If you are a cancer patient, pay attention:

Your immunohistochemistry (IHC) results may be misleading

Is therapy needed?

Ironically, this could happen in real life, the Ki67 scores from different pathologists leading to the contradictory recommendations. That is what the one study about Ki67 tells us (see the figure below). In fact, based on this study, if the patient of the 15th slide visits 22 hospitals, 12 hospitals will insist on the patient's chemotherapy, while the other 10 will insist that the patient does not need chemotherapy.


NPJ Breast Cancer 2: 16014, 2016 Fig 4a
How reliable of a biomarker?
The results were re-plotted, with X-axis representing 30 IHC slides, and Y-axis are the Ki67 scores. Each dot representing the Ki67 score of a IHC slide by a pathologist.

According to this study, the same 30 IHC slides were sent to 22 pathological labs in 11 countries for the pathologists to assess Ki67 score of these 30 slides independently, the percentage of Ki67 levels ranging from 0 to 95%.

As you can see in the figure, the Ki67 scores vary a lot for the same IHC slide depending on the pathologist, for example, at the 15th slide the Ki67 scores can be 11%, or 62%!

Ki67 is the most used protein biomarkers for cancer patients. It is used to evaluate how aggressive your cancer is, (1)to determine if you need adjuvant chemotherapy, and (2) to evaluate the effectiveness of the treatments over a period of time. The bottom line, it is a critical factor for physicians to consider.

According to the guidance, for Luminal-like breast cancer patients, you only need chemotherapy if your Ki67 >20%. For the 15th slide, 10 pathologists scored its Ki67 levels below 20%, while 12 other pathologists scored its levels above 20%. Who should you trust?

This is not a Ki67 issue only. You can have the same doubts on all the IHC results from your pathology report. To put it straight, IHC is not the right method for assessing protein biomarker levels. Yet, it is the predominant method currently in daily clinical practice.

At Quanticision Diagnostics, instead of providing the results in vague terms, we provide objective, quantitative levels of these biomarkers (nmol/g) to patients using quantitative dot blot (QDB) analysis, will revolutionize cancer diagnostics.

Differences between QDB & IHC

If have any questions or comments, please feel free to contact us at contact@quanticisiondiagnostics.com for further discussion.