Diagnosis Of High-grade Serous Carcinoma Research Articles

Abstract B102: Mutational and copy number-based ctDNA profiles mirror high-grade serous cancer tumors and enable detection of genetic changes appearing at recurrence

Abstract Circulating tumor DNA (ctDNA) is the cancer-derived fraction of extracellular DNA fragments present in the bloodstream as cell-free DNA (cfDNA). Consequently, ctDNA harbors the distinct genomic information specific to the cancer from which it derives. Therefore, ctDNA from liquid biopsies provides a non-invasive, universally available alternative to traditional tumor biopsies. ctDNA amount may provide insight into tumor burden, as its concentration is typically highest during diagnosis and relapse. The non-invasive nature of this method facilitates frequent monitoring, enabling longitudinal tracking of the disease's trajectory and response to treatments. By focusing on the key genomic changes, either short mutations or copy number aberrations (CNA), liquid biopsy allows the investigation of cancer progression and evolution over time, providing invaluable insight into the behavior and adaptability of the cancer. We collected 152 longitudinal plasma samples and 92 fresh tissue samples from 29 patients enrolled in the DECIDER cohort (NCT04846933), after a diagnosis of high-grade serous carcinoma (HGSC), the most common and deadliest histological subtype of ovarian cancer. With ultra-deep targeted sequencing of a gene panel of more than 700 cancer-related genes we were able to comprehensively evaluate the cancer-related genomic changes. The concordance rate between mutations in plasma compared to tumor tissue was 83 % at diagnosis and 90 % at relapse, confirming the reliability of exploiting ctDNA in monitoring genomic alterations. Furthermore, by comparing plasma- and tissue-derived mutations, we demonstrated that comparable levels of ctDNA are released from adnexa, intra-abdominal lesions, and ascites, proposing that a liquid biopsy represents mutations from various locations. Analysis of CNA showed that our approach successfully detected concordant profiles in most plasma samples, even with tumor content as low as 3%. Additionally, highly amplified regions were identified in samples with approximately 1% tumor content. Longitudinal analysis of both mutations and CNA revealed genomic changes in plasma samples at relapse. Twenty-four new exonic mutations were identified in eight patients at relapse; two of these alterations were related to HRD status, supporting PARP-inhibitors as a valid treatment option. Furthermore, mutations in FGFR3, JAK2, FLT3 and CDKN2A could be investigated as target indications for extended use of currently available therapies. Eleven patients had high tumor content in their plasma samples at the time of relapse. We detected altered CNA profiles in seven of these eleven patients, so that five patients harbored only a few novel focal amplifications or losses, while two patients showed significant changes in their copy-number profile during the therapy. In conclusion, our study identified recurrence-specific genomic aberrations, proposing that ctDNA more accurately represents the metastatic tumor and provides possibilities for personalized therapy options. Citation Format: Giovanni Marchi, Mai T.N. Nguyen, Anna Rajavuori, Taru Muranen, Kaisa Huhtinen, Sinikka Oksa, Sakari Hietanen, Johanna Hynninen, Jaana Oikkonen, Sampsa Hautaniemi. Mutational and copy number-based ctDNA profiles mirror high-grade serous cancer tumors and enable detection of genetic changes appearing at recurrence [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B102.

Tumor-Stroma Proportion to Predict Chemoresistance in Patients With Ovarian Cancer

