Cancer cell genotype associated tumor immune microenvironment exhibits differential response to therapeutic STING pathway activation in high-grade serous ovarian cancer.

BACKGROUND: High-grade serous ovarian carcinoma (HGSC) is the most lethal gynecologic malignancy characterized by resistance to chemotherapy and high rates of recurrence. HGSC tumors display a high prevalence of tumor suppressor gene loss. Given the type 1 interferon regulatory function of BRCA1 and PTENgenes and their associated contrasting T-cell infiltrated and non-infiltrated tumor immune microenvironment (TIME) states, respectively, in this study we investigated the potential of stimulator of interferon genes (STING) pathway activation in improving overall survival via enhancing chemotherapy response, specifically in tumors with PTEN deficiency. METHODS: Expression of PTEN protein was evaluated in tissue microarrays generated using pretreatment tumors collected from a cohort of 110 patients with HGSC. Multiplex immunofluorescence staining was performed to determine spatial profiles and density of selected lymphoid and myeloid cells. In vivo studies using the syngeneic murine HGSC cell lines, ID8-Trp53 -/-; Pten -/- and ID8-Trp53 -/-; Brca1 -/-, were conducted to characterize the TIME and response to carboplatin chemotherapy in combination with exogenous STING activation therapy. RESULTS: Patient tumors with absence of PTEN protein exhibited a significantly decreased disease specific survival and intraepithelial CD68+ macrophage infiltration as compared with intact PTEN expression. In vivo studies demonstrated that Pten-deficient ovarian cancer cells establish an immunosuppressed TIME characterized by increased proportions of M2-like macrophages, GR1+MDSCs in the ascites, and reduced effector CD8+ cytotoxic T-cell function compared with Brca1-deficient cells; further, tumors from mice injected with Pten-deficient ID8 cells exhibited an aggressive behavior due to suppressive macrophage dominance in the malignant ascites. In combination with chemotherapy, exogenous STING activation resulted in longer overall survival in mice injected with Pten-deficient ID8 cells, reprogrammed intraperitoneal M2-like macrophages derived from Pten-deficient ascites to M1-like phenotype and rescued CD8+ cytotoxic T-cell activation. CONCLUSIONS: This study reveals the importance of considering the influence of cancer cell intrinsic genetic alterations on the TIME for therapeutic selection. We establish the rationale for the optimal incorporation of interferon activating therapies as a novel combination strategy in PTEN-deficient HGSC.

The prognostic impact of PD-L1 and CD8 expression in anal cancer patients treated with chemoradiotherapy.

Background: Programmed death-ligand 1 (PD-L1) expression has been shown to be prognostic in many cancer types and used in consideration of checkpoint inhibitor immunotherapy. However, there are very limited and conflicting data on the prognostic impact of PD-L1 in patients with anal squamous cell carcinoma (ASCC). The objectives of this study were to measure the expression of PD-L1 and CD8 in patients with ASCC treated with radical chemoradiotherapy (CRT) and to correlate tumor expression with progression-free survival (PFS) and overall survival (OS). Methods: Ninety-nine patients with ASCC treated with primary CRT at two tertiary care cancer centers between 2000 and 2013, with available pre-treatment tumors, were included. Tissue microarrays (TMAs) from pre-treatment tumor specimens were stained for PD-L1 and CD8. PD-L1 expression in the tumor and stroma was quantified using HALO image analysis software, and results were interpreted using quantitative methods. The density of CD8 cells within the tumor was interpreted by a trained pathologist semi-quantitatively, using a 0-4 scoring system. Kaplan-Meier analysis with log-rank was used to determine the significance in the association of tumor markers with PFS and OS. Cox multivariate analysis was used to explore independent predictors of PFS and OS. Results: Of the 99 patients, 63 (64%) had sufficient tumor samples available for full analysis. CD8 high status was documented in 32 of 63 (50.8%) % of cases. PD-L1 expression was positive in 88.9% of cases. Approximately half the patients had tumor PD-L1 ≥ 5%. Patients with tumor PD-L1 ≥ 5% had better OS vs those with lower expression, HR=0.32 (95% CI 0.11-0.87), p=0.027; 10 years OS: 84% for tumor PD-L1 ≥ 5% vs 49% for PD-L1 < 5%. PD-L1 expression was not associated with PFS. On multivariate analysis, tumor PD-L1 ≥ 5% showed a trend to statistical significance for better OS, HR=0.55 (95% CI 0.12- 1.00), p=0.052. Conclusions: Tumor PD-L1≥5% is associated with OS in patients with ASCC treated with CRT. PD-L1 expression status using this unique cut-point warrants further validation for prognostication in patients with this disease. Future studies are required to determine the benefit of alternative treatment strategies based on PD-L1 status.

