Objective: To evaluate the relevance of intrinsic breast cancer subtyping (IBCS) on core biopsies (CB). Results: 39384 samples were tested in 2009. Score 0 was found in 45.43 % cases, 1+ in 28.86 %, 2+ in 12.97 %, 3+ in 14.73 %. The amplification was revealed in 32.12 % of 2+ cases, 15.82 % tumors were 3+/FISH+. 43485 cases were tested in 2011: score 0 −38.42 %, 1+ 30.61 %, 2+ 15.65 %, 3+ 15.32 %. The amplification was seen in 28.17 % 2+ cases and 18.68 % tumors became 3+/FISH+. There was no significant distinction using 10 % and 30 % cells score system for 3+ tumors, whereas for groups 1+ and 2+ it was. Conclusion: ASCO/CAP scoring criteria developed in 2007 have no effect on HER2-positive tumors detection but increases number of cases with equivocal result, what require retesting with ISH.