Purpose: The antibody–drug conjugate enfortumab vedotin (EV) releases a cytotoxic agent into tumor cells via binding to the membrane receptor NECTIN-4. EV was recently approved for patients with metastatic urothelial carcinoma (mUC) without prior assessment of the tumor receptor status as ubiquitous NECTIN-4 expression is assumed. Our objective was to determine the prevalence of membranous NECTIN-4 protein expression in primary tumors (PRIM) and patient-matched distant metastases (MET). Experimental Design: Membranous NECTIN-4 protein expression was measured (H-score) by IHC in PRIM and corresponding MET (N = 137) and in a multicenter EV-treated cohort (N = 47). Progression-free survival (PFS) after initiation of EV treatment was assessed for the NECTIN-4–negative/weak (H-score 0–99) versus moderate/strong (H-score 100–300) subgroup. The specificity of the NECTIN-4 IHC staining protocol was validated by establishing CRISPR-Cas9–induced polyclonal NECTIN-4 knockouts. Results: In our cohort, membranous NECTIN-4 expression significantly decreased during metastatic spread (Wilcoxon matched pairs P < 0.001; median H-score = 40; interquartile range, 0–140), with 39.4% of MET lacking membranous NECTIN-4 expression. In our multicenter EV cohort, absence or weak membranous NECTIN-4 expression (34.0% of the cohort) was associated with a significantly shortened PFS on EV (log-rank P < 0.001). Conclusions: Membranous NECTIN-4 expression is frequently decreased or absent in mUC tissue. Of note, the clinical benefit of EV strongly depends on membranous NECTIN-4 expression. Thus, our results are of highest clinical relevance and argue for a critical reconsideration of the current practice and suggest that the NECTIN-4 receptor status should be determined (ideally in a metastatic/progressive lesion) before initiation of EV. See related commentary by Aggen et al., p. 1377

There is growing scientific evidence for the crucial role of post-transcriptional RNA modifications in carcinogenesis, progression, metastasis, and drug resistance across various cancer entities. N6-methyladenosine (m6A) is the most abundant type of RNA modification. m6A is coordinated by a dynamic interplay of ‘writers’ (METTL3, METTL4, METTL14, WTAP, KIAA1429), ‘erasers’ (FTO, ALKBH5), and ‘readers’ (HNRNPA2B1, HNRNPC, YTHDC1, YTHDC1, YTHDF1-3). In this study, we comprehensively examined protein and mRNA expression levels of m6A writers, readers, and erasers in two cervical cancer (CC) cohorts (UHB CC cohort, N = 118; TCGA CC cohort, N = 307) with regard to clinical outcomes. In the UHB CC cohort, high protein expression levels of METTL14 (p = 0.016), WTAP (p = 0.007), KIAA1439 (p < 0.001), ALKBH5 (p < 0.001), HNRNPC (p = 0.012), YTHDC1 (p < 0.001), and YTHDF3 (p = 0.004) were significantly associated with a shorter overall survival (OS). In the TCGA CC cohort, mRNA expression levels of METTL14 (p = 0.012), WTAP (p = 0.041), KIAA1429 (p = 0.016), and YTHDC1 (p = 0.026) showed prognostic values. However, after correction for multiple testing, statistical significance remained only for m6A protein expression levels (q < 0.1). Our study points towards dysregulated m6A modification in CC. Hence, m6A might serve as a promising prognostic biomarker and therapeutical target in CC.

Purpose: Vulvar squamous cell carcinoma (VSCC) is a rare malignancy of the female genital tract with increasing incidence rates. Etiologically, HPV-dependent and HPV-independent VSCC are distinguished. Surgical treatment and/or radiotherapy represent the therapeutic mainstay for localized disease. For recurrent or metastatic VSCC, treatment options are limited. Research has identified trophoblast cell surface antigen 2 (TROP-2) to be broadly expressed across different tumor entities. The aim of the present study was to systematically investigate the expression of TROP-2 in VSCC. Methods: TROP-2 protein expression was investigated by immunohistochemistry in a cohort comprising n = 103 patients with primary VSCC. A four-tier scoring system (0: no staining, 1 + : low staining, 2 + : moderate staining, 3 + : high staining) was applied for quantification of protein expression. For further analyses, two groups (low TROP-2 expression: 0/1 + ; high TROP-2 expression: 2 + /3 +) were generated. The entire study cohort, as well as HPV-dependent and HPV-independent VSCC were considered separately. Results: In the entire VSCC study cohort, TROP-2 expression was present in 97.1% of all cases (n = 100) with 74.8% displaying high TROP-2 expression (2 + /3 +). Only 2.9% of tumors showed absent TROP-2 expression. Of note, all HPV-dependent VSCC (n = 18) demonstrated high TROP-2 expression (2 + /3 +). In the subgroup of HPV-independent VSCC (n = 70), high TROP-2 expression was associated with favorable clinical outcomes based on log rank test and univariate cox analysis. Conclusion: TROP-2 protein expression is of prognostic value in HPV-independent VSCC. The broad expression of TROP-2 in VSCC indicates the TROP-2 directed ADC Sacituzumab govitecan as a potential new therapeutic strategy for VSCC patients.

