August 13, 2020
Rosemary, a fragrant herb frequently used in recipes and perfumes, may contain properties that prevent breast cancer from progressing. Researchers at The University of Kansas Cancer Center recently received funding from the National Cancer Institute (NCI) to study this natural compound as a chemoprevention agent for women diagnosed with early-stage breast cancer.
Ductal carcinoma in situ (DCIS) is the presence of abnormal cells inside a milk duct in the breast. It is the earliest stage of breast cancer and non-invasive, meaning it has not spread into any surrounding tissue. About 60,000 women are diagnosed with DCIS every year. Fariba Behbod, PharmD, PhD, professor and member of the cancer center’s Cancer Prevention & Control research program, has studied this stage of breast cancer for nearly 2 decades.
“Nearly all women diagnosed with DCIS undergo treatment, but historical and prospective studies show not all cases will progress and spread,” Dr. Behbod said. “Depending on the DCIS grade, which is how quickly the cancer cells are likely to grow and spread, about 48% of high grade cases and 18% of low grade cases actually need treatment. Currently, we don’t know which groups are high risk and if left untreated, will develop later stage breast cancer.”
Doctors are left to grapple with this treatment conundrum. The standard of care for all DCIS patients is to undergo surgery, radiation and, if the tumors are hormone-receptor positive, long-term antihormone therapy. Most women follow this course of treatment, but for some, it may be unnecessary.
Understanding which cases are at greater risk of becoming invasive – and subsequently helping inform treatment decision – is imperative, and it is the basis for Dr. Behbod’s work. Over the years, she has fine-tuned a mouse model that takes human samples and implants them into laboratory mice. Today, her model is used by researchers across the globe to better understand how DCIS progresses from non-invasive to invasive.
“By examining the molecular alterations in these mice, we are able to characterize which cases are more likely to become aggressive,” Dr. Behbod said.
From the garden to the lab
Rosemary has long been hailed for its medicinal properties, and Dr. Behbod and her team are focusing on rosemary as well as its major ingredient, carnosic acid. A gene, called B-cell lymphoma 9 (BCL9), has a role in cancer development and when it is knocked down, progression stalls. Preclinical studies conducted by Dr. Behbod have demonstrated rosemary extract and carnosic acid effectively targets BCL9.
“The data from these early studies was so impressive that the NCI agreed to provide funding so we can conduct larger preclinical animal efficacy and pharmacokinetic studies,” Dr. Behbod said. “It is possible we may be able to convert would-be aggressive breast cancers to non-aggressive.”
Leveraging Dr. Behbod’s custom mouse model, carnosic acid and rosemary extract will be blended into the mice’s diet. Over the course of a year, her group will closely monitor the mice for cancer progression, identifying any toxic side effects as well as ideal dosage. Dr. Behbod, who was diagnosed with DCIS herself while finishing her postdoctoral work in 2004, hopes this natural compound may someday be an alternative treatment option to antihormone therapy.
“Less than 5 out of 10 women with DCIS who are prescribed antihormone therapy don’t take the medicine due to its side effects, which includes early menopause,” Dr. Behbod explained. “Our concept incorporates a compound that can be found at a grocery store. We’re excited at the prospect of creating a new therapy that is easy to take and improves a patient’s quality of life.”