An observational study in Pakistan associated higher tumour glucose uptake and a cell-proliferation marker with earlier metabolic progression in breast cancer. The analysis covered 110 patients, most with advanced disease. Its thresholds came from the same cohort; variation in treatment and incomplete pathology information constrain their application to other patients.
Patients at Aga Khan University Hospital in Karachi, Pakistan, supplied the data for a peer-reviewed observational study of breast cancer progression. Researchers selected a group of 110 with adequate imaging, pathology and clinical information, drawing on 342 examinations. Stage IV disease accounted for 74 per cent of the cohort. Different treatment pathways and incomplete pathology information limit how broadly the associations can be applied.[1]
The imaging measure was maximum standardized uptake value, or SUVmax, which records tumour glucose uptake on combined positron emission tomography and computed tomography, or PET/CT. Above 5.4, mean metabolic progression-free survival was 29 months, compared with 45 months at lower values. The interval begins with the initial scan and ends when metabolically active cancer progresses or returns, or when the patient dies. It measures a different outcome from general life expectancy.[1]
Ki-67, a marker of cell proliferation, was available for 77 patients. Values above 30 per cent accompanied mean metabolic progression-free survival of 27 months, compared with 48 months at lower values. Complete metabolic response was less likely among patients whose marker values were higher. The cut-offs were derived within this cohort, and the investigators call for larger, more homogeneous multicentre prospective studies to validate them.[1]
