Abstract 4810: Olive oil-derived (-)-oleocanthal for prevention of breast cancer recurrence

Abstract

Abstract Despite progress in BC therapy and improved survival rates, several breast cancer (BC) patients have poor recurrence-free rates. More than three million BC survivors are currently at the risk of disease recurrence without feasible preventive options. Surgical excision of early-stage confined breast tumors commonly used to minimize subsequent metastasis. Neoadjuvant and adjuvant therapeutic agents usually cannot prevent BC recurrence. There is a dire need to discover novel recurrence and metastasis inhibitory entities because clinical trials on early-stage cancer patients survival and metastases/recurrence reduction endpoint is not financially feasible and need large patients number. Mediterranean populations have less colon and breast cancers incidence due to their dietary consumption of significant amounts of phenolics-rich extra-virgin olive oil (EVOO). (-)-Oleocanthal (OC) is the most bioactive EVOO phenolic with diverse activities and exceptional in vivo potency. Validated molecular targets of OC in BC include the inhibition of the activation of the RTKs c-Met and HER2 and modulation of estrogen receptors (ER). Met/HER2/ER amplification is implicated in activation of quiescent breast tumor cells, repopulation, subsequent recurrence and relapse. This study reports the potent ability of four-weeks oral 10 mg/kg OC treatments to inhibit more than 90% of local and regional triple negative and hormone-dependent breast tumors recurrence after the surgical excision of orthotopically xenografted primary breast tumors. Oral OC treatments also potently inhibited recurrence after surgical excision of breast tumors subjected to neoadjuvant therapies with either lapatinib (50 mg/kg, 5X/week, 4 weeks) or paclitaxel (4.5 mg/kg, ip, 3X/week for 6 weeks) in athymic orthotopic nude mice models. This was associated with significant reductions of p-c-Met and p-HER2 levels in treated animal tumors by Western blotting. OC-treated mice sera completely lacked the BC recurrence marker CA 15-3, unlike vehicle treated controls which showed significantly high CA 15-3 levels. OC treatment did not show any observable toxicity and did not affect animals body weight over the experiment course. OC is a novel breast cancer recurrence inhibitory dietary supplement lead with excellent clinical applications potential. Note: This abstract was not presented at the meeting. Citation Format: Abu Bakar Siddique, Nehad M. Ayoub, Khalid A. El Sayed. Olive oil-derived (-)-oleocanthal for prevention of breast cancer recurrence [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4810.