Extraction of homogeneous lignin oligomers by ozonation of Miscanthus giganteus and vine shoots in a pilot scale reactor

Lignin, a complex phenolic polymer crucial for plant structure, is mostly used as fuel but it can be harnessed for environmentally friendly applications. This article explores ozonation as a green method for lignin extraction from lignocellulosic biomass, aiming to uncover the benefits of the extracted lignin. A pilot-scale ozonation reactor was employed to extract lignin from Miscanthus giganteus (a grass variety) and vine shoots (a woody biomass). The study examined the lignin extraction and modification of the fractions and identified the generation of phenolic and organic acids. About 48 % of lignin was successfully extracted from both biomass types. Phenolic monomers were produced, vine shoots yielding fewer monomers than Miscanthus giganteus. Ozonation generated homogeneous lignin oligomers, although their molecular weight decreased during ozonation, with vine shoot oligomers exhibiting greater resistance to ozone. Extracted fractions were stable at 200 °C, despite the low molecular weight, outlining the potential of these phenolic fractions.

Proposal of Novel Binary Grading Systems for Cervical Squamous Cell Carcinoma

We compared grading systems and examined associations with tumor stroma and survival in patients with cervical squamous cell carcinoma. Available tumor slides were collected from 10 international institutions. Broders tumor grade, Jesinghaus grade (informed by the pattern of tumor invasion), Silva pattern, and tumor stroma were retrospectively analyzed; associations with overall survival (OS), progression-free survival (PFS), and presence of lymph node metastases were examined. Binary grading systems incorporating tumor stromal changes into Broders and Jesinghaus grading systems were developed. Of 670 cases, 586 were reviewed for original Broders tumor grade, 587 for consensus Broders grade, 587 for Jesinghaus grade, 584 for Silva pattern, and 556 for tumor stroma. Reproducibility among grading systems was poor (κ = 0.365, original Broders/consensus Broders; κ = 0.215, consensus Broders/Jesinghaus). Median follow-up was 5.7 years (range, 0-27.8). PFS rates were 93%, 79%, and 71%, and OS rates were 98%, 86%, and 79% at 1, 5, and 10 years, respectively. On univariable analysis, original Broders ( P < 0.001), consensus Broders ( P < 0.034), and Jesinghaus ( P < 0.013) grades were significant for OS; original Broders grade was significant for PFS ( P = 0.038). Predictive accuracy for OS and PFS were 0.559 and 0.542 (original Broders), 0.542 and 0.525 (consensus Broders), 0.554 and 0.541 (Jesinghaus grade), and 0.512 and 0.515 (Silva pattern), respectively. Broders and Jesinghaus binary tumor grades were significant on univariable analysis for OS and PFS, and predictive value was improved. Jesinghaus tumor grade ( P < 0.001) and both binary systems (Broders, P = 0.007; Jesinghaus, P < 0.001) were associated with the presence of lymph node metastases. Histologic grade has poor reproducibility and limited predictive accuracy for squamous cell carcinoma. The proposed binary grading system offers improved predictive accuracy for survival and the presence of lymph none metastases.

Serous tubal intraepithelial carcinoma (STIC) outcomes in an average risk population

Objective

Serous tubal intraepithelial carcinoma (STIC) are precursors for high grade serous carcinomas (HGSC) of tubo-ovarian origin. It is a rare entity, most commonly described in patients with a BRCA pathogenic variant (PV) undergoing risk-reducing surgery. Little is known about the risk of subsequent HGSC in patients found to have an isolated STIC without a genetic PV. The objective of this study is to report the outcomes of STIC diagnosed in patients with negative genetic testing ("average risk").

Methods

Retrospective population-based cohort study from British Columbia, Canada. Chart review of patients diagnosed with an isolated STIC from January 2012 to May 2022. Average risk patients are defined as individuals with known negative genetic testing results. Treatment and outcomes are described in the "average risk", BRCA PV, and total cohorts.

Results

Twenty-nine patients with isolated STIC were identified. Ten patients had a BRCA PV, four had other variants identified (BRIP1, MLH1, BRIP1 VUS, BRCA 2 VUS), nine had no PV identified ("average risk"), and six were unknown (no genetic testing). Of the nine "average risk" patients, eight (89%) underwent surgical staging. Three (33.3%) had subsequent HGSC diagnosed 29, 70 and 86 months after STIC diagnosis.

Conclusions

STIC identified in patients with negative genetic testing are at risk of subsequent HGSC. Patients developed primary peritoneal HGSC despite surgical staging. These patients should also be included in future meta-analysis to determine outcomes and optimal treatment.

Incidence and Clinicopathologic Characteristics of Human Papillomavirus-independent Invasive Squamous Cell Carcinomas of the Cervix: A Morphologic, Immunohistochemical, and Human Papilloma-Virologic Study of 670 Cases

We aimed to determine the frequency of human papillomavirus-independent (HPVI) cervical squamous cell carcinoma (SCC) and to describe clinicopathologic characteristics. Among 670 patients with surgically treated SCCs in an established multi-institutional cohort, 447 had available tissue. Tissue microarrays were constructed and studied by in situ hybridization (ISH) for high-risk and low-risk human papillomavirus (HPV) mRNA and immunohistochemistry for p16 and p53. Tumors were HPVI if negative by HPV ISH and they failed to show diffuse p16 positivity by immunohistochemistry, and human papillomavirus-associated (HPVA) if positive by HPV ISH. Ten HPVI SCCs and 435 HPVA SCCs were identified; 2 cases were equivocal and excluded from analysis. The overall rate of HPVI SCC was low (2%) but was higher among older patients (7% in patients above 60 y of age and 17% in patients above 70 y of age). Compared with HPVA, patients with HPVI SCC were significantly older (median age, 72 vs. 49, P <0.001) and diagnosed at a higher stage (40% vs. 18% with stage III/IV disease, P =0.055). p53 expression was varied; 2 cases (20%) had null expression and 8 (80%) had wild-type expression. HPVI SCCs were heterogenous, with keratinizing, nonkeratinizing, and warty morphologies observed. Several cases had a precursor lesion reminiscent of differentiated vulvar intraepithelial neoplasia, with prominent basal atypia and hypereosinophilia or a basaloid-like morphology. Two patients (20%) had distant recurrences within 12 months, and 3 (30%) died of disease during follow-up. HPVI SCCs are rare tumors that are more common among older patients with higher stage disease and have important clinical and histologic differences from HPVA SCCs.

Extensive versus focal lymphovascular invasion in squamous cell carcinoma of the cervix: A comprehensive international, multicenter, retrospective clinicopathologic study

OBJECTIVE

We evaluated clinicopathologic parameters of patients with cervical squamous cell carcinoma (SCC) who were treated with initial surgical management and assessed their relation to survival outcomes. Specifically, we evaluated the relation between extent of lymphovascular invasion (LVI) and survival outcomes.

METHODS

All available tumor slides from patients with initially surgically treated cervical SCC were collected from 10 institutions and retrospectively analyzed. Standard clinicopathological parameters, tumor stroma, and extent of LVI were assessed (focal: <5 spaces, extensive: ≥5 spaces). PFS and OS were evaluated using Kaplan-Meier methodology. Univariable and multivariable Cox proportional hazards models were created to determine prognostic survival-related risk factors.

