The clinical utility of Tc-99m sestamibi scintimammography in detecting multicentric breast cancer.

The ability to recognize multicentric breast cancer preoperatively would assist in identifying appropriate candidates for breast conservation surgery. Tc-99m scintimammography (SMM) is an adjunct to conventional mammography in identifying selected patients with breast cancer. The purpose of this study is to report the utility of SMM in identifying patients with multicentric breast cancer. Breast cancer patients treated by mastectomy who underwent a preoperative SMM between 1992 and 1999 were identified using the institution's Tumor Registry. The pathology report of each patient was reviewed for multicentric disease defined as an additional focus of cancer within a different quadrant of the breast or greater than 2.5 cm from the dominant tumor mass. Each patient's preoperative SMM was reviewed and compared with the pathologic findings to obtain correlative data. Fifty-eight women treated by mastectomy had preoperative SMM (age range 35-78 years; median 52 years). Pathology revealed infiltrating ductal carcinoma in 49 patients (84.5%), infiltrating lobular carcinoma in five patients (8.6%), ductal carcinoma in situ in three patients (5.1%), and colloid carcinoma in one patient (1.7%). Multicentric disease was present in the specimens of eight patients for a prevalence of 10.3 per cent. SMM was positive for uptake in 36 of 58 patients (sensitivity 62.1%). The sensitivity, specificity, positive predictive value, and negative predictive value of SMM in the detection of multicentric disease were 62.5, 96, 71, and 94 per cent, respectively. Although the overall sensitivity of SMM in the detection of breast cancer is superior to that of conventional mammography and physical examination in identifying multicentric breast cancer it is not an accurate modality for detecting multicentric disease in this study group. However, it may have limited applications in specific cases.

State of the art of minimally invasive breast biopsy: principles and practice.

In the last two decades, the increasing use of screening mammography with the early detection of breast cancer and the newly gained understanding of the biology and changing therapy of breast cancer, emphasizing systemic therapy and minimizing extensive local surgery, has contributed to the increasing development of minimally invasive techniques for the diagnosis of breast lesions. Minimally invasive techniques provide increased patient comfort, excellent cosmetic result and minimal morbidity They are also responsible for decreased costs and better medical care by allowing an informed discussion of breast cancer therapy and planning of surgery with an emphasis on negative margins and the dissection of the sentinel node. Techniques in use include Fine-Needle Aspiration Cytology, Core-Needle biopsy, Vacuum-Assisted Core biopsy (Mammotome) and Large Core biopsy (ABBI, Site-select). We present a balanced, evidence-based approach to the diagnosis of patients with palpable or mammographic abnormalities.

Role of the aryl hydrocarbon receptor nuclear translocator protein in aryl hydrocarbon (dioxin) receptor action.

Immunoprecipitation experiments performed on cytosolic extracts of the mouse hepatoma cell line Hepa-1c1c7 (Hepa-1) confirm that the 9-S, unliganded, cytosolic aryl hydrocarbon (Ah) receptor complex contains the 90-kDa heat shock protein and the Ah receptor protein but reveal that it does not contain the Ah receptor nuclear translocator (ARNT) protein. These experiments confirm that the 6-S liganded form of the receptor identified in nuclear extracts of cells treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contains the Ah receptor protein and ARNT but not the 90-kDa heat shock protein. The 6-S liganded Ah receptor complex activates transcription of the CYP1A1 gene via its binding to upstream xenobiotic-responsive elements (XREs). Treatment of cytosolic extracts of Hepa-1 cells with TCDD in vitro transforms the Ah receptor complex to the XRE-binding state. No such transformation occurs in a C- mutant deficient in ARNT activity. When in vitro synthesized ARNT was added concomitantly with TCDD to C- cytosolic extracts, it associated with the Ah receptor and restored Ah receptor-dependent XRE-binding activity to the extracts. Covalent cross-linking experiments in nuclear extracts of Hepa-1 and human LS180 cells treated with TCDD in vivo demonstrate that both ARNT and the Ah receptor bind directly to the XRE core sequence.