Platinum-based chemotherapy is the backbone of standard-of-care treatment for patients with advanced-stage, high-grade serous carcinoma (HGSC), the most common form of ovarian cancer; however, one-third of patients have or acquire chemoresistance toward platinum-based therapies. To demonstrate the utility of tumor-stroma proportion (TSP) as a predictive biomarker of chemoresistance of HGSC, progression-free survival (PFS), and overall survival (OS). This prognostic study leveraged tumors from patients with HGSC in The Cancer Genome Atlas (TCGA) cohort (1993-2013) and an independent cohort of resected clinical specimens from patients with HGSC (2004-2014) available in diagnostic and tissue microarray formats from the University of Tübingen in Germany. Data analysis was conducted from January 2021 to January 2024. Diagnosis of HGSC. Principal outcome measures were the ability of TSP to predict platinum chemoresistance, PFS, and OS. Using hematoxylin and eosin-stained slides from the Tübingen cohort (used for routine diagnostic assessment from surgical specimens) as well as tissue microarrays, representative sections of tumors for scoring of TSP were identified using previously evaluated cutoffs of 50% stroma or greater (high TSP) and less than 50% stroma (low TSP). Digitized slides from the TCGA Cohort were analyzed and scored in a similar fashion. Kaplan-Meier time-to-event functions were fit to estimate PFS and OS. The study included 103 patients (mean [SD] age, 61.6 [11.1] years) from the TCGA cohort and 192 patients (mean [SD] age at diagnosis, 63.7 [11.1] years) from the Tübingen cohort. In the TCGA cohort, there was no significant association of TSP levels with chemoresistance, PFS, or OS. However, in the Tübingen cohort, high TSP was associated with significantly shorter PFS (HR, 1.586; 95% CI, 1.093-2.302; P = .02) and OS (hazard ratio [HR], 1.867; 1.249-2.789; P = .002). Patients with chemoresistant tumors were twice as likely to have high TSP as compared to patients with chemosensitive tumors (HR, 2.861; 95% CI, 1.256-6.515; P = .01). In tissue microarrays from 185 patients from the Tübingen cohort, high TSP was again associated with significantly shorter PFS (HR, 1.675; 95% CI, 1.012-2.772 P = .04) and OS (HR, 2.491; 95% CI, 1.585-3.912; P < .001). In this prognostic study, TSP was a consistent and reproducible marker of clinical outcome measures of HGSC, including PFS, OS, and platinum chemoresistance. Accurate and cost-effective predictive biomarkers of platinum chemotherapy resistance are needed to identify patients most likely to benefit from standard treatments, and TSP can easily be implemented and integrated into prospective clinical trial design and adapted to identify patients who are least likely to benefit long-term from conventional platinum-based cytotoxic chemotherapy treatment at the time of initial diagnosis.

Establishment and characterization of a novel ovarian high-grade serous carcinoma cell line\u2014IPO43

BackgroundEpithelial ovarian cancer (EOC) is an aggressive and lethal malignancy and novel EOC cell lines with detailed characterization are needed, to provide researchers with diverse helpful resources to study EOC biological processes and cancer experimental therapies.MethodsThe IPO43 cell line was established from the ascitic fluid of a patient with a diagnosis of high-grade serous carcinoma (HGSC) of the ovary, previously treated with chemotherapy.Cell immortalization was achieved in 2D cell culture and growth obtained in 2D and 3D cell cultures. The characterization of immortalized cells was done by immunocytochemistry, flow cytometry, cell proliferation, chromosomal Comparative Genomic Hybridization (cCGH), STR profile and Next Generation Sequencing (NGS).ResultsCharacterization studies confirmed that IPO43 cell line is of EOC origin and maintains morphological and molecular features of the primary tumor. cCGH analysis showed a complex profile with gains and losses of specific DNA regions in both primary ascitic fluid and cell line IPO43. The cell line was successfully grown in a 3D system which allows its future application in more complex assays than those performed in 2D models. IPO43 cell line is resistant to standard drug treatment in vitro.ConclusionsIPO43 is available for public research and we hope it can contribute to enrich the in vitro models addressing EOC heterogeneity, being useful to investigate EOC and to develop new therapeutic modalities.

Low-grade serous carcinoma with solid growth pattern: an unusual architecture and potential pitfall

Low-grade serous carcinoma of the ovary is an uncommon lesion, composing approximately 3% of ovarian neoplasms. It typically arises in association with a serous borderline tumor and is most often at an advanced stage upon diagnosis. Gene mutations in BRAF and KRAS are characteristic. Various histologic architectural patterns are known, such as papillary, micropapillary, inverted micropapillary, glandular and nested. We report a case of low-grade serous carcinoma arising years after a serous borderline tumor and contralateral teratoma; the low-grade serous carcinoma showed two patterns: micropapillary growth and a previously unreported form of solid pattern manifesting as large tumor islands without slit-like spaces. This unusual solid morphology raises the differential diagnosis of high-grade serous carcinoma, which would result in different clinical management. The presence of areas with classic micropapillary architecture, in addition to the absence of high-grade cytonuclear atypia and marked pleomorphism, support the diagnosis of low-grade serous carcinoma. Immunohistochemical stains for p53 and p16 failed to show abnormal patterns characteristic of high-grade serous carcinoma. The patient declined chemotherapy and is on letrozole; she has had recurrent right pleural effusions over six months of follow-up after surgery.