RESULTS

A total of 670 tumor samples were included in the analysis. Median age at diagnosis was 47 years (IQR: 38-60), 457 patients (72%) had a 2018 International Federation of Gynecology and Obstetrics (FIGO) stage I tumor, and 155 tumors (28%) were flat and/or ulcerated. There were 303 nonkeratinizing tumors (51%), 237 keratinizing tumors (40%), and 356 histologic grade 2 tumors (61%). Quantifiable LVI was present in 321 cases (51%; 23% focal and 33% extensive). On multivariable analysis for PFS, extensive and focal LVI had worse outcomes compared to negative LVI (HR: 2.38 [95% CI: 1.26-4.47] and HR: 1.54 [95% CI: 0.76-3.11], respectively; P = 0.02). The difference did not reach statistical significance for OS.

CONCLUSION

Presence of LVI is a prognostic marker for patients with cervical SCC. Quantification (extensive vs. focal vs. negative) of LVI may be an important biomarker for oncologic outcome.

Cervical PEComa: Challenges in diagnosis and prognosis of a rare neoplasm

•Cervical PEComas are rare neoplasms which present a diagnostic challenge.•Large tumour size is an important clinical prognosticator in cervical PEComa.•All reported cases of cervical PEComa classified as benign by Folpe criteria behaved in benign fashion clinically.•Tumours ≤ 4 cm may be assessed with cone biopsy, and simple hysterectomy considered if no adverse pathologic features.•Molecular characterization and linkage with coordinated rare tumour registries may identify novel treatments.

Cervical Adenosquamous Carcinoma: Detailed Analysis of Morphology, Immunohistochemical Profile, and Outcome in 59 Cases

Although both the 2014 and 2020 World Health Organization (WHO) criteria require unequivocal glandular and squamous differentiation for a diagnosis of cervical adenosquamous carcinoma (ASC), in practice, ASC diagnoses are often made in tumors that lack unequivocal squamous and/or glandular differentiation. Considering the ambiguous etiologic, morphologic, and clinical features and outcomes associated with ASCs, we sought to redefine these tumors. We reviewed slides from 59 initially diagnosed ASCs (including glassy cell carcinoma and related lesions) to confirm an ASC diagnosis only in the presence of unequivocal malignant glandular and squamous differentiation. Select cases underwent immunohistochemical profiling as well as human papillomavirus (HPV) testing by in situ hybridization. Of the 59 cases originally classified as ASCs, 34 retained their ASC diagnosis, 9 were reclassified as pure invasive stratified mucin-producing carcinomas, 10 as invasive stratified mucin-producing carcinomas with other components (such as HPV-associated mucinous, usual-type, or ASCs), and 4 as HPV-associated usual or mucinous adenocarcinomas with benign-appearing squamous metaplasia. Two glassy adenocarcinomas were reclassified as poorly differentiated HPV-associated carcinomas based on morphology and immunophenotype. There were no significant immunophenotypic differences between ASCs and pure invasive stratified mucin-producing carcinomas with regard to HPV and other markers including p16 expression. Although limited by a small sample size, survival outcomes seemed to be similar between all groups. ASCs should be diagnosed only in the presence of unequivocal malignant glandular and squamous differentiation. The 2 putative glassy cell carcinomas studied did not meet our criteria for ASC and categorizing them as such should be reconsidered.

Multisite gynecologic endometrioid adenocarcinomas: Can mutation profiling be used to distinguish synchronous primary cancers from metastases?

It is well recognized that some patients with endometrioid gynecological cancers have tumors arising in multiple sites (ovary, endometrium, and endometriosis) at the time of diagnosis. Molecular analysis has helped discern whether these multisite cancers represent synchronous primary tumors or alternatively metastatic disease. We present a complex case of a patient with endometrioid carcinomas arising in multiple sites. We discuss the use of mutation profiling to discern clonality and highlight how this information may inform the clinical management of such cases.

Claudin-18 as a Promising Surrogate Marker for Endocervical Gastric-type Carcinoma

HIK1083 and trefoil factor 2 (TFF2) are known to be expressed in gastric-type carcinoma (GAS), but they do not reliably mark all GASs, and focal expression can be missed in biopsy specimens. We aimed to investigate whether claudin-18 and alpha-methylacyl-CoA racemase (AMACR) could be surrogate markers to separate GAS from other types of endocervical adenocarcinoma (ECA) and to compare their usefulness with that of HIK1083 and TFF2. Claudin-18 and AMACR immunohistochemistry was performed, and the results were compared with that of TFF2 and HIK1083, using whole sections of 75 ECAs (22 GASs and 53 non-GASs) and 179 ECAs with tissue microarrays (TMAs). TMAs were built to simulate the assessment of immunohistochemical stains in small biopsies. Any membranous (claudin-18) or cytoplasmic/membranous (AMACR, TFF2, HIK1083) staining of >5% of tumor cells was considered positive. Of 75 ECAs with whole sections, claudin-18 was significantly more frequently expressed in GASs (21/22) compared with non-GASs (8/53) (P<0.01). In ECAs with TMAs, claudin-18 expression was significantly frequent in GASs (15/23, 65.2%) than in non-GASs (3/152, 2.0%; all usual-type) (P<0.01). All claudin-18-positive GASs showed intense staining except 1 case. Claudin-18 shared the same degree of sensitivity and specificity with HIK1083 and TFF2. Three clear cell carcinomas were positive for claudin-18, but none showed intense staining. AMACR was expressed in a subset of ECAs and showed no impact in distinguishing between GAS and other ECAs. Our results suggest that claudin-18 is a promising surrogate marker to separate GAS from other types of ECA, including clear cell carcinoma.

Clinical correlation of lymphovascular invasion and Silva pattern of invasion in early-stage endocervical adenocarcinoma: proposed binary Silva classification system

Silva invasion pattern can help predict lymph node metastasis risk in endocervical adenocarcinoma. We analysed Silva pattern of invasion and lymphovascular invasion to determine associations with clinical outcomes in stage IA and IB1 endocervical adenocarcinomas. International Federation of Gynecology and Obstetrics (FIGO; 2019 classification) stage IA-IB1 endocervical adenocarcinomas from 15 international institutions were examined for Silva pattern, presence of lymphovascular invasion, and other prognostic parameters. Lymph node metastasis status, local/distant recurrences, and survival data were compared using appropriate statistical tests. Of 399 tumours, 152 (38.1%) were stage IA [IA1, 77 (19.3%); IA2, 75 (18.8%)] and 247 (61.9%) were stage IB1. On multivariate analysis, lymphovascular invasion (p=0.008) and Silva pattern (p<0.001) were significant factors when comparing stage IA versus IB1 endocervical adenocarcinomas. Overall survival was significantly associated with lymph node metastasis (p=0.028); recurrence-free survival was significantly associated with lymphovascular invasion (p=0.002) and stage (1B1 versus 1A) (p=0.002). Five and 10 year overall survival and recurrence-free survival rates were similar among Silva pattern A cases and Silva pattern B cases without lymphovascular invasion (p=0.165 and p=0.171, respectively). Silva pattern and lymphovascular invasion are important prognostic factors in stage IA1-IB1 endocervical adenocarcinomas and can supplement 2019 International Federation of Gynecology and Obstetrics staging. Our binary Silva classification system groups patients into low risk (patterns A and B without lymphovascular invasion) and high risk (pattern B with lymphovascular invasion and pattern C) categories.

