De-escalation of axillary treatment in the event of a positive sentinel lymph node biopsy in cT1-2 N0 breast cancer treated with mastectomy: nationwide registry study (BOOG 2013-07).

BACKGROUND: Trials have demonstrated the safety of omitting completion axillary lymph node dissection in patients with cT1-2 N0 breast cancer operated with breast-conserving surgery who have limited metastatic burden in the sentinel lymph node. The aim of this registry study was to provide insight into the oncological safety of omitting completion axillary treatment in patients operated with mastectomy who have limited-volume sentinel lymph node metastasis. METHODS: Women diagnosed in 2013-2014 with unilateral cT1-2 N0 breast cancer treated with mastectomy, with one to three sentinel lymph node metastases (pN1mi-pN1a), were identified from the Netherlands Cancer Registry, and classified by axillary treatment: no completion axillary treatment, completion axillary lymph node dissection, regional radiotherapy, or completion axillary lymph node dissection followed by regional radiotherapy. The primary endpoint was 5-year regional recurrence rate. Secondary endpoints included recurrence-free interval and overall survival, among others. RESULTS: In total, 1090 patients were included (no completion axillary treatment, 219 (20.1%); completion axillary lymph node dissection, 437 (40.1%); regional radiotherapy, 327 (30.0%); completion axillary lymph node dissection and regional radiotherapy, 107 (9.8%)). Patients in the group without completion axillary treatment had more favourable tumour characteristics and were older. The overall 5-year regional recurrence rate was 1.3%, and did not differ significantly between the groups. The recurrence-free interval was also comparable among groups. The group of patients who did not undergo completion axillary treatment had statistically significantly worse 5-year overall survival, owing to a higher percentage of non-cancer deaths. CONCLUSION: In this registry study of patients with cT1-2 N0 breast cancer treated with mastectomy, with low-volume sentinel lymph node metastasis, the 5-year regional recurrence rate was low and comparable between patients with and without completion axillary treatment.

Performance of MRI for Detection of ≥pT1b Disease in Local Staging of Endometrial Cancer.

Magnetic resonance imaging (MRI) can be used for the preoperative local staging of endometrial cancer (EC). The presence of ≥pT1b disease (i.e., tumor invasion in ≥50% of the myometrium, into the cervical stroma or spread outside the uterus) has important prognostic value and implications for the decision to perform lymphadenectomy. The purpose of this study was to assess the performance of MRI for the detection of ≥pT1b disease and to evaluate whether tumor size measured via MRI was predictive for ≥pT1b disease, independent of imaging signs of deep invasion. MRI T-staging and tumor diameter and volume were correlated with histopathology of the hysterectomy specimen in 126 patients. MRI had a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 70.0%, 83.3%, 79.2%, 75.3% and 77.0%, respectively, for the detection of ≥pT1b disease. A tumor diameter of ≥40 mm and volume of ≥20 mL measured via MRI were predictive for ≥pT1b disease at rates of 78.3% and 87.1%, respectively. An EC size of at least 5 mm upon MRI was predictive for ≥pT1b disease in more than 50% of cases. Our results support the use of MRI in the preoperative staging of EC and suggest including size criteria in EC staging guidelines.

Identification of potentially actionable genetic variants in epithelial ovarian cancer: a retrospective cohort study.

Ovarian cancer is the most lethal gynecologic malignancy, mainly due to late-stage diagnosis, frequent recurrences, and eventually therapy resistance. To identify potentially actionable genetic variants, sequencing data of 351 Belgian ovarian cancer patients were retrospectively captured from electronic health records. The cohort included 286 (81%) patients with high-grade serous ovarian cancer, 17 (5%) with low-grade serous ovarian cancer, and 48 (14%) with other histotypes. Firstly, an overview of the prevalence and spectrum of the BRCA1/2 variants highlighted germline variants in 4% (11/250) and somatic variants in 11% (37/348) of patients. Secondly, application of a multi-gene panel in 168 tumors revealed a total of 214 variants in 28 genes beyond BRCA1/2 with a median of 1 (IQR, 1-2) genetic variant per patient. The ten most often altered genes were (in descending order): TP53, BRCA1, PIK3CA, BRCA2, KRAS, ERBB2 (HER2), TERT promotor, RB1, PIK3R1 and PTEN. Of note, the genetic landscape vastly differed between the studied histotypes. Finally, using ESCAT the clinical evidence of utility for every genetic variant was scored. Only BRCA1/2 pathogenic variants were classified as tier-I. Nearly all patients (151/168; 90%) had an ESCAT tier-II variant, most frequently in TP53 (74%), PIK3CA (9%) and KRAS (7%). In conclusion, our findings imply that although only a small proportion of genetic variants currently have direct impact on ovarian cancer treatment decisions, other variants could help to identify novel (personalized) treatment options to address the poor prognosis of ovarian cancer, particularly in rare histotypes.

