Non-histopathological parameters associated with upgrade of breast tumours yielding a core biopsy report of histological grade 2 ductal no special type to grade 3 on excision

Purpose: The aim of the study was to identify clinical, radiological and immuno-histochemical factors that may help predict upgrade of invasive ductal cancers of no special type (IDC-NST) with a core biopsy grade of 2 to grade 3 on final histology.

Methods: A prospectively maintained database of ultrasound visible solid masses was used to identify lesions yielding a core biopsy result of IDC-NST grade 2 who underwent immediate surgery yielding a grade 2 or grade 3 tumour. Associations were sought between the source of patient (screening/symptomatic), core biopsy receptor status and imaging findings and the grade of the excision specimen tumour. Statistical analysis, which included the chi-squared test, ROC curves and Cox regression analysis, was used to compare upgrade vs no upgrade for each factor.

Results: 463 IDC-NST breast cancers of core biopsy grade 2 gave 344 grade 2 and 119 grade 3 tumours at excision. Factors significantly associated with upgrade were large ultrasound (US) size, hyperechogencity, stiffness at shearwave elastography (SWE), calcification on mammography and oestrogen receptor (ER) and progesterone receptor (PR) negativity. Patient source, Human epidermal growth factor receptor 2 (HER-2) status, ultrasound (US) distal effect and mammographic spiculation were not significantly associated with chance of upgrade. On multivariate analysis, only US size maintained statistical significance.

Conclusion: Oncologists and surgeons should be aware that lesions with a core biopsy diagnosis of grade 2 IDC-NST measuring over 15 mm on US have a 37% chance of being grade 3 on excision and this should be considered when deciding pre-operative management.