SATB2 Expression in Uterine Sarcoma: A Multicenter Retrospective Study

Uterine sarcomas represent a clinical challenge because of their difficult diagnosis and the poor prognosis of certain subtypes. The aim of this study was to evaluate the expression of the special AT-rich sequence-binding protein 2 (SATB2) in endometrial stromal sarcoma (ESS) and other types of uterine sarcoma by immunohistochemistry. We studied the expression of SATB2 on 71 full tissue sections of endometrial stromal nodule, low-grade ESS, uterine leiomyomas and leiomyosarcoma, undifferentiated uterine sarcoma, adenosarcoma, and carcinosarcoma samples. Nuclear SATB2 expression was then evaluated in an extended sample set using a tissue microarray, including 78 additional uterine tumor samples. Overall, with a cut-off of ≥10% of tumor cell staining as positive, the nuclear SATB2 score was negative in all endometrial stromal nodule samples (n=10) and positive in 83% of low-grade ESS samples (n=29/35), 40% of undifferentiated uterine sarcoma (n=4/10), 13% of leiomyosarcoma (n=2/16), 14% of adenosarcoma (n=3/22), and 8% carcinosarcoma (n=2/25) samples. Furthermore, in ESS patients, direct comparison of nuclear SATB2 scores with clinicopathologic parameters and other reported biomarkers such as progesterone receptor and estrogen receptor showed that nuclear SATB2 was associated with PR expression and a decreased risk of disease-specific death (odds ratio=0.06, 95% confidence interval=0.04-0.81, P=0.04). Our data suggest that SATB2 could be a marker with relative sensitivity (83%) for distinguishing between endometrial stromal nodule and ESS with potential prognostic value.

Use of Treatment-Focused Tumor Sequencing to Screen for Germline Cancer Predisposition

Next-generation sequencing assays are capable of identifying cancer patients eligible for targeted therapies and can also detect germline variants associated with increased cancer susceptibility. However, these capabilities have yet to be routinely harmonized in a single assay because of challenges with accurately identifying germline variants from tumor-only data. We have developed the Oncology and Hereditary Cancer Program targeted capture panel, which uses tumor tissue to simultaneously screen for both clinically actionable solid tumor variants and germline variants across 45 genes. Validation using 14 tumor specimens, composed of patient samples and cell lines analyzed in triplicate, demonstrated high coverage with sensitive and specific identification of single-nucleotide variants and small insertions and deletions. Average coverage across all targets remained >2000× in 198 additional patient tumor samples. Analysis of 55 formalin-fixed, paraffin-embedded tumor samples for the detection of known germline variants within a subset of cancer-predisposition genes, including one multiexon deletion, yielded a 100% detection rate, demonstrating that germline variants can be reliably detected in tumor samples using a single panel. Combining targetable somatic and actionable germline variants into a single tumor tissue assay represents a streamlined approach that can inform treatment for patients with advanced cancers as well as identify those with potential germline variants who are eligible for confirmatory testing, but would not otherwise have been identified.

Abstract PR002: Global proteomic profiling of endometrial carcinomas identify prognostic markers

While endometrial cancer (EC) has an overall good prognosis, some patients do poorly and there is room for refinement within current classification systems. Using the TCGA prognostic grouping of EC, our group developed the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE), which reliably and reproducibly stratifies ECs into four prognostic groups: POLEmut, p53wt/NSMP, MMRd (mismatch repair deficient), and p53abn, with the best prognosis for POLEmut to worst prognosis for p53abn. In the current study, global proteomic analysis was performed using the clinical SP3-CTP workflow on archival tissues from 151 patients including 40 MMRd, 34 POLEmut, 34 p53abn and 43 p53wt/NSMP, with clinical follow up data. Included in the cohort were 11 replicate samples (different parts of the same tumor) to examine spatial heterogeneity in the proteomic profiles. Replicate samples were highly correlated to each other, with the exception of three POLEmut cases with very poor correlation in the proteome in different parts of the tumor. As POLEmut tumors have an exceedingly high mutation burden, it is not surprising that this translates to heterogeneity at the proteomic level. Disease specific survival was examined to determine prognostic significance within the whole cohort and within individual molecular subgroups. High TOMM34, PLTP or TSFM expression was correlated to poor disease specific survival in the whole cohort and independently prognostic when molecular subtype, grade and histotype are considered. High MGST, NCL or XPNPEP3 were associated with poor outcomes within the p53wt/NSMP group. POLD2 and ENAH were prognostic within the MMRd group. Within the p53abn group, ACADVL and BABAM1 were found to be prognostic, and GRB7 was found to be enriched in the p53abn group compared to other molecular subtypes. As the group with the worst prognosis, p53abn group could benefit from novel therapeutic avenues. ACADVL, BABAM1 and GRB7 all lie within pathways that are potentially targetable. Our proteomic analysis has identified prognostic markers that may be useful in further refining current molecular classification to help guide treatment decisions. Furthermore, new therapeutic interventions could be developed to target proteins and pathways identified by this proteomics screen.

Citation Format: Dawn R. Cochrane, Gian Negri, Jutta Huvila, David A. Farnell, Emily Thompson, Winnie Yang, Genny Trigo-Gonzales, Amy Lum, Sandra Spencer, Ryan Riley, Samuel Leung, Christine Chow, Jamie Lim, Martin Koebel, Stefan Kommoss, Friedrich Kommoss, Lien Hoang, David G. Huntsman, Gregg Morin, Jessica N. McAlpine. Global proteomic profiling of endometrial carcinomas identify prognostic markers [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PR002.

Trefoil Factor 2 (TFF2) as a Surrogate Marker for Endocervical Gastric-type Carcinoma

Gastric-type carcinoma (GAS) is the most common human papilloma virus-independent endocervical adenocarcinoma (ECA), characterized by an aggressive behavior. Trefoil factor 2 (TFF2) is a mucin-associated peptide expressed in normal gastric but not endocervical glands. This study was carried out to investigate whether TFF2 could be a surrogate marker to separate GAS from other types of ECA. ECAs from 9 international institutions were reviewed for consensus histotype. Of them, expression of TFF2 was immunohistochemically examined compared with that of HIK1083, using whole sections of 50 ECAs (10 GASs and 40 non-GASs) and 179 ECAs (24 GASs and 155 non-GASs) with tissue microarrays (TMAs). TMAs were assessed to simulate assessment of immunohistochemical stains in small biopsies. Both markers were similarly scored, and any cytoplasmic/membranous staining of >5% of tumor cells was considered positive. Of 50 ECAs with whole sections, TFF2 was significantly more frequently expressed in GASs (8/10) compared with non-GASs (5/40) (P<0.01). In 179 ECAs with TMAs, TFF2 was also significantly more frequently expressed in GASs (7/24) compared with non-GASs (4/155) (P<0.01). There was no significant difference in specificity among the 2 markers. Double positivity for TFF2 and HIK1083 in ECAs was highly specific in separating GASs from non-GAS (P<0.01). A significantly smaller percentage of GASs were TFF2 positive in TMAs than in whole sections (P<0.01). Our results suggest that TFF2 is a promising marker, along with HIK1083, to confirm a diagnosis of GAS. This marker may be negative in small biopsies, indicating the necessity of using other exclusionary markers in combination with rigorous morphologic review and extensive sampling in resection specimens.

