Molecular analysis of ascitic fluid cytology reflects genetic changes of malignancies of the ovary equivalent to surgically resected specimens

Next step of molecular pathology: next-generation sequencing in cytology

The evolving landscape of precision oncology underscores the pivotal shift from morphological diagnosis to treatment decisions driven by molecular profiling. Recent guidelines from the European Society for Medical Oncology recomend the use of next-generation sequencing (NGS) across a broader range of cancers, reflecting its superior efficiency and clinical value. NGS not only updates oncology testing by offering quicker, sample-friendly, and sensitive analysis but also reduces the need for multiple individual tests. Cytology samples, often obtained through less invasive methods, can yield high-quality genetic material suitable for molecular analysis. This article focuses on optimizing the use of cytology samples in NGS, and outlines their potential benefits in identifying actionable molecular alterations for targeted therapies across various solid tumors. It also addresses the need for validation studies and the strategies to incorporate or combine different types of samples into routine clinical practice. Integrating cytological and liquid biopsies into routine clinical practice, alongside conventional tissue biopsies, offers a comprehensive approach to tumor genotyping, early disease detection, and monitoring of therapeutic responses across various solid tumor types. For comprehensive biomarker characterization, all patient specimens, although limited, is always valuable.

Minimally Invasive, Maximally Effective: The Power of Precision Cytoanalysis on Effusion Samples-A Comprehensive Exploration from Traditional Methods to Innovative Approaches

Precision medicine translates through molecular assays and in minimally invasive diagnosis, evident in analyses of effusions that serve therapeutic and diagnostic purposes. This cost-effective and low-risk approach provides advantages, playing a pivotal role in late-stage oncology and frequently standing as the primary resource for cancer diagnosis and treatment pathways. This article outlines the workflow for managing serous fluid and explores how cytology effusion analysis extends beyond immunocytological diagnosis. Combined with current molecular tests it showcases the potential to be a skillful tool in precision cytopathology.

Clinical and molecular biomarkers predicting response to PARP inhibitors in ovarian cancer

OBJECTIVE

To determine the useful biomarker for predicting the effects of poly-(ADP ribose)-polymerase (PARP) inhibitors in Japanese patients with ovarian cancer.

METHODS

We collected clinical information and performed molecular biological analysis on 42 patients with ovarian, fallopian tube, and primary peritoneal carcinomas who received PARP inhibitors.

RESULTS

Among the analyzed patients with ovarian cancer, 23.8% had germline BRCA mutation (gBRCAm), 42.9% had homologous recombination repair-related gene mutation (HRRm), and 61.1% had a genomic instability score (GIS) of ≥42. Patients with HRRm had a significantly longer progression-free survival (PFS) than those without HRRm (median PFS 35.6 vs. 7.9 months; p=0.009), with a particularly marked increase in PFS in patients with gBRCAm (median PFS 42.3 months). Similarly, among patients with recurrent ovarian cancer, those with HRRm had a longer PFS than those without HRRm (median PFS 42.3 vs. 7.7 months; p=0.040). Multivariate Cox proportional hazards regression analysis found that performance status and gBRCAm status were independent factors associated with prolonged PFS with PARP inhibitors. In recurrent ovarian cancer, multivariate regression analysis identified platinum-free interval (PFI) in addition to performance status as a significant predictor of PFS. On the contrary, no significant association was observed between PFS and a GIS of ≥42 used in clinical practice.

CONCLUSION

We found that HRRm can be a useful biomarker for predicting the effects of PARP inhibitors in treating ovarian cancer and that the PFI can also be useful in recurrent ovarian cancer.

The prognostic impact of peritoneal tumour DNA in gastrointestinal and gynaecological malignancies: a systematic review

Peritoneal metastases from various abdominal cancer types are common and carry poor prognosis. The presence of peritoneal disease upstages cancer diagnosis and alters disease trajectory and treatment pathway in many cancer types. Therefore, accurate and timely detection of peritoneal disease is crucial. The current practice of diagnostic laparoscopy and peritoneal lavage cytology (PLC) in detecting peritoneal disease has variable sensitivity. The significant proportion of peritoneal recurrence seen during follow-up in patients where initial PLC was negative indicates the ongoing need for a better diagnostic tool for detecting clinically occult peritoneal disease, especially peritoneal micro-metastases. Advancement in liquid biopsy has allowed the development and use of peritoneal tumour DNA (ptDNA) as a cancer-specific biomarker within the peritoneum, and the presence of ptDNA may be a surrogate marker for early peritoneal metastases. A growing body of literature on ptDNA in different cancer types portends promising results. Here, we conduct a systematic review to evaluate the prognostic impact of ptDNA in various cancer types and discuss its potential future clinical applications, with a focus on gastrointestinal and gynaecological malignancies.

p53 Immunohistochemical Staining and TP53 Gene Mutations in Endometrial Cancer: Does Null Pattern Correlate With Prognosis?

