Serous Tubal Intraepithelial Carcinoma Research Articles

Serous Tubal Intraepithelial Carcinoma (STIC): A Review of the Literature on the Incidence at the Time of Prophylactic Surgery

Background: Serous tubal intraepithelial carcinoma (STIC) is an early-stage cancerous lesion found in the fallopian tubes, often at the fimbrial end. It is strongly associated with high-grade serous carcinoma (HGSC), a highly aggressive type of ovarian cancer. STIC is considered a precursor to many HGSC cases, originating in the fallopian tubes. Its development is frequently linked to mutations in the TP53 gene, leading to the formation of a p53 signature, an early abnormality that may progress to HGSC. This signature is more common in BRCA mutation carriers, explaining the higher incidence of STIC in this group. The aim of this review is to evaluate the literature on the incidence of serous tubal intraepithelial carcinoma in patients (both BRCA-positive and BRCA-negative) undergoing preventive salpingo-oophorectomy, analysing the available data and identifying associations between specific characteristics and the onset of STIC. Methods: A comprehensive review of the literature from 2016 to 2023 was conducted using PubMed, focusing on studies analysing the incidence of STIC in BRCA-positive patients undergoing preventive salpingo-oophorectomy. Data on patient characteristics, interventions, outcomes, and incidence of STIC were extracted and analysed. Results: Nine international studies were included in the review, reporting varying incidences of STIC among patients undergoing salpingo-oophorectomy. The overall incidence of STIC in all the women included in the studies was 7.31%, while that in the BRCA-mutated women was approximately 6.08%. Notably, the presence of the TP53 signature was significantly associated with the occurrence of STIC. Conclusions: The etiopathogenesis of STIC involves complex interactions between genetic, environmental, and molecular factors. Further research is needed to fully understand its mechanisms and identify additional risk factors beyond BRCA mutations. Establishing a national database of STIC cases could facilitate future research and improve patient outcomes.

Serous tubal intraepithelial carcinoma in high-risk patients: A comprehensive, single-institution study of 35 cases

Serous tubal intraepithelial carcinoma in high-risk patients: A comprehensive, single-institution study of 35 cases

STIC to it: The incidental finding of serous tubal intraepithelial carcinoma requires further testing

STIC to it: The incidental finding of serous tubal intraepithelial carcinoma requires further testing

Canadian management of Serous Tubal Intraepithelial Carcinoma (Can-STIC)

Canadian management of Serous Tubal Intraepithelial Carcinoma (Can-STIC)

Assessing the impact of deep-learning assistance on the histopathological diagnosis of serous tubal intraepithelial carcinoma (STIC) in fallopian tubes.

In recent years, it has become clear that artificial intelligence (AI) models can achieve high accuracy in specific pathology-related tasks. An example is our deep-learning model, designed to automatically detect serous tubal intraepithelial carcinoma (STIC), the precursor lesion to high-grade serous ovarian carcinoma, found in the fallopian tube. However, the standalone performance of a model is insufficient to determine its value in the diagnostic setting. To evaluate the impact of the use of this model on pathologists' performance, we set up a fully crossed multireader, multicase study, in which 26 participants, from 11 countries, reviewed 100 digitalized H&E-stained slides of fallopian tubes (30 cases/70 controls) with and without AI assistance, with a washout period between the sessions. We evaluated the effect of the deep-learning model on accuracy, slide review time and (subjectively perceived) diagnostic certainty, using mixed-models analysis. With AI assistance, we found a significant increase in accuracy (p < 0.01) whereby the average sensitivity increased from 82% to 93%. Further, there was a significant 44 s (32%) reduction in slide review time (p < 0.01). The level of certainty that the participants felt versus their own assessment also significantly increased, by 0.24 on a 10-point scale (p < 0.01). In conclusion, we found that, in a diverse group of pathologists and pathology residents, AI support resulted in a significant improvement in the accuracy of STIC diagnosis and was coupled with a substantial reduction in slide review time. This model has the potential to provide meaningful support to pathologists in the diagnosis of STIC, ultimately streamlining and optimizing the overall diagnostic process.

