termsTerm
Resection margins (R0 / R1 / R2)
aka margins, margin, surgical margins, negative margins, positive margins, margin-negative, margin-positive, clear margins, R0, R0 resection, R1 resection, R2 resection, microscopic residual disease, margin status, circumferential resection margin, CRM
Whether the edge of the removed tissue is free of cancer. R0 means clear under the microscope, R1 means microscopic cancer at the edge, R2 means visible tumour left behind. R0 is what 'complete resection' means.
Margin status is the most important surgeon-controlled predictor of local recurrence and, in many cancers, survival. An R1 margin often means further surgery, radiotherapy or, in pancreatic cancer, simply a worse prognosis; R2 resections are palliative. The required width varies: 'no ink on tumour' suffices for invasive breast cancer, 1 mm for the circumferential margin in rectal cancer, 1-2 cm for melanoma. Neoadjuvant therapy is often justified by its ability to raise the R0 rate, as with daraxonrasib in pancreatic cancer.
Category
Pathology & biomarkers