Multiplex real-time PCR assays for the prediction of cephalosporin, ciprofloxacin and azithromycin antimicrobial susceptibility of positive Neisseria gonorrhoeae nucleic acid amplification test samples

BACKGROUND

The incidence of antimicrobial-resistant Neisseria gonorrhoeae (GC) is rising in Canada; however, antimicrobial resistance (AMR) surveillance data are unavailable for infections diagnosed directly from clinical specimens by nucleic acid amplification tests (NAATs), representing over 80% of diagnoses. We developed a set of 10 improved molecular assays for surveillance of GC-AMR and prediction of susceptibilities in NAAT specimens.

METHODS

Multiplex real-time PCR (RT-PCR) assays were developed to detect SNPs associated with cephalosporin (ponA, porB, mtrR -35delA, penA A311V, penA A501, N513Y, G545S), ciprofloxacin (gyrA S91, parC D86/S87/S88) and azithromycin [23S (A2059G, C2611T), mtrR meningitidis-like promoter] resistance. The assays were validated on 127 gonococcal isolates, 51 non-gonococcal isolates and 50 NAATs with matched culture isolates. SNPs determined from the assay were compared with SNPs determined from in silico analysis of WGS data. MICs were determined for culture isolates using the agar dilution method.

RESULTS

SNP analysis of the 50 NAAT specimens had 96% agreement with the matched culture RT-PCR analysis. When compared with MICs, presence of penA A311V or penA A501 and two or more other SNPs correlated with decreased susceptibility and presence of three or more other SNPs correlated with intermediate susceptibility to cephalosporins; presence of any associated SNP correlated with ciprofloxacin or azithromycin resistance. NAAT-AMR predictions correlated with matched-culture cephalosporin, ciprofloxacin and azithromycin MICs at 94%, 100% and 98%, respectively.

CONCLUSIONS

We expanded molecular tests for N. gonorrhoeae AMR prediction by adding new loci and multiplexing reactions to improve surveillance where culture isolates are unavailable.

FIGO 2018 stage IB endocervical adenocarcinomas: an international study of outcomes informed by prognostic biomarkers

OBJECTIVE

Prognostic factors for endocervical adernocarcinomas are well known, but little is known about prognostic biomarkers influencing outcome for the newly defined International Federation of Gynecology and Obstetrics (FIGO) 2018 IB sub-stages. The aim of this study was to identify prognostic biomarkers influencing recurrence-free and overall survival for FIGO 2018 stage IB cervical adenocarcinoma sub-types. We sought to identify these factors using a large international multi-institutional series of cases.

METHODS

Stage IB endocervical adenocarcinomas were retrospectively collected from nine international institutions; full slide sets (n=464) were used to assign prognostic biomarkers. Inclusion criteria were the following: FIGO stage IB endocervical adenocarcinomas with follow-up in which all paraffin blocks/glass slides were available for review and/or additional studies and the patient was surgically treated from 1985 to 2019. The types of specimens included in the study were conizations, trachelectomies, and simple/radical hysterectomies with or without lymph node samples. We excluded in situ carcinomas, squamous cell carcinomas, adenosquamous carcinomas, tumors with a neuroendocrine component, carcinosarcomas, and any tumor showing clinical, macroscopic, or microscopic features suggesting a lower uterine segment, uterine corpus, or an adnexal primary origin. Tumors treated with neoadjuvant chemotherapy and/or radiation therapy were also excluded, as well as biopsies and loop electrosurgical excision procedures.

RESULTS

Of 464 cases, 225 (48%) were stage IB1, 177 (38%) were stage IB2, and 62 (13%) were stage IB3. Five-year and 10-year recurrence-free survivals were statistically different among stage IB sub-types (p=0.005). Silva pattern of invasion was significant for recurrence-free survival at 5 and 10 years (p=0.04); overall survival and recurrence-free survival were higher in human papillomavirus (HPV)-associated cases (p=0.007 and p=0.001, respectively) and in cases without lymphovascular invasion (p=0.004 and p=0.00001, respectively). Factors that significantly influenced recurrence-free survival were HPV-independent status (p=0.05; HR 2.31; 95% CI 1.02 to 5.46), presence of lymphovascular invasion (p=0.011; HR 3.50; 95% CI 1.33 to 9.19), and presence of lymph node metastasis (p=0.016; HR 2.66; 95% CI 1.20 to 5.90).

CONCLUSION

HPV status and the presence of lymphovascular invasion are prognosticators in stage IB endocervical adenocarcinoma sub-types. These parameters should be included in future sub-staging modifications of FIGO stage IB endocervical adenocarcinomas and in treatment strategies.

Comparison of p53 immunohistochemical staining in differentiated vulvar intraepithelial neoplasia (dVIN) with that in inflammatory dermatoses and benign squamous lesions in the vulva

AIMS

Differentiated vulvar intraepithelial neoplasia (dVIN), the precursor lesion to human papillomavirus-independent vulvar squamous cell carcinoma (VSCC), can be difficult to distinguish from vulvar inflammatory dermatoses. Our goal was to determine if p53 could be a useful biomarker for dVIN, by characterizing p53 percentage, intensity and patterns of staining in dVIN and its histological mimics.

METHODS AND RESULTS

We studied p53 immunohistochemical staining patterns in 16 dVIN cases and 46 vulvar non-neoplastic squamous lesions [12 lichen sclerosus (LS); seven lichen simplex chronicus; three lichen planus (LP); six psoriasis; 13 spongiotic dermatitis (SPO); and five candidiasis]. dVIN cases were adjacent to a p16-negative invasive VSCC in resection specimens. All dVIN cases showed null-type or moderate to strong uniform p53 staining in >70% of basal cells, with moderate to strong continuous parabasal staining extending to two-thirds of the epidermis. This was in contrast to weak or weak to moderate patchy p53 staining in the majority of other lesions. Moderate to strong and increased basal p53 staining (≥70%) was also observed in a subset of LS cases (5/12, 42%), LP cases (1/3, 33%), and SPO cases (36%, 4/11); however, in all categories, this was limited to the basal layer, and any staining in the parabasal layers was patchy.

CONCLUSION

Strong and uniform p53 staining of basal cells, extending into the parabasal layers, and a complete absence of staining (null type) is useful in distinguishing dVIN from other mimics in the vulva. p53 staining of lesser intensity or quantity, particularly basal overexpression only, overlaps with that in vulvar inflammatory lesions.

Single cell transcriptomes of normal endometrial derived organoids uncover novel cell type markers and cryptic differentiation of primary tumours

Endometrial carcinoma, the most common gynaecological cancer, develops from endometrial epithelium which is composed of secretory and ciliated cells. Pathologic classification is unreliable and there is a need for prognostic tools. We used single cell sequencing to study organoid model systems derived from normal endometrial endometrium to discover novel markers specific for endometrial ciliated or secretory cells. A marker of secretory cells (MPST) and several markers of ciliated cells (FAM92B, WDR16, and DYDC2) were validated by immunohistochemistry on organoids and tissue sections. We performed single cell sequencing on endometrial and ovarian tumours and found both secretory-like and ciliated-like tumour cells. We found that ciliated cell markers (DYDC2, CTH, FOXJ1, and p73) and the secretory cell marker MPST were expressed in endometrial tumours and positively correlated with disease-specific and overall survival of endometrial cancer patients. These findings suggest that expression of differentiation markers in tumours correlates with less aggressive disease, as would be expected for tumours that retain differentiation capacity, albeit cryptic in the case of ciliated cells. These markers could be used to improve the risk stratification of endometrial cancer patients, thereby improving their management. We further assessed whether consideration of MPST expression could refine the ProMiSE molecular classification system for endometrial tumours. We found that higher expression levels of MPST could be used to refine stratification of three of the four ProMiSE molecular subgroups, and that any level of MPST expression was able to significantly refine risk stratification of the copy number high subgroup which has the worst prognosis. Taken together, this shows that single cell sequencing of putative cells of origin has the potential to uncover novel biomarkers that could be used to guide management of cancers. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Abstract B30: The effect of OCP use on the incidence of precancerous p53 lesions in fallopian tube fimbria

Background: High-grade serous ovarian carcinoma (HGSOC) accounts for &gt;70% of ovarian cancer-related deaths and is the most common ovarian cancer histotype, most originating from precancerous p53 lesions in the fallopian tube (FT) fimbria. Use of oral contraceptive pills (OCPs) for 5 years or more is associated with a &gt;40% reduction in risk of HGSOC, but the mechanism is unknown. We hypothesize that OCP use reduces the incidence of p53 lesions. Our preliminary data show higher incidence of p53 lesions in post- compared to premenopausal women; therefore we aim to quantify p53 lesions in postmenopausal women who previously did or did not use OCPs. This will provide insight into the protective effects of OCPs against HGSOC.