Aberrant thyroid transcription factor-1 expression in ovarian and nasopharyngeal carcinoma: Case reports with review of literature

Introduction: Thyroid transcription factor-1 (TTF-1) is the recommended and sensitive immunohistochemical (IHC) marker for diagnosing lung adenocarcinomas and thyroid neoplasms, at the primary as well as the metastatic site, and is useful to rule out these sites in cases with adenocarcinomas of unknown primary. However, aberrant nuclear TTF-1 expression has also been reported in malignancies arising from gastrointestinal tract (GIT), breast carcinoma, female genital tract (FGT), and colon. Here, we present our experience of aberrant expression of TTF-1 in ovarian and nasopharyngeal carcinoma (NPC). Materials and Methods: TTF-1 immunostain was performed on 16 cases of NPC using clones SP141 and 8G7G3/1. A case of ovarian serous carcinoma with aberrant TTF-1 expression has also been discussed. Results: Of 16 cases of NPC, 2 cases (12.5%) showed strong TTF-1 expression with clone SP141, while all were negative with 8G7G3/1. In one of the case initial diagnosis of metastatic lung adenocarcinoma was made on cervical node biopsy as the tumor was negative for p40 and showed strong nuclear positivity for TTF-1 (SP141 clone). However, on clinical suspicion of NPC Epstein-Barr virus-encoded small RNA (EBER) by in situ hybridization was performed which was positive, and repeat TTF-1 using clone 8G7G3/1 was negative, suggested a NPC. In the case of ovarian tumor, cells were strongly positive for CK7 and TTF-1 (SP141 clone) expression, and thus the tumor was erroneously diagnosed as metastatic adenocarcinoma from a primary lung. However, IHC in the resected specimen showed strong expression for PAX-8 and TTF-1 using SP141 clone, while negative with clone 8G7G3/1 clone (Ventana), leading to final diagnosis of high-grade serous carcinoma of ovary with aberrant TTF-1 expression. In this case, addition of PAX-8 in initial biopsy diagnosis would have saved from labeling it as primary from lung. Conclusion: The sensitivity and aberrant expression vary between the various antibody clones used, with increased expression seen by SP141 clone as compared to 8G7G3/1 in our cases. Our findings highlight the significance of using a panel of diagnostic IHC markers before final diagnosis and importance of clinical details.

High-grade serous carcinoma with discordant p53 signature: report of a case with new insight regarding high-grade serous carcinogenesis

BackgroundAlthough p53 signature, benign-appearing epithelial cells with p53 diffuse expression, is frequently found in the fallopian tubes, the clinical and pathological significance of this lesion in the case of high-grade serous carcinoma (HGSC) patients still remains unclear.Case presentationA 56-year-old woman was referred to the gynecologist on account of abdominal distention. Since radiological and serological workup suggested that her illness was due to advanced ovarian cancer (FIGO Stage IVB), she received neoadjuvant chemotherapy, and the clinical evaluation of the chemotherapeutic response was a partial response. She underwent total hysterectomy with bilateral salpingo-oophorectomy, omentectomy, and intra-pelvic and para-aortic lymphadenectomy. Histologically, the cancer cells showed high-grade nuclear atypia and spread into the bilateral ovaries, omentum, uterine serosa, and left fallopian tube. The cancer cells showed complete absence of p53 but overexpressed p16, whereas some of benign-appearing tubal epithelial cells overexpressed p53 but lacked p16 expression. The results of direct sequence analysis revealed that the ovarian cancer contains a 1 bp deletion in exon 8 of TP53. Finally, the histological diagnosis of HGSC with discordant p53 signature was made. Interestingly, nuclear expression of γ-H2AX, a well-known marker of DNA damage, was not only observed in both p53 aberrantly-expressing lesions but also the benign-appearing tubal epithelium without p53 overexpression. After the histological confirmation, she received adjuvant chemotherapy and has been in disease-free condition without any detectable tumor for 5 months.ConclusionRecent evidence suggests that p53 signature is the putative precursor of p53 overexpression-type HGSC. Because the putative precursors of the other p53 immunophenotypical HGSC are not proposed, we presume γ-H2AX-expressing cells without p53 overexpression may be a potent candidate of null-type TP53-mutated tubal cells, which are named “γ-H2AX responsive foci.”