Pre-ciliated tubal epithelial cells are prone to initiation of high-grade serous ovarian carcinoma

The distal region of the uterine (Fallopian) tube is commonly associated with high-grade serous carcinoma (HGSC), the predominant and most aggressive form of ovarian or extra-uterine cancer. Specific cell states and lineage dynamics of the adult tubal epithelium (TE) remain insufficiently understood, hindering efforts to determine the cell of origin for HGSC. Here, we report a comprehensive census of cell types and states of the mouse uterine tube. We show that distal TE cells expressing the stem/progenitor cell marker Slc1a3 can differentiate into both secretory (Ovgp1+) and ciliated (Fam183b+) cells. Inactivation of Trp53 and Rb1, whose pathways are commonly altered in HGSC, leads to elimination of targeted Slc1a3+ cells by apoptosis, thereby preventing their malignant transformation. In contrast, pre-ciliated cells (Krt5+, Prom1+, Trp73+) remain cancer-prone and give rise to serous tubal intraepithelial carcinomas and overt HGSC. These findings identify transitional pre-ciliated cells as a cancer-prone cell state and point to pre-ciliation mechanisms as diagnostic and therapeutic targets.

Mutant p53 Misfolding and Aggregation Precedes Transformation into High-Grade Serous Ovarian Carcinoma.

High Grade Serous Ovarian Cancer (HG-SOC), the most prevalent and aggressive gynecological malignancy, is marked by ubiquitous loss of functional p53, largely due to point mutations that arise very early in carcinogenesis. These mutations often lead to p53 protein misfolding and subsequent aggregation, yet the alterations in intracellular p53 dynamics throughout ovarian cancer progression remain poorly understood. HG-SOC originates from the fallopian tube epithelium, with a well-documented stepwise progression beginning with early pre-malignant p53 signatures. These signatures represent largely normal cells that express and accumulate mutant p53, which then transform into benign serous tubal intraepithelial lesions (STIL), progress into late pre-malignant serous tubal intraepithelial carcinoma (STIC), and ultimately lead to HGSOC. Here, we show that the transition from folded, soluble to aggregated mutant p53 occurs during the malignant transformation of benign precursor lesions into HGSOC. We analyzed fallopian tube tissue collected from ten salpingo-oophorectomy cases and determined the proportion of cells carrying soluble versus mis-folded/mutant p53 through conformation-sensitive staining and quantification. Misfolded p53 protein, prone to aggregation, is present in STICs and HG-SOCs, but notably absent from preneoplastic lesions and surrounding healthy tissue. Overall, our results indicate that aggregation of mutant p53 is a structural defect that distinguishes preneoplastic early lesions from late premalignant and malignant ones, offering a potential treatment window for targeting p53 aggregation and halting ovarian cancer progression.

Histopathological spectrum of ovarian tumours

Background: Ovarian neoplasms include wide spectrum of various tumors, which differ in their histo-morphological features, also in their biological behaviour, tumorigenesis, clinical course, and prognosis. Aim of the study was to study the histopathological features of various ovarian tumors and correlate preoperative serum CA125 tumor marker level with histopathological types. Also to study fallopian tubes for fallopian tube precursor lesions such as serous tubal intraepithelial carcinoma (STIC) in serous carcinoma ovary. Methods: This cross-sectional observational study of the 80 specimens of ovarian tumors was conducted in department of pathology, Netaji Subhash Chandra Bose medical college Jabalpur (M.P.). The relevant data of the patients was collected and analysed as per designed proforma. Results: Out of 80 cases; majority cases 22 (27.5%) were seen in a 31-40 years age group, followed by 41-50 years age group 18 cases (22.5%). Youngest patient was 7 years old and oldest patient was 88 years old, forming the range of 7 years to 88 years. Epithelial tumors were the most common category, followed by germ cell tumors, sex cord stromal tumors and metastatic tumors. Benign tumors were much higher than borderline and malignant tumors mature cystic teratoma was the most common tumor encountered, followed by mucinous cystadenoma. The commonest malignant tumor was serous carcinoma followed by mucinous carcinoma. Conclusions: Ovarian neoplasms constitute a wide spectrum of tumors therefore exact categorization is important to adopt appropriate treatment protocols for the proper management of the patient. Histopathological examination is the gold standard for diagnosis and categorization of ovarian neoplasm.