Preliminary Results: We determined the presence of p53 lesions by immunohistochemistry (IHC) in FT of women up to 40 years old (n=27) and &gt;60 years old (n=24) who underwent salpingectomies for noncancer reasons. p53 lesions were identified in 3/27 cases of the younger cohort (11%) and in 10/24 of the older cohort (42%). Thus, we conclude an increased incidence of p53 lesions in older compared to younger women.

Proposed Design: IHC for p53 will be performed on FT fimbria of women &gt;55 years old who received salpingectomy for noncancer reasons. Based on an assumed reduction in p53 lesions of 35% in women who used OCPs for 5 years or more compared to nonusers (25 vs. 42%), analysis of 190 cases from each group will provide &gt;80% power (p&lt;0.05). Cases will be identified through Population Data BC and blind analysis by p53 IHC will be performed at the Vancouver General Hospital. Data will be flowed back to Pop Data BC to compare to OCP data.

Conclusion: Our preliminary study found that 42% of postmenopausal women had p53 lesions, informing this study design. The study registered through this abstract will be the first to examine the impact of OCPs on the earliest known precursors of HGSOC.

Citation Format: Kendall Greening, Anthony Karnezis, Dawn Cochrane, David Farnell, Lien Hoang, Gillian Hanley, David Huntsman. The effect of OCP use on the incidence of precancerous p53 lesions in fallopian tube fimbria [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B30.

SWI/SNF Complex Mutations in Gynecologic Cancers: Molecular Mechanisms and Models

The SWI/SNF (mating type SWItch/Sucrose NonFermentable) chromatin remodeling complexes interact with histones and transcription factors to modulate chromatin structure and control gene expression. These evolutionarily conserved multisubunit protein complexes are involved in regulating many biological functions, such as differentiation and cell proliferation. Genomic studies have revealed frequent mutations of genes encoding multiple subunits of the SWI/SNF complexes in a wide spectrum of cancer types, including gynecologic cancers. These SWI/SNF mutations occur at different stages of tumor development and are restricted to unique histologic types of gynecologic cancers. Thus, SWI/SNF mutations have to function in the appropriate tissue and cell context to promote gynecologic cancer initiation and progression. In this review, we summarize the current knowledge of SWI/SNF mutations in the development of gynecologic cancers to provide insights into both molecular pathogenesis and possible treatment implications for these diseases.

Molecular subtypes of clear cell carcinoma of the endometrium: Opportunities for prognostic and predictive stratification

OBJECTIVE

Our aim was to characterize the pathological, molecular and clinical outcomes of clear cell carcinoma of the endometrium (CCC).

METHODS

CCC underwent ProMisE (Proactive Molecular Risk Classifier for Endometrial Cancer) classification identifying four molecular subtypes: i) 'POLEmut' for ECs with pathogenic POLE mutations, ii) 'MMRd', if there is loss of mismatch repair proteins by immunohistochemistry (IHC), iii) 'p53wt' or iv) 'p53abn' based on p53 IHC staining. Clinicopathologic parameters, immune markers (CD3, CD8, CD79a, CD138, PD-1), ER, L1CAM, and outcomes were assessed.

RESULTS

52 CCCs were classified, including 1 (2%) POLEmut, 5 (10%) MMRd, 28 (54%) p53wt and 18 (35%) p53abn. Women with p53abn and p53wt CCCs were older than women with MMRd and POLEmut subtypes. p53wt CCC were distinct from typical p53wt endometrioid carcinomas; more likely to arise in older, thinner women, with advanced stage disease, LVSI and lymph node involvement, and a higher proportion ER negative, L1CAM overexpressing tumors with markedly worse outcomes. High levels of immune infiltrates (TIL^high) were observed in 75% of the CCC cohort. L1CAM overexpression was highest within p53abn and p53wt subtypes of CCC.

CONCLUSION

CCC is a heterogeneous disease encompassing all four molecular subtypes and a wide range of clinical outcomes. Outcomes of patients with POLEmut, MMRd and p53abn CCC are not distinguishable from those of other patients with these respective subtypes of EC; p53wt CCC, however, differ from endometrioid p53wt EC in clinical, pathological, molecular features and outcomes. Thus, p53wt CCC of endometrium appear to be a distinct clinicopathological entity within the larger group of p53wt ECs.

HPV-Related Neovaginal Squamous Cell Carcinoma Presenting as Lung Metastasis after Male-to-Female Gender Confirmation Surgery

There have been 4 reported cases of squamous cell carcinoma (SCC) of the neovagina in transgender women. In this report, we present another case of neovaginal SCC in a transgender woman, which was HPV-related, with lung metastasis as the initial presentation, and which was also complicated by her previous history of metastatic renal cell carcinoma. This unique case highlights the diagnostic challenges in these unusual scenarios. Through this report, we hope to address the benefits of multidisciplinary tumor board rounds, provision of detailed clinical information, and familiarization of the transgender anatomy within the pelvis in this group of patients. We also propose that transgender women undergo a continuous annual follow-up after postoperative follow-up is completed.

Association of human papilloma virus status and response to radiotherapy in vulvar squamous cell carcinoma

INTRODUCTION

Vulvar squamous cell carcinoma develops through two separate pathways, associated with the presence or absence of high-risk human papilloma virus (HPV). The objective of this study was to evaluate treatment response and clinical outcomes in women with HPV-associated versus HPV-independent vulvar squamous cell carcinoma treated with primary radiation therapy, in order to determine the ability to use HPV status as a predictor of response to radiation therapy.

METHODS

This was a retrospective cohort study combining data from British Columbia Cancer, Canada and Duke University, USA. Patients were included who had been treated with radiation therapy but excluded if they had received major surgical interventions. Immunohistochemistry for p16 (as a surrogate for high-risk HPV infection) and p53 was performed. We analyzed the univariable association between p16 status and clinico-pathological features and performed univariable survival analysis for p16.

RESULTS

Forty-eight patients with vulvar squamous cell carcinoma treated with primary radiation therapy were identified: 26 p16 positive/HPV-associated patients and 22 p16 negative/HPV-independent patients. p16 positive vulvar squamous cell carcinoma demonstrated a significantly improved overall survival (HR 0.39, p=0.03) and progression-free survival (HR 0.35, p=0.02). In women treated with definitive radiation therapy, p16 positivity was associated with improved overall survival (HR 0.29, p<0.01) and progression-free survival (HR 0.21, p<0.01). Among patients who received sensitizing chemotherapy, a significant association was observed with p16 positive tumors and overall survival (HR 0.25, p=0.03) and progression-free survival (HR 0.09, p<0.01).

