Omega 3 fatty acids could boost effectiveness of chemotherapy in breast cancer clinical trials

Q & A with Cancer Research Institute of Northern Alberta member Catherine Field on the therapeutic potential of supplements.

Kirsten Bauer with files from Shelby Soke - 29 October 2018

Catherine Field, '88 PhD, professor in the Faculty of Agricultural, Life & Environment Sciences, is investigating health outcomes through a dietary lens-including the effects of diet early in life on the development of a baby's immune system. Her team is also focusing their research on the effects of omega 3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on breast cancer tumours.

The adjunct professor in the Department of Medicine, current member and former co-director of theCancer Research Institute of Northern Alberta (CRINA), says her work with omega 3's and breast cancer has come together through professional collaborations, which will allow her research to be tested on patients in a clinical trial for the first time.

"This has been nearly 20 years in the making, so it's really exciting to see this finally coming together," Field said. "There is potential to significantly boost the effects of chemotherapy, which would reduce the amount of time people would need to tolerate that discomfort."

Q: What led to you getting involved in breast cancer research?

My longtime research interest has been in the omega 3 fatty acids. I worked on that for quite a long time in the area of immune development of infants, but omega 3's affect a lot of different areas in the body, especially cardiovascular disease, so I started to branch out.

I had a student about 20 years ago who wanted to do some work on mouse models looking at omega 3's and breast cancer. We were really studying changes in the immune system, but we noticed that the tumours we were testing wouldn't grow if you fed the mouse Omega 3's. I said, "Oh, this is kind of cool."

Researchers at the time were starting to associate fish consumption with reduced risk of cancer. And it was the group of cancers that are sort of similar: colon, breast and prostate. So we started doing work in cell culture with some of the human cell lines. We learned that the non-malignant cells grew fine, but the cancer cells would not. So we've been playing around with those for a long time.

I worked for a long time withJohn Mackey, '90 MD, Director of Clinical Trials at the Cross Cancer Institute, who said, "hey, well you know, we're never going to use omega 3's to just treat cancer because we have drugs and other treatments. So why don't you try them together?"

This was a great idea.

We started combining omega 3 mixtures with cancer drugs. The first one we started with was doxorubicin, which at that time was almost standardly used in all treatment of breast cancer. We found that one of these omega-3 fatty acids, DHA, increased the effectiveness of the drug.

That was very exciting. Saying, "wow, you know it increases how these drugs work." Then we moved to docetaxel, because there had been a lot of concern about doxorubicin causing cardiovascular complications for women, and we found that it improves docetaxel's effectiveness too.

We tested some of the traditional animal models with human tumours in them, and it reduced the tumour on its own, but it also increased the efficacy of the drug. So we began talking to oncologists about how this could be used to help patients.

Some of the hardest-to-treat breast cancers are the triple negative breast cancers. They do not have a drug target and become drug resistant very quickly, so women who are diagnosed with this form of cancer are usually offered what's called neoadjuvant therapy. They get cycles of chemotherapy prior to surgical removal, and at the Cross Cancer Institute they often are treated with docetaxel. We thought that this type of breast cancer would be a logical one to study because the prognosis isn't very good and the drug isn't super effective.

We've tested it now in an animal model with two different types of triple negative human tumours, and both times it worked so well that we got 50 per cent smaller tumours when we added the omega 3, DHA, compared to a North American fat mixture in our control models. We are now moving to a clinical trial that we hope will begin in January, 2019.

Q: Would this be a relatively low-cost or easy thing to implement into our health-care system?

It would be very inexpensive. The supplement, even if it was custom-made for this, is really not expensive. And if it does improve the effectiveness of the drug, we may actually be able to reduce the need for other expensive treatments. So if we can actually reduce the number of cycles of chemotherapy women need, or reduce their overall contact with the health-care system, that would be a huge savings.

Q: How does working with CRINA help enable this research?

I think CRINA has helped bring people together-to help understand who else is on campus and how we can combine our efforts. I had long time collaborations with John Mackey and Kerry Courneya which pre-dated CRINA, but I didn't know Lynne Postovit in the Department of Oncology, now CRINA co-director, for example, and we've worked with Lynne to do the really novel and important work in her unique animal model where we can study a women's tumour that we transplant into an animal. We just started some collaborations with her on ovarian cancer, another really hard-to-treat cancer in women.

It's helped us all build working relationships so ideas and even data can be shared more widely.

CRINA is still in its early stages, but I think it's made all of us realize that we have a bigger community and we have models and skills that can be combined. But that trust and that relationship has to start in little projects before you can come together and understand how everybody does their science, what they do and what's important to them.

Q: What would you want the general public to know about omega 3's?

Most people will be thinking about prevention. And the evidence is really compelling that it can prevent all experimental forms of cancer and reduce the growth if you put a human tumour into an animal, and feed the animal diets that have the long chain polyunsaturated omega-3 fatty acids supplemented in it.

In humans, research consistently shows that people who consume more omega 3's in their diets have a lower risk of cancer. In the past that basically meant eating diets that had lots of fish. Countries that eat a lot of fatty fish have lower risk of breast cancer, such as Japan. There is really compelling prevention data. But now with better supplements it can be taken at a much higher concentration than eating fish alone, we just haven't figured out the dose.

I don't see a reason not to take omega 3's. And for people who are vegans, there are vegan sources, so taking omega 3 fatty acids doesn't mean only eating fish and taking fish oil capsules.