Dataset Information

Comprehensive molecular profiling of Taiwanese breast cancers revealed potential therapeutic targets: prevalence of actionable mutations among 380 targeted sequencing analyses.

ABSTRACT:

Background

Breast cancer is one of the leading causes of cancer-related deaths in women, and there is a demand in developing an Asian-based genetic profiling database for breast cancer in improving the treatment response. This study aimed to determine molecular alternations and identify potential therapeutic targets by analyzing the genetic profiling from a cohort of Taiwanese breast cancers using a commercialized next-generation sequencing (NGS) targeted panel.

Methods

The study population comprised a broad spectrum of breast cancer patients in Taiwan, including Group 1: planned to receive first-line surgery and followed by adjuvant therapy, or early relapse within three years, Group 2: planned to receive first-line neoadjuvant therapy and followed by surgery, and Group 3: de novo stage IV, or stage IV with recurrence beyond three years. Molecular profiles were determined using Thermo Fisher™ Oncomine™ Comprehensive Assay version 3 (TMO comprehensive assay) from Formalin-Fixed Paraffin-Embedded (FFPE) tissues. Level of actionability was evaluated with the ESMO Scale of clinical actionability of molecular targets (ESCAT).

Results

A total of 380 TMO comprehensive assays were conducted on 372 patients, and we presented targeted sequencing analyses of Tier I: alteration-drug match associated with improved outcome in clinical trials including ERBB2 amplification, BRCA1/2 germline mutation, PIK3CA mutation, and NTRK translocation, and Tier II: antitumor activity associated with the matched alteration-drug but lack of prospective outcome data including PTEN loss, ESR1 mutation, AKT1 mutation, and ERBB2 mutation, and Tier III: matched drug-alteration that led to clinical benefit in another tumor type including MDM2 amplification, and ERBB3 mutation. Among them, 249 (66%) showed at least one actionable alternation based on the ESCAT criteria. The most frequent impacted genes (all variants combined within each sample) were PIK3CA (38%), followed by ERBB2 (23%), ESR1 (10%), AKT1 (6%), and BRCA2 (5%), and the remaining rare variants (less than 5% of assayed cohort) were BRCA1 (3%), MDM2 (2.2%), and ERBB3 (1.1%).

Conclusion

Targeted sequencing of actionable genes is believed to provide clinical applicability and substantial benefits for Taiwanese breast cancer patients. A valid scale of clinical actionability should be adopted for precision medicine practice under multidisciplinary molecular tumor board.

SUBMITTER: Huang CC

PROVIDER: S-EPMC7908797 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Biliary tract cancer (BTC) represents a heterogeneous disease with dismal outcome. Herein, we examined genotype and angiogenesis features in BTC. We applied genotyping (Sanger, qPCR, 101-gene panel NGS), mRNA relative quantification methods, and β-catenin immunohistochemistry in 84 FFPE BTC (55 gallbladder [GBC], 14 intrahepatic [ICC], 15 extrahepatic [ECC] carcinomas). We identified 541 mutations in 68 (81%) tumors. Top mutated genes were CTNNB1 (36%); PTEN (33%); TP53 (31%); PIK3R1 (29%); PIK3CA (13%); BRCA2 and KRAS (12%); BRCA1 (11%). Six GBCs were hypermutated [hm] displaying a distinct mutational pattern. Mutations in TP53 and PI3K, Wnt and RAS components were prevalent among non-hypermutated tumors. All hmGBCs carried mutations in BRCA2 and other homologous recombination repair (HRR) genes, in PD1, but not in CTNNB1 and KRAS. None of the pathogenic BRCA2 p.D2723G and BRCA1 p.Q563* and c.5266dupC was present at frequencies expected for germline mutations. We observed copy gains (>6 copies) in EGFR (9% of informative tumors), PRKAR1A (7%), PIK3CA (6%), ERBB2 (5%) and MET (4%). TP53 mutations were prevalent in GBC (P<0.001) and PRKAR1A copy gains in ICC (P=0.007). PTEN was frequently co-mutated with CTNNB1 (P<0.001). Unrelated to CTNNB1 mutations, nuclear β-catenin was detected in 45% of tumors, among them in 5/6 hmGBC. We observed strong mRNA expression correlation of the two neuropilins (NRP1 and NRP2) with each other (Spearman's rho 0.59) and with the endothelin receptor (NRP2 rho 0.66; NRP2 rho 0.51), and between VEGFA and its receptors (FLT1 rho 0.49; KDR rho 0.45). All PIK3CA mutated tumors expressed endothelin 1 mRNA (P=0.010). Most tumors expressing nuclear β-catenin were negative for VEGFC (P=0.009) and FLT4 (P=0.002) mRNA expression. In conclusion, we confirmed the presence of known genomic aberrations in BTC and different genotypes between BTC subsets. Novel findings are the coexistence of PI3K and WNT pathway gene alterations in BTC, their association with angiogenesis, and the hypermutated GBCs with HRR gene mutations, all of which may be considered for new treatment options in this difficult to treat disease.