Outcomes of patients with early stage mucinous ovarian carcinoma: a Dutch population-based cohort study comparing expansile and infiltrative subtypes.

OBJECTIVE: This study aimed to assess the outcomes of patients with early stage mucinous ovarian carcinoma based on subtype (expansile vs infiltrative). METHODS: We retrospectively analyzed all surgically treated patients with mucinous ovarian carcinoma in the Netherlands (2015-2020), using data from national registries. Subtypes were determined, with any ambiguities resolved by a dedicated gynecologic pathologist. Patients with International Federation of Gynecology and Obstetrics (FIGO) stage I were categorized into full staging, fertility-sparing, or partial stagings. Outcomes were overall survival and recurrence free survival, and recurrence rates. RESULTS: Among 409 identified patients, 257 (63%) had expansile and 152 (37%) had infiltrative tumors. Patients with expansile tumors had FIGO stage I more frequently (n=243, 95% vs n=116, 76%, p<0.001). For FIGO stage I disease, patients with expansile and infiltrative tumors underwent similar proportions of partial (n=165, 68% vs n=78, 67%), full (n=32, 13% vs n=23, 20%), and fertility-sparing stagings (n=46, 19% vs n=15, 13%) (p=0.139). Patients with expansile FIGO stage I received less adjuvant chemotherapy (n=11, 5% vs n=24, 21%, p<0.001), exhibited better overall and recurrence free survival (p=0.006, p=0.012), and fewer recurrences (n=13, 5% vs n=16, 14%, p=0.011). Survival and recurrence rates were similar across the expansile extent of staging groups. Patients undergoing fertility-sparing staging for infiltrative tumors had more recurrences compared with full or partial stagings, while recurrence free survival was similar across these groups. Full staging correlated with better overall survival in infiltrative FIGO stage I (p=0.022). CONCLUSIONS: While most patients with FIGO stage I underwent partial staging, those with expansile had better outcomes than those with infiltrative tumors. Full staging was associated with improved overall survival in infiltrative, but not in expansile FIGO stage I. These results provide insight for tailored surgical approaches.

Does "One Size Fits All"? Rethinking FIGO Depth of Invasion Measurements in Vulvar Cancer.

Depth of invasion (DOI) is an important diagnostic parameter in patients with vulvar carcinoma, where a cutoff value of 1 mm largely determines the tumor stage and the need for groin surgery. DOI measurement should be reproducible and straightforward. In light of the new recommendation on how to measure DOI in the International Federation of Gynecology and Obstetrics (FIGO) staging system 2021, an exploratory study was conducted on the current practice of DOI measurement in vulvar cancer. In this study of 26 selected cases, 10 pathologists with high exposure to vulvar cancer cases in daily practice assessed both the conventional (FIGO 2009) and alternative (FIGO 2021) DOI methods for applicability and preference. In this set of cases, the DOI measurement according to FIGO 2009 was generally considered easier to apply than the measurement according to FIGO 2021, with applicability being rated as "easy to reasonable" in 76.9% versus 38.5% of cases, respectively ( P =0.005). The preferred method was FIGO 2009 or tumor thickness in 14 cases and FIGO 2021 in 6 cases. No invasion was preferred in 1 case. For the remaining 5 cases, half of the pathologists opted for the FIGO 2009 method and half for the FIGO 2021 method. Although the FIGO 2009 method proved to be more readily applicable in most of the cases studied, the method may differ for each case. There may not be a "one size fits all" solution for all cases of vulvar cancer.