Purpose: N6-methyladenosine (m6A) is the most frequent type of messenger RNA (mRNA) modification and is implicated in diverse physiological processes. The procedure of m6A RNA modification is regulated by a dynamic interaction of writers (METTL3, METTL4, METTL14, WTAP, KIAA1429), erasers (FTO, ALKBH5), and readers (HNRNPA2B1, HNRNPC, YTHDC1, YTHDC1, YTHDF1-3). In the oncological context, alterations in m6A were identified to be critically involved in tumorigenesis, proliferation, angiogenesis, and drug resistance across diverse cancer entities including endometrial cancer (EC). Methods: In this study, we comprehensively examined the protein expression of m6A writers, readers and erasers by immunohistochemical staining in a cohort of N = 65 EC patients. Protein expression data were analyzed with regard to clinical outcomes. Results: We identified enhanced protein expression levels of METTL3, METTL14, FTO, HNRNPA2B1, and HNRNPC, respectively to be of prognostic value and linked to a shortened overall survival in EC. Conclusion: Overall, our study points toward dysregulated m6A modification in EC and its possibility to serve as a promising prognostic biomarker.

Background: Carney complex (CNC) is a rare multiple endocrine neoplasia syndrome with autosomal dominant inheritance. Affected individuals present with mucocutaneous lentigines/blue nevi, cardiac and noncardiac myxomatous tumors, and multiple endocrine tumors. Mutations in PRKAR1A have been identified as genetic cause of the disease. Here, we report on pregnancy, delivery and puerperium in a woman with genetically confirmed CNC and her newborn. Case: The 31 year-old gravida 5 para 1 with CNC was referred at 26 weeks of gestation. Adrenocorticotropin-independent hypercortisolism, hyperglycemia, hypertension, low serum potassium, and osteoporotic fractures were present. Treatment with metyrapone, a reversible 11-beta-hydroxylase inhibitor, was initiated. The maternal condition improved, and a 5 weeks' pregnancy prolongation could be achieved. Elective repeat cesarean section was performed at 31 weeks of gestation for recurrent vaginal bleeding. The neonate developed transient hyponatremia necessitating hydrocortisone substitution for 2 weeks. Conclusion: In our case, treatment of CNC-associated hypercortisolism in pregnancy with metyrapone was effective. Maternal side effects did not occur. The newborn presented with transient hypocortisolism most likely due to transplacental drug effect. Our case illustrates that the treatment of rare diseases in pregnancy represents a challenge requiring interdisciplinary team work.

Purpose: CDK4/6 inhibitors (CDK4/6i) represent the first-line therapy approach of choice for patients with hormone receptor-positive, HER2-negative advanced breast cancer (HR + /HER-ABC). Approximately 50% of HR + /HER2-ABC displays low HER2 expression (HER2 low). Recent data emerging from the DESTINY-Breast04 trial demonstrated practice-changing efficacy of the antibody–drug conjugate trastuzumab deruxtecan (T-DXd) in patients with low HER2 expression. Here, we aimed to analyze the impact of low HER2 expression on CDK4/6i therapy response in a well-characterized multicenter HR + /HER-ABC cohort. Methods: Patients diagnosed with HR + /HER2-ABC who were treated with CDK4/6i in clinical routine between November 2016 and December 2020 at four certified German Breast Cancer Centers were retrospectively identified. The cohort was stratified according to graduation of positivity in HER2 immunohistochemistry (IHC; HER2 zero = IHC score 0 and HER2 low = IHC score 1 + , 2 + /fluorescence in situ hybridization negative). Subgroups were analyzed with regard to progression-free survival (PFS) following CDK4/6i initiation. Findings: The study cohort comprised n = 448 patients. For n = 311 patients, HER2 status from the metastatic site was available. n = 91 (29.3%) cases were HER2 zero and n = 220 cases (70.7%) were HER2 low. There was no significant difference in PFS between the two groups (PFS: 17 months versus 18 months, log-rank p = 0.42). Further, we examined the influence of HER2 expression changes between primary and metastatic tissue (n = 171; HER2 gain/HER2 loss/HER2 stable expression) on CDK4/6i treatment response. Again, there was no significant difference between these three groups, respectively (PFS: 16 months versus 13 months versus 17 months, log-rank p = 0.86). Conclusions: In our analysis, HER2 status did not have a significant impact on treatment response to CDK4/6i.