Cancer science
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Comparative Study
Genetic and environmental predictors, endogenous hormones and growth factors, and risk of estrogen receptor-positive breast cancer in Japanese women.
The incidence of breast cancer in Japanese women has doubled in all age groups over the past two decades. We have recently shown that this marked increase is mostly due to an increase in the estrogen receptor (ER)-positive subtype. It is necessary to establish risk factors capable of predicting the risk of ER-positive breast cancer that will enable the efficient selection of candidates for preventive therapy. ⋯ In postmenopausal women, one SNP (TP53-rs1042522), age, body mass index, age at menopause, serum levels of testosterone, and IGF1 were identified as risk predictors. Risk factors may differ between women of different menopausal status, and inclusion of common genetic variants and serum hormone measurements as well as environmental factors might improve risk assessment models. Further validation studies will clarify appropriate risk groups for preventive therapy.
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The past decade has seen a dramatic increase in stem cell research that focuses on glioma stem cells (GSC) and their mechanisms of action, revealing multiple potential targets for primary malignant brain tumors. Herein, we present a novel framework for considering GSC targets based on direct and indirect strategies. Direct strategies target GSC molecular pathways to overcome their resistance to radiation and chemotherapy, block their function or induce their differentiation. ⋯ Progress made on GSC targets is reviewed in detail and specific pathways are identified in context of the proposed framework. The potential barriers for translation to the clinical setting are also discussed. Overall, targeting GSC provides an unprecedented opportunity for revolutionary approaches to treat high-grade gliomas that continue to have a poor patient prognosis.
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Dasatinib is a potent oral inhibitor of tyrosine kinases including the SRC family kinases, which are activated in tumors, and implicated in invasion and bone metastasis. This phase I dose-escalation study assessed safety, tolerability, maximum tolerated dose (MTD), antitumor activity, pharmacokinetics and pharmacodynamics in Japanese patients with refractory, advanced solid tumors. Dasatinib was administered once daily at 100, 150 and 200 mg/day. ⋯ Bone resorption markers, NTx and TRACP-5b, showed a decrease of 46.3% and 22.2%, respectively. No objective responses were observed, but three patients had stable disease that lasted for over 6 months. In this study population, the safety profile of dasatinib was generally acceptable and 150 mg of dasatinib administered once daily was determined to be the MTD.
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Patients with estrogen receptor (ER)-positive breast cancers have a better prognosis than those with ER-negative breast cancers, but often have low sensitivity to chemotherapy and a limited survival benefit. We have previously shown a combination effect of taxanes and fulvestrant and suggested that this treatment may be useful for ER-positive breast cancer. In this study, we evaluated the effects of combinations of hormone drugs and chemotherapeutic agents. ⋯ Regarding chemoresistant factors, Bcl2 and microtubule-associated protein tau were downregulated by fulvestrant. In vivo, a combination of fulvestrant and docetaxel had a synergistic effect on tumor growth, but fulvestrant and doxorubicin did not show this effect. In conclusion, fulvestrant showed good compatibility with all the evaluated chemotherapeutic agents, and especially with docetaxel, in vitro and in vivo.