(HealthDay News) – A published nomogram from the Memorial Sloan-Kettering Cancer Center (MSKCC) is imperfect for predicting the risk of ipsilateral breast tumor recurrence (IBTR) following excision of ductal carcinoma in situ (DCIS), according to a study published online January 17 in the Journal of Clinical Oncology.
Min Yi, MD, PhD, of the University of Texas M.D. Anderson Cancer Center (MDACC) in Houston, and colleagues retrospectively identified 794 patients with a diagnosis of DCIS who had undergone local excision procedures at MDACC from 1990 to 2007. For the 734 patients with complete data, clinicopathological features were recorded and performance of the MSKCC nomogram for prediction of IBTR was evaluated.
The researchers found that there were marked differences between the MDACC and the MSKCC cohorts with respect to tumor grade, prevalence of necrosis, initial presentation, final margins, and receipt of endocrine therapy. Significantly more patients received radiation in the MDACC cohort (75% at MDACC versus 49% at MSKCC). Compared with the MSKCC cohort, in the MDACC cohort, follow-up time was longer (median 7.1 versus 5.6 years) and the recurrence rate was lower (7.9 versus 11%). The median five-year and 10-year probabilities of recurrence were 5 and 7%, respectively, with the nomogram. Calibration and discrimination of the nomogram prediction was imperfect, with a concordance index of 0.63.
“Predictive models for IBTR in patients with DCIS who were treated with local excision are imperfect. Our current ability to accurately predict recurrence on the basis of clinical parameters alone is limited,” the authors write.