Could you skip chemo?
Posted on 2 October 2017
A new test is helping doctors understand the “personality” of breast cancer better – leading to earlier diagnosis and more effective treatment. This is how MammaPrint could save your life.
Words Gillian Klawansky
Breast cancer is an enigma. As many as one in 10 women in urbanised areas in South Africa will be affected by the disease, which is also the most common cancer in women across the world. “But while this number may seem alarming, breast cancer is a highly curable disease when detected early,” says Professor Justus Apffelstaedt, from Tygerberg Breast Clinic. Now, innovations in early detection, coupled with ground-breaking tests, like MammaPrint, which allows doctors to target their treatment to specific cases, are making outcomes more positive than ever.
[*Gutter credit: World Cancer Research Fund International]
One of the biggest factors in breast cancer treatment and recovery starts with you. “It’s important that women follow a proactive regimen of screening and self-examination,” says Professor Apffelstaedt. Step one is understanding how you may be affected, depending on your age. “Everyone from the ages of 20 to 39 should know their family history of breast cancer, schedule an annual consultation with a professional with a special interest in breast health (including a breast examination) and should conduct breast self-examinations monthly,” he says. This changes after the age of 40, at which point you should have an annual mammogram and clinical breast examination and conduct breast self-examinations every month.
Mammogram technology is more advanced than ever, with a variety of improvements over the past ten to 15 years, says Dr Etienne Myburgh, an oncology surgeon at Mediclinic Panorama. “There’s far less radiation, the quality of images is a lot better – for example, we can do three dimensional imaging through digital tomosynthesis. And as the technology has improved, so has the detection rate. An instantaneous image also limits the discomfort caused by having to repeat the procedure. That said, mammograms themselves are still the best tool for detection and are unlikely to be replaced by anything else in the near future. ”
Genetic testing also allows doctors to establish a patient’s genetic susceptibility to breast cancer, and there’s a wider panel of tests available than ever before. “Our understanding of genetic risks for breast cancer has improved significantly,” says Dr Myburgh – and where genetic risks are identified, patients are offered risk reduction options to reduce their chances of developing breast cancer.
“Once breast cancer is diagnosed,” says Professor Apffelstaedt, “treatment and follow-up by specialised doctors in a multidisciplinary environment has the best results.” And that treatment itself is continuously improving. “There are newer radiotherapy techniques for breast cancer where side effects are a lot less intense – it’s become safer for patients,” says Dr Myburgh. “A standard recipe for cancer treatment has been replaced with individualised care: we look at the person, from their body shape to their genetic risk. If we can individualise the patient’s care, we can improve their outcome significantly.”
There are few tools as useful in developing an individualised treatment plan as MammaPrint. “Traditionally we have a do a risk analysis on a breast cancer patient to decide whether they’d benefit from chemotherapy,” says Dr Myburgh. “Most breast cancers are hormone sensitive, which means they can be treated with anti-oestrogen treatment. Chemo adds a small percentage of additional benefit to these patients. There’s a large proportion that don’t probably don’t really benefit from chemo but undergo it to be safe – but are unnecessarily exposed to its risks and side effects.”
While it’s sometimes obvious whether the cancer is high or low risk and requires chemotherapy, there’s a large group in the middle where this isn’t immediately clear. “Oncologists are inclined to rather suggest chemotherapy than omit it, so as not to compromise the patient’s outcome,” explains Professor Apffelstaedt. Yet in about 50% of cases this is unnecessary, and this is where MammaPrint comes in.
“You could compare MammaPrint to a personality test for breast cancer,” says Dr Myburgh. “Instead of looking at external features of the cancer, we’re looking at the DNA of the disease strain to better predict its behaviour early on.” Results reveal either a high-risk cancer, which has a long-run risk of spreading – and those patients would probably benefit most from chemotherapy – or a low-risk cancer, which has a substantially lower risk of spreading. “Chemotherapy here wouldn’t improve the long-term success of treatment, so you can safely avoid chemotherapy and just have anti-oestrogen treatment, and that would give the biggest benefit.”
MammaPrint also involves a separate test, called Blueprint, which tells doctors exactly which genetic subgroup of cancer the patient has – and this further determines the best type of treatment combination. “This empowers us to make good treatment decisions for the patient,” says Dr Myburgh. About 350 MammaPrint tests have been done in SA in the past ten years, with numbers spiking over the last two years or so. While the test is costly, it’s still cost-effective when you consider the amount you save in avoiding unnecessary chemotherapy, and many medical aids largely cover the test these days, explains Dr Myburgh.
“With MammaPrint, genomic tests analyse a sample of a cancer tumour to see how active certain genes are,” explains Professor Apffelstaedt. “The activity level of these genes affects the behaviour of the cancer, including how likely it is to grow and spread. MammaPrint tests a sample of the actual tumour.” No additional surgery is necessary. “This can be done if the cancer is at stage I or stage II, invasive, smaller than five centimetres, or in three or fewer lymph nodes.”
Samples are sent to the Netherlands for analysis and results take around two to three weeks to come through. There are advantages for patients with low- and high-risk cancers says Dr Myburgh.
Pull quote: “Most of the MammaPrint patients are those who under normal circumstances would’ve had chemotherapy. For 50% of patients, you can give them the good news that they don’t require chemo and they can miss out on those six months of treatment and all the side effects.”
And the patients who have a high-risk MammaPrint test result, who do have to have chemotherapy, also benefit emotionally, he says. “They say because they know that they will definitely benefit from chemotherapy, that it motivates them to go through it, and they deal with it better. Every patient who has a form of breast cancer that meets the defined parameters should be considered for MammaPrint.”
A recent study in Cape Town, where a comprehensive breast centre has been documenting the clinical progress of over 150 patients diagnosed with breast cancer who underwent molecular genetic profiling of breast tumours, revealed the value of MammaPrint. “That study confirmed that molecular genetic testing can reduce the number of individuals who undergo chemotherapy – and that it can also save lives, by allowing for more aggressive treatment,” says Professor Apffelstaedt. “It gives medical professionals a new level of information from which to determine prognosis and treatment options, and ultimately allows for a more accurate approach to cancer prognosis and treatment.”
“MammaPrint helped me avoid unnecessary chemotherapy”
For breast cancer survivor Magdel Horrell, MammaPrint was a game-changer. Diagnosed with breast cancer in March this year after undergoing a mammogram and sonar scan, she was referred to Professor Apffelstaedt. She had a mastectomy in April and a sample of the removed lymph glands and breast tissue were used in a MammaPrint test in May. “The results of the test revealed that I have low-risk cancer and don’t need to have chemo,” she says. “I did have radiation therapy every day for five weeks, but my treatment is now done and dusted. I have my first six month check-up in October. It was fantastic to hear that I didn’t need to have chemo – it just makes you so sick, and I think the hair loss is terrible. If everyone diagnosed with breast cancer could do the MammaPrint test it would be marvellous.”