Recurrence rates and patterns of recurrence in stage IA p53abn endometrial cancer with and without myometrial invasion

OBJECTIVES

Optimal management of patients with stage IA p53abn endometrial cancer without myoinvasion, classified as intermediate risk in the 2020 European Society of Gynaecological Oncology, European Society for Radiotherapy and Oncology, and European Society of Pathology (ESGO-ESTRO-ESP) guidelines, and the 2022 European Society of Medical Oncology (ESMO) guidelines, is currently unclear. Practice varies from surgery alone to adjuvant radiation±chemotherapy. Our aim was to assess the risk of disease recurrence in patients with stage IA p53abn endometrial cancer without myoinvasion compared with stage IA with myoinvasion (<50%).

METHODS

Stage IA p53abn endometrial cancers were identified from retrospective cohorts. Cases were segregated into stage IA with no myoinvasion, including (1) tumor restricted to a polyp, (2) residual endometrial tumor, and (3) no residual tumor in hysterectomy specimen, versus stage IA p53abn with myoinvasion (<50%), with treatment and outcomes assessed.

RESULTS

There were 65 stage IA p53abn endometrial cancers with no myoinvasion (22 polyp confined, 38 residual endometrial tumor, 2 no residual in hysterectomy specimen, 3 not specified) and 97 with myoinvasion. There was no difference in survival outcomes in patients with stage IA without myoinvasion (16% of patients recurred, 19% if there was residual endometrial disease) compared with stage IA with myoinvasion (17%). The risk of recurrence was lowest in patients with stage IA p53abn endometrial cancer without myoinvasion treated with chemotherapy±radiation (8%). Most recurrences in patients with stage IA without myoinvasion were distant (89%), with no isolated vaginal vault recurrences, and all except one distant recurrence occurred in patients who had not received adjuvant chemotherapy.

CONCLUSION

The recurrence rate in patients with stage IA p53abn endometrial cancer without myoinvasion was 16%, highest in the setting of residual endometrial disease (19%), and exceeding the threshold where adjuvant therapy is often considered. The high frequency of distant recurrences observed may support chemotherapy as part of the treatment regimen.

Case report: Sustained complete remission with all-oral MEPED therapy in a patient with Hodgkin's disease developing resistance to pembrolizumab

Targeted chemotherapy and immune checkpoint inhibitors (ICPi) have expanded the spectrum of therapies for patients with relapsed/refractory (r/r) Hodgkin's disease and significantly improved the proportion of patients with long-term disease control. However, there is no standardized therapeutic option in case of further progression. Recently, we demonstrated that therapy with MEPED (metronomic chemotherapy, everolimus, pioglitazone, etoricoxib, dexamethasone) is highly effective in patients with r/r Hodgkin's disease. The benefit after pre-treatment with ICPi has not been studied, yet. Here, we report a patient with progressive Hodgkin's disease on Pembrolizumab for the first time who achieved sustained complete remission (CR) after initiation of MEPED therapy. A 57-year-old patient was pre-treated with brentuximab vedotin for relapsed advanced Hodgkin's disease and had received Pembrolizumab for progression from November 2020 to July 2022. Due to further progression, MEPED therapy was started in August 2022 and continued until May 2023. It consisted of a strictly oral daily (28-day cycle) application of low-dose treosulfan 250 mg, everolimus 15 mg, pioglitazone 45 mg, etoricoxib 60 mg, and dexamethasone 0.5 mg. Treatment response was evaluated by F-18 FDG-PET/CT (PET/CT). CR was defined by a negative Deauville score (DS) of 1-3. Already 3 months after starting MEPED, a CR (DS: 3) was confirmed by PET/CT in November 2022. The next follow-up in May 2023 continued to show CR (DS: 3). The therapy was very well tolerated. No hematological or other organ toxicity was observed. However, in May 2023 the patient presented with leg edema and weight gain, most likely due to pioglitazone and the PET/CT revealed suspected everolimus-induced pneumonitis, so MEPED was discontinued and diuretic therapy and treatment with prednisolone was started with gradual dose reduction. This resulted in a rapid complete resolution of the symptoms. The next PET-CT in July 2023 continued to show CR (DS: 3) without evidence of pneumonitis. Currently, therapy with MEPED has not been resumed. In conclusion, we demonstrate for the first time that MEPED therapy is highly effective in a patient with Hodgkin's disease who has been refractory to ICPi. Sustained CR was achieved over 11 months after initiation of MEPED therapy. Further studies on a larger patient cohort should be performed.

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

IMPORTANCE

Platinum-based chemotherapy is the backbone of standard-of-care treatment for patients with advanced-stage, high-grade serous carcinoma (HGSC), the most common form of ovarian cancer; however, one-third of patients have or acquire chemoresistance toward platinum-based therapies.

OBJECTIVE

To demonstrate the utility of tumor-stroma proportion (TSP) as a predictive biomarker of chemoresistance of HGSC, progression-free survival (PFS), and overall survival (OS).

DESIGN, SETTING, AND PARTICIPANTS

This prognostic study leveraged tumors from patients with HGSC in The Cancer Genome Atlas (TCGA) cohort (1993-2013) and an independent cohort of resected clinical specimens from patients with HGSC (2004-2014) available in diagnostic and tissue microarray formats from the University of Tübingen in Germany. Data analysis was conducted from January 2021 to January 2024.

EXPOSURE

Diagnosis of HGSC.

MAIN OUTCOMES AND MEASURES

Principal outcome measures were the ability of TSP to predict platinum chemoresistance, PFS, and OS. Using hematoxylin and eosin-stained slides from the Tübingen cohort (used for routine diagnostic assessment from surgical specimens) as well as tissue microarrays, representative sections of tumors for scoring of TSP were identified using previously evaluated cutoffs of 50% stroma or greater (high TSP) and less than 50% stroma (low TSP). Digitized slides from the TCGA Cohort were analyzed and scored in a similar fashion. Kaplan-Meier time-to-event functions were fit to estimate PFS and OS.