Diagnosis of verruciform acanthotic vulvar intra-epithelial neoplasia (vaVIN) using CK17, SOX2 and GATA3 immunohistochemistry.

AIMS: Verruciform acanthotic vulvar intra-epithelial neoplasia (vaVIN) is an HPV-independent, p53 wild-type lesion with distinct morphology and documented risk of recurrence and cancer progression. vaVIN is rare, and prospective distinction from non-neoplastic hyperplastic lesions can be difficult. CK17, SOX2 and GATA3 immunohistochemistry has emerging value in the diagnosis of HPV-independent lesions, particularly differentiated VIN. We aimed to test the combined value of these markers in the diagnosis of vaVIN versus its non-neoplastic differentials in the vulva. METHODS AND RESULTS: CK17, SOX2 and GATA3 immunohistochemistry was evaluated on 16 vaVINs and 34 mimickers (verruciform xanthoma, lichen simplex chronicus, lichen sclerosus, psoriasis, pseudo-epitheliomatous hyperplasia). CK17 was scored as 3+ = full-thickness, 2+ = partial-thickness, 1+ = patchy, 0 = absent; SOX2 as 3+ = strong staining ≥ 10% cells, 2+ = moderate, 1 + =weak, 0 = staining in < 10% cells; and GATA3 as pattern 0 = loss in < 25% basal cells, 1 = loss in 25-75% basal cells, 2 = loss in > 75% basal cells. For analysis, results were recorded as positive (CK17 = 3+, SOX2 = 3+, GATA3 = patterns 1/2) or negative (CK17 = 2+/1+/0, SOX2 = 2+/1+/0, GATA3 = pattern 0). CK17, SOX2 and GATA3 positivity was documented in 81, 75 and 58% vaVINs, respectively, versus 32, 17 and 22% of non-neoplastic mimickers, respectively; ≥ 2 marker positivity conferred 83 sensitivity, 88 specificity and 86% accuracy in vaVIN diagnosis. Compared to vaVIN, SOX2 and GATA3 were differentially expressed in lichen sclerosus, lichen simplex chronicus and pseudo-epitheliomatous hyperplasia, whereas CK17 was differentially expressed in verruciform xanthoma and adjacent normal mucosa. CONCLUSIONS: CK17, SOX2 and GATA3 can be useful in the diagnosis of vaVIN and its distinction from hyperplastic non-neoplastic vulvar lesions. Although CK17 has higher sensitivity, SOX2 and GATA3 are more specific, and the combination of all markers shows optimal diagnostic accuracy.

Practical guidelines of the EOTTD for pathological and genetic diagnosis of hydatidiform moles.

Hydatidiform moles are rare and thus most pathologists and geneticists have little experience with their diagnosis. It is important to promptly and correctly identify hydatidiform moles given that they are premalignant disorders associated with a risk of persistent gestational trophoblastic disease and gestational trophoblastic neoplasia. Improvement in diagnosis can be achieved with uniformization of diagnostic criteria and establishment of algorithms. To this aim, the Pathology and Genetics Working Party of the European Organisation for Treatment of Trophoblastic Diseases has developed guidelines that describe the pathological criteria and ancillary techniques that can be used in the differential diagnosis of hydatidiform moles. These guidelines are based on the best available evidence in the literature, professional experience and consensus of the experts' group involved in its development.

Fibroepithelial Stromal Polyp of the Vulvovaginal Region as Part of the RB1 Family of Tumors: Friend or Foe?

Fibroepithelial stromal polyps (FSPs) are benign mesenchymal lesions occurring in the vulvovaginal region. Following the identification of loss of Retinoblastoma 1 (RB1) on immunohistochemical staining in routine practice, we stained a series of FSPs and performed additional fluorescence in situ hybridization (FISH) and copy number variation (CNV) sequencing to detect losses/deletions in the Retinoblastoma transcriptional corepressor 1 (RB1) gene. Fifteen FSP cases were stained for RB1, and subsequently, 9 cases were examined by FISH to detect a loss of RB1 (13q). Next, CNV sequencing was performed to assess genomic alterations. The mean age of the patients was 50 years. Loss of RB1 expression on immunohistochemistry was seen in 13 cases, and heterogeneous RB1 staining in the remaining 2 cases. FISH showed deletion of RB1 in all of the cases. CNV sequencing failed in almost all cases due to a low tumor content. Based on our findings, we hypothesize that FSPs are part of a spectrum of genetically related lesions, namely the 13q/RB1 family of tumors (which includes pleomorphic fibromas and spindle cell/pleomorphic lipomas). Due to the clinical, morphologic, and molecular overlap, we suggest that FSPs are pleomorphic fibromas occurring in the specialized stroma of the genital region.

