An open-label phase II study found that 12 months of sulindac therapy reduced breast density (BD) in patients with breast cancer. These findings were published in Clinical Cancer Research.

As BD is an established risk factor for breast cancer, this clinical trial tested whether supplementation could reduce BD and its inherent cancer risk. Postmenopausal women with hormone receptor-positive breast cancer were administered aromatase inhibitor (AI) plus 150 mg sulindac twice daily (50 patients) or AI alone (46 patients) for 12 months. BD was assessed by magnetic resonance imaging and with paired biopsy.

The sulindac and AI cohorts comprised, respectively, women median age 62.6±8.0 and 63.0±10.8 years, 88.0% and 95.7% were White, BMI was 27.1±5.8 and 28.0±7.1 kg/m2, 64.00% and 67.39% had stage 0-I cancer, and median time on AI was 16.9±26.5 and 12.6±17.2 months.

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At 6 months, neither the AI monotherapy (relative change, 1.6%; 95% CI, -2.8% to 6.1%; P =.486) nor the sulindac dual therapy (relative change, -4.2%; 95% CI, -8.1% to -0.1%; P =.046) cohorts had significant changes in BD. At 12 months, BD was significantly decreased in the sulindac recipients (relative change, -9.8%; 95% CI, -14.6% to -4.7%; P <.001) but not the AI monotherapy recipients (relative change, -3.6%; 95% CI, -8.9% to 2.0%; P =.201).

Stratified by BD content, only women with BD greater than 25% had significantly decreased density (absolute change, -4.7%; 95% CI, -7.2% to -2.3%; P <.001).

At 6 months, mean collagen straightness was significantly reduced (P =.032), and at 12 months, the water volume was significantly reduced (P =.016) with sulindac therapy.

This study was limited by the low number of paired imaging and biopsy samples.

These data suggested that sulindac decreased BD after daily exposure for 12 months in patients with breast cancer.

Disclosure: Multiple authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Thompson PA, Huang C, Yang J, et al. Sulindac, a nonselective NSAID, reduces breast density in postmenopausal women with breast cancer treated with aromatase inhibitors. Clin Cancer Res. Published online August 17, 2021. doi:10.1158/1078-0432.CCR-21-0732