Sentinel Lymph Node Biopsy In Breast Cancer And Detection Of Micrometastases

SlN can predict the stutus of axillary lymph node. Through SLN biopsy, we can find patients without metastases in axillary lymph nodes to avoid axillary dissection. About 20%³0% patients without metastases in axillary by routine examination will relapse and matastases in 10 years, which are high dangerous patients. Although routine examination is negative, if detailed examination is done, micrometastases will be found usually. This study includes 2 parts, the first part is SLN biopsy by using different method, the second part is detection of micrometastases by using different method.This first part: SLN biopsy by radioisotopes or a combination of radioisotopes and blue dye(patent blue V and isosulphan blue). 0.25mCi/0.25ml ^99mTc-DX was injected intradermal 2⁴ hours prior to surgery. This injection is finished by 4 points. Preoperative lymphoscintigraphy is done. In operation we detect SLN by y probe. SLN was defined as hot-spot-counts/background counts > 10. In combination method, radioisotope was injected as the above. The blue dye was injected between every two radioisotope site , every point is 0.25ml. SLN was defined as any node which is blue and hot spot. We completed 121cases, successful rate is 96.7%, false negative rate is 8.6%. 70 cases were detected by radioisotopes, successful rate is 94.3%, false negative rate is 11.1%. 51 cases were detected by combination method, successful rate is 100%, false negative rate is 7.1%. In general, 30 procedures are required for a surgeon to master the method of radioisotope. A combined method is easier to master and superior to radioisotope.The second part: Detection of micrometastases by step sections, immunohistochemistry(IHC) and RT-PCR. We sectioned SLN at 100μm, 200μm and 300μm deep. Every section includes 4 pieces, which were stained by HE and IHC(AEl/3,CK19,mucl). In addition, we analysed the expression of CK19 and mucl by using RT-PCR. In order to find whether there is micrometastases, we completed 121 SLNs by using step section and IHC, 14% with micrometastases. 26 cases were analysed by using RT-PCR, 25.5% with micrometastases. Step section, IHC and RT-PCR are all sentitive method to detect micrometastases. The detection...