Endometrial Pipelle Biopsy Computer-Aided Diagnosis: A Feasibility Study.

Endometrial biopsies are important in the diagnostic workup of women who present with abnormal uterine bleeding or hereditary risk of endometrial cancer. In general, approximately 10% of all endometrial biopsies demonstrate endometrial (pre)malignancy that requires specific treatment. As the diagnostic evaluation of mostly benign cases results in a substantial workload for pathologists, artificial intelligence (AI)-assisted preselection of biopsies could optimize the workflow. This study aimed to assess the feasibility of AI-assisted diagnosis for endometrial biopsies (endometrial Pipelle biopsy computer-aided diagnosis), trained on daily-practice whole-slide images instead of highly selected images. Endometrial biopsies were classified into 6 clinically relevant categories defined as follows: nonrepresentative, normal, nonneoplastic, hyperplasia without atypia, hyperplasia with atypia, and malignant. The agreement among 15 pathologists, within these classifications, was evaluated in 91 endometrial biopsies. Next, an algorithm (trained on a total of 2819 endometrial biopsies) rated the same 91 cases, and we compared its performance using the pathologist's classification as the reference standard. The interrater reliability among pathologists was moderate with a mean Cohen's kappa of 0.51, whereas for a binary classification into benign vs (pre)malignant, the agreement was substantial with a mean Cohen's kappa of 0.66. The AI algorithm performed slightly worse for the 6 categories with a moderate Cohen's kappa of 0.43 but was comparable for the binary classification with a substantial Cohen's kappa of 0.65. AI-assisted diagnosis of endometrial biopsies was demonstrated to be feasible in discriminating between benign and (pre)malignant endometrial tissues, even when trained on unselected cases. Endometrial premalignancies remain challenging for both pathologists and AI algorithms. Future steps to improve reliability of the diagnosis are needed to achieve a more refined AI-assisted diagnostic solution for endometrial biopsies that covers both premalignant and malignant diagnoses.

Soft Tissue and Bone Tumor Diagnostics: Harnessing the Power of Molecular Techniques.

Since the introduction of new molecular techniques, the diagnostic landscape of soft tissue and bone tumors has expanded greatly over the past few years. The use of new molecular techniques has led to the identification of new genetic alterations and, therefore, to a better understanding of tumorigenesis, tumor detection and classification. Furthermore, methylation profiling has emerged as a classification tool for soft tissue and bone tumors. Molecular pathology also plays an important role in the determination of patient prognosis and in the identification of targets that can be used for targeted therapy. As a result, molecular pathology has gained a more prominent role in the daily practice of the surgical pathologist. This review delves into various molecular techniques applied in the surgical pathology of soft tissue and bone tumors. It highlights their applications through the analysis of five specific cases.

The prognostic value of tumor-stroma ratio and a newly developed computer-aided quantitative analysis of routine H&E slides in high-grade serous ovarian cancer.