Synchronous Bilateral Ovarian Carcinomas With Right Mesonephric-like Adenocarcinoma and Left High-grade Serous Carcinoma: A Case Report and Review of the Literature.

Mesonephric-like adenocarcinomas (MLAs) are rare neoplasms of the uterus corpus and ovary, while high-grade serous carcinoma (HGSC) is the most common and lethal epithelial ovarian malignancy. We report a case of a 56-yr-old woman who presented with bilateral solid and cystic ovarian masses. She underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy, lymphadenectomy, omentectomy, and peritoneal biopsies. Histopathologic examination of the bilateral ovarian masses revealed 1 ovary with MLA, and the other ovary showed HGSC in association with serous tubal intraepithelial carcinoma. The morphology, immunophenotypes, and molecular profiling of the HGSC and the MLA were distinct and as expected for the different tumor types: HGSC was diffusely positive for WT-1, estrogen receptor, and p53 (mutant pattern), while negative for GATA-3 and TTF-1; MLA was positive for GATA-3 and TTF-1, while negative for WT1, estrogen receptor, and p53 (wild-type pattern); both tumors were diffusely positive for PAX-8. The HGSC revealed a TP53 c.659A>G (p.Y220C) mutation, and the MLA revealed a KRAS c. 34G>T (p. G12C) mutation and a PIK3CA c. 1034A>T (p. N345I) mutation. To the best of our knowledge, this is the first reported case of synchronous bilateral ovarian carcinomas with MLA and contralateral ovarian HGSC.

Molecular Analysis of High-Grade Serous Ovarian Carcinoma Exhibiting Low-Grade Serous Carcinoma and Serous Borderline Tumor.

Ovarian cancer is classified as type 1 or 2, representing low- and high-grade serous carcinoma (LGSC and HGSC), respectively. LGSC arises from serous borderline tumor (SBT) in a stepwise manner, while HGSC develops from serous tubal intraepithelial carcinoma (STIC). Rarely, HGSC develops from SBT and LGSC. Herein, we describe the case of a patient with HGSC who presented with SBT and LGSC, and in whom we analyzed the molecular mechanisms of carcinogenesis. We performed primary debulking surgery, resulting in a suboptimal simple total hysterectomy and bilateral salpingo-oophorectomy due to strong adhesions. The diagnosis was stage IIIC HGSC, pT3bcN0cM0, but the tumor contained SBT and LGSC lesions. After surgery, TC (Paclitaxel + Carbopratin) + bevacizumab therapy was administered as adjuvant chemotherapy followed by bevacizumab as maintenance therapy. The tumor was chemo-resistant and caused ileus, and bevacizumab therapy was conducted only twice. Next-Generation Sequencing revealed KRAS (p.G12V) and NF2 (p.W184*) mutations in all lesions. Interestingly, the TP53 mutation was not detected in every lesion, and immunohistochemistry showed those lesions with wild-type p53. MDM2 was amplified in the HGSC lesions. DNA methylation analysis did not show differentially methylated regions. This case suggests that SBT and LGSC may transform into HGSC via p53 dysfunction due to MDM2 amplification.

Serous Tubal Intraepithelial Carcinoma After Neoadjuvant Chemotherapy: A Report of 2 Cases.

