Brief fixation enables same-day breast cancer diagnosis with reliable assessment of hormone receptors, E-cadherin and HER2/Neu

The risk of weekend biopsy: Impact of specimen source and fixation status on HER2 assessment in the treatment of advanced gastric cancer (The HER_WEEKEND study)

Accurate evaluation of human epidermal growth factor receptor type 2 (HER2) expression is crucial for determining chemotherapy regimens in gastric cancer. However, formalin fixation status has been identified as an important factor affecting HER2 assessment reliability. This retrospective cohort study aimed to investigate the correlation between sample collection day (weekday vs. weekend) and source (biopsy vs. surgical specimens) in assessing HER2 expression in patients with unresectable advanced/recurrent gastric cancer. Data were collected from gastric cancer patients who received chemotherapy at a single public hospital in Japan from 2008 to 2021. The analysis included 177 patients (109 men, 68 women) with a median age of 68.0 (21-88) years, and the primary outcome was the HER2 positivity rate. The overall HER2 positivity rate was 18.1%, with higher rates on weekdays (20.0%) compared to weekends (12.8%). Biopsies had higher positivity rates on weekdays (23.9%) but lower rates on weekends (11.1%) than surgical specimens. Significant differences were observed in formalin fixation times between weekdays and weekends for both biopsies and surgical samples. The study findings suggest that longer formalin fixation times on weekends may lead to underestimating HER2 expression, particularly in biopsies. Therefore, it is crucial to be cautious of excessive formalin fixation when collecting samples, especially during weekend biopsies.

Tissue Processing

Tissue processing is the technique by which fixed tissues are made suitable for embedding within a supportive medium such as paraffin, and consists of three sequential steps: dehydration, clearing, and infiltration. In most clinical and research settings, tissue processing is accomplished using an automated tissue processor, with or without microwave-assistance. To ensure high-quality results, processing protocols should be tailored to tissue size and composition by modifying variables such as reagents used and the timing of the various steps. Herein, we provide an overview of tissue processing theory and outline a basic tissue processing method for use with a conventional automated fluid transfer/enclosed processor. The principles described will assist readers in optimizing tissue processing for their own projects.

Diagnostics in Patients Suspect for Breast Cancer in The Netherlands

The goal of this study was to describe the variation in hospital-based diagnostic care activities for patients with symptomatology suspect for breast cancer in The Netherlands. Two cohorts were included: the ‘benign’ cohort (30,334 women suspected of, but without breast cancer) and the ‘malignant’ cohort (2236 breast cancer patients). Hospital-based financial data was combined with tumor data (malignant cohort) from The Netherlands Cancer Registry. Patterns within diagnostic pathways were analyzed. Factors influencing the number of visits and number of diagnostic care activities until diagnosis were identified in the malignant cohort with multivariable Cox and Poisson regression models. Compared to patients with benign diagnosis, patients with malignant disease received their diagnosis less frequently in one day, after an equal average number of hospital visits and higher average number of diagnostic activities. Factors increasing the number of diagnostic care activities were the following: lower age and higher cM-and cN-stages. Factors increasing the number of days until (malignant) diagnosis were as follows: higher BIRADS-score, screen-detected and higher cN-and cT-stages. Hospital of diagnosis influenced both number of activities and days to diagnosis. The diagnostic care pathway of patients with malignant disease required more time and diagnostic activities than benign disease and depends on hospital, tumor and patient characteristics.

Prognostic value of PSMA, c-MET and E-cadherin in salivary duct carcinoma

OBJECTIVES

Salivary duct carcinoma (SDC) is a rare and aggressive subtype of salivary gland cancer. Androgen receptor (AR) (96%) and HER2 (29-46%) expression, and a high propensity for regional lymph node metastases are hallmarks of the disease. We hypothesized that c-MET, E-cadherin, PSMA tumor and PSMA neovascular expression may be prognostic factors in SDC.

MATERIALS AND METHODS

Expression levels of these proteins were established on tissue microarrays containing 165 primary SDC tumor specimens. Association with survival was studied with Kaplan-Meier curves, and univariable and multivariable Cox regression models. Furthermore, association with lymph node status, AR and HER2 expression, and gender was studied.

RESULTS

We found that patients with high PSMA tumor expression showed a significantly longer overall survival (OS) (median 83 vs. 43 months, P = 0.022), a trend towards a longer DFS (median 51 vs. 22 months, P = 0.094), and significantly reduced hazard ratio for death in the univariable Cox regression model (HR 0.46, P = 0.034). In the multivariable model only a high number of tumor-positive lymph nodes and high age (>80) at diagnosis were prognostic for poor OS. High PSMA tumor expression was also significantly associated with low N-stage (P = 0.001) and expression was higher in women versus men (P = 0.029). High PSMA tumor expression and E-cadherin loss were significantly associated with strong and weak AR-expression, respectively (P = 0.033 and P = 0.007). None of the factors were significantly associated with HER2 expression.

CONCLUSION

c-MET, E-cadherin, and tumor and neovascular PSMA expression are no independent prognostic factors in SDC.

