67% of metastases. These data suggest that i) APM component deficiencies occur more frequently in Ki‐ras‐mutated colorectal carcinoma lesions and ii) APM abnormalities in conjunction with Ki‐ras mutations appear to be associated with disease stage. These findings support the hypothesis that Ki‐ras mutations may contribute to immune escape mechanisms of tumors by downregulating the MHC class I APM component expression.

Cytogenetic classification of renal cell cancer

Cytogenetic and molecular genetic investigations in cancer are important tools to address problems of oncogenesis and tumor progression, of classification, and of diagnosis of tumors. A combination of advanced molecular genetic, cytogenetic, and (immuno) histopathologic analysis will contribute significantly to the elucidation of the oncogenic steps that lead to immortalization and subsequent malignant behavior. In this review written on the occasion of Dr. Avery Sandbergs 75th anniversary, we will present a model for the pathogenesis of renal cell tumors based on a new cytomorphologic classification and our (cyto)genetic analysis of about 175 renal cell tumors, together with the accumulated data in the literature.

Analysis of multiple renal cell adenomas and carcinomas suggests allelic loss at 3p21 to be a prerequisite for malignant development

Multiple renal cell tumours from three unrelated patients have been analysed for loss of heterozygosity of 3p, mutation of VHL, and chromosome 7 and 17 imbalances. Loss of 3p alleles is characteristic for clear cell type tumours and the combination of +7, +17 for chromophilic cell type tumours. Thus, we could classify adenomas and carcinomas of the three patients according to the genomic patterns of the tumours. Adenomas appeared to be mostly of the chromophilic cell type. In some adenomas, however, allelic losses of chromosome 3 were detected, pointing to a clear cell phenotype. Irrespective of showing loss or retention of the 3p25 region, none of the adenomas had a VHL mutation. Therefore, inactivation of VHL does not seem to be an early event in the development of renal cell tumours. Results of an analysis of regions of loss and retention of alleles of 3p markers in multiple tumours of the individual patients suggest that losses at either 3p25 or 3p12‐p14 are associated with adenomas. Additional loss at 3p21 is most likely required to lead to development of a more malignant clear cell carcinoma. Genes Chromosom. Cancer 19:228–232, 1997.

Prostate-Specific Antigen Persistence After Radical Prostatectomy as a Predictive Factor of Clinical Relapse-Free Survival and Overall Survival: 10-Year Data of the ARO 96-02 Trial

OBJECTIVE The ARO 96-02 trial primarily compared wait-and-see (WS, arm A) with adjuvant radiation therapy (ART, arm B) in prostate cancer patients who achieved an undetectable prostate-specific antigen (PSA) after radical prostatectomy (RP). Here, we report the outcome with up to 12 years of follow-up of patients who retained a post-RP detectable PSA and received salvage radiation therapy (SRT, arm C). METHODS AND MATERIALS For the study, 388 patients with pT3-4pN0 prostate cancer with positive or negative surgical margins were recruited. After RP, 307 men achieved an undetectable PSA (arms A + B). In 78 patients the PSA remained above thresholds (median 0.6, range 0.05-5.6 ng/mL). Of the latter, 74 consented to receive 66 Gy to the prostate bed, and SRT was applied at a median of 86 days after RP. Clinical relapse-free survival, metastasis-free survival, and overall survival were determined by the Kaplan-Meier method. RESULTS Patients with persisting PSA after RP had higher preoperative PSA values, higher tumor stages, higher Gleason scores, and more positive surgical margins than did patients in arms A + B. For the 74 patients, the 10-year clinical relapse-free survival rate was 63%. Forty-three men had hormone therapy; 12 experienced distant metastases; 23 patients died. Compared with men who did achieve an undetectable PSA, the arm-C patients fared significantly worse, with a 10-year metastasis-free survival of 67% versus 83% and overall survival of 68% versus 84%, respectively. In Cox regression analysis, Gleason score ≥8 (hazard ratio [HR] 2.8), pT ≥ 3c (HR 2.4), and extraprostatic extension ≥2 mm (HR 3.6) were unfavorable risk factors of progression. CONCLUSIONS A persisting PSA after prostatectomy seems to be an important prognosticator of clinical progression for pT3 tumors. It correlates with a higher rate of distant metastases and with worse overall survival. A larger prospective study is required to determine which patient subgroups will benefit most from which treatment option.

Two new cases of papillary renal cell carcinoma with t(X;1)(p11;q21) in females.

Two cases of papillary renal cell carcinoma (RCC) with a karyotype 46,X,t(X;1)(p11.2;q21) in two female patients aged 9 and 29 years are reported. These observations, and the review of the 17 reported cases with a translocation at band Xp11 confirm that this abnormality delineates a clinicopathological entity within the classical papillary RCC, characterized by the early age of occurrence and, probably, distinct histological features. Including these two new female cases, the sex ratio in cases with t(X;1) appears similar to that observed in the other papillary RCC.

Renal oncocytoma with t(5;12;11), der(1)t(1;8) and add(19): ''True'' oncocytoma or chromophobe adenoma?

Renal oncocytomas reveal a considerable (cyto)genetic heterogeneity. At least 2 genetic subsets are currently recognized, characterized by (1) translocations involving breakpoint 11q13 and (2) the combined loss of chromosomes 1 and X/Y. We present a case of oncocytoma revealing a 3‐way translocation involving breakpoint 11q13, a der (1)t(1;8) and an add(19). The der(1) resulted in loss of chromosome 1 sequences. Using fluorescence in situ hybridization, the 11q13 breakpoint of the present case proved to be slightly different from the one observed previously in 3 cases of renal oncocytoma. Whether the 11q13 breakpoint observed in our case resides in or near another gene remains to be elucidated. Int. J. Cancer 73:521–524, 1997.