Study: Statin Use Associated With Reduced Breast Cancer Mortality

Statin use has been associated with reduce breast cancer (BC) mortality compared with those who did not take statins, according to results of a study published in JAMA Network Open. Investigators said the risk was associated with the change in serum cholesterol levels.

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Investigators included data on females who were recently diagnosed with invasive BC between January 1, 1995, and December 31, 2013, using the Finnish Cancer Registry. The registry included cancer diagnoses from pathology laboratories and health care institutions in the country, which accounted for approximately 99% of cases nationally. The data included patient age; diagnosis date; tumor extent (which was available for 85.6% of cases) categorized as localized, locally advanced, and metastatic; primary treatment; and humor histological characteristics, according to the study authors. Individuals included in the study had data on available hormone receptor and 1 cholesterol measurement.

There were 13,378 individuals with BC, with a mean age of 62 years and a median follow up of 4.5 years after BC diagnosis. In the follow-up, approximately 16.4% of patients died, 7% of which were due to BC, according to the study authors. Additionally, 31.2% of patients had an elevated median total cholesterol level over 193.05 mg/dL before their BC diagnosis and 50.3% of patients had elevated total cholesterol levels after diagnosis. Investigators said only 40.7% used statins.

The study authors said that none of the 4 lipid parameters used, either before or after diagnosis, were associated with BC death. In a further adjusted analysis, the simultaneous use of statin did not change any of the results, according to the results. In the multivariable-adjusted analysis, the investigators said the statin use before BC diagnosis was associated with an increased risk of BC death compared with those who did not take statins. They also found that the risk was not dose dependent, and pre-diagnostic statin usage was a risk factor even after adjustment for cholesterol level, according to the study authors.

However, after the adjustment, investigators found a statistically significant inverse association with BC death. This was true regardless of the lipid parameter that was adjusted for, according to the study authors. Furthermore, with increase intensity of usage, the risk reduction was greater with statin use.

Further, for 781 of 980 individuals who began statin use after diagnosis, the median cholesterol level decreased, but the levels were similar or increased compared to those with pre-statin purchase levels, according to the results of the study. For the analysis of change in cholesterol levels after initiation of statin, those who used it post-diagnosis had a lower risk of BC death when the median total cholesterol decreased, according to the study authors. However, without the cholesterol levels decreasing, the risk decrease was not significant in the results.

Additionally, elevated median cholesterol before or after diagnosis was associated with a decreased risk of overall death, but was not significantly changed after adjustment for statin use. There was also no association between BC-related death and post-diagnostic statin use in the lag time analysis for 1 year, 3 years, and 5 years, according to the study authors.

In the subgroup analysis, the risk difference in BC death was statistically significant in ER+ cases, but there was no risk difference between statin users and those who did not use statin for triple-negative BC, according to the results of the study. The study authors stated that these analysis were limited bya small sample size, but should be researched further.

Reference

Murto MO, Simolin N, Arponen O, Siltari A, et al. Statin Use, Cholesterol Level, and Mortality Among Females With Breast Cancer. JAMA Netw Open. 2023;6(11):e2343861. doi:10.1001/jamanetworkopen.2023.43861