RESULTS

The study included 103 patients (mean [SD] age, 61.6 [11.1] years) from the TCGA cohort and 192 patients (mean [SD] age at diagnosis, 63.7 [11.1] years) from the Tübingen cohort. In the TCGA cohort, there was no significant association of TSP levels with chemoresistance, PFS, or OS. However, in the Tübingen cohort, high TSP was associated with significantly shorter PFS (HR, 1.586; 95% CI, 1.093-2.302; P = .02) and OS (hazard ratio [HR], 1.867; 1.249-2.789; P = .002). Patients with chemoresistant tumors were twice as likely to have high TSP as compared to patients with chemosensitive tumors (HR, 2.861; 95% CI, 1.256-6.515; P = .01). In tissue microarrays from 185 patients from the Tübingen cohort, high TSP was again associated with significantly shorter PFS (HR, 1.675; 95% CI, 1.012-2.772 P = .04) and OS (HR, 2.491; 95% CI, 1.585-3.912; P < .001).

CONCLUSIONS AND RELEVANCE

In this prognostic study, TSP was a consistent and reproducible marker of clinical outcome measures of HGSC, including PFS, OS, and platinum chemoresistance. Accurate and cost-effective predictive biomarkers of platinum chemotherapy resistance are needed to identify patients most likely to benefit from standard treatments, and TSP can easily be implemented and integrated into prospective clinical trial design and adapted to identify patients who are least likely to benefit long-term from conventional platinum-based cytotoxic chemotherapy treatment at the time of initial diagnosis.

The Prognostic Effect of Immune Cell Infiltration Depends on Molecular Subtype in Endometrioid Ovarian Carcinomas

PURPOSE

Endometrioid ovarian carcinoma (ENOC) is the second most-common type of ovarian carcinoma, comprising 10%-20% of cases. Recently, the study of ENOC has benefitted from comparisons to endometrial carcinomas including defining ENOC with four prognostic molecular subtypes. Each subtype suggests differential mechanisms of progression, although tumor-initiating events remain elusive. There is evidence that the ovarian microenvironment may be critical to early lesion establishment and progression. However, while immune infiltrates have been well studied in high-grade serous ovarian carcinoma, studies in ENOC are limited.

EXPERIMENTAL DESIGN

We report on 210 ENOC, with clinical follow-up and molecular subtype annotation. Using multiplex IHC and immunofluorescence, we examine the prevalence of T-cell lineage, B-cell lineage, macrophages, and populations with programmed cell death protein 1 or programmed death-ligand 1 across subtypes of ENOC.

RESULTS

Immune cell infiltrates in tumor epithelium and stroma showed higher densities in ENOC subtypes with known high mutation burden (POLEmut and MMRd). While molecular subtypes were prognostically significant, immune infiltrates were not (overall survival P > 0.2). Analysis by molecular subtype revealed that immune cell density was prognostically significant in only the no specific molecular profile (NSMP) subtype, where immune infiltrates lacking B cells (TILB minus) had inferior outcome (disease-specific survival: HR, 4.0; 95% confidence interval, 1.1-14.7; P < 0.05). Similar to endometrial carcinomas, molecular subtype stratification was generally superior to immune response in predicting outcomes.

CONCLUSIONS

Subtype stratification is critical for better understanding of ENOC, in particular the distribution and prognostic significance of immune cell infiltrates. The role of B cells in the immune response within NSMP tumors warrants further study.

Targeted Molecular Testing in Endometrial Carcinoma: Validation of a Clinically Driven Selective ProMisE Testing Protocol

Incorporation of molecular classification into clinicopathologic assessment of endometrial carcinoma (EC) improves risk stratification. Four EC molecular subtypes, as identified by The Cancer Genome Atlas, can be diagnosed through a validated algorithm Pro active M olecular R is k Classifier for E ndometrial Cancer (ProMisE) using p53 and mismatch repair (MMR) protein immunohistochemistry (IHC), and DNA polymerase epsilon ( POLE) mutational testing. Cost and access are major barriers to universal testing, particularly POLE analysis. We assessed a selective ProMisE algorithm (ProMisE-S): p53 and MMR IHC on all EC's with POLE testing restricted to those with abnormal MMR or p53 IHC (to identify POLEmut EC with secondary abnormalities in MMR and/or p53) and those with high-grade or non-endometrioid morphology, stage >IA or presence of lymphovascular space invasion (so as to avoid testing on the lowest risk tumors). We retrospectively compared the known ProMisE molecular classification to ProMisE-S in 912 EC. We defined a group of "very low-risk" EC (G1/G2, endometrioid, MMR-proficient, p53 wild-type, stage IA, no lymphovascular space invasion) in whom POLE testing will not impact on patient care; using ProMisE-S, POLE testing would not be required in 55% of biopsies and 38% of all EC's, after evaluation of the hysterectomy specimen, in a population-based cohort. "Very low-risk" endometrioid EC with unknown POLE status showed excellent clinical outcomes. Fifteen of 166 (9%) of all p53abn EC showed G1/G2 endometrioid morphology, supporting the potential value of universal p53 IHC. The addition of molecular testing changed the risk category in 89/896 (10%) EC's. In routine practice, POLE testing could be further restricted to only those patients in whom this would alter adjuvant therapy recommendations.

Clinical Significance of the Stromatic Component in Ovarian Cancer: Quantity Over Quality in Outcome Prediction

Background

The tumor stroma is composed of a complex network of non-cancerous cells and extracellular matrix elements that collectively are crucial for cancer progression and treatment response. Within the realm of ovarian cancer, the expression of the stromal gene cluster has been linked to poorer progression-free and overall survival rates. However, in the age of precision medicine and genome sequencing, the notion that the simple measurement of tumor-stroma proportion alone can serve as a biomarker for clinical outcome is a topic that continues to generate controversy and provoke discussion. Our current study reveals that it is the quantity of stroma, rather than its quality, that serves as a clinically significant indicator of patient outcome in ovarian cancer.

