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Femara lowers IGF-1 as much as Arimidex?
- Thread starter pumped21
- Start date
Thanks for the great info as well.This paper came out very recently. It is significant in that as far as I know it is the first independent corroboration of the earlier reports showing that letrozole does not lower IGF-1 in women being treated for cancer.
Cancer Epidemiol Biomarkers Prev 2002 Jul;11(7):614-21
Effects of the aromatase inhibitor letrozole on normal breast epithelial cell proliferation and metabolic indices in postmenopausal women: a pilot study for breast cancer prevention.
Harper-Wynne C, Ross G, Sacks N, Salter J, Nasiri N, Iqbal J, A'Hern R, Dowsett M.
Academic Departments of Biochemistry [C. H-W., J. S., J. I., M. D.], Radiotherapy [G. R.], Surgery [N. S.], Histopathology [N. N.], and Statistics [R. A.], Royal Marsden Hospital, London SW3 6JJ, United Kingdom.
The aromatase enzyme converts androgens to estrogens and is the therapeutic target for aromatase inhibitors in postmenopausal patients with estrogen receptor-positive metastatic breast cancer. Third-generation inhibitors such as letrozole are being considered as potential prophylactic agents for breast cancer. The rationale for their preventive application would be aided by knowledge of their effects on the normal breast and on other estrogen-dependent processes such as bone and lipid metabolism. Thirty-two women without active breast disease were recruited to 3-month treatment with letrozole (2.5 mg/day). Core-cut biopsies from the breast and blood samples were collected before and at the end of treatment. Plasma estradiol levels were markedly suppressed in all but two patients, who were excluded from the efficacy assessment. There was no significant change in the proliferation marker Ki67 (mean change, -23%; 95% confidence interval, -50% to +23%) or estrogen receptor in breast epithelial cells with treatment. Similarly, there were no significant changes in plasma levels of insulin-like growth factor I or lipid profiles. However, there was a significant increase (25%) in the levels of the bone resorption marker C-telopeptide crosslinks (CTx). We conclude that any prophylactic effect of letrozole is not likely to be dependent on antiproliferative effects on normal breast. Studies in healthy patients will need to recognize the potential for enhanced bone resorption.
Cancer Epidemiol Biomarkers Prev 2002 Jul;11(7):614-21
Effects of the aromatase inhibitor letrozole on normal breast epithelial cell proliferation and metabolic indices in postmenopausal women: a pilot study for breast cancer prevention.
Harper-Wynne C, Ross G, Sacks N, Salter J, Nasiri N, Iqbal J, A'Hern R, Dowsett M.
Academic Departments of Biochemistry [C. H-W., J. S., J. I., M. D.], Radiotherapy [G. R.], Surgery [N. S.], Histopathology [N. N.], and Statistics [R. A.], Royal Marsden Hospital, London SW3 6JJ, United Kingdom.
The aromatase enzyme converts androgens to estrogens and is the therapeutic target for aromatase inhibitors in postmenopausal patients with estrogen receptor-positive metastatic breast cancer. Third-generation inhibitors such as letrozole are being considered as potential prophylactic agents for breast cancer. The rationale for their preventive application would be aided by knowledge of their effects on the normal breast and on other estrogen-dependent processes such as bone and lipid metabolism. Thirty-two women without active breast disease were recruited to 3-month treatment with letrozole (2.5 mg/day). Core-cut biopsies from the breast and blood samples were collected before and at the end of treatment. Plasma estradiol levels were markedly suppressed in all but two patients, who were excluded from the efficacy assessment. There was no significant change in the proliferation marker Ki67 (mean change, -23%; 95% confidence interval, -50% to +23%) or estrogen receptor in breast epithelial cells with treatment. Similarly, there were no significant changes in plasma levels of insulin-like growth factor I or lipid profiles. However, there was a significant increase (25%) in the levels of the bone resorption marker C-telopeptide crosslinks (CTx). We conclude that any prophylactic effect of letrozole is not likely to be dependent on antiproliferative effects on normal breast. Studies in healthy patients will need to recognize the potential for enhanced bone resorption.
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Golfer18--old
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Warmachine
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arimidex has been shown to RAISE IGF-1, while letrazole does not
Short-term effects of anastrozole treatment on insulin-like growth factor system in postmenopausal advanced breast cancer patients.