Treatment and outcomes in undifferentiated and dedifferentiated endometrial carcinoma.

OBJECTIVE: Undifferentiated and dedifferentiated endometrial carcinoma is a rare type of uterine malignancy. This study assesses disease characteristics, treatment and survival outcomes in patients with undifferentiated and dedifferentiated endometrial carcinoma treated at BC Cancer. METHODS: All patients diagnosed with undifferentiated and dedifferentiated endometrial carcinoma between 2000 and 2019 at BC Cancer were reviewed centrally. Clinical, pathologic, treatment and outcomes were reviewed retrospectively. The Kaplan-Meier method was used to evaluate overall survival (OS) and disease-free survival (DFS). Multivariable analysis was performed using Cox regression analysis. RESULTS: Fifty-two patients were included, 33% had undifferentiated carcinoma and 67% dedifferentiated carcinoma. Sixty-nine percent of those who had mismatch repair (MMR) testing of their tumor had an abnormal profile. The 5-year DFS was 80% (95% confidence interval [CI]=71%-89%) for stage I/II, 29% (95% CI=28%-40%) for stage III and 10% (95% CI 1%-19%) for stage IV. The 5-year OS was 84% (95% CI=75%-92%) for stage I/II, 38% (95% CI=26%-50%) for stage III and 12% (95% CI=1%-24%) for stage IV. Multivariate analysis showed that receiving adjuvant chemotherapy, adjuvant radiotherapy, lower stage and better Eastern Cooperative Group performance status were associated with improved DFS (p<0.05). CONCLUSION: Patients with stage I/II undifferentiated and dedifferentiated endometrial carcinoma had excellent survival outcomes, those with stage III/IV had worse outcomes, similar to previously reported. Adjuvant chemotherapy and radiotherapy were associated with improved DFS. MMR testing should be performed for these patients due to the high incidence of abnormal profiles.

Malignancy is in the eye of the beholder: Pathologic diagnosis of challenging follicular neoplasms in the era of noninvasive follicular thyroid neoplasms with papillary-like nuclear features and immunohistochemical and molecular adjuncts.

BACKGROUND: Classification of thyroid follicular neoplasms can be challenging for pathologists. Introduction of noninvasive follicular thyroid neoplasms with papillary-like nuclear features, the utilization of immunohistochemistry, and molecular analysis are all thought to be valuable diagnostic adjuncts. Our aim was to determine whether interobserver variability for follicular neoplasms has improved since the application of these adjuncts. METHODS: One representative section from a cohort of follicular neoplasms previously proven difficult for pathologists were examined independently by 7 pathologists and assigned to 1 of 3 diagnostic categories (benign, neoplasms with papillary-like nuclear features, or malignant). This process was carried out separately 3 times: (1) after viewing hematoxylin and eosin stain slides, (2) hematoxylin and eosin stain in conjunction with immunohistochemistry, and (3) hematoxylin and eosin stain/immunohistochemistry in conjunction with molecular analysis. The interobserver variability and overall agreement were then calculated using the free-marginal kappa coefficient. RESULTS: Agreement on hematoxylin and eosin stain was 57%, with a kappa coefficient of 0.36 (minimal agreement). The agreement improved slightly with the application of immunohistochemistry (kappa coefficient = 0.49 [weak agreement] and a percentage agreement 67%). The level of agreement decreased slightly after the addition of molecular analysis (kappa coefficient = 0.43 [weak agreement] and percentage agreement 62%). CONCLUSION: Despite attempts to standardize the diagnostic criteria for neoplasms with papillary-like nuclear features and the utilization immunohistochemistry and molecular analysis, attaining pathologic consensus for difficult follicular neoplasms of the thyroid remains a challenge.