Methods

This study leveraged the High-Grade-Serous-Carcinoma (HGSC) cohort of the publicly accessible Cancer Genome Atlas Program (TCGA) along with an independent cohort comprising HGSC clinical specimens in diagnostic and Tissue Microarray formats. Our objective was to investigate the correlation between the Tumor-Stroma-Proportion (TSP) and progression-free survival (PFS), overall survival (OS), and response to chemotherapy. We assessed these associations using H&E-stained slides and tissue microarrays. Our analysis employed semi-parametric models that accounted for age, metastases, and residual disease as controlling factors.

Results

We found that high TSP (>50% stroma) was associated with significantly shorter progression-free survival (PFS) (p=0.016) and overall survival (OS) (p=0.006). Tumors from patients with chemoresistant tumors were twice as likely to have high TSP as compared to tumors from chemosensitive patients (p=0.012). In tissue microarrays, high TSP was again associated with significantly shorter PFS (p=0.044) and OS (p=0.0001), further confirming our findings. The Area Under the ROC curve for the model predicting platinum was estimated at 0.7644.

Conclusions

In HGSC, TSP was a consistent and reproducible marker of clinical outcome measures, including PFS, OS, and platinum chemoresistance. Assessment of TSP as a predictive biomarker that can be easily implemented and integrated into prospective clinical trial design and adapted to identify, at time of initial diagnosis, patients who are least likely to benefit long-term from conventional platinum-based cytotoxic chemotherapy treatment.

p53 and ovarian carcinoma survival: an Ovarian Tumor Tissue Analysis consortium study

Our objective was to test whether p53 expression status is associated with survival for women diagnosed with the most common ovarian carcinoma histotypes (high-grade serous carcinoma [HGSC], endometrioid carcinoma [EC], and clear cell carcinoma [CCC]) using a large multi-institutional cohort from the Ovarian Tumor Tissue Analysis (OTTA) consortium. p53 expression was assessed on 6,678 cases represented on tissue microarrays from 25 participating OTTA study sites using a previously validated immunohistochemical (IHC) assay as a surrogate for the presence and functional effect of TP53 mutations. Three abnormal expression patterns (overexpression, complete absence, and cytoplasmic) and the normal (wild type) pattern were recorded. Survival analyses were performed by histotype. The frequency of abnormal p53 expression was 93.4% (4,630/4,957) in HGSC compared to 11.9% (116/973) in EC and 11.5% (86/748) in CCC. In HGSC, there were no differences in overall survival across the abnormal p53 expression patterns. However, in EC and CCC, abnormal p53 expression was associated with an increased risk of death for women diagnosed with EC in multivariate analysis compared to normal p53 as the reference (hazard ratio [HR] = 2.18, 95% confidence interval [CI] 1.36-3.47, p = 0.0011) and with CCC (HR = 1.57, 95% CI 1.11-2.22, p = 0.012). Abnormal p53 was also associated with shorter overall survival in The International Federation of Gynecology and Obstetrics stage I/II EC and CCC. Our study provides further evidence that functional groups of TP53 mutations assessed by abnormal surrogate p53 IHC patterns are not associated with survival in HGSC. In contrast, we validate that abnormal p53 IHC is a strong independent prognostic marker for EC and demonstrate for the first time an independent prognostic association of abnormal p53 IHC with overall survival in patients with CCC.

L1-CAM in Mucinous Ovarian Carcinomas and Borderline Tumors: Impact on Tumor Recurrence and Potential Role in Tumor Progression

Mucinous ovarian carcinoma (MOC) is a rare histotype of primary ovarian carcinoma. Frequent pathogenic molecular alterations include mutations in KRAS , TP53 , and overexpression of human epidermal growth factor receptor 2, but without having prognostic relevance. As L1-CAM (cell adhesion molecule) has previously shown prognostic relevance in other epithelial tumors of the female genital tract, we analyzed whether L1-CAM expression affected MOC prognosis. In addition, we investigated L1-CAM expression in mucinous borderline tumors (MBOTs) with and without adjacent MOC to identify its potential role in the pathogenesis of MOC. We examined a well-characterized collective of 39 MOCs by immunohistochemistry and compared their expression with clinicopathologic data. L1-CAM positivity was defined as any (even single-cell) positivity. Furthermore, we compared the L1-CAM expression in 20 MBOT regions adjacent to a MOC with that of 15 pure MBOTs. L1-CAM expression in MOC was significantly associated with recurrence, independent of tumor stage. Overall, 7/20 positive cases recurred versus 0/19 L1-CAM-negative cases ( P =0.032), showing a significant difference in time to progression. Furthermore, the presence of at least 1 defined molecular alteration (L1-CAM, aberrant p53, or human epidermal growth factor receptor 2) was found more frequently in the MBOT regions adjacent to a MOC (14/20) than in pure MBOTs (3/15) ( P =0.024). Expression of the tumor marker L1-CAM is frequent (51%) in MOC and is associated with tumor recurrence. The lack of L1-CAM may serve to characterize cases with a low risk of recurrence. Furthermore, the presence of specific molecular alterations in MBOTs is associated with adjacent carcinomas and may define potential pathways in tumor progression.

Depression and anxiety in women with malignant ovarian germ cell (MOGCT) and sex cord stromal tumors (SCST): an analysis of the AGO-CORSETT database

INTRODUCTION

The intention of this study was to evaluate the level of anxiety and depression of malignant ovarian germ cell (MOGCT) and sex cord stromal tumors (SCST) survivors and to identify possible alterable cofactors.

METHODS

CORSETT was an observational, multicenter, mixed retrospective/prospective cohort study of the AGO Studygroup. Women who had been diagnosed with MOGCTs and SCSTs between 2001 and 2011 were asked to complete the Hospital Anxiety and Depression Scale (HADS) to evaluate distress. Predictors of distress (type of surgery, chemotherapy, time since diagnosis, recurrence, second tumor, pain) were investigated using multivariate linear regression analysis.

RESULTS

150 MOGCT and SCST patients with confirmed histological diagnosis completed the questionnaire median seven years after diagnosis. They had a HADS total score ≥ 13 indicating severe mental distress in 34% of cases. Patients after fertility-conserving surgery had lower probability of severe mental distress than those without fertility-conserving treatment (β = - 3.1, p = 0.04). Pain was associated with the level of distress in uni- and multivariate analysis (coef 0.1, p < 0.01, coef. Beta 0.5).

