The Impact of Fluorescence in situ Hybridization on the Staging of Upper Tract Urothelial Carcinoma

<b><i>Objectives:</i></b> The aim of the study was to evaluate the impact of fluorescence in situ hybridization (FISH) diagnostics on the T stage in final histology specimen of patients undergoing radical nephroureterectomy (RNU) due to upper tract urothelial carcinoma (UTUC) at a large tertiary care center. <b><i>Methods:</i></b> We retrospectively analyzed patients who underwent RNU at our center between 2008 and 2020. Inclusion criteria were RNU due to UTUC. Urine cytologies were used for FISH analysis to detect chromosomal abnormalities. Pre-FISH group was defined as patients without access to routine preoperative urinary FISH testing (2008–2014), and FISH group was defined as patients with access to routine FISH testing. Primary outcome was T stage in final histology. Statistical analysis was performed by χ² test and Mann-Whitney <i>U</i> test. <b><i>Results:</i></b> Out of 212 patients who underwent RNU at our center between 2008 and 2020, 155 patients were included into the final analysis. The median age was 71 (range 33–90) years, and 108 (69.7%) patients were male and 47 (30.3%) female. Age and gender were not differently distributed in both groups (age: <i>p</i> = 0.925; gender: <i>p</i> = 0.682). Organ-confined disease was found in 37/72 patients in the pre-FISH cohort and in 48/83 patients in the FISH cohort (<i>p</i> = 0.422). Within organ-confined disease, 18/37 patients revealed a T stage smaller than T1 in the pre-FISH cohort and 35/48 patients in the FISH cohort (<i>p</i> = 0.022). <b><i>Conclusions:</i></b> Preoperative FISH diagnostics add important information to preoperative diagnostic workup of patients with UTUC. Within organ-confined disease, a significant shift toward T stages lower than T1 is observed. Further research is required to determine the impact of this shift on survival in UTUC.

Quality considerations and malformation surveillance in a marine stocking program

Marine enhancement programs can be helpful for the conservation of important species. Many variables are considered in managing a marine enhancement program, and external fish quality prior to release should be one of them. Quality assessment aids in understanding the influence of rearing variables, limits a recognizable cultured fish phenotype, and maximizes the success of the conservation program by emulating the survivorship potential of wild stocks. We rear white seabass, Atractoscion nobilis, for stock enhancement and developed a semiquantitative assessment and control program to document and reduce the incidence of abnormal physical attributes prior to their release. Clearing and staining techniques were used to define normal processes of ossification, and wild fish surveys were performed to understand variability in natural stock morphology. In the hatchery, A. nobilis were examined in lots of 125 fish cohort−1 at 50 and 80 d post hatch of their development. Specimens evaluated were normal or classified as having malformations involving the bone or cartilage (13 categories) ranked 1–3, mild to severe. Malformations that were unique or differed substantially from wild A. nobilis specimens were culled from the cultured cohort as part of a quality control process prior to release. The most common malformations involved the head region, which accounted for 98% of all hard tissue malformations. Malformations of the jaws accounted for 30% of observed malformations and lower jaw prognathism was the most common observation. This program has proven useful for identifying malformations and minimizing the release of affected cultured marine fish.

The Paris System for reporting urinary cytology in daily practice with emphasis on ancillary testing by multiprobe FISH

AimsThe Paris System (TPS) was introduced in the diagnostic routine with the goal to simplify and standardise diagnostic reporting of urinary cytology. The diagnostic categories of TPS are based on defined cytological criteria, with a focus on high-grade urothelial carcinoma (HGUC). While the categories ‘negative for HGUC (NHGUC)’ and ‘HGUC’ are straightforward, the categories ‘atypical urothelial cells (AUC)’ and ‘suspicious of HGUC (SHGUC)’ remain inconclusive. In this study, we evaluated the feasibility of TPS in daily practice with special emphasis on ancillary fluorescence in situ hybridisation (FISH) testing in the setting of TPS categories.MethodsIn a 19-month period, TPS was prospectively applied in the routine diagnostic setting on 3900 urinary cytology cases comprising bladder and upper urinary tract washings and voided urine specimens. Additionally, we analysed the results of the FISH assay UroVysion prospectively performed on a cohort of 128 cases enriched for AUC and SHGUC categories.ResultsThe most frequently reported category was NHGUC (n=3496, 89.7%), followed by AUC (n=178, 4.6%), HGUC (n=155, 4%), SHGUC (n=61, 1.6%), low-grade urothelial neoplasia (n=6, 0.1%) and other malignancies (n=4, 0.1%). In the FISH cohort, 40/90 (44%) cases within the AUC category were FISH positive, consistent with urothelial neoplasia. In the SHGUC category, 16/21 (76%) cases were FISH positive.ConclusionsWhen prospectively applying TPS in urinary cytology, inconclusive atypia accounts only for a small subset of cases. FISH additionally improves the stratification between reactive and malignant cells in the indeterminate AUC and SHGUC categories.

Variability of pikeperch Sander lucioperca (L. 1758) cohorts in early life history

Year to year fluctuations in 0+ fish cohort strength are a common phenomenon. Many factors can affect cohort strength during the fish's early life period. In this study, development of a 0+ pikeperch Sander lucioperca cohort in the pelagic zone was studied by trawling for 50 days from first larvae hatching, in two consecutive years. In 2007, an abundant S. lucioperca cohort collapsed suddenly soon after hatching. After the incident, slow-growing S. lucioperca prevailed in the catch. In 2008, the catch gradually increased during the whole study period because of prolonged hatching. Environmental factors differed mainly in a slower temperature increase, higher water level and higher zooplankton abundance in 2008 compared to 2007. Our study revealed that a strong 0+ S. lucioperca cohort at the time of hatching might not result in a strong S. lucioperca cohort in general.

