Search PubMedSearch

Biomedical subjects

Arndt Hartmann

Publications and source records attributed to Arndt Hartmann.

2 recordsLinked to original sources

Integrating NECTIN4 Amplification With Membranous Nectin-4 Expression to Develop a Scoring System for Predicting Enfortumab Vedotin Response in Urothelial Carcinoma.

PURPOSE: Enfortumab vedotin (EV) is standard therapy for metastatic urothelial carcinoma (mUC), yet the predictive relevance of NECTIN4 expression-especially membranous versus cytoplasmic-remains unclear. Here, we sought to extend previous findings on NECTIN4 gene amplification in parallel with a systematic subcellular evaluation of NECTIN4 expression. EXPERIMENTAL DESIGN: We retrospectively analyzed 179 EV-treated mUC patients. NECTIN4 amplification was assessed by FISH and NECTIN4 protein levels by IHC. A four-tier membranous scoring algorithm (0,1+,2+,3+) adapted from CAP HER2 gastric guidelines was benchmarked against H-score. We integrated amplification status with membranous staining to refine predictive stratification and compared associations with objective response rate (ORR) to EV-301 data. RESULTS: Combining membranous and cytoplasmic compartments resulted in a median composite H-score of 260 (78.2% &#x2265;150), closely matching NECTIN4 expression prevalence reported in EV-301 (median 250; 82.6% &#x2265; 150). A &#x2265;150 cut-off enriched for EV responders in both cohorts; in EV-301 with ORR of 45.8% vs. 20% (P = 0.001). High membranous expression based on the scoring (2+/3+) predicted response (ORR 55.1% vs. 25.5%; P < 0.001), with longer PFS (7.1 vs. 2.9 months; HR 0.45) and OS (12.3 vs. 6.9 months; HR 0.57), whereas cytoplasmic expression lacked predictive value. NECTIN4-amplified tumors showed particularly favorable outcomes (PFS 12.2 months; OS 30.1 months). An integrated three-tier model-amplified, non-amplified/high-membranous, and non-amplified/low-membranous-yielded ORRs of 77.2%, 42.9%, and 26.1% and separated survival outcomes. CONCLUSIONS: Our NECTIN4 scoring system integrating NECTIN4 amplification with membranous NECTIN4 expression accurately predicts outcomes, supporting combined genomic and membranous assessment as complementary biomarkers for optimizing EV selection.

Journal Article

Beyond BRCA deficiency: Clinical and molecular predictors of survival in patients with BRCA-deficient tubo-ovarian high-grade serous carcinoma.

BRCA-associated homologous recombination deficiency (HRD) is present in ~50% of high-grade serous carcinomas (HGSC) and predicts sensitivity to platinum-based therapy. However, there is little understanding of why some patients with BRCA-deficient tumors experience unexpectedly poor outcomes. We profiled 154 tumors, enriched for patients with BRCA-deficient tumors that experienced short overall survival (&#x2264;3 years, n=42), using whole-genome, transcriptome, and methylation analyses. All but one BRCA-deficient tumor exceeded an accepted HRD genomic scarring threshold. However, patients with BRCA1-deficient HGSC with a more elevated HRD score survived significantly longer. Patients with BRCA2-deficient HGSC and loss of NF1 survived twice as long as those without NF1 loss, whereas PIK3CA or RAD21 amplification defined BRCA2-deficient HGSC with exceptionally short survival. BRCA1-deficient tumors in short survivors had evidence of immunosuppressive c-kit signaling and EMT. In a large HGSC cohort (n=1,389) including 282 individuals with pathogenic germline BRCA variants (gBRCApv), the location of the mutation within functional domains stratified clinical outcomes. Notably, residual disease after primary surgery had limited prognostic effect in gBRCApv-carriers compared to non-carriers. Our findings indicate that tumor HR proficiency in the context of therapy response and survival is not a binary property, and highlight genomic and immune modifiers of outcomes in BRCA-deficient HGSC.

Journal Article