Queen Mary University of London has today launched a simple, web-based calculator to estimate the risk of late distant recurrence (DR) in women with oestrogen receptor-positive breast cancer after 5 years of endocrine treatment.
The Clinical Treatment Score post-5-years (CTS5) uses routinely collected clinical data – tumour size, tumour grade, age and number of involved nodes to estimate 5-10-year risk for DR in women who remained recurrence-free for 5 years of endocrine therapy.
The score was developed by researchers at the university and the Royal Marsden NHS Foundation Trust using the data set (n=4735) from the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial and has been validated against the Breast International Group (BIG) 1-98 data set (n=6711).
CTS5 was significantly prognostic for late DR in the ATAC cohort (HR, 2.47; 95% CI, 2.24-2.73; P<.001) and BIG 1-98 (HR, 2.07; 95% CI, 1.88-2.28; P<.001) cohorts.
It identified 43% of the validation cohort as low risk, with an observed DR rate of 3.6% (95% CI, 2.7%-4.9%) at 5-10 years and for whom the benefits of continuing endocrine therapy would be limited. Sixty-three per cent of node-negative patients were low risk, with a DR rate of 3.9% (95% CI, 2.9%-5.3%), while 24% of women with 1 to 3 positive nodes were low risk, with a DR rate of 1.5% (95% CI, 0.5% to 3.8%).
The online CTS5 calculator is now available free-for-use at www.cts5-calculator.com.
