This dissertation, "Application of the Sentinel Node Concept in Breast Cancer Surgery" by Wai-ka, Hung, 熊維嘉, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: This thesis consisted a series of sentinel node biopsy (SNB) studies in Chinese patients to evaluate its impact on the management of breast cancer. Pilot studies The first SNB pilot study was performed in 30 patients using the blue dye technique. Accuracy was verified by axillary lymph node dissection (ALND). The success rate was 83% and the false-negative rate was 25%. The second pilot study was performed in 50 patients using combined mapping with isotope and dye. The success rate was 94% with no false-negative. SNB is shown to be feasible and accurate in Chinese. The optimal mapping method Combined mapping was superior to the blue dye technique. This could be due to the mapping technique or improved experience. One hundred and twenty-three women were randomly assigned to either the blue dye or combined mapping. Combined mapping had a higher success rate than the blue dye technique (100% versus 86%). False-negative rates were similar (0% versus 4.5%). Combined mapping is the preferred method. Accuracy of frozen section (FS) FS was used intra-operatively to guide the need of ALND. In 260 SNB, FS was compared to serial section and immuno-histochemical staining. FS detected 53 of 86 patients with SN metastases with a false-negative rate of 38.4%. The false-negative rates for macro-, micro-metastases and isolated tumour cells (ITC) were 2.4%, 57.7% and 94.4%. FS was accurate to diagnose macro-metastases but not micro-metastases and ITC. Can we skip ALND in SN metastases? 139 patients with SNB and ALND were studied to identify predictive factors for non-SN metastases. 55 had metastatic SN but 38 (69%) had no residual metastases in non-SN. Tumours and absence of extra-capsular spread were significant factors to predict no residual nodal disease. Non-SN metastases were found in 42%, 19% and 0% when SN contained macro-, micro-metastases and ITC. Based on risk of non-SN involvement, ALND is indicated for macro- and micro-metastases but not for ITC. Extended indication for ductal carcinoma in situ (DCIS) SNB may be useful for staging of patients with a pre-operative diagnosis of DCIS because invasive cancer is not infrequently found on pathological examination of resected specimens after surgical excision. One hundred and seven patients with DCIS on core biopsy underwent SNB. Thirty-two patients (29.9%) were upstaged to invasive cancer and 9 (28.1%) had SN metastases. Performing SNB reduced the re-operation rate from 29.9% to 1.9%. Palpable mass and radiological mass lesion were associated with upstage. Extended indication: Sentinel Node Occult Lesion Localisation (SNOLL) Radioisotope is used to localise non-palpable breast cancer and SN. Seventy-four patients with non-palpable breast cancers underwent SNOLL. Radioisotope was injected into cancer and gamma probe guided breast cancer and SN resection. Primary cancer was removed in 73 patients (99%) after the first-round excision and 82% had complete excision. Gamma probe identified SN in 82% and supplementary blue dye increased SN detection to 97%. SNB modified the practice of breast canc