Introduction: Tumor-stroma ratio (TSR) is prognostic in multiple cancers, while its role in high-grade serous ovarian cancer (HGSOC) remains unclear. Despite the prognostic insight gained from genetic profiles and tumor-infiltrating lymphocytes (TILs), the prognostic use of histology slides remains limited, while it enables the identification of tumor characteristics via computational pathology reducing scoring time and costs. To address this, this study aimed to assess TSR's prognostic role in HGSOC and its association with TILs. We additionally developed an algorithm, Ovarian-TSR (OTSR), using deep learning for TSR scoring, comparing it to manual scoring. Methods: 340 patients with advanced-stage who underwent primary debulking surgery (PDS) or neo-adjuvant chemotherapy (NACT) with interval debulking (IDS). TSR was assessed in both the most invasive (MI) and whole tumor (WT) regions through manual scoring by pathologists and quantification using OTSR. Patients were categorized as stroma-rich (≥ 50% stroma) or stroma-poor (< 50%). TILs were evaluated via immunohistochemical staining. Results: In PDS, stroma-rich tumors were significantly associated with a more frequent papillary growth pattern (60% vs 34%), while In NACT stroma-rich tumors had a lower Tumor Regression Grading (TRG 4&5, 21% vs 57%) and increased pleural metastasis (25% vs 16%). Stroma-rich patients had significantly shorter overall and progression-free survival compared to stroma-poor (31 versus 45 months; P < 0.0001, and 15 versus 17 months; P = 0.0008, respectively). Combining stromal percentage and TILs led to three distinct survival groups with good (stroma-poor, high TIL), medium (stroma-rich, high TIL, or; stroma-poor, Low TIL), and poor(stroma-rich, low TIL) survival. These survival groups remained significant in CD8 and CD103 in multivariable analysis (Hazard ratio (HR) = 1.42, 95% Confidence-interval (CI) = 1.02-1.99; HR = 1.49, 95% CI = 1.01-2.18, and HR = 1.48, 95% CI = 1.05-2.08; HR = 2.24, 95% CI = 1.55-3.23, respectively). OTSR was able to recapitulate these results and demonstrated high concordance with expert pathologists (correlation = 0.83). Conclusions: TSR is an independent prognostic factor for survival assessment in HGSOC. Stroma-rich tumors have a worse prognosis and, in the case of NACT, a higher likelihood of pleural metastasis. OTSR provides a cost and time-efficient way of determining TSR with high reproducibility and reduced inter-observer variability.

Histologic tumor type as a determinant of survival in hormone receptor-positive, HER2-negative, pT1-3 invasive ductal and lobular breast cancer.

PURPOSE: The aim of the study was to compare the difference in survival between invasive ductal (IDC) and lobular carcinoma (ILC). METHODS: Data of patients (n = 1843) with a hormone receptor-positive, HER2-negative, pT1-3 IDC or ILC cancer without distant metastasis, treated at the Ghent University Hospital over the time period 2001-2015, were analyzed. RESULTS: ILC represented 13.9% of the tumors, had a higher percentage of pT3 and pN3 stages than IDC, lymphovascular space invasion (LVSI) was less present and Ki-67 was mostly low. 73.9% of ILCs were grade 2, whereas IDC had more grade 1 and grade 3 tumors. Kaplan-Meier curves and log-rank testing showed a significant worse DFS for ILC with pN ≥ 1 than for their IDC counterpart. In a multivariable Cox regression analysis the histologic tumor type, ductal or lobular, was a determinant of DFS over 120 months (IDC as reference; hazard ratio for ILC 1.77, 95% CI 1.08-2.90) just as the ER Allred score (hazard ratio 0.84, 95% CI 0.78-0.91), LVSI (hazard ratio 1.75, 95% CI 1.12-2.74) and pN3 (hazard ratio 2.29, 95% CI 1.03-5.09). Determinants of OS over ten years were age (hazard ratio 1.05, 95% CI 1.02-1.07), LVSI (hazard ratio 3.62, 95% CI 1.92-6.82) and the ER Allred score (hazard ratio 0.80, 95% CI 0.73-0.89). CONCLUSION: The histologic tumor type, ductal or lobular, determines DFS in hormone receptor-positive, HER2-negative, pT1-3 breast cancer besides the ER Allred score, LVSI and pN3.

A preclinical platform for assessing long-term drug efficacy exploiting mechanically tunable scaffolds colonized by a three-dimensional tumor microenvironment.

