- A web-based calculator has been developed to predict the risk of breast cancer returning to another part of the body, post-hormone therapy for breast cancer
- There is an increased risk of developing a late metastasis or cancer spreading in over 50 percent of women who have finished hormonal treatment for their breast cancer
- The new tool can help oncologists and patients predict women who are at highest risk and decide whether extending hormone therapy beyond five years is worthwhile and appropriate
A prognostic online tool that can better predict
the long-term risk of breast cancer returning in other areas of the body has
been devised by a research team from London. The study has been published
online in the Journal of
cancer over the last three decades – invasive refers to cancer that has spread outside the breast to other parts of the body.
‘Risk of cancer returning in another part of the woman’s body, after completion of five years of hormone therapy for breast cancer can now be calculated by a new web-based calculator.’
Studies have also shown that approximately 85
percent of patients were diagnosed with estrogen-receptor-positive
or ER+ cancer, which means that the cancer cells receive signals from estrogen just
like normal breast cells and can hence grow in response to the hormone.
Why was the New Tool Developed?
therapy for breast cancer includes standard
treatment (surgery, chemotherapy, and/or
radiation therapy) followed by five years of hormone therapy for almost all the
patients, to lower the risk of cancer returning.
Oncologists usually have to decide whether the endocrine or
hormone therapy has to be continued or stopped beyond five years since the
therapy can have significant side effects for some patients, including weakness
of bone tissue, and worsening of menopausal symptoms.
Hormone-sensitive breast cancer is also one of the few
cancers where the recurrence at a later date is common; hence, predicting who
is at high risk is particularly important.
- The new tool was devised to address this problem – to decide which patients are at high enough risk of their cancer returning after receiving the hormone therapy, and so could benefit from the continuation of treatment.
- The tool has another benefit of predicting which patients are at low risk of recurrence, and so can avoid any further therapy along with the potential adverse side effects.
Study – Clinical Treatment Score Post-5-years
Treatment Score Post-5-years (CTS5)
was developed after
reviewing data from two previously published studies which together provided
information on 11,446 postmenopausal women with ER-positive breast cancer who
had received five years of hormone
therapy (tamoxifen, anastrozole, or letrozole).
Professor Mitch Dowsett, Head of The Royal Marsden
Ralph Lauren Centre for Breast Cancer Research and Professor of Biochemical
Endocrinology at The Institute of Cancer Research (ICR), and Professor Jack
Cuzick and Dr. Ivana
Sestak from Queen Mary University of London were instrumental in the
development of the web-based tool.
They obtained the data set from one of the studies and
measured the number of women who
developed metastasis or cancer that had spread, five to 10 years after they
finished endocrine therapy.
They combined this information with details about
the tumor that had been measured at the time of diagnosis and produced a risk
equation known as CTS5.
The validity of CTS5 was determined by testing it
against the data from the second study. CTS5 could –
- Accurately separate women into groups of low, intermediate, or high risk of developing breast cancer again at a later date, after five years of hormone therapy.
- Identify that 42 percent of the women had a sufficiently low risk of recurring cancer so that extending hormone therapy would have been of very little value.
Co-lead researcher Professor Mitch Dowsett, Head of
The Royal Marsden Ralph Lauren Centre for Breast Cancer Research and Professor
of Biochemical Endocrinology at The Institute of Cancer Research, London, 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 crucial
decision on treatment for patients, decisions that can make a difference to
patient’s quality of life.”
The researchers from Queen Mary University of London
went ahead with the development of the
web-based CTS5 calculator that would benefit clinicians.
Once the patients’ details like age, tumor size and
tumor grade are inputted, the calculator gives an estimated 5-10 year risk
of cancer returning in another part of the woman’s body, along with an
estimated benefit from extending their hormone therapy.
Co-lead researcher Professor Jack Cuzick from Queen
Mary University of London said: “While our ability to predict hormone sensitive
breast cancer is highly likely to improve in the future, we’re providing a
simple tool which is available now, and is easily used and well tested. Our 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 data collected and used were from studies that began over 20 years ago on
patients with hormone receptor-positive tumors. These studies did not use the
drug trastuzumab for cancer management; hence, clinicians should be cautious
when using CTS5 on the specific patient population that uses trastuzumab.