Another Whipple's triad? Pericardial, myocardial and valvular disease in an unusual case presentation from a Canadian perspective.

BACKGROUND: Whipple's disease is a clinically relevant multi-system disorder that is often undiagnosed given its elusive nature. We present an atypical case of Whipple's disease involving pan-valvular endocarditis and constrictive pericarditis, requiring cardiac intervention. A literature review was also performed assessing the prevalence of atypical cases of Whipple's disease. CASE PRESENTATION: A previously healthy 56-year-old male presented with a four-year history of congestive heart failure with weight loss and fatigue. Notably, he had absent gastrointestinal symptoms. He went on to develop pan-valvular endocarditis and constrictive pericarditis requiring urgent cardiac surgery. A clinical diagnosis of Whipple's disease was suspected, prompting duodenal biopsy sampling which was unremarkable, Subsequently, Tropheryma whipplei was identified by 16S rDNA PCR on the cardiac valvular tissue. He underwent prolonged antibiotic therapy with recovery of symptoms. CONCLUSIONS: Our study reports the first known case of Whipple's disease involving pan-valvular endocarditis and constrictive pericarditis. A literature review also highlights this presentation of atypical Whipple's with limited gastrointestinal manifestations. Duodenal involvement was limited and the gold standard of biopsy was not contributory. We also highlight the Canadian epidemiology of the disease from 2012 to 2016 with an approximate 4% prevalence rate amongst submitted samples. Routine investigations for Whipple's disease, including duodenal biopsy, in this case may have missed the diagnosis. A high degree of suspicion was critical for diagnosis of unusual manifestations of Whipple's disease.

Expression of L1 retrotransposon open reading frame protein 1 in gynecologic cancers.

LINE-1 (L1) retrotransposons are mobile genetic elements capable of "copy-and-pasting" their own sequences into random genomic loci, and one of the proteins it uses to achieve mobility is LINE-1 open reading frame 1 protein (L1ORF1p). L1ORF1p expression is found across many epithelial cancers, including small cohorts of ovarian and endometrial cancers, and is highly expressed in cancers with mutant p53 expressions. Here we aimed to gain insights into L1ORF1p expression levels within specific histotypes of ovarian cancers: high-grade serous (n = 585), low-grade serous (n = 26), clear cell (n = 132), endometrioid (n = 148), and mucinous (n = 32) ovarian cancers, as well as endometrial cancers (n = 607) using tissue microarray (TMA's). We demonstrated that L1ORF1p expression is associated with advanced stage and serous histotype in gynecological cancers. Like previous studies, we found a higher proportion of L1ORF1p expression in cases with aberrant p53 expression. We evaluated the expression of L1ORF1p in serous tubal intraepithelial carcinomas (STICs) (n = 6) and p53 signature lesions (n = 2) in fallopian tubes. Three STIC cases displayed aberrant p53 overexpression with corresponding L1ORF1p expression in the same tissues, but such correlation was not seen in the two p53 signature lesions, suggesting that L1 protein may be expressed after dysplastic transformation. The remaining three STIC cases have TP53 nonsense mutations with absent p53 expression but a strong and clear L1ORF1p expression within the STIC lesions. While L1ORF1p may not be prognostic in gynecological cancers, it may be useful clinically as a diagnostic IHC marker for p53 null STIC lesions and this warrants further investigation.

International Society of Gynecological Pathologists (ISGyP) Endometrial Cancer Project: Guidelines From the Special Techniques and Ancillary Studies Group.

