法乐通治疗晚期乳腺癌临床总结

目的 考察法乐通治疗晚期绝经后乳腺癌的放疗及其不良反应。方法：法乐通一线治疗每日一次６０ｍｇ口服,二线治疗每日一次１２０ｍｇ口服。结果：共６０例,有效率１８．３％,一线治疗１８例,有效率３３．３％,二线治疗４２例,有效率１１．９％,淋巴结和骨转移疗效较好,肝转移,肺转移及胸壁转移也有一定疗效。一线治疗较二线治疗,未用内分泌治疗较曾用内分泌治疗,绝经时间长（≥１０年）较经时间短（〈１０年）以及疗后无     

Endometrial K-ras mutations in postmenopausal breast cancer patients treated with adjuvant tamoxifen or toremifene

Purpose Long-term use of tamoxifen is associated with a two- to threefold increased risk of endometrial cancer in postmenopausal women. Toremifene is another triphenylethylene antiestrogen, which is as effective as tamoxifen in postmenopausal breast cancer. Thus far, its use has not been associated with an increased risk of endometrial cancer. K-ras codon 12 mutations seem to be important in endometrial carcinogenesis, and these mutations have been found in endometrial samples of patients on tamoxifen. The present study was undertaken to investigate if there is any difference in the frequency of endometrial K-ras mutations among patients treated with tamoxifen or toremifene.Methods Endometrial samples were taken from 23 postmenopausal breast cancer patients (tamoxifen, n=11; toremifene, n=12) before and after 36 months of treatment. DNA was isolated from formalin-fixed paraffin-embedded samples using a routine proteinase K digestion protocol. K-ras mutations in codon 12 were screened using real-time PCR and melting curve analysis in LightCycler equipment. Wild-type PNA oligomer was used to increase the sensitivity of the assay.Results All baseline samples contained wild-type K-ras, while 10/23 (43%) of the follow-up samples carried a codon 12 mutation. Mutations were identified in 3 of the 11 in the tamoxifen group and in 7 of the 12 in the toremifene group. Seven were transitions (GA), and three were transversions (two GT, one GC). One of the mutations in the toremifene group was associated with a polypoid endometrium. All the other mutations were found in an atrophic (n=6) or proliferative (n=3) endometrium.Conclusions Both tamoxifen and toremifene induce endometrial K-ras codon 12 mutations. The significance of this finding to endometrial carcinogenesis remains to be elucidated.     

Endometrial mullerian adenosarcoma after toremifene treatment in breast cancer patients: a case report

Toremifene is an anti-estrogen which has been shown to be effective in the treatment of breast cancer, and is thought to be a less uterotrophic agent than tamoxifen. The risk assessment concerning endometrial cancer has been inconclusive because of its rare use up to the mid-1990s. We report a case of an adenosarcoma, which is a very rare type of uterine malignancy, after toremifene treatment for 5 years in a breast cancer patient. After 1 year of toremifene use, the patient had a benign Mullerian adenofibroma. After an additional 4 years of toremifene treatment, the endometrial polypoid lesion was transformed into a Mullerian adenosarcoma. Although toremifene is a promising anti-estrogenic agent in the treatment of breast cancer patients, clinicians should not neglect the possibility of a uterine malignancy.     

The role of hormonal therapy in breast cancer

This review reassesses the role of hormonal therapy in breast cancer specifically the sequential or concurrent use of endocrine therapy and the combined use of chemotherapy with endocrine therapy. In advanced disease the sequential use of hormone therapies is generally recommended rather than the combined use of various hormonal agents, though combination hormonal therapy offers advantages in certain subsets of patients. The efficacy of combined chemo-endocrine therapy is questionable. Chemotherapy with estrogenic recruitment is an attractive but still experimental concept. However, in an adjuvant setting there is evidence that combined chemo-endocrine therapy causes a significant increase in disease-free and/or overall survival, particularly in postmenopausal patients with estrogen receptor (Expositive tumors. While hormonal treatment strategies have clearly benefitted from randomized studies, data regarding optimal endocrine therapy are still insufficient.     