BACKGROUND: Long-term drug evaluation heavily relies upon rodent models. Drug discovery methods to reduce animal models in oncology may include three-dimensional (3D) cellular systems that take into account tumor microenvironment (TME) cell types and biomechanical properties. METHODS: In this study we reconstructed a 3D tumor using an elastic polymer (acrylate-endcapped urethane-based poly(ethylene glycol) (AUPPEG)) with clinical relevant stiffness. Single cell suspensions from low-grade serous ovarian cancer (LGSOC) patient-derived early passage cultures of cancer cells and cancer-associated fibroblasts (CAF) embedded in a collagen gel were introduced to the AUPPEG scaffold. After self-organization in to a 3D tumor, this model was evaluated by a long-term (> 40 days) exposure to a drug combination of MEK and HSP90 inhibitors. The drug-response results from this long-term in vitro model are compared with drug responses in an orthotopic LGSOC xenograft mouse model. RESULTS: The in vitro 3D scaffold LGSOC model mimics the growth ratio and spatial organization of the LGSOC. The AUPPEG scaffold approach allows to test new targeted treatments and monitor long-term drug responses. The results correlate with those of the orthotopic LGSOC xenograft mouse model. CONCLUSIONS: The mechanically-tunable scaffolds colonized by a three-dimensional LGSOC allow long-term drug evaluation and can be considered as a valid alternative to reduce, replace and refine animal models in drug discovery.

Cytoreductive surgery with or without hyperthermic intraperitoneal chemotherapy in patients with advanced ovarian cancer (OVHIPEC-1): final survival analysis of a randomised, controlled, phase 3 trial.

BACKGROUND: The OVHIPEC-1 trial previously showed that the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) to interval cytoreductive surgery resulted in improved progression-free and overall survival compared with cytoreductive surgery alone at 4·7 years of follow-up in patients with stage III epithelial ovarian cancer who were ineligible for primary cytoreduction. We report the final survival outcomes after 10 years of follow-up. METHODS: In this open-label, randomised, controlled, phase 3 trial, patients with primary epithelial stage III ovarian cancer were recruited at eight HIPEC centres in the Netherlands and Belgium. Patients were eligible if they were aged 18-76 years, had not progressed during at least three cycles of neoadjuvant carboplatin plus paclitaxel, had a WHO performance status score of 0-2, normal blood counts, and adequate renal function. Patients were randomly assigned (1:1) to undergo interval cytoreductive surgery without HIPEC (surgery group) or with HIPEC (100 mg/m2 cisplatin; surgery-plus-HIPEC group). Randomisation was done centrally by minimisation with a masked web-based allocation procedure at the time of surgery when residual disease smaller than 10 mm diameter was anticipated, and was stratified by institution, previous suboptimal cytoreductive surgery, and number of abdominal regions involved. The primary endpoint was progression-free survival and a secondary endpoint was overall survival, analysed in the intention-to-treat population (ie, all randomly assigned patients). This study is registered with ClinicalTrials.gov, NCT00426257, and is closed. FINDINGS: Between April 1, 2007, and April 30, 2016, 245 patients were enrolled and followed up for a median of 10·1 years (95% CI 8·4-12·9) in the surgery group (n=123) and 10·4 years (95% CI 9·5-13·3) in the surgery-plus-HIPEC group (n=122). Recurrence, progression, or death occurred in 114 (93%) patients in the surgery group (median progression-free survival 10·7 months [95% CI 9·6-12·0]) and 109 (89%) patients in the surgery-plus-HIPEC group (14·3 months [12·0-18·5]; hazard ratio [HR] 0·63 [95% CI 0·48-0·83], stratified log-rank p=0·0008). Death occurred in 108 (88%) patients in the surgery group (median overall survival 33·3 months [95% CI 29·0-39·1]) and 100 (82%) patients in the surgery-plus-HIPEC group (44·9 months [95% CI 38·6-55·1]; HR 0·70 [95% CI 0·53-0·92], stratified log-rank p=0·011). INTERPRETATION: These updated survival results confirm the long-term survival benefit of HIPEC in patients with primary stage III epithelial ovarian cancer undergoing interval cytoreductive surgery. FUNDING: Dutch Cancer Foundation (KWF Kankerbestrijding).

Tumor-Infiltrating Lymphocytes and PD-L1 Expression in Pleomorphic Lobular Breast Carcinoma.

