Nature and breast cancer: the plants that saved a botanist's life
Botanist Dr Sandy Knapp has studied plants for 40 years. When she received a breast cancer diagnosis, the natural world she knows so well was what saved her life.
Sandy has spent a career championing nature on an international stage, speaking up for the preservation of species all over the world. When a cancer diagnosis came in 2018, it was nature's time to repay her. As she was treated with drugs originally derived from trees and soils, the great diversity of life on planet Earth became her literal support system.
In October 2018 Sandy was on a complicated overseas work trip for a museum review in Boston, a herbarium visit in Missouri and a conference speech in Ecuador. About halfway through she discovered a lump in her breast.
She says, 'I thought it was nothing and carried on, but just to be safe I called my GP and made an appointment for when I got back. I returned and was referred straight away. Fast forward to the hospital and me feeling shocked to discover that the 'nothing to worry about' lump was quite probably malignant. Gulp.
'The NHS is amazing. Like a juggernaut, it just went into action.'
Sandy returned to her consultant the following week accompanied by her friend Vanessa. The diagnosis was triple-negative breast cancer which would need a treatment programme of chemotherapy followed by surgery and radiotherapy.
Incredibly, in the face of such a life-changing diagnosis, Sandy flew to Kenya the very next day to strategise for a non-profit organisation in the conservation conservancy of Ol Pejeta. She was urged to do so by her consultant.
She says, 'I could have stayed home and worried about my state and the treatment to come, but nothing was going to happen for a week or so, and my trip was only for four days. It turned out to be one of the best decisions I ever made.
'Going to see wild plants and animals in an area where innovative conservation practices are being used to protect both wildlife and people's livelihoods was life affirming. I truly think my experience with the natural world in Africa set me up mentally for what was a long haul ahead. A lot of data show that nature can improve people's wellbeing and mental health. I can truly say that for me I know it did.'
Back in the UK and on the treatment treadmill, she was enrolled in a clinical trial and proceeded with five months of chemotherapy, a treatment that poisons cancer cells. Sandy underwent two different chemotherapy regimens, both involving compounds derived from nature.
Breast cancer and Taxol
The first round was a combination of two drugs called paclitaxel and carboplatin. Paclitaxel is one of the Taxol compounds that was originally extracted from Pacific yew trees (Taxus brevifolia).
Taxol is a life-saving drug that stops cancer cells from dividing. It was discovered in the 1960s when the American National Cancer Institute partnered with the U.S. Department of Agriculture to search for possible cancer cures from natural plant and animal products.
Between 1960 and 1981, researchers tested 30,000 samples under this programme and found that extracts from the Pacific yew were toxic to living cells. After years of clinical trials, they developed a synthetic version of the compound that avoids harm to the trees.
Taxol is now on the World Health Organization's Model List of Essential Medicines, and it's still one of the best plant-based cancer treatments available. It's used to treat breast, ovarian, lung and pancreatic cancers and AIDS-related Kaposi's sarcoma.
Epirubicin - a drug from the soil
Sandy's second round of chemotherapy contained epirubicin, a compound that was isolated from a soil bacterium called Streptomyces, one of those little elements of the natural world we often ignore.
Soil bacteria provide the basis of a huge range of modern medicines, including antibiotics, anticancer, anti-parasitic and immunosuppressant drugs. Streptomyces produces broad-spectrum antibiotics that kill or inhibit the growth of other organisms.
Sandy says, 'For 21 weeks I was infused with these drugs under the incredibly kind and watchful eyes of the nurses in the chemotherapy day unit. The Museum also sprang into action and provided me a safety net. I couldn't face not working, so I was given a not-so-fun sabbatical and worked from home the whole time.
'My colleagues and family made sure I never went to chemotherapy alone, for which I am so grateful.
'The chemotherapy did its job, but those researchers who extracted and experimented with the compounds derived from nature could not have developed the drugs that saved my life without biodiversity, or the variety of life.
'I've always known that biodiversity provides us with drugs for combatting conditions like cancer, but being on the receiving end of this treatment made me think about it in a new way.
'It is not just the diversity of large exciting animals like those I saw in Africa and that set me up mentally for my journey through treatment that's important. It's also those elements of biodiversity that can be overlooked: plants and even tinier creatures like bacteria. Nature is the best chemist of all, and although we can invent compounds, those that have stood the test of millions of years of evolution are often the most efficacious.
'The interesting thing about being a biologist and being diagnosed with cancer is that you are equipped with the skills to research your condition and learn. I learned more than I ever wanted to know about triple negative breast cancer: its types and subtypes, its genetic causes and ultimately some of what lay ahead for the generations that come after me in terms of treatment.
'I am glad I did the clinical trial - it involved another chemotherapy drug on top the usual ones - because that's how treatments get better for people in the future.'
Looking to the future
Over a year later, in early 2020, Sandy was setting off to do fieldwork in South America again. She had all the side effects of chemotherapy, including hair loss and neuropathy, plus surgery and radiotherapy. But she is out the other side, ready to go again.
Sandy says, 'The drugs did their work and killed off my populations of badly behaving cells. I refused to call myself "ill". Cancer is a disease, but my way of coping was to think of it in a biological sense. Those tumours were populations of cells that were not behaving correctly - they had run amok - so I wasn't ill, I was dealing with my own cells that were out of control.
'Who knows where the next drug will come from? It will almost certainly be something we have never considered. The utilitarian argument for conserving biodiversity (we must conserve life on Earth because it will help us) can be a double-edged sword: it takes a long time for drugs to come into therapeutic use.
'This is true, but don't we owe it to future generations to benefit from the good biodiversity can bring us in all areas of health and well-being, no matter how small?
'My own journey started out from a place where I already appreciated the usefulness of life of Earth for solving human problems. But when it becomes personal, those drugs derived from plants and bacteria actually did save my life. The value of biodiversity itself becomes personal, too. I am now determined to fight for its survival even harder than I did before.
'For me, David Attenborough was right when he said, "no one will protect what they don't care about, and no one will care about what they have never experienced".
'I wouldn't wish my cancer journey on anyone, but if we each can find it in us to get to know nature a bit better, together we can support that diversity of life that ultimately saved mine.'
Sandy has recovered from cancer but is now self-isolating because of the coronavirus outbreak.
She says, 'After last year working from home, I am at it again - this time armed with knowing what to expect. I also know I need my daily dose of nature - which I can now only get in my own garden - to keep me mentally and physically healthy.
'I’m now classed as a vulnerable person and so I am staying inside for the 12 weeks the NHS recommends, so a daily dose will be more important every day!'
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- If you've been affected by breast cancer you can access support through Macmillan Cancer Support and Breast Cancer Now.
- If you are worried about your breast health, speak to your GP as soon as you can.
- Your GP and oncology specialists can advise on the best courses of cancer treatment for an individual. There is no reliable evidence from human studies that herbal or traditional remedies can treat, prevent or cure any type of cancer. You could harm your health if you stop your cancer treatment for an unproven treatment. Visit Cancer Research UK to find out more.