Serous tubal intraepithelial carcinoma (STIC) is regarded as the origin of most high-grade serous carcinomas (HGSC). After a diagnosis of isolated STIC, risk of developing HGSC is substantial. Since surveillance cannot detect HGSC in time to cure the disease, there is no consensus on the optimal treatment after a diagnosis of isolated STIC, but chemotherapy is considered one of the possible strategies. In this case report, we describe 2 women with advanced-stage HGSC treated with 3 cycles of neoadjuvant chemotherapy followed by interval debulking surgery. In both women, histopathological examination showed a complete histopathological tumor response, but a vital STIC was found in both cases. The 2 cases presented here indicate that STICs may not respond to chemotherapy. Further research focused on the underlying biology and chemosensitivity of STIC, as well as the effectiveness of treatment to prevent HGSC in case of isolated STIC, is needed.

Diagnosis and management of isolated serous tubal intraepithelial carcinoma: A qualitative focus group study.

A Serous Tubal Intraepithelial Carcinoma (STIC) without concomitant invasive carcinoma is occasionally identified and associated with a high risk of subsequent peritoneal carcinomatosis. Management needs optimisation. This study explores professionals' opinions and clinical practices regarding the diagnosis, counselling, treatment and follow-up of isolated STIC to facilitate clinical decision making and optimise the direction of future research. A secondary aim is to assess international clinical guidelines. Focus group study. Four online sessions. International panel (n = 12 countries) of gynaecologists, gynaecologic oncologists, pathologists and medical oncologists (n = 49). A semi-structured interview guide was used. Two independent researchers analysed transcripts by open and axial coding. Results were organised in domains. Relevant (inter)national guidelines were screened for recommendations regarding isolated STIC. Professionals' opinions and clinical practices regarding isolated STIC management. Regarding pathology, most professionals identified the SEE-FIM protocol as standard of care for high-risk patients, whereas variation exists in the histopathological examination of fallopian tubes in the general population. Confirmation of STIC diagnosis by a specialised pathologist was recommended. Regarding work-up and follow-up after STIC diagnosis, there was variety and discordance. Data on outcomes is limited. As for treatment, chemotherapy and PARP inhibitors were not recommended by most. Eleven guidelines provided limited recommendations. We identified recommendations and highlighted knowledge gaps in the diagnosis and management of isolated STIC. Moreover, recommendations in clinical guidelines are limited. There is an agreed need for international collaboration for the prospective registration of isolated STIC.

High-grade serous ovarian cancer (HGSOC) with fallopian tube involvement.

Literature data present new studies about precancerous lesions of pelvic serous carcinoma that originate from the tubal secretory cells. It has long been thought that ovarian cancer cannot be prevented by prophylactic screening or surgery. In recent years, gynecologists have adapted to new principles and so, during routine hysterectomies in perimenopausal women for benign uterine pathologies, salpingo-oophorectomy is performed as a prophylactic approach. The purpose of our article was to draw attention to the association between abnormal fallopian tube pathology and the presence of serous ovarian neoplasia in perimenopausal women at risk. We report the case of a 45-year-old woman who had unspecific symptoms of abdominal pain and loss of appetite and weight. A pelvic magnetic resonance imaging was performed, and an ovarian mass was detected. Our case shows that the fallopian tube can be the primary point of origin for a pelvic disease, therefore prevention is possible with early computed tomography scan and annual ultrasound. The patient presented with a T1c staging post-surgery and her chances of survival could have decreased if she had postponed medical examination longer. We found a significant increase in the absolute number of tubal secretory cells in patients with ovarian neoplasia, which supports the assumption that serous tubal intraepithelial carcinoma lesions are found especially in the serous ovarian type. Our article is a strong suggestion that serous ovarian cancer originates from the fallopian tube and can potentially serve as a sensitive biomarker for early serous carcinogenesis within the fallopian tube.

The pathologic and clinical outcomes of risk-reducing salpingo-oophorectomy in asymptomatic carriers of homologous recombination repair gene mutation.