CONCLUSION

This study suggests that HPV status in vulvar squamous cell carcinoma has both prognostic and predictive implications, with increased radiosensitivity demonstrated in HPV-associated vulvar squamous cell carcinoma. Implications may include radiation dose de-escalation for HPV-associated vulvar squamous cell carcinoma and increased surgical aggressiveness for HPV-independent vulvar squamous cell carcinoma.

Recent advances in invasive adenocarcinoma of the cervix

Endocervical adenocarcinomas (ECAs) are currently classified according to the 2014 World Health Organization (WHO) system, which is predominantly based on descriptive morphologic characteristics, considers factors bearing minimal etiological, clinical, or therapeutic relevance, and lacks sufficient reproducibility. The 2017 International Endocervical Adenocarcinoma Criteria and Classification (IECC) system was developed by a group of international collaborators to address these limitations. The IECC system separates ECAs into two major groups-those that are human papillomavirus-associated (HPVA) and those that are non-HPV-associated (NHPVA)-based on morphology (linked to etiology) alone, precluding the need for an expensive panel of immunohistochemical markers for most cases. The major types of HPVA ECA include the usual (with villoglandular and micropapillary architectural variants) and mucinous types (not otherwise specified [NOS], intestinal, signet-ring, and invasive stratified mucin-producing carcinoma). Invasive adenocarcinoma NOS is morphologically uninformative, yet considered part of this group when HPV positive. NHPVA ECAs include gastric, clear cell, endometrioid, and mesonephric types. The IECC system is supported by demographic and clinical features (HPVA ECAs develop in younger patients, are smaller, and are diagnosed at an earlier stage), p16/HPV status (almost all HPVA ECAs are p16 and/or HPV positive), prognostic parameters (NHPVA ECAs more often have lymphovascular invasion, lymph node metastases, and are Silva pattern C), and survival data (NHPVA ECAs are associated with worse survival). A move from the morphology-based WHO system to the IECC system will likely provide clinicians with an improved means to diagnose and classify ECAs, and ultimately, to better personalize treatment for these patients.

Increase in ST-11 serogroup W Neisseria meningitidis invasive meningococcal disease in Canada, 2016-2018

BACKGROUND

Many countries have experienced increases in invasive meningococcal disease (IMD) due to a serogroup W Neisseria meningitidis (MenW) strain of the multilocus sequence type (ST)-11 clonal complex (CC). MenW ST-11 was first reported in Ontario, Canada, in 2014. By 2016, this strain caused IMD in five provinces and was responsible for 18.8% of the IMD cases in Canada.

OBJECTIVE

To provide an update on invasive MenW disease in Canada including the strain characteristics, specimen source of isolates, age, sex and geographic distribution of cases.

METHODS

N. meningitidis from culture-positive IMD cases are routinely submitted to the National Microbiology Laboratory (NML) for serogroup, serotype, serosubtype and sequence type analysis. The data from January 1, 2016 to December 31, 2018 were analyzed by calculating the proportion of IMD cases caused by MenW compared with other serogroups. In addition, trends based on age, sex and geographic distribution of cases and specimen source of isolates were analyzed based on information on specimen requisition forms.

RESULTS

Over the 3-year period, 292 individual IMD case isolates were analyzed. The percentage of IMD case isolates typed as MenW more than doubled from 19% (n=15) to 44% (n=51) in 2018 when MenW became the most common serogroup, exceeded the number of MenB, MenC or MenY. In total, 93 MenW case isolates were identified, 91% (n=85) belonged to the ST-11 CC. The increase in MenW affected all age groups (but was most common in those older than 60) and both sexes, and occurred across the country but most prevalent in western Canada. The most common specimen source was blood.

CONCLUSION

In 2018, MenW was the most common serogroup for isolates received by the NML from culture-positive IMD cases in Canada. Over 90% of the MenW serogroup isolates belonged to the ST-11 CC. The quadrivalent ACWY meningococcal conjugate vaccine protects against IMD caused by strains in the A, C, W or Y serogroups and therefore may protect against IMD caused by the new MenW ST-11 strain; however, more research is needed. The emergence of variant strains highlight the importance of strain characterization in IMD surveillance and research.

RETRACTED ARTICLE: Cervical adenosquamous carcinoma: detailed analysis of morphology, immunohistochemical profile, and clinical outcomes in 59 cases

Although 2014 World Health Organization criteria require unequivocal glandular and squamous differentiation for a diagnosis of cervical adenosquamous carcinoma, in practice, adenosquamous carcinoma diagnoses are often made in tumors that lack unequivocal squamous and/or glandular differentiation. Considering the ambiguous etiologic, morphological, and clinical features and outcomes associated with adenosquamous carcinomas, we sought to redefine these tumors. We reviewed slides from 59 initially diagnosed adenosquamous carcinomas (including glassy cell carcinoma and related lesions) to confirm an adenosquamous carcinoma diagnosis only in the presence of unequivocal malignant glandular and squamous differentiation. Select cases underwent immunohistochemical profiling as well as human papillomavirus (HPV) testing by in situ hybridization. Of the 59 cases originally classified as adenosquamous carcinomas, 34 retained their adenosquamous carcinoma diagnosis, 9 were reclassified as pure invasive stratified mucin-producing carcinomas, 10 as invasive stratified mucin-producing carcinomas with other components (such as HPV-associated mucinous, usual-type, or adenosquamous carcinomas), and 4 as HPV-associated usual or mucinous adenocarcinomas with benign-appearing squamous metaplasia. Two glassy cell carcinomas were reclassified as poorly differentiated usual-type carcinomas based on morphology and immunophenotype. There were significant immunophenotypic differences between adenosquamous carcinomas and pure invasive stratified mucin-producing carcinomas with regard to HPV (p < 0.0001), PAX8 (p = 0.038; more in adenosquamous carcinoma), p40 (p < 0.0001; more in adenosquamous carcinoma), p63 (p = 0.0018; more in adenosquamous carcinoma) and MUC6 (p  < 0.0001; less in adenosquamous carcinoma), HNF-1beta (p = 0.0023), vimentin (p = 0.0003), p53 (p = 0.0004), and CK7 (p = 0.0002) expression. Survival outcomes were similar between all groups. Adenosquamous carcinomas should be diagnosed only in the presence of unequivocal malignant glandular and squamous differentiation. The two putative glassy cell carcinomas studied did not meet our criteria for adenosquamous carcinoma, and categorizing them as such should be reconsidered.

