EGFR and neoplasm: When CA XII was assessed as a continuous variable, there was a strong correlation between CA XII expression and tumour grade (r=−0.39, P<0.0001 Spearman's test), ER level (r=0.53, P<0.0001), EGFR (r=−0.38, P<0.0001) and extent of necrosis (r=−0.44, P<0.0001).