To investigate the prevalence of pathological findings and clinical outcomes of risk-reducing salpingo-oophorectomy (RRSO) in asymptomatic carriers with germline homologous recombination repair (HRR) gene pathogenic/likely pathogenic variants (PV/LPV). This retrospective study enrolled asymptomatic carriers with germline HR gene PV/LPV who underwent RRSO between 2006 and 2022 at the National Cancer Center in Korea. Clinical characteristics, including history of breast cancer, family history of ovarian/breast cancer, parity, and oral contraceptive use, were analyzed. Of the 255 women who underwent RRSO, 129 (50.6%) had PV/LPV in BRCA1, 121 (47.5%) in BRCA2, and 2 (0.7%) had both BRCA1 and BRCA2 PV/LPV. In addition, 1 carried PV/LPV in RAD51D, and 2 in BRIP1. Among the BRCA1/2 PV/LPV carriers, occult neoplasms were identified in 3.5% of patients: serous tubal intraepithelial carcinoma (1.1%, n=3), fallopian tubal cancers (0.8%, n=2), ovarian cancer (1.2%, n=3), and breast cancer (0.4%, n=1). Of the 9 patients with occult neoplasms, 5 (2.0%) were identified from the 178 breast cancer patients, and 4 (1.6%) were detected in 65 healthy mutation carriers. During the median follow-up period of 36.7 months (interquartile range, 25.9-71.4), 1 (0.4%) BRCA1 PV carrier with no precursor lesions at RRSO developed primary peritoneal carcinomatosis after 30.1 months. Women with HRR gene mutations PV/LPV who undergo RRSO are at a risk of detecting occult neoplasms, with a of 3.5%. Even in the absence of precursor lesions during RRSO, there was a cumulative risk of peritoneal carcinomatosis development, emphasizing the need for continued surveillance.

The genomic trajectory of ovarian high-grade serous carcinoma can be observed in STIC lesions.

Ovarian high-grade serous carcinoma (HGSC) originates in the fallopian tube, with secretory cells carrying a TP53 mutation, known as p53 signatures, identified as potential precursors. p53 signatures evolve into serous tubal intraepithelial carcinoma (STIC) lesions, which in turn progress into invasive HGSC, which readily spreads to the ovary and disseminates around the peritoneal cavity. We recently investigated the genomic landscape of early- and late-stage HGSC and found higher ploidy in late-stage (median 3.1) than early-stage (median 2.0) samples. Here, to explore whether the high ploidy and possible whole-genome duplication (WGD) observed in late-stage disease were determined early in the evolution of HGSC, we analysed archival formalin-fixed paraffin-embedded (FFPE) samples from five HGSC patients. p53 signatures and STIC lesions were laser-capture microdissected and sequenced using shallow whole-genome sequencing (sWGS), while invasive ovarian/fallopian tube and metastatic carcinoma samples underwent macrodissection and were profiled using both sWGS and targeted next-generation sequencing. Results showed highly similar patterns of global copy number change between STIC lesions and invasive carcinoma samples within each patient. Ploidy changes were evident in STIC lesions, but not p53 signatures, and there was a strong correlation between ploidy in STIC lesions and invasive ovarian/fallopian tube and metastatic samples in each patient. The reconstruction of sample phylogeny for each patient from relative copy number indicated that high ploidy, when present, occurred early in the evolution of HGSC, which was further validated by copy number signatures in ovarian and metastatic tumours. These findings suggest that aberrant ploidy, suggestive of WGD, arises early in HGSC and is detected in STIC lesions, implying that the trajectory of HGSC may be determined at the earliest stages of tumour development. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Evaluation of the efficacy of marine natural products against PARP-1/2 proteins in high-grade serous ovarian cancer: insights into MD and SMD simulations

