Nanotechnology: A new treatment for breast cancer
Nanotechnology — the use of extremely small particles (far smaller than the one above) — has already resulted in numerous health and beauty innovations. Now it promises to make a huge difference in diagnosing, treating and even preventing breast cancerBy Lesley Young
The future of health and medicine is so tiny, it's hard to visualize — never mind see. It's called nanotechnology, and it's about manipulating substances (such as gold or silica) to alter existing matter or even to create a new molecular or physical structure with potentially beneficial properties. This is all happening at an atomic or molecular scale — that is, at 1/100,000th the width of a human hair.
What does this mean to you? Well, for starters, nanotechnology today is key to more than 1,000 consumer products, including many related to health and beauty. It's responsible, for example, for the anti-odour protection woven into clothing, for the ability of zinc oxide in some sunscreens to go on clear instead of white, and for the superior antimicrobial protection now offered by the nanoparticle silver lining in certain bandages you can buy in drugstores.
More exciting is that the growing field of nanotechnology holds real promise for conquering diseases. For breast cancer in particular — which was diagnosed in an estimated 23,400 Canadian women in 2011 alone — nanotechnology advances are pervasive. Researchers are aiming to develop specifically designed molecules to diagnose, treat and, eventually, prevent this disease. Here's an update on what's being used now, and where medical research is headed.
What's happening now
Two nanotechnology-based cancer drugs, called Doxil and Abraxane, became available to cancer patients in North America about five years ago, and are now readily accessible. But these barely scratch the surface of the potential benefits that nanotechnology holds for breast cancer, according to Dr. Stephen Grobmyer. He is a breast cancer surgeon — and a researcher leading the way in translating medical research into clinical practice — who specializes in using nanotechnology to treat breast cancer at the University of Florida in Gainesville.
"These nano-based drugs are important treatment advancements," says Dr. Steven Narod, director of the Familial Breast Cancer Research Unit at Women's College Research Institute in Toronto, who holds a Canada Research Chair in breast cancer at the University of Toronto. Doxil and Abraxane enable more targeted delivery of existing chemotherapies through a special coating that evades attack by the immune system; this allows precise delivery of drugs to the cancer cells, subsequently reducing the side effects. "An important goal of cancer treatment is to reduce the side effects of existing drugs," Narod adds.
But the ability of doctors to cure breast cancer hinges on how early they are able to detect the disease. "We are at a standstill with the quality of current imaging devices such as mammography and MRI [magnetic resonance imaging], which lack specificity and as a result lead to invasive biopsies," explains Grobmyer. "What we really need are breakthroughs that allow us — a safe and comfortable fashion for patients — to more precisely identify breast cancer."
In animal studies, researchers have shown that nanoparticles injected by needle can work effectively as imaging probes that detect the presence of cancer by binding to certain proteins on cancer cells, such as one called mammaglobin on breast cancer cells. Better yet, research shows that nanoparticle imaging contrast agents, which travel to a tumour site and thereby allow the cancer cells to be detected, also can enable non-invasive therapies. Once the nanoparticles are in the tumour, researchers can remotely activate them — by using infrared light, for example — to destroy the cancer cells.
"Once we overcome the image challenges using nanotechnology, then it is just a matter of tweaking these nano-based imaging particles to deliver a therapy that treats the tumour," explains Grobmyer. So in one fell swoop, nanoparticles will detect and destroy breast cancer cells.
When are we expected to get past the image challenges? Grobmyer predicts broad-scale implementation could occur in the next five to 10 years.
Promising breast cancer research
According to the U.S. National Cancer Institute's Alliance for Nanotechnology in Cancer, the following nanotechnology advancements that will make a difference in breast cancer are expected to be available in the next five to 10 years. (In February 2011, it was announced that the first human trial of a nano-based cancer treatment for melanoma had been approved by the U.S. Food and Drug Administration.)
These are the most promising findings, though an array of research is underway thatis exploring various ways nanotechnology may help treat breast cancer in the future.
Prognosis: Most women with breast cancer have to undergo invasive surgery to test their lymph nodes to determine whether the cancer has spread, when in most cases it has not. Promising research published in the Journal of Biophotonics shows at least one nanotechnology-based imaging approach that could eliminate the need for surgery both to determine a patient's prognosis and to treat breast cancer that has spread to lymph nodes.
Treating metastatic disease: "We've been recycling the same treatments for years for treating breast cancer," says Narod. "What we really need are brand new ones." This is especially true, adds Grobmyer, for cases where the breast cancer has metastasized (spread), which is the leading cause of death in patients and for which the treatments are limited and not generally curative. Now there is hope: Researchers at the University of Arkansas have shown that nanoparticles can tag circulating breast tumour cells (those that cause new cancer), and allow them to be imaged, and subsequently captured and destroyed — all without surgery. "This has tremendous potential for catching and treating metastatic breast cancer early," explains Grobmyer.
Prevention: Various nanoparticles and nanoformulations are showing promise in preventing breast cancer cell proliferation and growth. Nanoformulations of anti-estrogens, and gold nanoparticles using phytochemicals extracted from green tea, among other sources, have been shown in various animal studies to inhibit cancer cell growth.
What about safety?
Before any more nano-based breast cancer treatments become available, researchers will need to show that nanomaterials target a tumour preferentially (current research challenges include the high number of variables, including the properties of the various nanoparticles being studied). Researchers will also need to show that these materials are being safely cleared from the body, says Grobmyer, adding that these hurdles will be overcome over the next three to five years.
Some groups contend there is a lack of research on the potential effects of nanotechnology on our health. (One of these groups is The Project on Emerging Nanotechnologies, based in Washington, D.C., which aims to identify and address gaps in knowledge around the safety of the commercialization of this new science.) Both the Canadian and U.S. governments are working on safety requirements for the production and use of new nanomaterials.
Grobmyer adds that medicine is giving a lot of attention to safety concerns in developing nano-based treatments. "We are working with and building on materials that are already known to be safe, which is the best path for getting human trials moving quickly. It is a priority to ensure advancements move forward quickly and safely."
As a doctor who works with patients every day, Grobmyer is excited about the potential for nanotechnology to redefine the treatment and outcomes of breast cancer over the next decade or so. "The priority is to find a better way to treat this disease. Nanotechnology definitely has strong promise to help do that."
A perfect outcome (and certainly the goal of nanotechnology researchers): Someday in the not-too-distant future, a woman could have her breast cancer diagnosed, treated and cured with a simple day treatment. Wow.
This article was originally titled "The tiny particles that can save your life" in the Jan/Feb 2012 issue of Best Health. Subscribe today to get the full Best Health experience–and never miss an issue!