A third of breast cancer patients may not need chemo after all: Spain takes part in global research

A GROUND-BREAKING study that could change treatment for breast cancer for the first time in 30 years has included a major contribution by Spanish researchers.

Working with scientists from the USA and South Korea, the team concluded that a third of patients in Spain who would otherwise have been treated with chemotherapy may not, in fact, need it.

A total of 792 women, via 21 Spanish hospitals, made up nearly 20% of the 5,083 patients studied worldwide in trials conducted by Canada's NCIC CTG, France's Unicancer hospital network, the National Cancer Center-Korea, the US-based groups ECOG-ACRIN Cancer Research Group, NRG Oncology and The Alliance for Clinical Trials in Oncology, and Spain's Breast Cancer Research Group (GEICAM).

The clinical trials were launched by the United States' SWOG Cancer Research Network and the National Cancer Institute (NCI) as part of the RxPONDER project, and discussed at the 43rd San Antonio Breast Cancer Symposium – held via video conference this year and due to conclude on Saturday.

Women who have gone through the menopause and whose breast cancer is HER2-negative with positive hormone receptors (RH+), with one to three lymph nodes affected and a recurrence score of 25 or less – on a scale of 0 to 100 – make up a third of patients in Spain with breast cancer and, like everywhere else in the world since around 1980, have been treated with chemotherapy and hormone therapy, typically by taking Tamoxifen or similar for five to 10 years after surgery.

But the RxPONDER project has found that the prognosis for this patient typology is just the same with hormone therapy only as it is with both.

GEICAM chairman Dr Miguel Martín, who invested some of his own, personal money in financing the research, says the RxPONDER study has involved a 'major international investigation effort' and provided 'extremely relevant data' for patients with 'operable breast cancer'.

About 8,000 women a year in Spain fall into the category of patients studied, he says.

A genomic test, 'Oncotype DX', was used for the trials – a predictive tool created by Exact Sciences and distributed in Spain, exclusively, by Palex Medical – examines 21 genes in the tumour and indicates whether or not the cancer is likely to return, and whether the patient would benefit from chemotherapy.

The 'Oncotype DX' test was carried out on 5,083 patients worldwide, of whom two-thirds were post-menopausal and the rest pre-menopausal; those with a recurrence score of 25 or lower were split into randomly-selected groups to be given either hormone treatment and chemotherapy or just hormone treatment.

They were monitored for five years, says Spain's chief researcher involved, Dr Emilio Alba, and it was found that where they had between one and three affected lymph nodes – a situation that arises in about 5,300 women annually in Spain – their prognosis was no worse without chemotherapy than for those who were given it.

Among the pre-menopausal patients, though, chemotherapy is still strongly advised to prevent a recurrence; post-five year survival rates, which is a cautious way of referring to a complete cure, rose by 5.2 percentage points where both types of treatment were given.

Patients who had not yet gone through the menopause were alive and cancer-free after five years in 94.2% of cases, compared with 89% of those who only had hormone treatment and no chemotherapy.

The research showed that prognosis for all groups was 'excellent', even where they had up to three affected lymph nodes, with a post-cancer five-year survival rate averaging over 90%.

Dr Alba says this is one of the largest clinical trials and will trigger the biggest clinical practice change in over a quarter of a century.

Previously, the TAILORx study had found hormone treatment alone, without chemotherapy, was equally as effective as both together in women with a recurrence score of 0-24 inclusive and with no affected lymph nodes, but the RxPONDER study focused on those thought to have a greater initial risk of the cancer coming back.

Dr Carlos Hagen, director of Palex Medical, calls it a 'privilege' that research which will 'have a positive impact' on 'tens of thousands of patients worldwide' has involved Spanish scientists.

It will mean a huge weight off the shoulders of thousands of women in Spain and beyond every year, since often, knowing they have to go through chemotherapy is every bit as devastating as a cancer diagnosis in itself, given the unpleasant side-effects and, particularly, the knowledge that their hair would fall out.