BMC Cancer (Jun 2018)

Impact of pre-diagnostic triglycerides and HDL-cholesterol on breast cancer recurrence and survival by breast cancer subtypes

  • Trygve Lofterød,
  • Elin S. Mortensen,
  • Hawa Nalwoga,
  • Tom Wilsgaard,
  • Hanne Frydenberg,
  • Terje Risberg,
  • Anne Elise Eggen,
  • Anne McTiernan,
  • Sura Aziz,
  • Erik A. Wist,
  • Andreas Stensvold,
  • Jon B. Reitan,
  • Lars A. Akslen,
  • Inger Thune

DOI
https://doi.org/10.1186/s12885-018-4568-2
Journal volume & issue
Vol. 18, no. 1
pp. 1 – 11

Abstract

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Abstract Background High triglycerides and low levels of high density lipoprotein (HDL)-cholesterol are observed to promote tumor growth. However, whether breast cancer heterogeneity may explain the contradictory influence of triglycerides and cholesterol observed on breast cancer prognosis remains unclear. Methods A population-based survival study among 464 breast cancer cases identified within the Tromsø study was conducted. Pre-diagnostic triglycerides, total-cholesterol and HDL-cholesterol were measured, and detailed clinical and histopathological data were obtained. Using tissue microarray, all breast cancer cases were reclassified into the following subtypes: Luminal A, Luminal B, HER2-enriched, and triple negative breast cancer (TNBC). Multivariable Cox proportional hazards regression models were used to study the associations between pre-diagnostic lipids and breast cancer recurrence, mortality, and survival. Results A total of 464 breast cancer patients, with mean age at diagnosis of 57.9 years, were followed for a mean 8.4 years. TNBC patients in the highest tertile of triglycerides (≥ 1.23 mmol/l) had 3 times higher overall mortality compared to TNBC patients in the lowest tertile (≤ 0.82 mmol/l) (HR 2.99, 95% CI 1.17–7.63), and the 5-year overall survival was 19% lower for TNBC patients in the highest vs. lowest tertile of triglycerides (65% vs. 84%). TNBC patients in the highest tertile of the HDL-cholesterol/total-cholesterol ratio (≥0.35), compared to those in the lowest tertile (≤0.27), had a 67% reduced overall mortality risk (HR 0.33, 95% CI 0.12–0.89). No associations were observed between lipids and prognostic outcome among breast cancer patients overall, or among patients with luminal A and luminal B subtypes. Among HER2-enriched patients, pre-diagnostic triglyceride level was inversely associated with overall mortality. Conclusion Our study suggests that pre-diagnostic triglycerides and the HDL-cholesterol/total-cholesterol ratio may independently provide unique information regarding prognostic outcome among triple negative breast cancer patients. However, a small sample size underlines the need for additional studies.

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