BACKGROUNDBreast cancer has become one of the most common malignant tumors among females over the past several years. Breast carcinogenesis is a continuous process, which is featured by the normal epithelium progressing to premalignant lesions and then to invasive breast cancer (IBC). Targeting premalignant lesions is an effective strategy to prevent breast cancer. The establishment of animal models is critical to study the mechanisms of breast carcinogenesis, which will facilitate research on breast cancer prevention and drug behaviors. In this study, we established a feasible chemically-induced rat model of premalignant breast cancer.

METHODSFollowing the administration of the drugs (carcinogen, estrogen, and progestogen) to Sprague-Dawley (SD) rats, tumors or suspicious tumors were identified by palpation or ultrasound imaging, and were surgically excised for pathological evaluation. A series of four consecutive steps were carried out in order to determine the carcinogen: 7,12-dimethylbenzaanthracene (DMBA) or 1-methyl-1-nitrosourea, the route of carcinogen administration, the administration period of estrogen and progestogen, and the DMBA dosage.

RESULTSStable premalignant lesions can be induced in SD rats on administration of DMBA (15 mg/kg, administered three times) followed by administration of female hormones 5-day cycle.

RESULTSwere confirmed by ultrasound and palpation.

CONCLUSIONUnder the premise of drug dose and cycle, DMBA combined with estrogen and progestogen can be used as a SD rat model for breast premalignant lesions.

9,10-Dimethyl-1,2-benzanthracene ; Animals ; Breast Diseases ; chemically induced ; Disease Models, Animal ; Female ; Mammary Neoplasms, Experimental ; chemically induced ; Rats ; Rats, Sprague-Dawley

OBJECTIVESTo summarize the results of liver transplantation for various end-stage liver diseases at the Sun Yat-Sen University of Medical Sciences (SUMS), define the role of liver transplantation in the treatment of hepatocellular carcinoma and fulminant hepatitis B, and assess the efficiency of lamivudine on preventing HBV recurrence.

METHODSSeventy liver transplants performed at the SUMS between April 1993 and December 2000 were retrospectively analyzed. The main indications for liver transplant were hepatocellular carcinoma (26 cases), liver cirrhosis (21 cases), fulminant hepatitis B (12 cases), sclerosing cholangitis (4 cases) and other terminal liver diseases (7 cases). Lamivudine was used in twelve patients suffering from fulminant hepatitis B. Logistic multivariate regression analysis was applied to determine the risk factors predicting liver transplantation outcomes.

RESULTSFifty-four patients survived for more than one month, and 16 patients died within 30 days after orthotopic liver transplantation (OLT). The overall hospital survival rate was 77.1%. The hospital survival rates in the Child's A and B patients were 87.5% and 83.3%, respectively. Those rates were superior to those of the Child's C patients (P < 0.05). The outcome of patients with small hepatocellular carcinoma (HCC) was superior to that of patients with large HCC. Preoperative APACE III scores, the severity of ascites and serum creatine level had independent influence on outcome. Of the patients with fulminant HBV infection, 9 recipients survived for a follow-up period of 2 - 24 months. Treatment with lamivudine monotherapy was both well tolerated and efficacious in patients with fulminant hepatitis B.

CONCLUSIONSThe results indicate that orthotopic liver transplantation could provide long-term cure and palliation for patients with HCC, and that patient selection is extremely important in predicting outcome. The results support the continued application of liver transplantation as a therapeutic modality for various end-stage liver diseases and that lamivudine is an effective and safe monotherapy in OLT for patients with HBV infection.

Adolescent ; Adult ; Carcinoma, Hepatocellular ; mortality ; surgery ; Child ; Child, Preschool ; China ; Cholangitis, Sclerosing ; mortality ; surgery ; Female ; Follow-Up Studies ; Hepatitis B ; mortality ; surgery ; Humans ; Infant ; Liver ; pathology ; surgery ; Liver Cirrhosis ; mortality ; surgery ; Liver Neoplasms ; mortality ; surgery ; Liver Transplantation ; Male ; Middle Aged ; Schools, Medical ; Survival Rate ; Treatment Outcome