Inter-tumor genomic heterogeneity of breast cancers: comprehensive genomic profile of primary early breast cancers and relapses

Breast Cancer Research

Sara Gandini¹  Federica Corso¹  Alberto Ranghiero²  Elisa De Camilli²  Alessandra Rappa²  Davide Vacirca²  Sergio Taormina²  Massimo Barberis²  Caterina Fumagalli²  Giuseppe Viale³  Elena Guerini-Rocco³ 

[1] Division of Epidemiology and Biostatistics, IEO, European Institute of Oncology IRCCS, Milan, Italy;Division of Pathology and Laboratory Medicine, IEO, European Institute of Oncology, IRCCS, Milan, Italy;Division of Pathology and Laboratory Medicine, IEO, European Institute of Oncology, IRCCS, Milan, Italy;Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy;

关键词: Breast cancer;    Recurrence;    Genomic heterogeneity;    TP53;    MYC;    Next-generation sequencing;    Comprehensive genomic profile;   

DOI  :  10.1186/s13058-020-01345-z

来源: Springer

【 摘 要 】

BackgroundThe breast cancer genome dynamically evolves during malignant progression and recurrence. We investigated the genomic profiles of primary early-stage breast cancers and matched relapses to elucidate the molecular underpinnings of the metastatic process, focusing on potentially actionable alterations in the recurrences.MethodsA mono-institutional cohort of 128 patients with breast cancers (n = 68 luminal B HER2, n = 6 luminal B HER2+, n = 1 HER2+ non-luminal, n = 56 triple negative) and at least one recurrence in a timeframe of 17 years was evaluated. Next-generation sequencing comprehensive genomic profiling was performed on 289 formalin-fixed paraffin-embedded (FFPE) samples, including primary tumors and matched relapses. Correlations of genomic aberrations with clinicopathologic factors and time to breast cancer relapse were analyzed.ResultsGenomic data were available for 188 of 289 FFPE samples that achieved the sequencing quality parameters (failure rate 34.9%), including 106 primary tumors and 82 relapses. All primary and relapse samples harbored at least one genomic alteration, with a median number of six alterations per sample (range 1–16). The most frequent somatic genomic alterations were mutations of TP53 (primary tumors = 49%, relapses = 49%) and PIK3CA (primary tumors = 33%, relapses = 30%). Distinctive genomic alterations of primary tumors were significantly associated with molecular subtypes. TP53, PIK3R1, and NF1 somatic alterations were more frequently detected in triple negative tumors (p value < 0.05); CCND1, FGF3, and FGFR1 copy number gains were recurrently identified in luminal cases (p value < 0.05). Moreover, TP53 mutations and MYC amplification were significantly and independently associated with a shorter time to relapse (p value < 0.05). Molecular subtype changes between primary tumors and relapses were seen in 10 of 128 (7.8%) cases. Most driver genomic alterations (55.8%) were shared between primary tumors and matched recurrences. However, in 39 of 61 cases (63.9%), additional private alterations were detected in the relapse samples only, including 12 patients with potentially actionable aberrations.ConclusionsSpecific genomic aberrations of primary breast cancers were associated with time to relapse. Primary tumors and matched recurrences showed a core of shared driver genomic aberrations but private actionable alterations have been identified in the relapses.

【 授权许可】

CC BY