Association of serum phospholipid fatty acids with breast cancer risk among postmenopausal cigarette smokers

Objective  To examine the association between breast cancer risk and the fatty acid composition of phospholipids in prediagnostic serum samples. Methods  We analyzed the fatty acid composition in 130 incident postmenopausal breast cancer cases and 257 matched controls nested within the β-Carotene and Retinol Efficacy Trial Cohort. The fatty acid composition was measured by gas chromatography. Multivariate-adjusted odds ratios and corresponding 95% confidence intervals for the risk of breast cancer were estimated using logistic regression. Stratified analysis was conducted by smoking status. Results  There were no associations with breast cancer risk for total saturated, monounsaturated, n-3, n-6, or trans fatty acids among all women. For individual fatty acids, we observed an inverse association with the trans linoleic acid, 18:2n6tt (p _trend = 0.0002). Among current smokers, long-chain saturated fatty acids (22:0 and 24:0) and total 16:1 trans fatty acids were positively associated with the risk of breast cancer, whereas these fatty acids showed no association among former smokers. Conclusion  Overall, we observed no significant association between serum phospholipid fatty acids and breast cancer risk, except for the trans linoleic acid isomer 18:2n6tt, which was unexpected. Our finding of a positive association of long-chain saturated fatty acids (22:0 and 24:0) and total 16:1 trans fatty acids with the risk of breast cancer only in current smokers may suggest an effect modification by smoking status. Our findings need to be replicated in future epidemiologic studies.     

氟维司群治疗绝经后转移性乳腺癌患者的疗效及安全性

背景与目的:氟维司群是一种雌激素受体(estrogen receptor,ER)拮抗剂,该药对既往经内分泌治疗后进展的转移性乳腺癌(MBC)仍有较好疗效。本研究观察氟维司群对他莫昔芬(TAM)治疗后进展的绝经后MBC患者的疗效及安全性。方法:氟维司群250 mg,肌肉注射,每月1次,直至肿瘤进展。主要研究终点为至疾病进展时间(TTP),次要终点为客观有效率(ORR),缓解期(DoR)及临床获益率(CBR)。结果:本组21例患者中位TTP为4个月,ORR为19.0%,CBR为33.3%,其中部分缓解(PR)4例,疾病稳定(SD)超过24周3例,有效患者的中位DoR为8个月,1年生存率为42.8%,2年生存率为23.8%,中位总生存时间(OS)为11个月。氟维司群的疗效与患者ER状态、术后无病生存期(DFS)及是否为初始治疗等因素相关:ER高表达者较ER低表达者更易从氟维司群治疗中获益(CBR分别为100%和17.6%,P=0.002),DFS超过2年者的CBR明显较DFS小于2年者高(分别为46.7%和0,P=0.040),氟维司群为MBC初始治疗者的CBR较非初始治疗者明显增高(分别为80.0%和18.8%,...     

Endocrine mechanism of action of toremifene at the level of the central nervous system in advanced breast cancer patients

Purpose: To differentiate the antagonistic and agonistic effect of toremifene at the level of the hypothalamus-hypophysis axis a leutinizing hormone-releasing hormone (LHRH) test was performed during a phase II clinical trial. Methods: In 15 postmenopausal patients with advanced breast cancer, follicle-stimulating hormone (FSH) and LH release – induced by an LHRH agonist (Suprefact injection, 0.5 mg s.c.) – was monitored during a 16-week period of toremifene treatment (60 mg/day p.o.). Prolactin, estradiol, and sex hormone-binding globulin (SHBG) levels were also measured. The functional test was carried out prior to toremifene therapy and then 4, 8, 12, and 16 weeks afterward. Results: The drug sensitized the pituitary to the action of the gonadotrophins; the LHRH-induced FSH and LH release showed a considerably increasing tendency during the toremifene therapy. Estradiol levels decreased statistically significantly and SHBG levels showed a statistically significant increase. A decreased level of prolactin is the sign of an antiestrogenic effect of toremifene on the hypophysis and, as a result, provides evidence for a direct influence of toremifene upon the pituitary. An increase in LH and prolactin release in response to the LHRH test was characteristic in the responders. Conclusion: According to the LHRH test, the antagonistic effect of toremifene seems to be more dominant than the concomitantly existing agonistic property. Neither clinical nor endocrinological side effects could be observed at the level of the CNS during a prolonged period of toremifene administration. Received: 13 July 1997 / Accepted: 17 February 1998     

