In:
Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 27, No. 4 ( 2021-02-15), p. 967-974
Abstract:
Low-dose tamoxifen reduces breast cancer risk, but remains untested in chest-irradiated cancer survivors—a population with breast cancer risk comparable with BRCA mutation carriers. We hypothesized that low-dose tamoxifen would be safe and efficacious in reducing radiation-related breast cancer risk. Patients and Methods: We conducted an investigator-initiated, randomized, phase IIb, double-blinded, placebo-controlled trial (FDA IND107367) between 2010 and 2016 at 15 U.S. sites. Eligibility included ≥12 Gy of chest radiation by age 40 years and age at enrollment ≥25 years. Patients were randomized 1:1 to low-dose tamoxifen (5 mg/day) or identical placebo tablets for 2 years. The primary endpoint was mammographic dense area at baseline, 1 and 2 years. IGF-1 plays a role in breast carcinogenesis; circulating IGF-1 and IGF-BP3 levels at baseline, 1 and 2 years served as secondary endpoints. Results: Seventy-two participants (low-dose tamoxifen: n = 34, placebo: n = 38) enrolled at a median age of 43.8 years (35–49) were evaluable. They had received chest radiation at a median dose of 30.3 Gy. Compared with the placebo arm, the low-dose tamoxifen arm participants had significantly lower mammographic dense area (P = 0.02) and IGF1 levels (P & lt; 0.0001), and higher IGFBP-3 levels (P = 0.02). There was no difference in toxicity biomarkers (serum bone-specific alkaline phosphatase, lipids, and antithrombin III; urine N-telopeptide cross-links) between the treatment arms. We did not identify any grade 3–4 adverse events related to low-dose tamoxifen. Conclusions: In this randomized trial in chest-irradiated cancer survivors, we find that low-dose tamoxifen is effective in reducing established biomarkers of breast cancer risk and could serve as a risk-reduction strategy.
Type of Medium:
Online Resource
ISSN:
1078-0432
,
1557-3265
DOI:
10.1158/1078-0432.CCR-20-3609
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2021
detail.hit.zdb_id:
1225457-5
detail.hit.zdb_id:
2036787-9
