Thyroid hormone receptor beta-1 expression in early breast cancer: a validation study

Area of Science:

• Oncology
• Endocrinology
• Molecular Biology

Background:

• Preliminary studies indicated a correlation between high thyroid hormone receptor beta 1 (TRβ1) tumor suppressor expression and improved survival in early breast cancer patients.
• Thyroid hormone receptors play crucial roles in cellular differentiation and metabolism, with potential implications in cancer progression.

Purpose of the Study:

• To validate the prognostic significance of TRβ1 protein expression in early-stage breast cancer.
• To determine if TRβ1 expression is an independent prognostic factor for breast cancer survival.

Main Methods:

• A prospective cohort study involving 796 women with early breast cancer from the Henrietta Banting Breast Cancer database.
• TRβ1 protein expression was assessed using the Allred scoring system.
• Clinical outcomes, including breast cancer recurrence and death, were tracked with a median follow-up of 9.6 years.

Main Results:

• High TRβ1 expression (Allred score > 4) was significantly associated with longer breast cancer-specific survival (univariable HR 0.45, P < 0.0001).
• This association remained significant after adjusting for multiple prognostic factors including age, tumor size, nodal status, and therapies (multivariable HR 0.61, P = 0.004).

Conclusions:

• High TRβ1 expression is an independent prognostic marker for improved breast cancer-specific survival.
• TRβ1 may serve as a predictive biomarker, especially given its association with chemotherapy resistance in vitro.
• TRβ1 agonists could potentially be explored as a therapeutic strategy for breast cancer.