Women who were aged 66 years or older between January 1, 2007 and December 31, 2017 and who had received an anthracycline and/or trastuzumab within 1 year of the diagnosis of EBC were included in the study. Women who were “statin-exposed” included those who were dispensed at least two statin prescriptions in the year preceding the index date, with the second statin order dispensed within 150% of the number of days supplied by the first prescription; one of the prescriptions’ supply periods had to contain the EBC index date. The primary outcome of this study was a composite of hospitalizations or ED visits where HF was the most responsible diagnosis.
A total of 3,916 older women were enrolled in this study, with 2,545 receiving an anthracycline (mean age 69 years) and 1,371 receiving trastuzumab (mean age 71 years). One-third (33.8%) of women in the anthracycline group and 37.9% of those in the trastuzumab group received a statin. Statin-exposed women had a higher prevalence of pre-existing cardiovascular disease and more often received antihypertensive therapy and other lipid-lowering agents prior to chemotherapy. Those who had received statins in the trastuzumab group were less likely to have been given an anthracycline.
Among those who received an anthracycline and a statin, the most common lipid-lowering agents were rosuvastatin followed by atorvastatin, simvastatin, and pravastatin. For the trastuzumab group, this rank order was rosuvastatin followed by atorvastatin and simvastatin.
Almost all (98.7%) of the anthracycline-treated women who received a statin were alive at 12 months, and over 93% of these women continued to receive statins during the first 6 to 12 months of the treatment period. Similarly, 99.2% of trastuzumab-treated women who received a statin were alive at 12 months, and over 96% of these women were on a statin at 6 to 12 months. Statin usage was around 4% at 6 to 12 months in the unexposed groups.
Statin use was associated with a reduced risk of hospitalization due to HF at 5 years. For the anthracycline-treated group, the 5-year cumulative incidence of HF hospital admission was 1.2% in statin-exposed women versus 2.9% in statin-unexposed women, representing a statistically significant 55% reduction in cause-specific hospital presentations (hazard ratio [HR] = 45, 95% CI, 0.24-0.85; P = .01).
The benefits of statins were not as dramatic in the trastuzumab-treated group as there was a nonsignificant trend toward lower risk of HF hospital presentations in statin-exposed women. For the trastuzumab-treated group, the 5-year cumulative incidence of HF hospital admissions was 2.7% in statin-exposed women versus 3.7% statin-unexposed women, with a 54% reduction in cause-specific hospital presentations (HR = 0.46, 95% CI, 0.20-1.07; P = .07).
A similar lack of statin benefit was seen in women who received both an anthracycline and trastuzumab.
The authors concluded that statin-exposed older women with EBC had a lower risk of HF hospital presentations after anthracycline therapy but that this trend was not significant among trastuzumab-treated women, although they called for more studies to further examine this correlation.
Pharmacists can utilize the information presented in this study to take a more active role in recommending statin therapy for older women with EBC, especially for those receiving anthracyclines.
Pharmacists should take an active role in educating and counseling women at high risk for BC on lifestyle modifications, such as weight loss, and on the benefits and management of adverse events associated with ET therapy.
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