Gynecologic Serous Carcinoma: An Immunohistochemical Analysis of Malignant Body Fluid Specimens.

Evaluation of fluid specimens involved by serous carcinoma might potentially include PAX8, GATA3, Uroplakin II, SOX2, and SALL4 antibodies. Those markers are commonly employed for diagnosing carcinomas of various types, including urothelial malignancies and germ cell tumors. There have been no comprehensive immunohistochemical studies, to our knowledge, for those markers on fluid specimens involved by serous carcinoma. To evaluate immunohistochemical markers PAX8, GATA3, SOX2, uroplakin II, and SALL4 in the diagnosis of high-grade serous carcinoma in fluid specimens. We examined 113 fluids (96 ascites specimens and 17 pleural fluid specimens) that were positive for carcinoma. Most (94 cases; 83.2%) consisted of high-grade serous carcinoma of Müllerian origin. Nineteen cases of non-high-grade serous carcinoma (including one case of low-grade serous carcinoma) of gynecologic origin were also included as anecdotal data. In 113 fluid specimens with positive results for carcinoma, including nonserous types, 99 (87.6%) had positive results for PAX8, 19 (16.8%) for GATA3; 19 (16.8%) for SOX2, 23 (20.4%) for uroplakin II, and 8 (7.1%) for SALL4. Of 94 fluids (83.2%) involved with high-grade serous carcinoma, 84 (89.4%) had positive results for PAX8, 18 (19.1%) for GATA3, 17 (18.1%) for SOX2, 22 (23.4%) for uroplakin II, and 8 (8.5%) for SALL4. Some of these specimens showed reactivity for more than one immunohistochemical marker. Most fluids involving high-grade serous carcinoma showed positive results for PAX8, and some cases expressed GATA3, SOX2, uroplakin II, and SALL4. Serous carcinoma in fluids may be positive for immunohistochemical markers not thought of traditionally as associated with gynecologic malignancy, an important consideration in avoiding misdiagnosis.

The histomorphology of Lynch syndrome-associated ovarian carcinomas: toward a subtype-specific screening strategy.

Women with Lynch syndrome (LS) are at increased risk for the development of epithelial ovarian cancer (OC). Analogous to previous studies on BRCA1/2 mutation carriers, there is evidence to suggest a histotype-specific association in LS-associated OCs (LS-OC). Whereas the diagnosis of high-grade serous carcinoma is an indication for BRCA1/2 germline testing, in contrast, there are no screening guidelines in place for triaging OC patients for LS testing based on histotype. We performed a centralized pathology review of tumor subtype on 20 germline mutation-confirmed LS-OCs, on the basis of morphologic assessment of hematoxylin and eosin-stained slides, with confirmation by immunohistochemistry when necessary. Results from mismatch-repair immunohistochemistry (MMR-IHC) and microsatellite instability (MSI) phenotype status were documented, and detailed pedigrees were analyzed to determine whether previously proposed clinical criteria would have selected these patients for genetic testing. Review of pathology revealed all LS-OCs to be either pure endometrioid carcinoma (14 cases), mixed carcinoma with an endometrioid component (4 cases), or clear cell carcinoma (2 cases). No high-grade or low-grade serous carcinomas or mucinous carcinomas of intestinal type were identified. Tumor-infiltrating lymphocytes were prominent (≥40 per 10 high-powered fields) in 2 cases only. With the exception of 1 case, all tumors tested for MMR-IHC or MSI had an MMR-deficient phenotype. Within this cohort, 50%, 55%, 65%, and 85% of patients would have been selected for genetic workup by Amsterdam II, revised Bethesda Guidelines, SGO 10% to 25%, and SGO 5% to 10% criteria, respectively, with <60% of index or sentinel cases detected by any of these schemas. To further support a subtype-driven screening strategy, MMR-IHC reflex testing was performed on all consecutive non-serous OCs diagnosed at 1 academic hospital over a 2-year period; MMR deficiency was identified in 10/48 (21%) cases, all with endometrioid or clear cell histology. We conclude that there is a strong association between endometrioid and clear cell ovarian carcinomas and hereditary predisposition due to MMR gene mutation. These findings have implications for the role of tumor subtype in screening patients with OC for further genetic testing and support reflex MMR-IHC and/or MSI testing for newly diagnosed cases of endometrioid or clear cell ovarian carcinoma.