Early switch with aromatase inhibitors as adjuvant hormonal therapy for postmenopausal breast cancer: pooled-analysis of 8794 patients

BACKGROUND: The magnitude of the survival benefit of aromatase inhibitors (AIs) after 2-3 years of tamoxifen as adjuvant hormonal therapy for early breast cancer is still unclear. We performed a literature-based meta-analysis, to look how much advantages adjuvant the "early switch" strategy add over standard tamoxifen for 5 years. METHODS: A pooled analysis of all phase-III trials was accomplished, and event-based relative risk ratios (RR) with 95% confidence interval (CI) were derived. Significant differences in primary outcome (EFS and RFS, event- and relapse-free survival), and secondary outcomes (OS, overall survival, deaths without progression, other cancers and toxicities), were explored. Magnitude outcome measures were absolute benefits and number of patients needed to treat. Heterogeneity test was applied as well. RESULTS: Five trials (8794 patients) were gathered. The risk of any event is reduced with AIs of 23%, with an absolute benefit of 3.8% (RR 0.67, 95% CI 0.59, 0.76). Again, RFS (RR 0.68, 95% CI 0.59, 0.79) or both LRFS and DFRS, were significantly improved with AIs. OS was significantly prolonged with AIs, with an absolute benefit of 1.2% (RR 0.76, 95% CI 0.62, 0.93), without significant heterogeneity. Bone fractures were significantly higher in patients receiving AIs (RR 1.50, 95% CI 1.12, 2.02), and endometrial cancer in patients who continued to receive tamoxifen (RR 0.32, 95% CI 0.13, 0.77), without significant heterogeneity. CONCLUSIONS: The early switch strategy improves survival over standard tamoxifen for 5 years, with a different toxicity profile. The lack of significant heterogeneity in the analysis underscores the homogenous effect across all trials.     

Aromatase inhibitor versus tamoxifen in postmenopausal woman with advanced breast cancer: a literature-based meta-analysis

Clinical trials have reported conflicting results as to whether Aromatase inhibitors (AIs) as first-line hormonal therapy improve outcome over tamoxifen in postmenopausal women with advanced breast cancer. We performed a meta-analysis comparing primary and secondary endpoints of AIs to tamoxifen as first-line hormonal therapy in postmenopausal women with advanced breast cancer. The event-based odds ratio (OR) with 95% confidence interval (95% CI) were derived, and a test of heterogeneity was applied. Six eligible trials (2560 patients) were selected from 488 studies that initially were identified. A significant difference in favoring AIs over tamoxifen was observed in overall response rate (ORR; OR, 1.56; 95% CI, 1.17-2.07; P = .002) and clinical benefit (CB; OR, 1.70; 95% CI, 1.24-2.33; P = .0009).Whereas the trend toward an improved overall survival (OS) rate was not significant (OR, 1.95; 95% CI, 0.88-4.30; P = .10).Toxicities did not differ significantly except vaginal bleeding (OR, 0.30; 95% CI, 0.16-0.56; P = .0002) and thromboembolic event (OR, 0.47; 95% CI, 0.28-0.77; P = .003). AIs appeared to be effective and feasible compared with tamoxifen as first-line hormonal therapy in postmenopausal women with advanced breast cancer. Further prospective, randomized, controlled trials will be necessary.     

