Comparing the Detection of Lymph Nodes Micrometastasis in Breast Cancer by the Hematoxylin and Eosin Staining Method (H&E) and the Immunohistochemical Method (IHC)

Background: Breast cancer is the most common cancer in women. The most important factor in determining the prognosis and treatment of invasive breast cancer is axillary lymph nodes involvement. It is possible not to detect micrometastasis with applying staining tissues by the Hematoxylin and Eosin (H & E) staining method. Therefore, this study was conducted to determine and compare the detection of axillary lymph node micrometastasis in breast cancer by H & E and immunohistochemical (IHC) method. Methods: A cross sectional analytical study was carried out. By using census method, 80 female patients diagnosed with breast cancer and lymph node non-involvement were selected in Shahid Sadoughi General Hospital pathology ward, Yazd, up to 2016. IHC was performed to re-detect lymph node micrometastasis. The checklist was used to collect data of demographic, clinical, and pathological characteristics of the study population. The data collection was analyzed, using statistical software version SPSS-18, descriptive statistics, and Chi-Square analysis test. P value less than 0.05 was considered statistically significant. Results: Of the 80 samples using H & E staining method, no case was diagnosed with lymph node micrometastasis, but using IHC, 50 cases (62.5%) were found negative and 30 cases (37.5%) were found positive. The majority of tumors in the positive group had poorly differentiated grade and the difference between the tumor grade in both positive and negative group was statistically significant (P = 0.001). Also, the majority of tumors in the positive group were located in the upper-outer and lower-outer quadrant of breast and the difference between tumor locations in both positive and negative group was statistically significant (P = 0.001). Conclusions: According to the results, IHC is more beneficial than the H&E method to detect micrometastatic cells and to examine tissues that have high-grade tumors and also tumors located in upper-outer or lower-outer more possibility of metastasis.