BACKGROUND: The prognostic and predictive role of stromal tumor-infiltrating lymphocytes (sTILs) is undetermined in pleomorphic invasive lobular cancer (pILC). The same applies for the expression of PD-1/PD-L1 in this rare breast cancer subtype. Here, we aimed to investigate the expression of sTILs and analyze the PD-L1 expression levels in pILC. METHODS: Archival tissues from sixty-six patients with pILC were collected. The sTIL density was scored as a percentage of tumor area using the following cut-offs: 0%; <5%; 5-9%; and 10-50%. The PD-L1 expression was analyzed using IHC on formalin-fixed, paraffin-embedded tissue sections using SP142 and 22C3 antibodies. RESULTS: A total of 82% of the sixty-six patients were hormone receptor positive and 8% of cases were triple negative (TN), while 10% showed human epidermal growth factor receptor 2 (HER2) amplification. sTILs (≥1%) were present in 64% of the study population. Using the SP142 antibody, 36% of tumors demonstrated a positive PD-L1 score of ≥1%, and using the 22C3 antibody, 28% had a positive PD-L1 score of ≥1. There was no correlation between sTILs or PD-L1 expression and tumor size, tumor grade, nodal status, expression of estrogen receptor (ER), or amplification of HER2. Our data did not show any difference in survival between the three molecular subtypes of pILC with respect to sTILs and PD-L1 expression. CONCLUSION: This study shows that pILCs show some degree of sTILs and PD-L1 expression; however, this was not associated with a survival improvement. Additional large trials are needed to understand immune infiltration in lobular cancer, especially in the pleomorphic subtype.

Distinct histopathological features are associated with molecular subtypes and outcome in low grade serous ovarian carcinoma.

Low grade serous ovarian carcinoma (LGSOC) demonstrates unique clinical and molecular features compared to other ovarian cancer types. The relationship between common histological features of LGSOC and molecular events, such as hormone receptor expression patterns and MAPK gene mutation status, remains poorly understood. Recent data suggest some of these molecular features may be biomarkers of response to recently introduced biologically-targeted therapies, namely endocrine therapy and MEK inhibitors. We utilize a cohort of 63 pathologically-confirmed LGSOC cases with whole exome sequencing and hormone receptor expression data to investigate these relationships. LGSOC cases demonstrated uniformly high oestrogen receptor (ER) expression, but variable progesterone receptor (PR) expression intensity. 60% and 37% of cases demonstrated micropapillary and macropapillary patterns of stromal invasion, respectively. 63% of cases demonstrated desmoplasia, which was significantly associated with advanced disease stage and visible residual disease after cytoreductive surgery. MAPK-mutant cases (KRAS, BRAF, NRAS) more frequently demonstrated macropapillary stromal invasion, while Chr1p loss was associated with desmoplasia and low PR expression. Presence of micropapillary stromal invasion and low PR expression were associated with significantly poorer survival after accounting for stage and residual disease status. Together, these data identify novel relationships between histopathological features and molecularly-defined subgroups in LGSOC.

Whole exome sequencing of low grade serous ovarian carcinoma identifies genomic events associated with clinical outcome.

OBJECTIVES: Low-grade serous ovarian carcinoma (LGSOC) is a distinct, rare, ovarian cancer type characterised by younger patient age and intrinsic chemoresistance. Understanding the molecular landscape is crucial for optimising targeted therapy. METHODS: Genomic data from whole exome sequencing of tumour tissue was analysed in a LGSOC cohort with detailed clinical annotation. RESULTS: 63 cases were analysed and three subgroups identified based on single nucleotide variants: canonical MAPK mutant (cMAPKm: 52%, KRAS/BRAF/NRAS), MAPK-associated gene mutation (MAPK-assoc: 27%) and MAPK wild-type (MAPKwt: 21%). NOTCH pathway disruption occurred across all subgroups. Tumour mutational burden (TMB), mutational signatures and recurrent copy number (CN) changes varied across the cohort with co-occurrence of chromosome 1p loss and 1q gain (CN Chr1pq) a recurrent feature. Low TMB and CN Chr1pq were associated with inferior disease-specific survival (HR 6.43; p < 0.001 and HR 3.29, p = 0.011 respectively). Stepwise genomic classification in relation to outcome resulted in four groups (TMB low; CN Chr1pq; MAPKwt/MAPKassoc; cMAPKm). 5 year disease-specific survival was 46%, 55%, 79% and 100% respectively for these groups. The two most favourable genomic subgroups were enriched for the SBS10b mutational signature, particularly the cMAPKm subgroup. CONCLUSIONS: LGSOC comprises multiple genomic subgroups with distinct clinical and molecular features. Chr1pq CN arm disruption and TMB represent promising methods to identify individuals with poorer prognosis. Further investigation of the molecular basis for these observations is required. MAPKwt cases represent around a fifth of patients. NOTCH inhibitors represent a candidate therapeutic strategy worthy of exploration across these cases.