托瑞米芬逆转乳腺癌耐药蛋白介导的多药耐药机制

目的 探讨托瑞米芬逆转乳腺癌耐药蛋白(BCRP)介导的多药耐药机制。方法 通过基因扩增,构建分别由BCRP启动子和巨细胞病毒(CMV)启动子启动表达BCRP的重组质粒pcDNA3-Promoter-BCRP和作为对照的质粒pcDNA3-CMV-BCRP,将其分别转染雌激素受体α（ERα）阳性的MCF-7和ERα阴性的MDA-MB-231乳腺癌细胞系,建立由BCRP启动子和CMV启动子启动表达BCRP的4种耐药细胞系MCF-7/Promoter-BCRP、MCF-7/CMV-BCRP、MDA-MB-231/PromoterBCRP和MDA-MB-231/CMV-BCRP。在耐药细胞培养基中加入托瑞米芬,通过逆转录聚合酶链反应(RT-PCR)、Western blot、外排实验以及细胞毒性实验观察托瑞米芬对不同细胞系的耐药逆转效果。结果与空白对照组（未加药物）相比,托瑞米芬以剂量依赖方式抑制BCRP mRNA的表达,0.1、1和10 μmol/L托瑞米芬处理组MCF-7/Promoter-BCRP细胞中BCRP mRNA的表达水平分别下调29.5％(P＜0.05)、68.1％ (P＜0.01)和97.4％(P＜0.01);MCF-7/Promoter-BCRP细胞经托瑞米芬和17β-雌二醇联合处理后,细胞中BCRP mRNA的相对表达水平为64.2％±1.3％,明显高于托瑞米芬单独处理组(3.8％±0.2％,P＜0.01)。托瑞米芬对各组细胞系中BCRP蛋白表达的调控作用与mRNA相似。经托瑞米芬处理后,MCF-7/Promoter-BCRP细胞内米托蒽醌的荧光强度显著增强,外排米托蒽醌的能力降低了 47.3％ (P ＜0.05);经托瑞米芬和17β-雌二醇联合处理后,MCF-7/Promoter-BCRP细胞内米托蒽醌的荧光强度明显低于托瑞米芬单独处理组,外排米托蒽醌的能力升高了61.5％。托瑞米芬可有效逆转MCF-7/Promoter-BCRP细胞对米托蒽醌的耐药性。上述作用在MCF-7/CMV-BCRP、MDA-MB-231/Promoter-BCRP和MDA-MB-231/CMV-BCRP细胞中未能体现。结论 托瑞米芬可能通过ERot的介导与BCRP启动子上游调控序列中的ERE结合,负性调节BCRP的表达,抑制BCRP蛋白的功能,在体外有效逆转BCRP介导的多药耐药。     

Prospective assessment of the endometrium in postmenopausal breast cancer patients treated with fulvestrant

This prospective study assessed the endometrial effects of fulvestrant, a pure estrogen-receptor antagonist, in postmenopausal women with breast cancer. This single-center study enrolled postmenopausal patients who had an intact uterus at baseline with progressive metastatic breast cancer on tamoxifen followed by an oral aromatase inhibitor (AI). Fulvestrant (250 mg) was administered every 28 ± 3 days via IM injection. Transvaginal ultrasonography (TVUS) was performed at baseline and after 3 months of therapy. Primary and secondary endpoints were changes from baseline in double endometrial thickness (DET) and uterine volume (UV), respectively. No interventions were performed on any asymptomatic uterine abnormalities that were detected at baseline. In total, 32 women were enrolled. Five patients had no repeat TVUS because of early progression before 3 months, leaving 27 evaluable patients for final analysis. After 3 months therapy, mean DET had significantly decreased by 23.08% (P = 0.010). Mean UV also decreased by 10.88%, although this change was not significant (P = 0.119). After 3 months of therapy, none reported vaginal bleeding, there were no changes noted in most of the uterine pathologies present at baseline and no new uterine abnormalities were detected. We observed that 3 months of fulvestrant treatment resulted in a significant decrease in endometrial growth and a non-significant decrease in UV in postmenopausal women with metastatic breast cancer previously exposed to tamoxifen and AIs. Furthermore, no new uterine pathologies were detected, indicating that fulvestrant behaves as a pure antiestrogen at the uterine level.     