DISCUSSION

Severe mental distress was frequent in patients with MOGCT and SCST and the level of pain was associated with the level of distress. Fertility conserving therapy, however, was associated with less mental distress. Screening and treatment of pain and depression is required to improve mental well-being in survivors of MOGCT and SCST.

Treatment and survival of patients with malignant ovarian sex cord-stromal cell tumours: An analysis of the Arbeitsgemeinschaft für Gynäkologische Onkologie (AGO) study group CORSETT database

BACKGROUND

Malignant sex cord-stromal cell tumours (SCST) account for only 7% of ovarian malignancies. The Arbeitsgemeinschaft fuer Gynaekologische Onkologie (AGO) study group has established a clinicopathological database to provide an overview of the current treatment strategies and survival of SCST patients and to identify research needs.

METHODS

Twenty centres provided mixed retro- and prospective data of patients with tumour specimens and second-opinion pathology review treated between 2000 and 2014. Descriptive analyses of treatment strategies, Kaplan-Meier curves and cox regression analyses were conducted.

RESULTS

Two hundred and sixty-two SCST patients were included. One hundred and ninety-one Granulosa-cell tumour (GCT) and 17 Sertoli-Leydig cell tumour (SLCT) patients were stage I disease (>80%). Forty four GCT (18.7%) and two (8.3%) SLCT patients received adjuvant systemic treatment. After a median observation time of 78.2 months, 46% of all SCST patients experienced disease recurrence, treated predominantly with secondary debulking surgery (> 90%). Advanced FIGO stage, lymph node involvement and intra-operative capsule rupture were associated with disease recurrence on univariate analysis (all p < 0.05). Median OS time was not reached.

DISCUSSION

In this analysis of SCST patients, adjuvant chemotherapy was unable to prevent disease recurrence. Despite high recurrence rates, overall survival rates were excellent.

CCNE1 and survival of patients with tubo-ovarian high-grade serous carcinoma: An Ovarian Tumor Tissue Analysis consortium study

BACKGROUND

Cyclin E1 (CCNE1) is a potential predictive marker and therapeutic target in tubo-ovarian high-grade serous carcinoma (HGSC). Smaller studies have revealed unfavorable associations for CCNE1 amplification and CCNE1 overexpression with survival, but to date no large-scale, histotype-specific validation has been performed. The hypothesis was that high-level amplification of CCNE1 and CCNE1 overexpression, as well as a combination of the two, are linked to shorter overall survival in HGSC.

METHODS

Within the Ovarian Tumor Tissue Analysis consortium, amplification status and protein level in 3029 HGSC cases and mRNA expression in 2419 samples were investigated.

RESULTS

High-level amplification (>8 copies by chromogenic in situ hybridization) was found in 8.6% of HGSC and overexpression (>60% with at least 5% demonstrating strong intensity by immunohistochemistry) was found in 22.4%. CCNE1 high-level amplification and overexpression both were linked to shorter overall survival in multivariate survival analysis adjusted for age and stage, with hazard stratification by study (hazard ratio [HR], 1.26; 95% CI, 1.08-1.47, p = .034, and HR, 1.18; 95% CI, 1.05-1.32, p = .015, respectively). This was also true for cases with combined high-level amplification/overexpression (HR, 1.26; 95% CI, 1.09-1.47, p = .033). CCNE1 mRNA expression was not associated with overall survival (HR, 1.00 per 1-SD increase; 95% CI, 0.94-1.06; p = .58). CCNE1 high-level amplification is mutually exclusive with the presence of germline BRCA1/2 pathogenic variants and shows an inverse association to RB1 loss.

CONCLUSION

This study provides large-scale validation that CCNE1 high-level amplification is associated with shorter survival, supporting its utility as a prognostic biomarker in HGSC.

Increased FOXJ1 protein expression is associated with improved overall survival in high-grade serous ovarian carcinoma: an Ovarian Tumor Tissue Analysis Consortium Study

BACKGROUND

Recently, we showed a >60% difference in 5-year survival for patients with tubo-ovarian high-grade serous carcinoma (HGSC) when stratified by a 101-gene mRNA expression prognostic signature. Given the varied patient outcomes, this study aimed to translate prognostic mRNA markers into protein expression assays by immunohistochemistry and validate their survival association in HGSC.

METHODS

Two prognostic genes, FOXJ1 and GMNN, were selected based on high-quality antibodies, correlation with protein expression and variation in immunohistochemical scores in a preliminary cohort (n = 134 and n = 80, respectively). Six thousand four hundred and thirty-four (FOXJ1) and 5470 (GMNN) formalin-fixed, paraffin-embedded ovarian neoplasms (4634 and 4185 HGSC, respectively) represented on tissue microarrays from the Ovarian Tumor Tissue Analysis consortium underwent immunohistochemical staining and scoring, then univariate and multivariate survival analysis.

RESULTS

Consistent with mRNA, FOXJ1 protein expression exhibited a linear, increasing association with improved overall survival in HGSC patients. Women with >50% expression had the most favourable outcomes (HR = 0.78, 95% CI 0.67-0.91, p < 0.0001). GMNN protein expression was not significantly associated with overall HSGC patient survival. However, HGSCs with >35% GMNN expression showed a trend for better outcomes, though this was not significant.

CONCLUSION

We provide foundational evidence for the prognostic value of FOXJ1 in HGSC, validating the prior mRNA-based prognostic association by immunohistochemistry.

Gene-Expression Profiling of Mucinous Ovarian Tumors and Comparison with Upper and Lower Gastrointestinal Tumors Identifies Markers Associated with Adverse Outcomes

PURPOSE

Advanced-stage mucinous ovarian carcinoma (MOC) has poor chemotherapy response and prognosis and lacks biomarkers to aid stage I adjuvant treatment. Differentiating primary MOC from gastrointestinal (GI) metastases to the ovary is also challenging due to phenotypic similarities. Clinicopathologic and gene-expression data were analyzed to identify prognostic and diagnostic features.