Whether immunohistochemistry (IHC) of p53 accurately reflects the TP53 mutational status of endometrial carcinoma (EC) has not yet been established. This study aimed to clarify the relationship between p53 IHC and TP53 mutations in EC and to examine whether p53 IHC can be a more convenient prognostic marker than TP53 mutation in EC. We performed p53 IHC staining of EC samples obtained via surgery and genetic analyses using next-generation sequencing. p53 IHC results showed that of the 101 cases, 71 (70%) were wild-type (WT), 12 (12%) were overexpression (OE), and 18 (18%) were in the null group. Missense mutations were found in 9 cases (47.4%) in OE, 2 (10.5%) in null, and 8 (42.1%) in the WT group. Truncating mutations were found in 1 case (8.3%) in OE, 6 (50%) in null, and 5 (41.7%) in the WT group. The 5-year progression-free survival was 0% in OE, 74.8% in null, and 79.0% in the WT group. In the prognosis for each type of TP53 mutation, the 5-year progression-free survival was missense (32.2%), truncating (65.6%), and WT (79.7%). These survival comparisons showed that the p53 IHC OE had the poorest prognosis. These results suggest that the p53 IHC OE is an independent poor prognostic factor for EC and can be used as a simple and rapid surrogate marker for TP53 mutations. Contrastingly, the complete absence of p53 IHC-the null staining pattern-may not accurately predict a TP53 mutation in EC, and it is necessary to be more careful in making the diagnosis of "abnormal."

Nucleic Acid Quality Assessment is Critical to the Success of the Oncomine Dx Target Test for Lung Cancer

BACKGROUND AND OBJECTIVE

The Oncomine Dx Target Test (ODxTT) has been used as a companion diagnostic test for lung cancer. Here, we evaluated whether the amount of nucleic acid and the degree of RNA degradation are related to the success of the ODxTT.

METHODS

This study included 223 samples from 218 patients with lung cancer. For all samples, DNA and RNA concentrations were quantified using Qubit, and the degree of RNA degradation was evaluated using the Bioanalyzer.

RESULTS

Of the 223 samples, 219 samples were successfully analyzed in the ODxTT and four were not. DNA analysis failed in two samples, which were attributed to low DNA concentrations and both were cytology specimens. Meanwhile, RNA analysis failed in the other two samples. These samples had sufficient amounts of RNA, but it was highly degraded with DV200 (the percentage of RNA fragments > 200 base pairs) less than 30. Compared with RNA samples with DV200 ≥ 30, analysis of RNA with DV200 < 30 yielded significantly fewer reads for the internal control genes. This test showed actionable mutations were identified in 38% (83/218) of all patients and in 46.6% (76/163) of patients with lung adenocarcinoma.

CONCLUSIONS

DNA concentration and degree of RNA degradation are key factors determining the success of diagnostic testing by the ODxTT.

Cytopathological assessment is an accurate method for identifying immunophenotypic features and BRCA1/2 mutations of high-grade serous carcinoma from ascites

BACKGROUND

High-grade serous carcinoma (HGSC) is the most common and aggressive type of ovarian cancer, and it is often associated with ascites at presentation. The objective of this study was to evaluate the accuracy of cytopathology to identify immunophenotypic features of HGSC and BRCA1/2 mutations from ascites.

METHODS

The study included 45 patients with histologically confirmed primary HGSC and malignant ascites. Immunocytochemistry (ICC) staining for PAX8, WT1, P53, P16, and Ki-67 was performed on cytospins and cytoblocks prepared from ascites. Next-generation sequencing (NGS) was used to detect germline/somatic BRCA1/2 mutations in the ascites. Both ICC and NGS results were compared with immunohistochemistry (IHC) and NGS results from tissue blocks of primary tumor. Cronbach α and χ² statistics, respectively, were used.

RESULTS

ICC/IHC results for PAX8, WT1, P53, and P16 showed good reliability between cytospins, cytoblocks, and tissue blocks (α > 0.75), whereas poor reliability and significant differences were observed for Ki-67 between ascites and tissue blocks (α < 0.26; p < .001 [Kruskal-Wallis]). For germline BRCA1/2 mutations, 100% concordance was confirmed, but only 14% concordance was confirmed for somatic mutations.

CONCLUSIONS

These results demonstrate that cytopathology is an accurate method for identifying immunophenotypic features of HGSC and detecting germline BRCA1/2 mutations from ascites. However, further investigation is required for assessing the proliferation activity of HGSC in ascites and for detecting somatic BRCA1/2 mutations.