RESUMO
BACKGROUND: Basal-like breast carcinoma (BLBC) has attracted considerable attention over the past few years. It has been suggested that tumours expressing basal markers have a more aggressive clinical behaviour. However, a molecular basis for this disease remains unclear, and it lacks currently used therapeutic targets. Therefore developing a novel treatment strategy is crucial for improving the prognosis. The aim of this study was to characterise the immunohistochemical (IHC) expression of p16 in patients with BLBC compared with non-BLBC. MATERIALS AND METHODS: Eighty-five cases of grade-3 invasive ductal carcinomas not otherwise specified (IDC-NOS) were analyzed. Immunohistochemical stains for oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor type 2 (HER2), cytokeratin (CK) 5/6, epidermal growth factor receptor (EGFR) and p16 were performed. BLBC was defined as ER-, PR-, Her2- and CK5/6+, and/or EGFR+. RESULTS: Twenty cases were categorised as BLBC versus 65 as non-basal. High mitotic count and presence of necrosis were associated with basal-like phenotype. Distant metastasis developed in 40% of cases of BLBC with frequent spread to brain and lung. p16 had significantly higher expression in the basal subgroup (80% versus 50.8%, P = 0.04). Patients with BLBCs were found to have a lower disease-free survival (DFS) rate (60% versus 70.8%, P = 0.03). CONCLUSION: BLBC typically demonstrates a unique profile. p16 is frequently expressed in breast cancers with basal-like phenotype; this suggests that p16 may play a role in the poor prognosis of this tumour, and it may be used in the development of a targeted therapy that will result in improved patient prognostication and outcome.
RESUMO
BACKGROUND: Breast cancer is one of the most commonly occurring malignancies in females in the Eastern Mediterranean Region. Axillary clearance is an integral part of the surgical treatment of breast cancer. Precise analysis of lymph node involvement for proper staging and adjuvant therapy is therefore necessary. During axillary dissection, lymph nodes at levels I, II and III are removed, while the important axillary structures ( axillary vein, long thoracic and thoracodorsal nerves ) are preserved. The latter two structures are particularly vulnerable to injury when dissecting the tissue between them ( the internerve tissue). PATIENTS AND METHODS: This study evaluates the necessity of dissecting the internerve tissue during axillary dissection in breast cancer surgery by reviewing the lymph node yield and metastasis rate in this tissue. This is a prospective non-randomized study, conducted on 50 female patients, who underwent axillary lymphadenectomy for breast cancer. The internerve tissue was excised separately after a routine axillary dissection. RESULTS: Twenty eight ( 56% ) of the 50 internerve specimens contained lymph nodes; the internerve nodes were positive for carcinoma in 5 patients ( 10%). In those 5 patients, metastasis was also found in some other axillary lymph nodes. There was no incidence of isolated metastasis in the internerve tissue nodes in absence of metastatic disease to other lymph nodes in the axilla. CONCLUSIONS: There is a significant incidence of lymph nodes ( 56% ) and axillary node metastases ( 10% ) in the tissue lying between the long thoracic and thoracodorsal nerves. Therefore, meticulous dissection and excision of this internerve tissue is strongly recommended in order to optimize decision making regarding adjuvant treatment and outcome in women with operable breast cancer. Key Words:Breast cancer - Axillary lymphadenectomy - Internerve tissue.