EXPERIMENTAL DESIGN

Discovery analyses selected 19 genes with prognostic/diagnostic potential. Validation was performed through the Ovarian Tumor Tissue Analysis consortium and GI cancer biobanks comprising 604 patients with MOC (n = 333), mucinous borderline ovarian tumors (MBOT, n = 151), and upper GI (n = 65) and lower GI tumors (n = 55).

RESULTS

Infiltrative pattern of invasion was associated with decreased overall survival (OS) within 2 years from diagnosis, compared with expansile pattern in stage I MOC [hazard ratio (HR), 2.77; 95% confidence interval (CI), 1.04-7.41, P = 0.042]. Increased expression of THBS2 and TAGLN was associated with shorter OS in MOC patients (HR, 1.25; 95% CI, 1.04-1.51, P = 0.016) and (HR, 1.21; 95% CI, 1.01-1.45, P = 0.043), respectively. ERBB2 (HER2) amplification or high mRNA expression was evident in 64 of 243 (26%) of MOCs, but only 8 of 243 (3%) were also infiltrative (4/39, 10%) or stage III/IV (4/31, 13%).

CONCLUSIONS

An infiltrative growth pattern infers poor prognosis within 2 years from diagnosis and may help select stage I patients for adjuvant therapy. High expression of THBS2 and TAGLN in MOC confers an adverse prognosis and is upregulated in the infiltrative subtype, which warrants further investigation. Anti-HER2 therapy should be investigated in a subset of patients. MOC samples clustered with upper GI, yet markers to differentiate these entities remain elusive, suggesting similar underlying biology and shared treatment strategies.

Bevacizumab May Differentially Improve Prognosis of Advanced Ovarian Cancer Patients with Low Expression of VEGF-A165b, an Antiangiogenic VEGF-A Splice Variant

PURPOSE

The identification of a robust IHC marker to predict the response to antiangiogenic bevacizumab in ovarian cancer is of high clinical interest. VEGF-A, the molecular target of bevacizumab, is expressed as multiple isoforms with pro- or antiangiogenic properties, of which VEGF-A165b is the most dominant antiangiogenic isoform. The balance of VEGF-A isoforms is closely related to the angiogenic capacity of a tumor and may define its vulnerability to antiangiogenic therapy. We investigated whether the expression of VEGF-A165b could be related to the effect of bevacizumab in advanced ovarian cancer patients.

EXPERIMENTAL DESIGN

Formalin-fixed paraffin-embedded tissues from 413 patients of the ICON7 multicenter phase III trial, treated with standard platinum-based chemotherapy with or without bevacizumab, were probed for VEGF-A165b expression by IHC.

RESULTS

In patients with low VEGF-A165b expression, the addition of bevacizumab to standard platinum-based chemotherapy significantly improved progression-free (HR: 0.727; 95% CI, 0.538-0.984; P = 0.039) and overall survival (HR: 0.662; 95% CI, 0.458-0.958; P = 0.029). Multivariate analysis showed that the addition of bevacizumab in low VEGF-A165b-expressing patients conferred significant improvements in progression-free survival (HR: 0.610; 95% CI, 0.446-0.834; P = 0.002) and overall survival (HR: 0.527; 95% CI, 0.359-0.775; P = 0.001), independently from established risk factors.

CONCLUSIONS

We demonstrate for the first time that bevacizumab may differentially improve the prognosis of advanced ovarian cancer patients with low expression of VEGF-A165b, an antiangiogenic VEGF-A splice variant. We envision that this novel biomarker could be implemented into routine diagnostics and may have direct clinical implications for guiding bevacizumab-related treatment decisions in advanced ovarian cancer patients.

Molecular analysis suggests oligoclonality and metastasis of endometriosis lesions across anatomically defined subtypes

OBJECTIVE

To investigate the heterogeneity of somatic cancer-driver mutations within patients and across endometriosis types.

DESIGN

A single-center cohort, retrospective study.

SETTING

Tertiary specialist-care center at a university hospital.

PATIENT(S)

Patients with surgically and histologically confirmed endometriosis of at least 2 anatomically distinct types (ovarian, deep infiltrating, and superficial).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Specimens were analyzed for the presence or absence of somatic cancer-driver mutations using targeted panel sequencing with orthogonal validation using droplet digital polymerase chain reaction and mutation-surrogate immunohistochemistry.

RESULT(S)

It was found that 13 of 27 patients had informative somatic driver mutations in endometriosis lesions; of these 13 patients, 9 had identical mutations across distinct lesions. Endometriomas showed a higher mutational complexity, with functionally redundant driver mutations in the same gene and within the same lesions.

CONCLUSION(S)

Our data are consistent with clonality across endometriosis lesions, regardless of subtype. Further, the finding of redundancy in mutations within the same gene and lesions is consistent with endometriosis representing an oligoclonal disease with dissemination likely to consist of multiple epithelial clones traveling together. This suggests that the current anatomically defined classification of endometriosis does not fully recognize the etiology of the disease. A novel classification should consider genomic and other molecular features to promote personalized endometriosis diagnosis and care.

Improved preoperative risk stratification in endometrial carcinoma patients: external validation of the ENDORISK Bayesian network model in a large population-based case series

PURPOSE

Preoperative risk stratification of newly diagnosed endometrial carcinoma (EC) patients has been hindered by only moderate prediction performance for many years. Recently ENDORISK, a Bayesian network model, showed high predictive performance. It was the aim of this study to validate ENDORISK by applying the model to a population-based case series of EC patients.

METHODS

ENDORISK was applied to a retrospective cohort of women surgically treated for EC from 2003 to 2013. Prediction accuracy for LNM as well as 5-year DSS was investigated. The model's overall performance was quantified by the Brier score, discriminative performance by area under the curve (AUC).