Abstract B39: The origins of endometriosis-associated cancers

Both clear cell ovarian carcinoma (CCOC) and endometrioid ovarian carcinoma (ENOC) are associated with ovarian endometriotic cysts, which is believed to be the precursor lesion of these cancers. Women with endometriotic cysts have up to a 3-fold increased risk of developing CCOC and ENOC. It is perplexing that these two clinically distinct histotypes of ovarian cancer arise from the same precursor lesion. We have performed whole-genome sequencing of ovarian cancer histotypes and found that while some genomic features are more common to one histotype than the other, there is not a single feature that is unique to either histotype. Lacking genomic evidence that could explain the differences between these histotypes, we hypothesized that these cancers arise from distinct cells of origin within endometrial tissue, and the cellular context accounts for their differences. We performed global proteomic analysis of ovarian cancer histotypes and identified CTH as a marker for CCOC. Upon examination of normal Müllerian tissues, we found that CTH is highly expressed in the ciliated cells of endometrium (both ectopic endometrium and endometriosis) and of the fallopian tube, with very little expression in the secretory cells of these tissues. We also find that other ciliated cell markers are expressed in CCOC, whereas endometrial secretory cell markers are expressed in ENOC. We propose a new model of CCOC and ENOC histogenesis wherein ENOC is derived from cells of secretory cell lineage whereas CCOC is derived from, or shares similarities to, cells of ciliated cell lineage. There remain, however, many unanswered questions. For example, while CCOC and ENOC occur at roughly equal prevalence, ciliated cells of the endometrium are rare compared to secretory cells. Cells in the endometriotic cyst are exposed to factors such as inflammation and reactive oxygen species, which could influence differentiation of endometrial progenitor cells into the secretory or ciliated cell lineage. To test factors that promote ciliated cell differentiation in normal endometrium, we treated organoid cultures of normal endometrium with IL-6 and Notch pathway modulators. We propose that ovarian cancer histotypes arise from different cells of origin and that the biology of the normal cells will be partly responsible for determining the phenotype of the cancers.

Citation Format: Dawn Cochrane, Basile Tessier-Cloutier, Katherine Lawrence, Tayyebeh Nazeran, Anthony Karnezis, Clara Salamanca, Timothy Lee, Angela Cheng, Jessica McAlpine, Lien Hoang, Blake Gilks, David Huntsman. The origins of endometriosis-associated cancers. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B39.

Stromal invasion pattern identifies patients at lowest risk of lymph node metastasis in HPV-associated endocervical adenocarcinomas, but is irrelevant in adenocarcinomas unassociated with HPV

OBJECTIVE

The Silva invasion pattern-based classification system stratifies endocervical adenocarcinomas (ECAs) into 3 categories corresponding to risk of metastasis and recurrence, but has only been evaluated for HPV-associated ECAs of usual type. We examined whether the Silva system is applicable to all endocervical adenocarcinomas, especially those not associated with HPV.

METHODS

Complete slide sets from 341 surgical specimens of ECA were collected from 7 institutions worldwide. All specimens were associated with clinical records covering at least 5 years of follow-up. Tumors were classified as HPV-associated (HPVA) or not (NHPVA) by both morphology and detection of HPV using in situ hybridization. Recurrence and survival were analyzed by multivariate Mantel-Haenszel methods.

RESULTS

Most specimens (292; 85.6%) were HPVA, while 49 (14.3%) were NHPVA. All NHPVAs were Silva pattern C, while 76.0% of HPVAs were pattern C, 14.7% pattern A, and 9.3% pattern B. Including both HPVAs and NHPVAs, lymphovascular invasion (LVI) was detected in 0% of pattern A, 18.5% of pattern B and 62.6% of pattern C cases (p < 0.001). None of the pattern A or B cases were associated with lymph node metastases (LNM), in contrast to pattern C cases (21.8%). Among patients with Silva pattern C ECA, those with HPVA tumors had a lower recurrence rate and better survival than those with NHPVA; however, when adjusted for stage at diagnosis, the difference in recurrence and mortality was small and not statistically significant.

CONCLUSIONS

Application of the Silva system is only relevant in HPVA cervical adenocarcinoma.

International Endocervical Adenocarcinoma Criteria and Classification (IECC): A New Pathogenetic Classification for Invasive Adenocarcinomas of the Endocervix

We sought to classify endocervical adenocarcinomas (ECAs) based on morphologic features linked to etiology (ie, human papillomavirus [HPV] infection), unlike the World Health Organization 2014 classification. The International Endocervical Adenocarcinoma Criteria and Classification (IECC criteria), described herein, distinguishes between human papillomavirus-associated adenocarcinoma (HPVA), recognized by the presence of luminal mitoses and apoptosis seen at scanning magnification, and no or limited HPVA features (nonhuman papillomavirus-associated adenocarcinoma [NHPVA]). HPVAs were then subcategorized based on cytoplasmic features (mostly to provide continuity with preexisting classification schemes), whereas NHPVAs were subclassified based on established criteria (ie, gastric-type, clear cell, etc.). Complete slide sets from 409 cases were collected from 7 institutions worldwide. Tissue microarrays representing 297 cases were constructed; immunohistochemistry (p16, p53, vimentin, progesterone receptor) and chromogenic in situ hybridization using an RNA-based probe set that recognizes 18 varieties of high-risk HPV were performed to validate IECC diagnoses. The 5 most common IECC diagnoses were usual-type (HPVA) (73% of cohort), gastric-type (NHPVA) (10%), mucinous adenocarcinoma of HPVA type, including intestinal, mucinous not otherwise specified, signet-ring, and invasive stratified mucin-producing carcinoma categories (9%), clear cell carcinoma (NHPVA) (3%) and adenocarcinoma, not otherwise specified (2%). Only 3 endometrioid carcinomas were recognized and all were NHPVA. When excluding cases thought to have suboptimal tissue processing, 90% and 95% of usual-type IECC cases overexpressed p16 and were HPV, whereas 37% and 3% of NHPVAs were p16 and HPV, respectively. The 1 HPV gastric-type carcinoma was found to have hybrid HPVA/NHPVA features on secondary review. NHPVA tumors were larger and occurred in significantly older patients, compared with HPVA tumors (P<0.001). The high-risk HPV chromogenic in situ hybridization probe set had superior sensitivity, specificity, and positive and negative predictive values (0.955, 0.968, 0.992, 0.833, respectively) compared with p16 immunohistochemistry (0.872, 0.632, 0.907, 0.545, respectively) to identify HPV-related usual carcinoma and mucinous carcinoma. IECC reliably segregates ECAs into HPVA and NHPVA types using morphology alone. This study confirms that usual-type ECAs are the most common type worldwide and that mucinous carcinomas comprise a mixture of HPVA and NHPVA, with gastric-type carcinoma being the major NHPVA type. Endometrioid and serous carcinomas of the endocervix are extraordinarily rare. Should clinical outcomes and genomic studies continue to support these findings, we recommend replacement of the World Health Organization 2014 criteria with the IECC 2017.

Decline in Decreased Cephalosporin Susceptibility and Increase in Azithromycin Resistance in Neisseria gonorrhoeae, Canada

Antimicrobial resistance profiles were determined for Neisseria gonorrhoeae strains isolated in Canada during 2010–2014. The proportion of isolates with decreased susceptibility to cephalosporins declined significantly between 2011 and 2014, whereas azithromycin resistance increased significantly during that period. Continued surveillance of antimicrobial drug susceptibilities is imperative to inform treatment guidelines.

Differential susceptibility of invasive Haemophilus influenzae serotype a and serotype b to ampicillin and other commonly prescribed antibiotics

Haemophilus influenzae serotype a (Hia) has become an important pathogen in the post-H. influenzae serotype b (Hib) vaccine era. Antibiotic resistance in H. influenzae is a global phenomenon, but few studies have looked at antibiotic resistance profiles with regard to serotype. Invasive Hia (n = 157), noninvasive Hia (n = 2) and invasive Hib (n = 42) collected over the last two decades from three Canadian Provinces were examined for resistance to several commonly prescribed antibiotics, and sequence types (STs) were determined by MLST. Only 1·9% of Hia showed antibiotic resistance, while 31% of Hib were resistant to one or more antibiotic. Resistance to ampicillin, sulfamethoxazole-trimethoprim, chloramphenicol and tetracycline was observed, with β-lactamase-mediated ampicillin resistance being the most common. Nine STs were identified for Hia with 7 STs belonging to the same clonal complex. Ten STs were observed in Hib strains, and all of them belonged to a single clonal complex. A possible correlation between sequence type and ampicillin resistance was observed for Hib, while no correlations were observed for Hia.