Ferrari L, Martinetti A, Zilembo N, Pozzi P, Buzzoni R, La Torre I, Gattinoni L, Catena L, Vitali M, Celio L, Seregni E, Bombardieri E, Bajetta E.
Nuclear Medicine, Istituto Nazionale per lo Studio e la Cura dei Tumori of Milan, Via G. Venezian, 1, 20133 Milan, Italy.
Insulin-like growth factors (IGFs) play a fundamental role in cancer development by acting in both an endocrinal and paracrinal manner, and hormone breast cancer treatments affect the IGF system by modifying circulating growth factor levels. We evaluated total IGF-1, IGF-2, IGF binding protein (IGFBP)-1 and IGFBP-3 in the blood of 34 postmenopausal advanced breast cancer patients (median age 63 years, range 41-85) treated with anastrozole, a non-steroidal structure aromatase inhibitor (NSS-AI). The plasma samples were obtained at baseline, and after 2, 4, 8 and 12 weeks of treatment. The IGFs were quantitated by means of sensitive radioimmunoassays (RIAs). IGF-1 significantly increased during anastrozole treatment (baseline versus 12 weeks, P=0.031), IGF-2 showed a trend towards an increase, and IGFBP-1 constantly but not significantly decreased; IGFBP-3 did not seem to be affected at all. The anastrozole-induced changes in IGFs and IGFBP-1 appeared to be different in the patients receiving a clinical benefit from those observed in non-responders. We have previously shown that letrozole (a different type of NSS-AI) modifies blood IGF-1 levels, and the results of this study of the biological effects of anastrozole on the components of the IGF system confirm our previous observations.
PMID: 11983488 [PubMed - indexed for MEDLINE]
Again:
). IGF-1 significantly increased during anastrozole treatment (baseline versus 12 weeks, P=0.031), IGF-2 showed a trend towards an increase
Short-term effects of anastrozole treatment on insulin-like growth factor system in postmenopausal advanced breast cancer patients.
Ferrari L, Martinetti A, Zilembo N, Pozzi P, Buzzoni R, La Torre I, Gattinoni L, Catena L, Vitali M, Celio L, Seregni E, Bombardieri E, Bajetta E.
Nuclear Medicine, Istituto Nazionale per lo Studio e la Cura dei Tumori of Milan, Via G. Venezian, 1, 20133 Milan, Italy.
Insulin-like growth factors (IGFs) play a fundamental role in cancer development by acting in both an endocrinal and paracrinal manner, and hormone breast cancer treatments affect the IGF system by modifying circulating growth factor levels. We evaluated total IGF-1, IGF-2, IGF binding protein (IGFBP)-1 and IGFBP-3 in the blood of 34 postmenopausal advanced breast cancer patients (median age 63 years, range 41-85) treated with anastrozole, a non-steroidal structure aromatase inhibitor (NSS-AI). The plasma samples were obtained at baseline, and after 2, 4, 8 and 12 weeks of treatment. The IGFs were quantitated by means of sensitive radioimmunoassays (RIAs). IGF-1 significantly increased during anastrozole treatment (baseline versus 12 weeks, P=0.031), IGF-2 showed a trend towards an increase, and IGFBP-1 constantly but not significantly decreased; IGFBP-3 did not seem to be affected at all. The anastrozole-induced changes in IGFs and IGFBP-1 appeared to be different in the patients receiving a clinical benefit from those observed in non-responders. We have previously shown that letrozole (a different type of NSS-AI) modifies blood IGF-1 levels, and the results of this study of the biological effects of anastrozole on the components of the IGF system confirm our previous observations.
PMID: 11983488 [PubMed - indexed for MEDLINE]
Again:
). IGF-1 significantly increased during anastrozole treatment (baseline versus 12 weeks, P=0.031), IGF-2 showed a trend towards an increase
norr
New member
I agree about the lipid profile thing being more important than all those speculations about IGF-1 levels. Here's a link to a nurse's PDR showing that Anastrozole increases: GGT, AST, ALT, alkaline phosphatase, total cholesterol, LDL cholesterol while Letrozole only: AST, ALT, GGT
http://www.nursespdr.com/members/database/ndrhtml/
http://www.nursespdr.com/members/database/ndrhtml/
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