RESULTS

A complete dataset was evaluable from 247 patients. 78.1% cases were endometrioid histotype. The majority of patients (n = 156;63.2%) had stage IA disease. Overall, positive lymph nodes were found in 20 (8.1%) patients. Using ENDORISK predicted probabilities, most (n = 156;63.2%) patients have been assigned to low or very low risk group with a false-negative rate of 0.6%. AUC for LNM prediction was 0.851 [95% confidence interval (CI) 0.761-0.941] with a Brier score of 0.06. For 5-year DSS the AUC was 0.698 (95% CI 0.595-0.800) as Brier score has been calculated 0.09.

CONCLUSIONS

We were able to successfully validate ENDORISK for prediction of LNM and 5-year DSS. Next steps will now have to focus on ENDORISK performance in daily clinical practice. In addition, incorporating TCGA-derived molecular subtypes will be of key importance for future extended use. This study may support further promoting of data-based decision-making tools for personalized treatment of EC.

Fusarium and allied fusarioid taxa (FUSA). 1

Seven Fusarium species complexes are treated, namely F. aywerte species complex (FASC) (two species), F. buharicum species complex (FBSC) (five species), F. burgessii species complex (FBURSC) (three species), F. camptoceras species complex (FCAMSC) (three species), F. chlamydosporum species complex (FCSC) (eight species), F. citricola species complex (FCCSC) (five species) and the F. concolor species complex (FCOSC) (four species). New species include Fusicolla elongata from soil (Zimbabwe), and Neocosmospora geoasparagicola from soil associated with Asparagus officinalis (Netherlands). New combinations include Neocosmospora akasia, N. awan, N. drepaniformis, N. duplosperma, N. geoasparagicola, N. mekan, N. papillata, N. variasi and N. warna. Newly validated taxa include Longinectria gen. nov., L. lagenoides, L. verticilliforme, Fusicolla gigas and Fusicolla guangxiensis. Furthermore, Fusarium rosicola is reduced to synonymy under N. brevis. Finally, the genome assemblies of Fusarium secorum (CBS 175.32), Microcera coccophila (CBS 310.34), Rectifusarium robinianum (CBS 430.91), Rugonectria rugulosa (CBS 126565), and Thelonectria blattea (CBS 952.68) are also announced here. Citation: Crous PW, Sandoval-Denis M, Costa MM, Groenewald JZ, van Iperen AL, Starink-Willemse M, Hernández-Restrepo M, Kandemir H, Ulaszewski B, de Boer W, Abdel-Azeem AM, Abdollahzadeh J, Akulov A, Bakhshi M, Bezerra JDP, Bhunjun CS, Câmara MPS, Chaverri P, Vieira WAS, Decock CA, Gaya E, Gené J, Guarro J, Gramaje D, Grube M, Gupta VK, Guarnaccia V, Hill R, Hirooka Y, Hyde KD, Jayawardena RS, Jeewon R, Jurjević Ž, Korsten L, Lamprecht SC, Lombard L, Maharachchikumbura SSN, Polizzi G, Rajeshkumar KC, Salgado-Salazar C, Shang Q-J, Shivas RG, Summerbell RC, Sun GY, Swart WJ, Tan YP, Vizzini A, Xia JW, Zare R, González CD, Iturriaga T, Savary O, Coton M, Coton E, Jany J-L, Liu C, Zeng Z-Q, Zhuang W-Y, Yu Z-H, Thines M (2022). Fusarium and allied fusarioid taxa (FUSA). 1. Fungal Systematics and Evolution 9: 161-200. doi: 10.3114/fuse.2022.09.08.

Electrosurgery and Other Technical Advancements in Minimally Invasive Gynecological Surgery - An Update

Electrosurgery in gynecology has changed over the past few decades. The use of energy-based devices, especially in minimally invasive procedures, is extremely important for preparation, short reconvalescence and patient safety. Recently, there have been major advances in energy-based surgical devices that have further shortened OR time and increased patient safety. Although bipolar and monopolar electrosurgery is still very important, the introduction of high-frequency ultrasound in gynecologic surgery has improved cutting and coagulation by lowering thermal damage in the surrounding tissue. Furthermore, new technical inventions have fundamentally changed the treatment of specific diseases. The introduction of ablation in the therapy of uterine fibroids, for example, has made conventional myomectomy no longer necessary in some cases, as necrosis of fibroids can be induced by placing very small thermal probes into the fibroids. Robotic surgery will change the face of gynecological surgery in the near future, as the initial studies could show lower surgical morbidity and faster recovery of patients after robotic-assisted laparoscopy. In this article we provide a short overview of current technical advances, review possible indications as well as limitations, and take a look into the future of minimally invasive surgery in gynecology.

Validated biomarker assays confirm that ARID1A loss is confounded with MMR deficiency, CD8+ TIL infiltration, and provides no independent prognostic value in endometriosis-associated ovarian carcinomas

ARID1A (BAF250a) is a component of the SWI/SNF chromatin modifying complex, plays an important tumour suppressor role, and is considered prognostic in several malignancies. However, in ovarian carcinomas there are contradictory reports on its relationship to outcome, immune response, and correlation with clinicopathological features. We assembled a series of 1623 endometriosis-associated ovarian carcinomas, including 1078 endometrioid (ENOC) and 545 clear cell (CCOC) ovarian carcinomas, through combining resources of the Ovarian Tumor Tissue Analysis (OTTA) Consortium, the Canadian Ovarian Unified Experimental Resource (COEUR), local, and collaborative networks. Validated immunohistochemical surrogate assays for ARID1A mutations were applied to all samples. We investigated associations between ARID1A loss/mutation, clinical features, outcome, CD8+ tumour-infiltrating lymphocytes (CD8+ TILs), and DNA mismatch repair deficiency (MMRd). ARID1A loss was observed in 42% of CCOCs and 25% of ENOCs. We found no associations between ARID1A loss and outcomes, stage, age, or CD8+ TIL status in CCOC. Similarly, we found no association with outcome or stage in endometrioid cases. In ENOC, ARID1A loss was more prevalent in younger patients (p = 0.012) and was associated with MMRd (p < 0.001) and the presence of CD8+ TILs (p = 0.008). Consistent with MMRd being causative of ARID1A mutations, in a subset of ENOCs we also observed an association with ARID1A loss-of-function mutation as a result of small indels (p = 0.035, versus single nucleotide variants). In ENOC, the association with ARID1A loss, CD8+ TILs, and age appears confounded by MMRd status. Although this observation does not explicitly rule out a role for ARID1A influence on CD8+ TIL infiltration in ENOC, given current knowledge regarding MMRd, it seems more likely that effects are dominated by the hypermutation phenotype. This large dataset with consistently applied biomarker assessment now provides a benchmark for the prevalence of ARID1A loss-of-function mutations in endometriosis-associated ovarian cancers and brings clarity to the prognostic significance. © 2021 The Pathological Society of Great Britain and Ireland.