High-grade serous ovarian cancer (HGSOC) is the most malignant and ubiquitous phenotype of epithelial ovarian cancer. Originating in the fallopian tubes and rapidly spreading to the ovaries, this highly heterogeneous disease is a result of serous tubal intraepithelial carcinoma. The proteins known as poly(ADP-ribose) polymerase (PARP) aid in the development of HGSOC by repairing the cancer cells that proliferate and spread metastatically. By using molecular docking to screen 1100 marine natural products (MNPs) from different marine environments against PARP-1/2 proteins, prominent PARP inhibitors (PARPi) were identified. Four compounds, alisiaquinone A, alisiaquinone C, ascomindone D and (+)-zampanolide referred to as MNP-1, MNP-2, MNP-3 and MNP-4, respectively, were chosen based on their binding affinity towards PARP-1/2 proteins, and their bioavailability and drug-like qualities were accessed using ADMET analysis. To investigate the structural stability and dynamics of these complexes, molecular dynamics simulations were performed for 200 ns. These results were compared with the complexes of olaparib (OLA), a PARPi that has been approved by the FDA for the treatment of advanced ovarian cancer. We determined that MNP-4 exhibited stronger binding energies with PARP-1/2 proteins than OLA by using MM/PBSA calculations. Hotspot residues from PARP-1 (E883, M890, Y896, D899 and Y907) and PARP-2 (Y449, F450, A451, S457 and Y460) showed strong interactions with the compounds. To comprehend the unbinding mechanism of MNP-4 complexed with PARP-1/2, steered molecular dynamics (SMD) simulations were performed. We concluded from the free energy landscape (FEL) map that PARP-1/2 are well-stabilised when the compound MNP-4 is bound rather than being pulled away from its binding pockets. This finding provides significant evidence regarding PARPi, which could potentially be employed in the therapeutic treatment of HGSOC. Communicated by Ramaswamy H. Sarma

Incidental Serous Tubal Intraepithelial Carcinoma Finding in a Nepalese Patient Undergoing Opportunistic Salpingectomy and the Discovery of a BRCA1 Pathogenic Variant

BACKGROUND: Serous tubal intraepithelial carcinoma lesions are the precursor to high-grade serous ovarian carcinomas, which have the highest mortality rate among gynecologic malignancies. In women diagnosed with high-grade serous ovarian carcinoma, 20% of the carcinomas are found to be secondary to hereditary causes, with the majority being associated with germline pathogenic variants in BRCA1 and BRCA2 genes. Patients with a pathogenic variant are at high risk for developing high-grade serous ovarian carcinoma, so it is recommended that they undergo risk-reducing salpingo-oophorectomy in their 30s–40s. Opportunistic salpingectomy is the only ovarian cancer prevention method available for patients at average risk. Although serous tubal intraepithelial carcinoma lesions are rare in women at average risk, studies quote incidental serous tubal intraepithelial carcinoma lesion findings in 1–7% of patients undergoing opportunistic salpingectomy. CASE: A 38-year-old woman, gravida 2 para 2, of Nepalese ethnicity had an incidental finding of a serous tubal intraepithelial carcinoma lesion at the time of opportunistic salpingectomy for permanent sterilization at cesarean delivery. The serous tubal intraepithelial carcinoma lesion was found with representative sampling of the fallopian tubes because the patient was considered to be at average risk for ovarian cancer. This method is much less sensitive than the Sectioning and Extensively Examining the Fimbriated End (SEE-FIM) protocol, which is used with women known to be at high risk. This ultimately led to discovery of a BRCA1 mutation in the patient. CONCLUSION: The SEE-FIM protocol is used to identify serous tubal intraepithelial carcinoma lesions, but it is not routinely used on fallopian tubes of patients at average risk. Using the SEE-FIM protocol would lead to fewer missed serous tubal intraepithelial carcinoma lesions, but it is unclear how much extra cost and effort would be required to implement this protocol. There are knowledge gaps when it comes to understudied populations and hereditary breast and ovarian cancer gene prevalence. Studies show that current BRCA prediction models underestimate hereditary breast and ovarian cancer gene prevalence in Asian populations. Diagnosing serous tubal intraepithelial carcinoma lesions in understudied populations could lead to the discovery of a hereditary breast and ovarian cancer pathogenic variant that the patient may not have discovered until after a cancer diagnosis. Identification of a serous tubal intraepithelial carcinoma in a patient at average risk should lead to a referral for genetic counseling and screening.