Accelerated Tissue Processing With Minimal Formalin Fixation Time for 9-Gauge Vacuum-Assisted Breast Biopsy Specimens

Objectives

Vacuum-assisted biopsy (VAB) of the breast seems unsuitable for rapid processing due to large size. We tested microwave-based acceleration.

Methods

As a proof-of-principle study, 9-gauge VAB specimens were taken from eight mastectomy specimens. Forty-two biopsy specimens were processed. Quality of H&E was evaluated in 84 slides, and estrogen receptor (ER), progesterone receptor (PR), E-cadherin, and human epidermal growth factor receptor 2 (HER2) stains were evaluated in six slides. Preoperative biopsy specimens were used as a control.

Results

Diagnostic quality of H&E slides was good in 87%, reasonable in 12%, and low in 1%. Quality of E-cadherin was good in 75% and reasonable in 25%. Quality of ER was good in 83% and reasonable in 17%. PR and both HER2 immunohistochemistry and fluorescence in situ hybridization were good in all slides. Quality of experimental slides was similar to control slides.

Conclusions

Nine-gauge VAB specimens can be processed within 4 hours. Slides are suitable for all routine pathologic stains. This enables a same-day diagnosis.

HER2, chromosome 17 polysomy and DNA ploidy status in breast cancer; a translational study

Breast cancer treatment depends on human epidermal growth factor receptor-2 (HER2) status, which is often determined using dual probe fluorescence in situ hybridisation (FISH). Hereby, also loss and gain of the centromere of chromosome 17 (CEP17) can be observed (HER2 is located on chromosome 17). CEP17 gain can lead to difficulty in interpretation of HER2 status, since this might represent true polysomy. With this study we investigated whether isolated polysomy is present and how this effects HER2 status in six breast cancer cell lines and 97 breast cancer cases, using HER2 FISH and immunohistochemistry, DNA ploidy assessment and multiplex ligation dependent probe amplification. We observed no isolated polysomy of chromosome 17 in any cell line. However, FISH analysis did show CEP17 gain in five of six cell lines, which reflected gains of the whole chromosome in metaphase spreads and aneuploidy with gain of multiple chromosomes in all these cases. In patients' samples, gain of CEP17 indeed correlated with aneuploidy of the tumour (91.1%; p < 0.001). Our results indicate that CEP17 gain is not due to isolated polysomy, but rather due to widespread aneuploidy with gain of multiple chromosomes. As aneuploidy is associated with poor clinical outcome, irrespective of tumour grade, this could improve future therapeutic decision making.

Evaluation of Formalin Fixation for Tissue Biopsies Using Shear Wave Laser Speckle Imaging System

Chemical fixation is the slowest and often the most uncontrolled step in the multi-step process of preparing tissue for histopathology. In order to reduce the time from taking a core needle biopsy to making a diagnosis, a new approach is proposed that optically monitors the common formalin fixation process. A low-cost and highly-sensitive laser speckle imaging technique is developed to measure shear wave velocity in a biospecimen as small as 0.5 mm in thickness submerged in millifluidic channels. Shear wave velocity, which is the indicator of tissue mechanical property and induced by piezoelectric-actuation, was monitored using gelatin phantom and chicken breast during fixation, as well as post-fixed liver and colon tissues from human. Fixation levels in terms of shear wave velocity increased by approximately 271.0% and 130.8% in gelatin phantom and chicken breast, respectively, before reaching the plateaus at 10.91 m/s and 7.88 m/s. Within these small specimens, the plateaus levels and times varied with location of measurement, and between gelatin and chicken breast. This optical-based approach demonstrates the feasibility of fine-tuning preanalytical variables, such as fixation time, for a rapid and accurate histopathological evaluation; provides a quality metric during the tissue preparation protocol performed in most pathology labs; and introduces the millifluidic chamber that can be engineered to be a future disposable device that automates biopsy processing and imaging.

Assessment of HER2 status in breast cancer biopsies is not affected by accelerated tissue processing

AIMS

To establish whether core needle biopsy (CNB) specimens processed with an accelerated processing method with short fixation time can be used to determine accurately the human epidermal growth factor receptor 2 (HER2) status of breast cancer.

METHODS AND RESULTS

A consecutive case-series from two high-volume breast clinics was created. We compared routine HER2 immunohistochemistry (IHC) assessment between accelerated processing CNB specimens and routinely processed postoperative excision specimens. Additional amplification-based testing was performed in cases with equivocal results. The formalin fixation time was less than 2 h and between 6 and 72 h, respectively. Fluorescence in-situ hybridisation and multiplex ligation-dependent probe amplification were used for amplification testing. One hundred and forty-four cases were included, 15 of which were HER2-positive on the routinely processed excision specimens. On the CNB specimens, 44 were equivocal on IHC and required an amplification-based test. Correlation between the CNB specimens and the corresponding excision specimens was high for final HER2 status, with an accuracy of 97% and a kappa of 0.85.

CONCLUSIONS

HER2 status can be determined reliably on CNB specimens with accelerated processing time using standard clinical testing methods. Using this accelerated technology the minimum 6 h of formalin fixation, which current guidelines consider necessary, can be decreased safely. This allows for a complete and expedited histology-based diagnosis of breast lesions in the setting of a one-stop-shop, same-day breast clinic.