MCM3 is a novel proliferation marker associated with longer survival for patients with tubo-ovarian high-grade serous carcinoma

Tubo-ovarian high-grade serous carcinomas (HGSC) are highly proliferative neoplasms that generally respond well to platinum/taxane chemotherapy. We recently identified minichromosome maintenance complex component 3 (MCM3), which is involved in the initiation of DNA replication and proliferation, as a favorable prognostic marker in HGSC. Our objective was to further validate whether MCM3 mRNA expression and possibly MCM3 protein levels are associated with survival in patients with HGSC. MCM3 mRNA expression was measured using NanoString expression profiling on formalin-fixed and paraffin-embedded tissue (N = 2355 HGSC) and MCM3 protein expression was assessed by immunohistochemistry (N = 522 HGSC) and compared with Ki-67. Kaplan-Meier curves and the Cox proportional hazards model were used to estimate associations with survival. Among chemotherapy-naïve HGSC, higher MCM3 mRNA expression (one standard deviation increase in the score) was associated with longer overall survival (HR = 0.87, 95% CI 0.81-0.92, p < 0.0001, N = 1840) in multivariable analysis. MCM3 mRNA expression was highest in the HGSC C5.PRO molecular subtype, although no interaction was observed between MCM3, survival and molecular subtypes. MCM3 and Ki-67 protein levels were significantly lower after exposure to neoadjuvant chemotherapy compared to chemotherapy-naïve tumors: 37.0% versus 46.4% and 22.9% versus 34.2%, respectively. Among chemotherapy-naïve HGSC, high MCM3 protein levels were also associated with significantly longer disease-specific survival (HR = 0.52, 95% CI 0.36-0.74, p = 0.0003, N = 392) compared to cases with low MCM3 protein levels in multivariable analysis. MCM3 immunohistochemistry is a promising surrogate marker of proliferation in HGSC.

Fusarium: more than a node or a foot-shaped basal cell

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org).

Endometrial Cancer Molecular Risk Stratification is Equally Prognostic for Endometrioid Ovarian Carcinoma

PURPOSE

Endometrioid ovarian carcinoma (ENOC) is generally associated with a more favorable prognosis compared with other ovarian carcinomas. Nonetheless, current patient treatment continues to follow a "one-size-fits-all" approach. Even though tumor staging offers stratification, personalized treatments remain elusive. As ENOC shares many clinical and molecular features with its endometrial counterpart, we sought to investigate The Cancer Genome Atlas-inspired endometrial carcinoma (EC) molecular subtyping in a cohort of ENOC.

EXPERIMENTAL DESIGN

IHC and mutation biomarkers were used to segregate 511 ENOC tumors into four EC-inspired molecular subtypes: low-risk POLE mutant (POLEmut), moderate-risk mismatch repair deficient (MMRd), high-risk p53 abnormal (p53abn), and moderate-risk with no specific molecular profile (NSMP). Survival analysis with established clinicopathologic and subtype-specific features was performed.

RESULTS

A total of 3.5% of cases were POLEmut, 13.7% MMRd, 9.6% p53abn, and 73.2% NSMP, each showing distinct outcomes (P < 0.001) and survival similar to observations in EC. Median OS was 18.1 years in NSMP, 12.3 years in MMRd, 4.7 years in p53abn, and not reached for POLEmut cases. Subtypes were independent of stage, grade, and residual disease in multivariate analysis.

CONCLUSIONS

EC-inspired molecular classification provides independent prognostic information in ENOC. Our findings support investigating molecular subtype-specific management recommendations for patients with ENOC; for example, subtypes may provide guidance when fertility-sparing treatment is desired. Similarities between ENOC and EC suggest that patients with ENOC may benefit from management strategies applied to EC and the opportunity to study those in umbrella trials.

Disentangling functional trait variation and covariation in epiphytic lichens along a continent-wide latitudinal gradient

Characterizing functional trait variation and covariation, and its drivers, is critical to understand the response of species to changing environmental conditions. Evolutionary and environmental factors determine how traits vary among and within species at multiple scales. However, disentangling their relative contribution is challenging and a comprehensive trait-environment framework addressing such questions is missing in lichens. We investigated the variation in nine traits related to photosynthetic performance, water use and nutrient acquisition applying phylogenetic comparative analyses in lichen epiphytic communities on beech across Europe. These poikilohydric organisms offer a valuable model owing to their inherent limitations to buffer contrasting environmental conditions. Photobiont type and growth form captured differences in certain physiological traits whose variation was largely determined by evolutionary processes (i.e. phylogenetic history), although the intraspecific component was non-negligible. Seasonal temperature fluctuations also had an impact on trait variation, while nitrogen content depended on photobiont type rather than nitrogen deposition. The inconsistency of trait covariation among and within species prevented establishing major resource use strategies in lichens. However, we did identify a general pattern related to the water-use strategy. Thus, to robustly unveil lichen responses under different climatic scenarios, it is necessary to incorporate both among and within-species trait variation and covariation.

High rates of cirrhosis and severe clinical events in patients with HBV/HDV co-infection: longitudinal analysis of a German cohort

Background

Chronic hepatitis delta virus (HDV) infection causes severe liver disease which often leads to cirrhosis and hepatocellular carcinoma (HCC). Aim of this study was to establish the disease severity and prognostic factors for disease outcome by analysing frequencies of clinical events and their correlation with baseline virological and biochemical parameters as well as interferon and nucleos(t)ide analogue treatment choice.

