Correlation of tumour subtype with long-term outcome in small breast carcinomas: a Swedish population-based retrospective cohort study

• Purpose To investigate if molecular subtype is associated with outcome in stage 1 breast cancer (BC). Methods Tissue samples from 445 women with node-negative BC <= 15 mm, treated in 1986-2004, were classified into surrogate molecular subtypes [Luminal A-like, Luminal B-like (HER2-), HER2-positive, and triple negative breast cancer (TNBC)]. Information on treatment, recurrences, and survival were gathered from medical records. Results Tumour subtype was not associated with overall survival (OS). Luminal B-like (HER2-) and TNBC were associated with higher incidence of distant metastasis at 20 years (Hazard ratio (HR) 2.26; 95% CI 1.08-4.75 and HR 3.24; 95% CI 1.17-9.00, respectively). Luminal B-like (HER2-) and TNBC patients also had worse breast cancer-specific survival (BCSS), although not statistically significant (HR 1.53; 95% CI 0.70-3.33 and HR 1.89; 95% CI 0.60-5.93, respectively). HER2-positive BC was not associated with poor outcome despite no patient receiving HER2-targeted therapy, with most of these tumours being ER+. Conclusions Stage 1 TNBC or Luminal B-like (HER2-) tumours behave more aggressively. Women with HER2+/ER+ tumours do not have an increased risk of distant metastasis or death, absent targeted treatment.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Breast cancer

Molecular subtypes

TMA

Long-term outcome

adjuvant chemotherapy

cancer subtypes

receptors

estrogen

immunohistochemistry

heterogeneity

amplification

antigenicity

trastuzumab

expression

Oncology

Breast cancer

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)