Immunohistochemical (IHC) technology holds a core position in cancer research. It can precisely locate and quantitatively analyze specific biomarkers in tumor tissues, providing an objective basis for pathological diagnosis. According to the data from the American Cancer Society in 2022, over 95% of pathology laboratories worldwide use IHC as a routine testing method, processing more than 100 million samples each year. A multicenter study on HER2 detection for breast cancer showed that the sensitivity of IHC detection reached 98.7%, the specificity was 95.4%, and the consistency of its test results with FISH (fluorescence in situ hybridization) was as high as 97.3%, significantly reducing the probability of false negatives. This technology, through the binding of specific antibodies to antigens, can detect target proteins at concentrations as low as 0.01 μg/mL at the single-cell level, with a spatial resolution of up to 0.2 μm, enabling the effective recognition of rare cell subpopulations in the tumor microenvironment (such as circulating tumor cells accounting for only 0.1%).
In terms of clinical translation, IHC technology directly guides the selection of targeted treatment regimens, significantly improving the survival rate of patients. For instance, in the detection of PD-L1 expression levels in non-small cell lung cancer, the ihc immunohistochemistry method (such as the 22C3 pharmDx kit) can increase the probability of patients responding to immunotherapy from 20% to 45%, and extend the median survival period to 28 months. Roche Pharmaceuticals’ statistics show that companion diagnostics based on IHC have increased the clinical application accuracy of trastuzumab by 30%, avoiding over 100,000 ineffective treatments each year and saving approximately 5 billion US dollars in medical expenses. In addition, the cost of IHC testing is only 15% of that of next-generation sequencing (a single test costs approximately $150), and results can be output within 4 hours, significantly accelerating the clinical decision-making process.
Technological innovation continuously expands the application boundaries of IHC. Multiplex fluorescence immunohistochemistry (mIHC) technology can simultaneously detect seven biomarkers. By using spectral unmixing algorithms, the detection throughput is increased by 400%, and it supports three-dimensional reconstruction of the spatial structure of tumors. A study published in the journal Cell in 2023 demonstrated that by analyzing colorectal cancer samples using mIHC, the spatial distribution patterns of 12 immune cell subtypes were successfully identified, and the correlation coefficient between the density gradient and the 5-year survival rate of patients reached 0.89. The introduction of an automated platform has further reduced the coefficient of variation of detection from 15% to below 5%. For instance, the Leica Bon-Max system can process 36 slices per batch and complete 500 tests daily, which is six times more efficient than manual operation.
The standardization system of this technology ensures the comparability of global data. The quality verification standard for ihc immunohistochemistry formulated by ASCAP/CAP requires that the consistency of inter-laboratory detection reach κ>0.8, and the coincidence rate of both positive and negative controls should exceed 99%. The UK Biobank screened the expression of BRCA1 protein in 500,000 samples using a standardized IHC process, with data variance controlled within ±2.5%, providing a reliable basis for large-scale epidemiological studies. In the future, with the introduction of artificial intelligence image analysis algorithms, the accuracy rate of IHC data interpretation is expected to exceed 99.5%, further consolidating its cornerstone position in precision cancer medicine.