We examined how ionizing radiation (IR) delivered under either severe hypoxia (< 0.1% O 2 ) or normoxia affects the expression of hypoxia inducible factor 1␣ (HIF-1␣) and the angiogenic factors vascular endothelial growth factor (VEGF) and angiopoietins 1, 2 and 4 in U87 human glioblastoma cells. IR was delivered as single doses of 0, 2, 5, 10 and 20 Gy after 6-hr hypoxic incubation and in normoxic controls. Irradiation at any dose did not affect the cellular protein levels of any of the angiopoietins, whereas hypoxia led to increasing levels of both angiopoietin-4 and angiopoietin-2. Levels of angiopoietin-1 protein were unaltered throughout the observation period. A dose-dependent increase in levels of secreted VEGF in the medium occurred after IR at doses from 5-20 Gy. In hypoxic cells, 20 Gy IR induced an additional significant increase in VEGF relative to nonirradiated hypoxic control cells with elevated baseline VEGF levels induced by hypoxia. HIF-1␣ and glucose transporter-1 (Glut-1) were not correspondingly upregulated by IR. Blocking HIF-1␣ by antisense treatment induced a reduced baseline VEGF at normoxia, while the relative upregulation of VEGF by IR was unaffected. These data provide evidence that VEGF is upregulated by IR by mechanisms independent of HIF-1 transactivation.
Toremifene (TOR) is a triphenylethylene derivative related to tamoxifen (TAM). TOR has antitumor activity, not dependent on estrogen receptors, and responses with TOR have been observed in patients with progressive disease during TAM-treatment. To elucidate possible cross-resistance between these two antiestrogens, we compared their anti-tumor activity in a randomized, double-blind, cross-over study. 66 postmenopausal women with advanced estrogen receptor positive or unknown breast cancer and a median age of 63 years (range 38-82) were included. Patients were randomized to TAM 40 mg/day or TOR 240 mg/day. Treatment continued until progressive disease, when cross-over to the alternative treatment was done. The response rate with first line TOR was 29% (95% confidence limits 10-41%) and with TAM 42% (95% confidence limits 25-61%). Response rates and response durations, survival and toxicity were not significantly different between the two treatments. 44 patients progressing on first line TAM or TOR were evaluable for second line TOR or TAM treatment. As no responses were observed, the possibility of over-looking a response rate of 20% or more is less than 1%. In conclusion, this study strongly indicates that TOR and TAM are clinically cross-resistant in patients with advanced breast cancer.
PT clearly benefitted the patients studied, except for IC disease where differences between PT and XT were modest, and comparative PT and XT treatment planning is warranted prior to referral.
The objective of this prospective study was to compare the sensitivities and the specificities of combined 2-(F) fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (PET/CT), abdominal/transvaginal ultrasound (US), and CT for diagnosing recurrent ovarian cancer (OC) and to evaluate the influence of PET/CT on referral of patients with solitary recurrence to secondary cytoreductive surgery. From April 2005 to November 2007, 60 patients were consecutively included to PET/CT 68 times. The inclusion criteria were remission of 3 months or longer and recurrent OC suspected from physical examination, US, or increasing cancer antigen 125 (CA125) level (>50 U/mL or >15% above baseline level). Recurrent OC was diagnosed 58 times in 52 patients. The sensitivities of US, CT, and PET/CT for diagnosing recurrence were 66% (P = 0.003), 81% (P = 0.0001), and 97% (P < 0.0001), respectively. The specificity of US, CT, and PET/CT for diagnosing recurrence was 90%. Positron emission tomography/CT diagnosed recurrence in 19 (66%) of 29 patients without recurrence according to US and in 10 (50%) of 20 patients without recurrence after CT. Multiple recurrent tumors were found using PET/CT in 27 (69%) of 39 patients with solitary tumors on US and in 8 (42%) of 19 patients with solitary tumors on CT. We conclude that the diagnostic value of PET/CT for detecting recurrent OC was higher than those of US and CT and that PET/CT more accurately identified patients with solitary recurrence. However, prospective clinical trials are needed to specify the characteristics of patients most likely to undergo complete secondary surgery and to further clarify the role of PET/CT in selecting patients for secondary surgery.
Topotecan at a dose of 1.0 mg/m(2) has similar efficacy based on response rate and lower toxicity compared with the approved schedule of 1.5 mg/m(2) for 5 days every 3 weeks in second-line treatment for patients with platinum-resistant and paclitaxel-resistant epithelial ovarian carcinoma. However, a comparison of different topotecan doses and schedules preferably should be made in a randomized setting in well-characterized populations with regard to established prognostic factors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.