This app can predict long-term risk of breast cancer

Researchers have come up with a web-based calculator named 'CTS5 calculator' that can help you predict the long-term risk of breast cancer.

The web-based calculator can be used to decide which patients are at high enough risk of their cancer returning after receiving the standard five years of endocrine therapy (Endocrine are glands in the body that make hormones), and so could benefit from the continuation of treatment. It could also predict which patients are at low risk of recurrence, and so can avoid any further therapy along with the potential adverse side effects.

According to the research, over the last three decades, there has been a major increase in the rate of invasive breast cancer in Western countries. Approximately 85 per cent of patients are now diagnosed as oestrogen (female sex hormones) receptor (ER) positive, which means that cancer grows in response to the hormone oestrogen. Almost all of these patients are prescribed five years of hormone therapy after having standard treatment.

However, hormone therapy can have significant side effects for some patients, including weakness of bone tissue, and exacerbation of menopausal symptoms. Oncologists along with patients have to decide after five years of hormone treatment whether extending this type of therapy is worthwhile and appropriate.

After reviewing the data from two previously published studies, the researchers provided information on 11,446 postmenopausal women with ER-positive breast cancer who had received five years of hormone therapy (tamoxifen, anastrozole, or letrozole).

Using the data set from one previously published study, they measured how many women developed metastasis five to 10 years after they finished endocrine therapy. This was then combined with information about a tumour, which had been measured at the point of diagnosis, to produce a risk equation - CTS5.

To investigate the validity of the tool, researchers then tested CTS5 against data from the second study. As a result, CTS5 was shown to be able to accurately separate women into groups of a low, intermediate, or high risk of developing a late distant recurrence breast cancer after five years of hormone therapy.

Professor Mitch Dowsett, one of the researchers said, "What we have developed could improve clinical practice, benefiting breast cancer patients by avoiding potentially unnecessary extended treatment. Clinicians require expertise and the best tools to help them make a crucial decision on treatment for patients, decisions that can make a difference to patient's quality of life."

Queen Mary University of London researchers led on the development of the web-based CTS5 calculator, which has been designed with clinicians in mind. After inputting patient details, including age, tumour size and tumour grade, it gives an estimated 5-10 year risk of the cancer returning in another part of the woman's body, with an estimated benefit from extending their hormone therapy.

Co-lead researcher Professor Jack Cuzick said, "Hormone-sensitive breast cancer is one of the few cancers where late recurrence is common, and predicting who is at high risk is particularly important so that they can continue hormone treatment."

According to Dr Ivana Sestak, the tool provides a very simple way of obtaining the risk of a late metastasis for each woman individually. It is very important to identify these women in the clinic and the calculator provides help in the decision-making process.

The findings appeared in the Journal of Clinical Oncology.