The 21-gene recurrence score in special histologic subtypes of breast cancer with favorable prognosis. Academic Article uri icon

Overview

abstract

  • BACKGROUND/PURPOSE: The 21-gene recurrence score (RS) assay predicts the likelihood of distant recurrence and chemotherapy benefit in early-stage, estrogen receptor (ER)-positive, HER2-negative breast cancer. Data on the RS of special histologic subtypes of invasive breast carcinoma with favorable prognosis are limited. METHODS: We reviewed our institutional database to identify patients with special histologic subtypes of breast cancer associated with favorable prognosis and available RS results. Our cohort consists of fifty-seven women: thirty-three patients with pure mucinous carcinoma (MC), ten with tubular carcinoma (TC), nine with encapsulated papillary carcinoma (EPC), and five with solid papillary carcinoma (SPC). RESULTS: Most (44/57, 77.2%) carcinomas had low RS (≤17), and none had high RS (≥31). All EPCs had low RS, but other subtypes had RS 18-30. Higher RS was associated with lower progesterone receptor (PR) expression by immunohistochemistry and lower PR mRNA scores (P ≤ 0.007). No morphologic feature (tumor grade, biopsy site changes, cellular stroma, inflammatory cells) was associated with RS ≥ 18. At a median follow-up of 40 months, the distant recurrence-free survival was 100%. One patient with SPC developed locoregional recurrence at 22 months. CONCLUSIONS: As the largest series to date, our study raises the question of whether the RS assay is necessary for breast cancers with favorable histology. Reflex testing of node-negative, ER+/HER2- breast cancers may be deferred for these special histologic subtypes, emphasizing the need for multidisciplinary discussions between breast pathologists and other members of the breast cancer team.

publication date

  • June 3, 2017

Research

keywords

  • Adenocarcinoma, Mucinous
  • Biomarkers, Tumor
  • Breast Neoplasms
  • Carcinoma, Papillary
  • Gene Expression Profiling
  • Transcriptome

Identity

PubMed Central ID

  • PMC5572649

Scopus Document Identifier

  • 85020115310

Digital Object Identifier (DOI)

  • 10.1111/j.1440-1827.2007.02118.x

PubMed ID

  • 28577081

Additional Document Info

volume

  • 165

issue

  • 1