SIGNIFICANCE AND IMPACT OF THE STUDY

Despite H. influenzae serotype b (Hib) vaccine programs, invasive disease due to Hib still exists in Canada and is either second or third most common behind nontypeable and/or serotype a (Hia). Many previous studies on antibiotic resistance have focussed on respiratory isolates, and few have looked at resistance with regard to serotype. This study analysed antibiotic resistance in invasive Hia and Hib collected over 20 years from three provinces, and results found that significantly more Hib showed resistance compared to Hia. This provides a small snapshot of H. influenzae disease in Canada and highlights the importance to continually monitor antibiotic resistance profiles.

Serratia marcescens harbouring SME-type class A carbapenemases in Canada and the presence of blaSME on a novel genomic island, SmarGI1-1

OBJECTIVES

An increasing prevalence since 2010 of Serratia marcescens harbouring the Ambler class A carbapenemase SME prompted us to further characterize these isolates.

METHODS

Isolates harbouring bla(SME) were identified by PCR and sequencing. Phenotypic analysis for carbapenemase activity was carried out by a modified Hodge test and a modified Carba NP test. Antimicrobial susceptibilities were determined by Etest and Vitek 2. Typing was by PFGE of macrorestriction digests. Whole-genome sequencing of three isolates was carried out to characterize the genomic region harbouring the bla(SME)-type genes.

RESULTS

All S. marcescens harbouring SME-type enzymes could be detected using a modified Carba NP test. Isolates harbouring bla(SME) were resistant to penicillins and carbapenems, but remained susceptible to third-generation cephalosporins, as well as fluoroquinolones and trimethoprim/sulfamethoxazole. Isolates exhibited diverse genetic backgrounds, though 57% of isolates were found in three clusters. Analysis of whole-genome sequence data from three isolates revealed that the bla(SME) gene occurred in a novel cryptic prophage genomic island, SmarGI1-1.

CONCLUSIONS

There has been an increasing occurrence of S. marcescens harbouring bla(SME) in Canada since 2010. The bla(SME) gene was found on a genomic island, SmarGI1-1, that can be excised and circularized, which probably contributes to its dissemination amongst S. marcescens.

S3-5: Next Generation Sequencing Reveals Co-Activating Events in the MAPK and P13K/AKT Pathways in Metastatic Triple Negative Breast Cancers

INTRODUCTION: The clinical application of next generation sequencing to comprehensively characterize groups of driving mutations in individual metastatic triple negative breast cancer (mTNBC) genomes has the potential to reveal therapeutically relevant pathway dependencies. Towards this end, we harvested tissue from 14 patients with mTNBC and are conducting deep whole genome and transcriptome sequencing for each case to identify mutations that can guide therapeutic targeting within available phase I/II clinical trials.

METHODS: Metastatic tumor tissue was harvested from 14 mTNBC patients, and 7 samples have undergone total genome and transcriptome sequencing with the others currently underway. We are utilizing the Life Technologies SOLiD® system to sequence germline and tumor DNA to sufficient depth to identify somatic genome alterations including point mutations, indels, and structural events including translocations. Furthermore, RNA-seq is being performed on these tumors, along with a series of age- and ethnicity-matched normal breast controls to perform deep differential expression analysis, isoform expression analysis, and fusion transcript detection. Our team of genome scientists and clinical oncologists are evaluating the sequencing findings and are prioritizing the investigational therapeutic options for each patient.

RESULTS: Our whole genome and transcriptome sequencing study has revealed numerous known and novel mutations in mTNBC. However, all patients’ cancers analyzed to date had alterations that would activate the MAPK pathway, but through various mechanisms in different patients. These include BRAF amplification and overexpression, NF1 homozygous deletion, and consistent IQGAP3 overexpression. Furthermore, all patients’ cancers also harbor mutations that would activate the PI3K/AKT pathway including PTEN homozygous deletion or down-regulation, consistent INPP4B down-regulation, FBXW7 homozygous deletion, and ERAS overexpression. Moreover, although we and others show ERBB4 down-regulation in breast tumors, we are the first to report unique somatic genomic events that significantly alter the ERBB4 locus leading to its loss in the majority (5/7) of our patients’ tumors. Importantly, we are beginning to use these insights to prioritize therapeutic targeting and have observed that one chemotherapy-refractory mTNBC patient, with a high-level BRAF amplification/overexpression along with down-regulation of PTEN and INPP4B, had a major response to combined mek plus akt inhibitors on a phase I study.

CONCLUSIONS: Comprehensive genomic and transcriptomic interrogation of mTNBCs has revealed events supporting co-activation of the MAPK and PI3K/AKT pathways in all the tumors albeit by different mutational mechanisms and supports potential effectiveness of combination therapy in the treatment of mTNBC. We plan to treat these patients with combined mek plus akt inhibitors on a new phase I study beginning in August 2011 to determine the effectiveness of co-inhibition of these pathways based on this frequent genomic context.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr S3-5.

[Severe cases of A(H1N1)v2009 infection in Réunion Island in 2009 and 2010]

Dans l’hémisphère sud, La Réunion est la sentinelle des infections survenant préférentiellement au cours de l’hiver austral, susceptibles de gagner quelques mois plus tard l’hémisphère nord, telle l’infection à A(H1N1)v2009. Nous rapportons les caractéristiques des patients admis en 2009 et 2010 dans notre service de réanimation principalement pour détresse respiratoire aiguë, à la suite d’une infection à A(H1N1)v2009. Les données démographiques, cliniques, biologiques, ainsi que les traitements et le devenir des patients admis pour infection virale à A(H1N1)v2009 exclusivement confirmée par RT-PCR ont été recueillis de façon prospective. Au cours des années 2009 et 2010, 25 patients ont répondu aux critères définis d’infection à A(H1N1)v2009. L’âge médian était de 40,4 (±17,4) ans. La plupart d’entre eux (22/25) présentaient des facteurs de comorbidité: pathologies chroniques, surpoids ou obésité, grossesse, trisomie. Les principaux motifs d’admission en réanimation ont été les pneumonies virales avec tableau de syndrome de détresse respiratoire aiguë. Le recours à la ventilation artificielle a été nécessaire chez 22 des 25 patients, avec recours à des méthodes sophistiquées et réservées à quelques centres au niveau national, telles que les techniques d’oxygénation extracorporelle (ECMO) ou ventilation à haute fréquence (HFO). Au cours des deux années, 12 décès (48 %) sont survenus essentiellement dans des tableaux de défaillance multiviscérale. Au cours des hivers et automnes australs 2009 et 2010 et pendant une période de plusieurs semaines, l’infection à A(H1N1) v2009 a entraîné une surcharge d’activité notable dans les services de réanimation de La Réunion. L’échec de la campagne de vaccination, notamment des personnes à risques, a eu pour conséquence la survenue de nouveaux cas graves en 2010, notamment parmi les personnes à risques. Le recueil de ces données peut aider à la planification et à l’anticipation de la prise en charge d’autres épidémies grippales.