The Anti-Proliferative Effects of a Frankincense Extract in a Window of Opportunity Phase Ia Clinical Trial for Patients with Breast Cancer

Background: Boswellic acids, the active components of frankincense, have been shown to suppress tumor proliferation and apoptosis in vitro with a strong clinical trial safety profile in patients with inflammatory diseases. We performed a Phase Ia window of opportunity trial of Boswellia serrata (B. serrata) , the plant that produces frankincense, in patients with breast cancer to evaluate its biologic activity and safety. Methods This was a Phase Ia window of opportunity trial invasive breast cancer patients treated pre-operatively with B. Serrata (2400 mg/day PO) until the night before surgery. Paraffin-embedded sections from pretreatment diagnostic core biopsies were evaluated using a tunnel assay and immunohistochemistry staining with Ki-67 antibodies. A non-intervention control arm consisted of core and surgical tissue specimens from untreated patients was used to compare to patients treated with B. Serrata . The change in proliferation and apoptosis between diagnostic core specimens and specimens obtained at surgery was compared between the control and treatment groups using a two-tailed paired t-test. Results There was an increase in percent change in proliferation from core biopsy to surgical excision in the control group (n = 18) of 54.6 ± 21.4%. In the B. serrata -treated group there was a reduction in proliferation between core biopsy and excision (n = 18) of 13.8 ± 11.7%. The difference between core and surgical specimens was statistically significant between the control and B. serrata -treated groups (p = 0.008). There was no difference in change in apoptosis. There were no serious adverse events related to the drug. Conclusion Boswellia serrata inhibited breast cancer proliferation in vivo in a clinically well-tolerated Phase Ia window of opportunity trial. Trial registration: ClinicalTrials.gov. Identifier NCT03149081, date of registration May 11, 2017