Deep learning detects premalignant lesions in the Fallopian tube

Tubo-ovarian high-grade serous carcinoma is believed to originate in the fallopian tubes, arising from precursor lesions like serous tubal intraepithelial carcinoma (STIC) and serous tubal intraepithelial lesion (STIL). Adequate diagnosis of these precursors is important, but can be challenging for pathologists. Here we present a deep-learning algorithm that could assist pathologists in detecting STIC/STIL. A dataset of STIC/STIL (n = 323) and controls (n = 359) was collected and split into three groups; training (n = 169), internal test set (n = 327), and external test set (n = 186). A reference standard was set for the training and internal test sets, by a panel review amongst 15 gynecologic pathologists. The training set was used to train and validate a deep-learning algorithm (U-Net with resnet50 backbone) to differentiate STIC/STIL from benign tubal epithelium. The model’s performance was evaluated on the internal and external test sets by ROC curve analysis, achieving an AUROC of 0.98 (95% CI: 0.96–0.99) on the internal test set, and 0.95 (95% CI: 0.90–0.99) on the external test set. Visual inspection of all cases confirmed the accurate detection of STIC/STIL in relation to the morphology, immunohistochemistry, and the reference standard. This model’s output can aid pathologists in screening for STIC, and can contribute towards a more reliable and reproducible diagnosis.

High-grade Serous Carcinoma Occurring in a Serous Cystadenoma on the Background of a Serous Tubal Intraepithelial Carcinoma (STIC)-like Lesion: A Case Report With Literature Review.

At present, the prevailing concept is that high-grade serous carcinoma (HGSC) arises from the fallopian tubes (FTs). We report an HGSC case occurring in a serous ovarian cyst against the background of a serous tubal intraepithelial carcinoma (STIC)-like lesion. We also provide a literature review that contains references to clinical cases of the occurrence of STIC-like lesions in the ovary and phylogenetic studies that do not always reveal obvious bonds between early dysplastic serous lesions and HGSC. The article discusses cases of association between HGSCs of serous borderline tumors (SBTs) and low-grade serous carcinomas (LGSCs) in the context of their possible histogenetic relationship. We propose a concept in which high-grade serous carcinogenesis, represented by the p53-signature-STIC-HGSC continuity, occurs in the serous epithelium of both the FT and other locations.

Genomic Catastrophe (Chromothripsis and Polyploidy) Correlates With Tumor Distribution in Extrauterine High-grade Serous Carcinoma.

Most extrauterine high-grade serous carcinomas (HGSCs) are thought to develop first in the distal fallopian tube. Most models of HGSC assume origin from relatively stable, noninvasive serous tubal intraepithelial carcinomas. However, widespread tumor involvement in the absence of a serous tubal intraepithelial carcinoma could occur after catastrophic genomic events (CGEs; such as chromothripsis or polyploidy). Twenty-six HGSCs assigned to fallopian tube (n = 9, group 1) and/or ovary (n = 9, group 2), and primary peritoneal (n = 8, group 3) were assessed by microarray (Oncoscan). CGEs were identified in 15/26 (57.7%); chromothripsis-like pattern in 13/26 (50.0%) and polyploidy in 6/26 (23.1%). CGE was seen in 4/9 (44.4%), 9/9 (100%), and 2/8 (25%) cases in groups 1. 2, and 3, respectively. Overall, CGEs were seen in 9/9 (100%) cases with grossly evident ovarian parenchymal involvement versus 6/17 (35.3%) without ( P = 0.0024). Ovarian size (measured on the long axis) correlated with CGE positivity ( P = 0.016). CGEs are significantly more common in HGSCs with ovarian parenchymal involvement compared with those limited to the fallopian tube and/or extraovarian tissues. These associations suggest geographically different tumor growth patterns and support the subdivision of HGSCs according to not only the stage but also tumor distribution. They have implications for clinical and pathologic presentation, trajectory of tumor evolution, and in the case of primary peritoneal HGSCs, potentially unique precursors to tumor transitions that could inform or influence cancer prevention efforts.