GRACE-trial: a randomised active-controlled trial for vulvovaginal atrophy in patients with breast cancer on endocrine therapy - study protocol.

INTRODUCTION: Breast cancer is the most common cancer type in women worldwide. Due to hormone receptor positivity in the majority of the breast cancer tumours is endocrine therapy a crucial part in the treatment landscape of breast cancer. Endocrine therapy consists of the use of selective oestrogen-receptor modulators or aromatase inhibitors. These medicines generate a hypoestrogenic environment by reducing circulating oestrogen or by altering the effect of oestrogen on tissue cells by receptor blockade. As a common side effect, vulvovaginal atrophy occurs in the majority of patients with breast cancer using endocrine therapy. Vulvovaginal atrophy has a significant impact on physical and psychological well-being due to negative influence on quality-of-life, self-esteem and sexuality. As a consequence, adherence to endocrine therapy for the standard duration of 5-10 years is challenging, resulting in higher rates of therapy interruption, leading to poorer prognosis with shorter distant disease-free survival. The standard treatment for vulvovaginal atrophy in postmenopausal women is based on the use of local hormonal treatment. However, when a patient has a history of breast cancer, delay of treatment and undertreatment are ubiquitous. METHODS AND ANALYSIS: In this first ever prospective randomised trial patients with breast cancer on endocrine therapy with vulvovaginal atrophy will be treated with the available local treatment modalities with a 1:1:1:1 randomisation: oestrogen, dehydroepiandrosterone, moisturisers and a co-treatment of oestrogen and probiotics. Patient-reported outcomes measurements will be implemented to investigate the efficacy of the implemented treatments. Safety of the treatments will be evaluated by assessing systemic sex hormones concentrations. ETHICS AND DISSEMINATION: This study was approved by the Ethical Committee of Ghent University Hospital and by the Federal Agency for Medicines and Health Products. Results will be published in peer-reviewed journals and released in international conferences. TRIAL REGISTRATION NUMBER: 2021-001921-31.

Direct co-registration of [18F]FDG uptake and histopathology in surgically excised malignancies of the head and neck: a feasibility study.

PURPOSE: Recent technical advancements in PET imaging have improved sensitivity and spatial resolution. Consequently, clinical nuclear medicine will be confronted with PET images on a previously unfamiliar resolution. To better understand [18F]FDG distribution at submillimetric scale, a direct correlation of radionuclide-imaging and histopathology is required. METHODS: A total of five patients diagnosed with a malignancy of the head and neck were injected with a clinical activity of [18F]FDG before undergoing surgical resection. The resected specimen was imaged using a preclinical high-resolution PET/CT, followed by slicing of the specimen. Multiple slices were rescanned using a micro-PET/CT device, and one of the slices was snap-frozen for frozen sections. Frozen sections were placed on an autoradiographic film, followed by haematoxylin and eosin staining to prepare them for histopathological assessment. The results from both autoradiography and histopathology were co-registered using an iterative co-registration algorithm, and regions of interest were identified to study radiotracer uptake. RESULTS: The co-registration between the autoradiographs and their corresponding histopathology was successful in all specimens. The use of this novel methodology allowed direct comparison of autoradiography and histopathology and enabled the visualisation of uncharted heterogeneity in [18F]FDG uptake in both benign and malignant tissue. CONCLUSION: We here describe a novel methodology enabling the direct co-registration of [18F]FDG autoradiography with the gold standard of histopathology in human malignant tissue. The future use of the current methodology could further increase our understanding of the distribution of radionuclides in surgically excised malignancies and hence, improve the integration of pathology and molecular imaging in a multiscale perspective. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05068687.