Therapeutic Strategies Using the Aromatase Inhibitor Letrozole and Tamoxifen in a Breast Cancer Model
| العنوان: | Therapeutic Strategies Using the Aromatase Inhibitor Letrozole and Tamoxifen in a Breast Cancer Model |
|---|---|
| المؤلفون: | Nicol Macpherson, Danijela Jelovac, Olga Goloubeva, Brian J. Long, Apinya Thiantanawat, Venkatesh D. Handratta, Joseph Ragaz, Angela Brodie |
| المصدر: | JNCI Journal of the National Cancer Institute. 96:456-465 |
| بيانات النشر: | Oxford University Press (OUP), 2004. |
| سنة النشر: | 2004 |
| مصطلحات موضوعية: | Oncology, Cancer Research, medicine.medical_specialty, Neoplasms, Hormone-Dependent, medicine.drug_class, Ovariectomy, Transplantation, Heterologous, Mice, Nude, Anastrozole, Breast Neoplasms, Pharmacology, Drug Administration Schedule, Mice, Breast cancer, Estrogen Receptor Modulators, Internal medicine, Antineoplastic Combined Chemotherapy Protocols, Nitriles, medicine, Animals, Humans, Enzyme Inhibitors, Aromatase, skin and connective tissue diseases, Mice, Inbred BALB C, Aromatase inhibitor, biology, Fulvestrant, Aromatase Inhibitors, business.industry, Letrozole, Uterus, Organ Size, Triazoles, Antiestrogen, medicine.disease, Disease Models, Animal, Tamoxifen, Disease Progression, Linear Models, biology.protein, Female, business, hormones, hormone substitutes, and hormone antagonists, medicine.drug |
| الوصف: | Background: The antiestrogen tamoxifen has potent activity against estrogen receptor–positive breast cancer, but two nonsteroidal aromatase inhibitors, letrozole and anastrozole, show considerable advantages over tamoxifen with respect to patient survival and tolerability. To determine the optimal way to use letrozole and tamoxifen, we studied their effects on a breast tumor xenograft model, MCF-7Ca, that is responsive to both antiestrogens and aromatase inhibitors. Methods: Female ovariectomized BALB/c athymic nude mice carrying xenograft tumors were treated daily subcutaneously with one of the following fi rst-line therapies for varying durations: no drug (control), tamoxifen (100 g/day) alone, letrozole (10 g/ day) alone, both drugs at the same time, or alternating 4-week courses of each drug (beginning with a course of tamoxifen or beginning with a course of letrozole). Tumor volumes and weights were estimated using linear mixedeffects models. The time to tumor doubling was calculated, and tumor weights in the treatment groups were compared, with adjustments for multiple comparisons being made with either Tukey’s or Dunnett’s procedure. Second-line therapies (with tamoxifen, letrozole, or fulvestrant) were initiated when tumors doubled in size under fi rst-line therapies. All statistical tests were two-sided. Results: The times for doubling of tumor volume were as follows: control, 3– 4 weeks; tamoxifen alone, 16 weeks; tamoxifen alternating with letrozole, 17–18 weeks; tamoxifen plus letrozole, 18 weeks; letrozole alternating with tamoxifen, 22 weeks; letrozole alone, 34 weeks. First-line treatment with letrozole was superior to treatment with tamoxifen alone or with the two drugs combined (at week 16, both P |
| تدمد: | 1460-2105 0027-8874 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f9c44fc5a0a1eafee2346a9d40c0e718Test https://doi.org/10.1093/jnci/djh076Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....f9c44fc5a0a1eafee2346a9d40c0e718 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14602105 00278874 |
|---|