How likely is it that my breast cancer will return?

A new gene test offers sufferers a chance to avoid chemotherapy – and its side effects, says Cherrill Hicks.

A new gene test that is being hailed by specialists in the UK as a breakthrough in breast cancer diagnosis can help women and their doctors decide if they need chemotherapy after breast cancer surgery.

Like many women, Charlotte Dew dreaded the prospect of chemotherapy after having surgery to remove a cancerous lump in her breast, especially since her doctors were uncertain if these powerful drugs were actually needed to prevent the disease from spreading.

Dew’s cancer, diagnosed last summer, was found to be small and slow-growing, although a biopsy showed that some cells had spread to one of the nearby lymph nodes, under the arm, indicating a risk that the cancer could come back.

“The doctors couldn’t tell me if I would benefit from chemotherapy or not,” the 49-year-old gynaecologist recalls. “It was hard to make a decision. Chemotherapy is horrible, and I wanted to avoid the side effects such as nausea and hair loss if I could, but at the same time I was worried – supposing I didn’t have chemotherapy and the cancer recurred?”

It was then that Dew learnt from her surgeon about a new gene test that is being hailed by specialists in the UK as a breakthrough in breast cancer diagnosis. Developed by a California-based company and called Oncotype DX, it can help women and their doctors decide if they need chemotherapy after breast cancer surgery. Already used extensively in the US, it is now available privately in the UK, at a cost of about £2,500.

Known as a genomic assay, Oncotype DX involves extracting RNA (part of the genomic make-up of cells) from a sample of the breast tumour and analysing the activity of 21 genes controlling the behaviour of cancer cells. It gives a recurrence score, which indicates how likely the cancer is to return within 10 years of the initial diagnosis, with the risk being graded as low, intermediate or high. It also calculates how likely an individual woman is to benefit from chemotherapy.

According to Simon Cawthorn, a breast surgeon at the Breast Care Centre at Southmead Hospital, Bristol, the test is an “exciting breakthrough” which could benefit about half of all women with breast cancer. It is suitable, he says, for women with early-stage cancer that is fuelled by oestrogen – known as oestrogen receptor positive – in which the tumour is small and classified as slow-growing, and where no more than three nearby lymph nodes are affected.

It has been previously difficult to establish which women with this type and grade of cancer would benefit from chemotherapy – and which women do not need it, because there is little risk of the cancer spreading. Doctors generally try to calculate the risk by looking at the size and grade of the tumour and whether there is cancer in the lymph nodes; but in practice, says Mr Cawthorn, most women in this position have chemotherapy, with all the side effects it entails.

“This test can give us a far more accurate prediction about the risk of a cancer returning,” he says. “There is also good solid evidence that it is accurate.”

Oncotype DX has been validated by 13 studies in more than 4,000 patients and, according to the company, has been used with more than 200,000 patients in over 60 countries. In the US, it is recommended in breast cancer treatment guidelines and is used by 60 per cent of women with the type of breast cancer considered suitable. In the UK, along with other gene predictive tests, it is now being considered for use in the NHS by the National Institute for Health and Clinical Excellence, which is expected to reach a decision late next year.

In about a quarter of cases in the US in which the test is used, doctors and women decide against having chemotherapy. In a further 10 per cent of women, doctors realise chemotherapy is needed when they previously thought hormone therapy alone (another treatment used to prevent recurrence in this type of breast cancer) would be sufficient.

In Dew’s case, the gene test showed that the risk of the cancer recurring was low.

“Had the result been medium or high risk I would have had the chemo, but now I have only had to have radiotherapy (given to breast tissue to kill of any remaining cancer cells) and hormone treatment,” says Dew, who works at the Aneurin Bevan Health Board in Gwent.

“I feel good about the decision. Because my mother had breast cancer at an early age, without the information the test gave me, I’d probably have gone for the chemotherapy. It was a massive relief to know I didn’t have to. I was back at work three months after the surgery.”

So why don’t more women in the UK know about Oncotype DX? “With the NHS, the difficulty is always – how do you introduce new technology which could improve women’s quality of life and save money [in the long term] – but which costs money to introduce in the first place?” says Mr Cawthorn, who is involved in a study of the test’s cost effectiveness in Avon and Somerset.

“But if studies here also show that 25 per cent of women who have the test do not go ahead with chemotherapy, it could be a big saving for the NHS.”

He stresses that the test can only predict risk – it cannot tell a woman with certainty if her cancer will recur.

“Research has shown that chemotherapy – and its side effects – is one of the worst parts of having cancer for women,” he adds. “Chemotherapy is such a blunderbuss. If it was my wife I would want her to have this test.”

Dr Lesley Walker, director of cancer information at Cancer Research UK, adds: “We look forward to seeing if this test, or others like it, will become available soon.”

source: telegraph