Krebswissenschaft und -therapie

Many cancers resist to chemotherapy drugs during treatment and it have been proposed various mechanisms in connection with drug resistance. High expression of ATP-dependent membrane proteins as a family of ATP binding cassette (ABC) are one of the main reasons for drug resistance so that P-glycoprotein (a member of this family) plays an important role in drug resistance. ATP-binding cassette (ABC) transporters are an example of ATP-dependent pumps. ABC transporters are ubiquitous membrane-bound proteins, present in all prokaryotes, as well as plants, fungi, yeast and animals. These pumps can move substrates in (influx) or out (efflux) of cells. In mammals, ABC transporters are expressed predominantly in the liver, intestine, blood-brain barrier, blood-testis barrier, placenta and kidney. In addition, multidrug resistance associated protein as other membrane of this family is involved in drug resistance. These proteins have property of endogenous substrates transferring. Over-expression of these proteins in cancer cells is most important obstacle to treat cancer. However, drug resistance can occur through other ways such as anti-cancer drugs associated with metabolism purines and pyrimidines or microtubules dysfunction. In this review, mechanisms of drug resistance were described.

Ovarian sex cord-stromal tumors are a group of rare neoplasms, considered to be low-grade malignant tumors. The Sertoli-Leydig cell tumors subgroup occur mostly in young patients and reveals itself with virilization symptoms. Here we report a rare case of a voluminous well differentiated tumor in a 75-year-old patient with no sign of secretory effects. The radical treatment was impossible, and a palliative chemotherapy was indicated.

Unlike genetic mutations, epigenetic disruptions are reversible therefore, it can be a promising idea to treat cancer. This strategy can be a new view in order to management and treatment cancer however, understanding of this idea has dire require performing further studies. In addition, researcher should be considering that this idea has to not obvious side effect and it leaded not to prominent damage. In this study, we review effect of cancer treatment based on epigenetic strategy. Finally, we found the promising effect of this idea while other aspects of a useful therapy have to perform in further studies.

Purpose: The aim of our study is to evaluate the outcome and prognostic factors of triple negative breast cancers in our own experience and we give a critical analysis and an overview of the current prognostic from other institutions.
Materials and methods: One hundred and forty-two patients were evaluated who presented to National Institute of Oncology of Rabat with triple negative breast cancers between January 2010 and December 2010. They were retrospectively analyzed. All patients had invasive breast carcinoma and distribution of stage was 19%, 49.3%, 11.2% and 20.5% for T1, T2, T3 and T4, respectively. Treatment consisted in a mastectomy or conservative surgery with lymphadenectomy, chemotherapy and adjuvant radiotherapy. Overall survival (OS) and relapse-free survival (DFS) were calculated using Kaplan Meier method.
Results: Median age was 48 years (range: 27-86 years). Postmenopausal women presented 47.2% of cases. With a median follow-up of 24.5 months (10-60 months), the rate of local control was 59.9%. We found 18 (12.7%) local relapses, 26 (18.3%) distant relapses. At 5 years, Overall survival(OS), Relapse free survival (RFS) were 61.7% and 53.2% respectively.
Conclusion: Our results emphasize that triple negative breast cancers have a worse prognosis and tend to relapse early which is consistent with other studies.