Equivocal results of HER2 fluorescent in situ hybridization (FISH) assessment in breast cancer: Diagnostic limitations and therapeutical implications.

e11058 Background: HER2/neu status is a well established prognostic and predictive factor for breast cancer (BC) patients. However, HER2 testing remains controversial because of technical issues, lack of consensus on cut point determinations and pathology interpretation. As a result, some patients present tumors with inconclusive or equivocal tests, making the indication of anti-HER2 therapy questionable. Methods: We evaluated the incidence of inconclusive and equivocal HER2 amplification by FISH after an equivocal HER2 immunohistochemical (IHC) result in a cohort of breast cancer patients treated at a cancer center. Equivocal IHC was defined as tumor cells showing 2+ membranous immunoreactivity out of a possible 3+. Inconclusive FISH was considered when probe signs were weak and did not allow proper evaluation. Equivocal FISH was defined according to ASCO/CAP recommendation. Patients’ clinical characteristics, treatments and outcomes were evaluated. Results: From 2006 to 2011 we analyzed BC tissue samples from 404 patients that underwent HER2 FISH assessment after equivocal IHC. Gene amplification was found in 28,7% (n=116) of samples; 65,5% (n=265) showed non-amplification results. Inconclusive (n=12) plus equivocal (n=11) FISH results were found in 5,7% (n=23) of patients. In the inconclusive/equivocal FISH cohort, 78% of evaluated tissue came from breast biopsy and 22% were extracted from metastatic sites. When HER2 amplification by FISH was reclassified according to the FDA criteria (HER2/CEP17 FISH ratio above 2.0), 45% of patients previously classified as equivocal became HER2 positive. None of equivocal HER2 FISH patients received anti-HER2 therapy. Conclusions: The incidence of BC patients with equivocal HER2 FISH at our institution is similar to other large series, reflecting our adequate quality assurance methods. Anti-HER2 therapy is the backbone for HER2-positive BC patients irrespective of hormone receptor status. Further analyses using different techniques for HER2 expression and amplification status assessment are urged in order to better select patients for appropriate therapy.

HER2 positive gastroesophageal cancer in an Irish population.

e14687 Background: Gastroesophageal cancer is a major cause of cancer-related mortality. HER2 is overexpressed in ~ 7-34% of gastroesophageal (GE) adenocarcinomas. The ToGA study, established the benefit of trastuzumab in combination with chemotherapy in HER2 positive metastatic GE tumours. In this study, 22% of patients were HER2 positive {immunohistochemistry (IHC)3+ or fluorescence insitu hybridization (FISH)(+)}. Potential heterogeneity of HER2 amplification, overexpression, and incomplete membrane staining of HER2 by IHC leaves some ambiguity in HER2 testing and definition of HER2 positive GE tumours. We report a multi-center Irish experience by examining HER2 status by IHC and FISH in GE tumours. Methods: HER2 testing was performed on adenocarcinoma biopsy or resection specimens of patients with early stage and metastatic GE tumors between 2008 - 2011. We defined HER2 positive as IHC3+ or FISH(+) {HER2:17ch ≥ 2}. In addition, age, gender, smoking history, histology, stage of disease, treatment, and survival data were recorded. Results: A total of136 Caucasian patients with early stage and metastatic GE cancers were identified. Median age was 69 yrs (ranging from 25 – 96). Data available for analysis was conducted from 111 patients with 10% FISH(+). There are 73 patients with early stage and 38 with metastatic disease. Five metastatic cases (13%) were FISH(+) (of whom 3 IHC3+, 1 IHC2+, 1 IHC1+), 33 cases were FISH(-). Sites of metastatic disease in the FISH(+) cohort were liver, peritoneal, and bone metastasis. In the FISH(-) group, sites of metastatic disease were predominantly liver. Interestingly CNS disease is seen exclusively in the FISH(-) cohort. Of the early stage patients, only 6 patients (8.2%) were FISH(+) (of whom 3 IHC3+, 2 IHC2+, 1 IHC1+). With respect to tumour heterogeneity of HER2 amplification, in IHC3+, 82% were FISH(+), IHC2+, 17% were FISH(+) and IHC1+, 6% were FISH(+). There was 100% concordance between IHC0 and FISH(-). Conclusions: HER2 positive GE adenocarcinomas in the analyzed cohort displays similar pattern of heterogeneity in IHC staining and FISH positivity but with lower incidence (10%) of HER2 amplification than was reported in the ToGA study. Further data on location, histological pattern and survival will be reported.

Disentangling the effects of size-dependent encounter and susceptibility to predation with an individual-based model for fish larvae

We investigated the effects of size-dependent encounter and susceptibility, the role of variation in the size distribution of predators, and the timing of prey-predator interaction during the larval phase in shaping the length frequency distribution of surviving fish larvae. These analyses based on general empirical size-dependent relationships may have broad implications in understanding larval fish cohort dynamics. We demonstrated that the formulations of encounter and susceptibility to predation counteract each other, an increased range of predator sizes reduces only slightly the evidence for size-selective mortality, and synchronous spawning and hatching events have the potential to yield strong size-selective mortality of a cohort of fish larvae. The important factors in generating size-selective mortality are either the timing of encounters between fish larvae and their predators or high mortality rates. We demonstrated a direct relationship between the potential of size-selective mortality and the overall mortality rate of the cohort. We suggest that it may be difficult to detect the effect of size-dependent processes in the field. A better understanding of the factors influencing encounter represents a critical element in extrapolating laboratory studies of predation to the field.