The aim of this article is to propose guidelines and recommendations in problematic areas in pathologic reporting of endometrial carcinoma (EC) regarding special techniques and ancillary studies. An organizing committee designed a comprehensive survey with different questions related to pathologic features, diagnosis, and prognosis of EC that was sent to all members of the International Society of Gynecological Pathologists. The special techniques/ancillary studies group received 4 different questions to be addressed. Five members of the group reviewed the literature and came up with recommendations and an accompanying text which were discussed and agreed upon by all members of the group. Twelve different recommendations are made. They address the value of immunohistochemistry, ploidy, and molecular analysis for assessing prognosis in EC, the value of steroid hormone receptor analysis to predict response to hormone therapy, and parameters regarding applying immunohistochemistry and molecular tests for assessing mismatch deficiency in EC.

Adult lifetime alcohol consumption and invasive epithelial ovarian cancer risk in a population-based case-control study.

OBJECTIVE: Meta-analyses report a null association between recent alcohol consumption and ovarian cancer risk. However, because few studies investigated different types of alcohol over adult ages, we investigated adult lifetime and type (beer, wine, spirits) of consumption and risk. METHODS: Consumption after age 20years was ascertained in 1144 invasive epithelial ovarian cancer cases and 2513 controls in a population-based case-control study (Alberta and British Columbia, Canada, 2001-2012). Non-drinkers consumed any types of alcohol <12 times per year on average. Logistic regression was use to estimate adjusted odds ratios [aOR] and 95% confidence intervals [CIs]. RESULTS: Wine consumption was associated with a risk reduction (aOR=0.67, 95% CI: 0.50-0.88) relative to non-drinkers, but not beer (aOR=1.06, 95% CI: 0.71-1.58) or spirits (aOR=0.98, 95% CI: 0.69-1.39). The reduced risk was stronger for exclusive red wine drinkers (aOR=0.44, 95% CI: 0.19-0.92) than white wine drinkers (aOR=0.79, 95% CI: 0.46-1.34), although most women drank both types of wine. Risk decreased with increasing cumulative consumption of any wine (P-trend<0.05) and was evident for the serous histotype. Wine consumption initiated prior to age 50 was associated with a risk reduction (e.g., at 40-49years, aOR=0.58, 95% CI: 0.42-0.78), but not drinking initiated after 50years of age. For any type, level, or age at initiation of alcohol consumption, we found no increased risks. CONCLUSIONS: For the moderate consumption in this study, higher levels of wine consumption were generally associated with risk reductions; reductions may be stronger for red wine. Our results suggest that alcohol consumption that is guideline concordant will not increase epithelial ovarian cancer risk.

Biobanking in the Twenty-First Century: Driving Population Metrics into Biobanking Quality.

Biospecimens are the essential substrates for human biomarker research. Across the globe, biobanks have developed the facilities and mechanisms to collect, process, store and distribute those substrates to researchers. However, despite some notable successes, less than one hundred of the tens of thousands of purported biomarkers have been independently validated. We propose the need for a new paradigm in biobanking; simply pursuing larger numbers of participants, larger networks of biobanks and higher sample integrity will not, in itself, transform the success rate or efficiency of biomarker research. We propose that biobanks must embrace the intrinsic observational nature of biospecimens and furnish the recipients of biospecimens with the population metrics (descriptive statistics) that can facilitate the scientific rigor that is mandated in other areas of observational research. In addition, we discuss the value of population-based ascertainment and recruitment and the importance of the timing of biospecimen collections. Any assessment of biospecimen quality must go beyond the sample itself and consider both the patient/participant selection and the most appropriate and informative timing for specimen collection, particularly prior to any treatment intervention in diseased populations. The examples and rationales that we present are based largely on cancer-related collections because the feasibility of population metrics is greatly assisted by the comprehensive registries that are more common for cancer than other chronic diseases. Changing the biobanking paradigm from tacitly 'experimental' to explicitly 'observational' represents a profound but urgent methodological shift that will influence the establishment, management, reporting and impact of biobanks in the twenty-first century.