Methods

We studied a single-centre cohort of 49 anti-HDAg-positive patients with HBsAg persistence for at least 6 months. Virological and biochemical parameters, interferon and nucleos(t)ide analogue treatment choice as well as clinical events during follow-up were analysed by retrospective chart review (mean follow-up time 3 years, range 0.25–7.67 years).

Results

Severe clinical events occurred in 11/49 hepatitis D patients, including HCC (8/49), death (8/49) or liver transplantation (2/49). HCCs only occurred secondary to liver cirrhosis and their event rates in this cohort of hepatitis D patients did not differ from a matched HBV mono-infected cohort with comparable frequency of liver cirrhosis. A stepwise multivariate logistic regression revealed low platelet count (p = 0. 0290) and older age (p = 0.0337) correlating most strongly with overall clinical events, while serum HDV RNA positivity at baseline did not correlate with any clinical outcome. Interferon-free but not nucleos(t)ide analogue-free patient care correlated with the occurrence of HCC at logistic regression, although only 3/18 interferon-treated patients demonstrated repeatedly negative HDV PCR results post therapy.

Conclusions

Our data indicate that progressive liver disease at baseline plays a major role as predictive factor for overall clinical outcome of hepatitis D patients. In particular, HCC risk may not be underestimated in hepatitis D virus RNA negative hepatitis D patients with advanced liver fibrosis.

Uterine Fibroids - Current Trends and Strategies

Fibroids are the most common benign tumors in women of childbearing age and can be found in almost 80-90% of all women by age 50 years. They can cause pain, excessive menstrual bleeding or infertility. The development of fibroids increases with age. Since the age of women in industrial countries who are trying to conceive is generally increasing, there has been a growing demand for minimally invasive and uterine-sparing surgical treatment of fibroids. Whereas the main focus of previous surgical techniques for the treatment of fibroids was enucleation of the tumour with subsequent closure of the uterine incision, modern devices developed over the past decade can destroy fibroids by using ultrasound or radio-frequency without incising the uterine wall. Thus, there is no uterine scar, which would impart a risk of rupture during labour or pregnancy. This article provides an overview of the latest techniques and devices used for uterine-sparing surgical treatment of fibroids. While laparoscopic myomectomy is still the gold standard, novel laparoscopic and transcervical radiofrequency ablation techniques use low-voltage and alternating current to induce heat in the uterine tissue, which triggers necrosis in fibroids. This enables the removal of multiple fibroids without the need for large incisions in the uterine wall. In addition, we address the benefits and potential risks, as well as the impact on fertility and pregnancy, of the different surgical approaches used for the treatment of uterine fibroids.

Evidence for causal top-down frontal contributions to predictive processes in speech perception

Perception relies on the integration of sensory information and prior expectations. Here we show that selective neurodegeneration of human frontal speech regions results in delayed reconciliation of predictions in temporal cortex. These temporal regions were not atrophic, displayed normal evoked magnetic and electrical power, and preserved neural sensitivity to manipulations of sensory detail. Frontal neurodegeneration does not prevent the perceptual effects of contextual information; instead, prior expectations are applied inflexibly. The precision of predictions correlates with beta power, in line with theoretical models of the neural instantiation of predictive coding. Fronto-temporal interactions are enhanced while participants reconcile prior predictions with degraded sensory signals. Excessively precise predictions can explain several challenging phenomena in frontal aphasias, including agrammatism and subjective difficulties with speech perception. This work demonstrates that higher-level frontal mechanisms for cognitive and behavioural flexibility make a causal functional contribution to the hierarchical generative models underlying speech perception.

Intestinal and hepatic contributions to the pharmacokinetic interaction between gamithromycin and rifampicin after single-dose and multiple-dose administration in healthy foals

BACKGROUND

Standard treatment of foals with severe abscessing lung infection caused by Rhodococcus equi using rifampicin and a macrolide antibiotic can be compromised by extensive inhibition and/or induction of drug metabolising enzymes (e.g. CYP3A4) and transport proteins (e.g. P-glycoprotein), as has been shown for rifampicin and clarithromycin. The combination of rifampicin with the new, poorly metabolised gamithromycin, a long-acting analogue of azithromycin and tulathromycin with lower pharmacokinetic interaction potential, might be a suitable alternative.

OBJECTIVES

To evaluate the pharmacokinetic interactions and pulmonary distribution of rifampicin and gamithromycin in healthy foals, and to investigate the cellular uptake of gamithromycin in vitro.

STUDY DESIGN

Controlled, four-period, consecutive, single-dose and multiple-dose study.

METHODS

Pharmacokinetics and lung distribution of rifampicin (10 mg/kg) and gamithromycin (6 mg/kg) were measured in nine healthy foals using LC-MS/MS. Enzyme induction was confirmed using the 4β-OH-cholesterol/cholesterol ratio. Affinity of gamithromycin to drug transport proteins was evaluated in vitro using equine hepatocytes and MDCKII-cells stably transfected with human OATP1B1, OATP1B3 and OATP2B1.

RESULTS

Rifampicin significantly (P<0.05) increased the plasma exposure of gamithromycin (16.2 ± 4.77 vs. 8.57 ± 3.10 μg × h/mL) by decreasing the total body clearance. Otherwise, gamithromycin significantly lowered plasma exposure of single- and multiple-dose rifampicin (83.8 ± 35.3 and 112 ± 43.1 vs. 164 ± 96.7 μg × h/mL) without a change in metabolic ratio and half-life. Gamithromycin was identified as an inhibitor of human OATP1B1, OATP1B3 and OATP2B1 and as a substrate of OATP2B1. In addition, it was extracted by equine hepatocytes via a mechanism which could be inhibited by rifampicin.

MAIN LIMITATIONS

Influence of gamithromycin on pulmonary distribution of rifampicin was not evaluated.

CONCLUSION

The plasma exposure of gamithromycin is significantly increased by co-administration of rifampicin which is most likely caused by inhibition of hepatic elimination.