Tumour grade does not change between primary and recurrent mammary carcinoma.

The primary tumour grade in 115 patients with infiltrating ductal carcinoma of the breast was compared with the type of the ductal carcinoma in situ (DCIS) component and with the grade of 169 locally recurrent and metastatic lesions. 102 patients had axillary lymph node metastases at the time of primary surgery, 49 had subsequent recurrences and 36 had both. There was concordance of grade between the primary tumour and axillary lymph node metastases and with subsequent locally recurrent and metastatic lesions. The type of the DCIS component was also significantly associated with the grade of the infiltrating component. No evidence of progression of tumour grade between these phases of mammary carcinoma was found.