Statins help prevent breast cancer recurrence in Asians

Breast cancer patients who take statins see a sharp decline in the risk of tumour recurrence, according to a recent Singapore study. This protective effect seems to be stronger in ER+ and HER2- malignancies.

“This is the first known retrospective study on the effect of statin use and breast cancer recurrence in an Asian population. Similar to previous international studies, statin use is associated with a risk reduction in breast cancer recurrence,” the researchers said. “Statin use is also associated with a reduced risk of breast cancer recurrence in all subtypes of breast cancer in the long term.”

The retrospective analysis included 7,858 women with breast cancer, of whom 17.2 percent (n=1,353) used statins after surgery. Cox proportional hazards regression analysis was performed to assess the risk of recurrence over a median follow-up of 8.67 years according to statin use.

Statin users and nonusers had statistically comparable recurrence risks in the first 5 years of follow-up (hazard ratio [HR], 0.98, 95 percent confidence interval [CI], 0.77–1.26; p=0.898). [Front Oncol 2022;doi:10.3389/fonc.2022.835320]

However, from year 6 onwards, statins showed a significantly protective effect against cancer recurrence, reducing such risk by more than 50 percent in users vs nonusers (HR, 0.48, 95 percent CI, 0.30–0.80; p=0.005).

Stratified analyses revealed nuances in the effect of statins on cancer recurrence. For instance, statin users vs nonusers with stage I–III malignancies saw significant protection from recurrence starting from year 6 (HR, 0.48, 95 percent CI, 0.31–0.84; p=0.009), but not before (HR, 0.94, 95 percent CI, 0.72–1.21; p=0.620). Meanwhile, recurrence in patients with ductal carcinoma in situ was not affected by statin use (HR, 1.24, 95 percent CI, 0.64–2.40; p=0.525).

Moreover, those with ER+ breast cancers significantly benefited from statin use, which cut the risk of recurrence by over 40 percent (HR, 0.59, 95 percent CI, 0.45–0.78; p<0.001). Of note, the risk of recurrence was almost doubled in patients with ER- breast cancers during the first 5 years (HR, 2.03, 95 percent CI, 1.37–3.02; p<0.001). From year 6 onwards, statins suppressed the risk of recurrence in ER- breast cancer patients (HR, 0.65, 95 percent CI, 0.12–0.86; p=0.025).

Statins likewise reduced recurrence risk in ER+ HER2- (HR, 0.59, 95 percent CI, 0.43–0.89; p=0.001) and ER+ HER2+ (HR, 0.46, 95 percent CI, 0.22–0.95; p=0.037) invasive cancers.

“Despite possible genetic differences in Asian breast cancer, pharmacokinetic differences in statin metabolism, and lifestyle difference, we have demonstrated that, similar to previous international studies, statin use can help reduce a risk of breast cancer recurrence,” the researchers said.

“This risk-reducing effects of statins on breast cancer recurrence, coupled with their cardioprotective effect, demonstrate the underlying complexity in cancer pathways and metabolism and may open up new potential anticancer targets for future therapeutics,” they added.