By Professor Anna-Mart Engelbrecht*
Every October the world turns pink. We wear the ribbons, run the races and remind one another to book the check-up we have been postponing. But this Breast Cancer Awareness Month I want to ask for more than awareness. I want to ask you to imagine.
Imagine a woman; let us call her Thandi. She is 46, a teacher, a mother of two, and she has just heard the words nobody wants to hear: you have breast cancer. Within days she will sit across from an oncologist who will recommend a treatment. That recommendation will rest on the best evidence in the world, gathered from thousands of women who came before her.
But none of those women was Thandi.
Today, cancer treatment is chosen largely on averages. We know that a drug works for many patients with a certain type of tumour. What we cannot know, until treatment has started, is whether it will work for this patient, and what it will cost her body.
Will it shrink her tumour? Will it weaken her heart? Will it raise her risk of a dangerous blood clot, or leave her in the fog of memory and concentration that patients call “chemo brain”? For now, we find out the hard way: we give the treatment, and we wait.
We believe South Africans deserve better than waiting. That is why sixteen researchers and clinicians from Stellenbosch University and the South African Medical Research Council and Tygerberg Hospital have come together around a project we call PROMISE.
Tiny copy
The idea at the heart of PROMISE sounds like science fiction, but it is already working in our laboratories. From a small piece of tissue taken during a routine biopsy or operation, we can grow miniature, living, three-dimensional copies of a patient’s own tumour. Scientists call them organoids. Think of them as stand-ins: tiny versions of the cancer that behave much like the real thing.
On these stand-ins we can try out the options. The different drugs an oncologist is weighing up can be tested on the mini-tumours first, to see which one this particular cancer is most sensitive to.
By adding the patient’s own immune cells, we can also ask whether she is among the minority of patients likely to benefit from immunotherapy.
Tests of this kind are beginning to be offered in Europe. They are not available in South Africa.
Question
PROMISE goes a step further. Existing tests ask one question: will this treatment kill the tumour? We want to answer the question every patient actually asks: which treatment will work for me, while doing me the least harm?
A woman who beats breast cancer but is left with a damaged heart has traded one illness for another. So, alongside the mini-tumours, we will test the same drugs on heart cells, on a laboratory model of the barrier that protects the brain, and on a sample of the patient’s own blood, looking for early signs of clotting trouble.
The results come together on a single page: a personal scorecard. For each treatment option, it shows how well that treatment is likely to work against her cancer, and how gently or harshly it is likely to treat her heart, her brain and her blood.
The scorecard goes to the team of oncologists, surgeons, pathologists and geneticists who already meet to decide difficult cases. It is one more piece of evidence on the table, and this time it is about her alone.
To our knowledge, nobody has yet brought all of these pieces together in one report for the treating doctor.
Starting with breast cancer
We begin with breast cancer, the most common cancer among South African women, and with patients at Tygerberg Hospital. Over three years we plan to invite 150 women to take part, and to check the scorecard’s predictions carefully against what actually happens to each of them. Every mini-tumour will be stored in a living “biobank”, one of the first of its kind built from African patients.
The same platform has a second purpose. South African scientists are developing new cancer medicines from our own natural resources, from new chemistry, and from nanomedicine, where tiny carriers deliver a drug to where it is needed. Too few of these ever reach patients, because there has been no affordable local way to test, early on, whether they are both effective and safe.
PROMISE will put these candidates up against the hardest opponents first: mini-tumours grown from cancers that did not respond to standard treatment. Those that succeed must then prove they are kind to heart, blood and brain. Only candidates that pass every gate move forward, and none of this work involves animals.
A dream, told honestly
Let me be clear about where we stand. PROMISE is research, and we are now seeking the funding to do it. It is not yet a test you can ask your doctor for, and a scorecard must earn its trust by being proven right, patient by patient.
But here is the dream. A day when every South African woman diagnosed with breast cancer, in a private clinic or a public hospital, receives a treatment chosen for her and not for the average patient. A day when “we will have to wait and see” is replaced by “we tested it first”.
This October, wear the ribbon. Book the screening. And imagine, with us, what breast cancer care could become.
We call it PROMISE. We intend to keep it.
*Prof Anna-Mart Engelbrecht leads the cancer research group in the Department of Physiological Sciences at Stellenbosch University.
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