Thyrotropin suppression therapy using levothyroxine does not negatively affect breast cancer prognosis

Cancer Treat Res Commun. 2022:31:100525. doi: 10.1016/j.ctarc.2022.100525. Epub 2022 Jan 29.

Abstract

Introduction: Breast cancer (BC) and thyroid dysfunction are common in females, yet the relationship between thyroid hormone and BC is unclear. To search for the connection between thyrotropin and BC, we contradistinguished BC patients with or without synchronous second primary thyroid cancer (TC) with surgery using data from the Surveillance, Epidemiology, and End Results (SEER) database. Theoretically, according to the ATA (American Thyroid Association) guidelines, all TC patients were treated with thyrotropin suppressive therapy only from 2010 to 2015.

Materials and methods: Data from BC patients with a synchronous second TC with surgery (BC2TC) and only BC patients (1BC) during 2010-2015 were extracted from the SEER database. Differences in the clinicopathological characteristics between BC2TC and 1BC patients were analyzed by chi-square tests. Comparisons of the disease-specific survival (DSS) and overall survival (OS) curves between these two groups were performed with the log-rank (Mantel-Cox) test.

Results: Within this dataset, we identified 134 BC2TC patients during the period from 2010 to 2015. Significant differences between the BC2TC and 1BC groups were found only for different ages and TNM (tumor-node-metastasis status) stages. There were no significant differences in DSS between the two cohorts (P = 0.060). The same tendencies in OS or DSS were observed for the different age groups and different TNM groups, even the stage I, N0 (without metastases to lymph nodes), and ER (+) (estrogen receptor (ER)-positive) groups.

Conclusions: There were no remarkable differences in survival between the BC2TC and 1BC groups, and thyrotropin suppression therapy using levothyroxine did not negatively affect BC prognosis.

Keywords: Breast cancer; Prognosis; Second synchronous cancer; Thyroid cancer; Thyrotropin suppression therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents* / therapeutic use
  • Breast Neoplasms* / drug therapy
  • Breast Neoplasms* / metabolism
  • Breast Neoplasms* / mortality
  • Breast Neoplasms* / pathology
  • Female
  • Humans
  • Neoplasms, Second Primary* / drug therapy
  • Neoplasms, Second Primary* / metabolism
  • Neoplasms, Second Primary* / mortality
  • Neoplasms, Second Primary* / pathology
  • Prognosis
  • SEER Program
  • Thyroid Neoplasms* / drug therapy
  • Thyroid Neoplasms* / mortality
  • Thyroid Neoplasms* / pathology
  • Thyrotropin* / metabolism
  • Thyroxine / therapeutic use
  • United States / epidemiology

Substances

  • Antineoplastic Agents
  • Thyrotropin
  • Thyroxine