Pharmacokinetic analysis of a combined chemoendocrine treatment with paclitaxel and toremifene for metastatic breast cancer

Background  Multidrug resistance protein could be a target for improving the efficacy of paclitaxel (PXL). Toremifene (TOR) may moderate P-gp-related drug resistance in vitro. Some P-gp moderators may change the pharmacokinetic parameters of PXL in vivo. A pharmacokinetic (PK) study in metastatic breast cancer patients (MBC) was conducted to determine the safety and efficacy of PXL and TOR. Method and patients  Fifteen patients received 80 mg/m² PXL (i.v.) weekly and 120 mg/body TOR (p.o.) daily. For the pharmacokinetic study, PXL was administered on days 1, 8, 15, 32, and 39; TOR was given from day 18 to the end of study. On days 1, 8, 15, 18, 32, and 39, blood samples were collected from the patients who received either PXL alone or PXL + TOR, and these were analyzed by high-performance liquid chromatography. Results  Among the 15 patients enrolled in the study, one showed a partial response, and eight had a stable disease. TOR caused no specific adverse events that were greater than grade 3, and its toxicity profile in combination with PXL was similar to that of PXL monotherapy. The PK profile of PXL was similar with or without TOR. The PK parameters of PXL indicated no inter- or intra-patient variability in previously treated patients with MBC. No increased PXL toxicity was observed. Conclusion  The PK profile of combined PXL and TOR was similar to that of PXL monotherapy. The addition of TOR to PXL in previously treated patients with MBC appears safe.     

Competing risks of death in younger and older postmenopausal breast cancer patients

AIM: To show a new paradigm of simultaneously testing whether breast cancer therapies impact other causes of death.METHODS: MA.14 allocated 667 postmenopausal women to 5 years of tamoxifen 20 mg/daily ± 2 years of octreotide 90 mg, given by depot intramuscular injections monthly. Event-free survival was the primary endpoint of MA.14; at median 7.9 years, the tamoxifen+octreotide and tamoxifen arms had similar event-free survival (P = 0.62). Overall survival was a secondary endpoint, and the two trial arms also had similar overall survival (P = 0.86). We used the median 9.8 years follow-up to examine by intention-to-treat, the multivariate time-to-breast cancer-specific (BrCa) and other cause (OC) mortality with log-normal survival analysis adjusted by treatment and stratification factors. We tested whether baseline factors including Insulin-like growth factor 1 (IGF1), IGF binding protein-3, C-peptide, body mass index, and 25-hydroxy vitamin D were associated with (1) all cause mortality, and if so and (2) cause-specific mortality. We also fit step-wise forward cause-specific adjusted models.RESULTS: The analyses were performed on 329 patients allocated tamoxifen and 329 allocated tamoxifen+octreotide. The median age of MA.14 patients was 60.1 years: 447 (82%) < 70 years and 120 (18%) ≥ 70 years. There were 170 deaths: 106 (62.3%) BrCa; 55 (32.4%) OC, of which 24 were other malignancies, 31 other causes of death; 9 (5.3%) patients with unknown cause of death were excluded from competing risk assessments. BrCa and OC deaths were not significantly different by treatment arm (P = 0.40): tamoxifen patients experienced 50 BrCa and 32 OC deaths, while tamoxifen + octreotide patients experienced 56 BrCa and 23 OC deaths. Proportionately more deaths (P = 0.004) were from BrCa for patients < 70 years, where 70% of deaths were due to BrCa, compared to 54% for those ≥ 70 years of age. The proportion of deaths from OC increased with increasing body mass index (BMI) (P = 0.02). Higher pathologic T and N were associated with more BrCa deaths (P < 0.0001 and 0.002, respectively). The cumulative hazard plot for BrCa and OC mortality indicated the concurrent accrual of both types of death throughout follow-up, that is the existence of competing risks of mortality. MA.14 therapy did not impact mortality (P = 0.77). Three baseline patient and tumor characteristics were differentially associated with cause of death: older patients experienced more OC (P = 0.01) mortality; patients with T1 tumors and hormone receptor positive tumors had less BrCa mortality (respectively, P = 0.01, P = 0.06). Additionally, step-wise cause-specific models indicated that patients with node negative disease experienced less BrCa mortality (P = 0.002); there was weak evidence that, lower C-peptide (P = 0.08) was associated with less BrCa mortality, while higher BMI (P = 0.01) was associated with worse OC mortality.CONCLUSION: We demonstrate here a new paradigm of simultaneous testing of therapeutics directed at multiple diseases for which postmenopausal women are concurrently at risk. Octreotide LAR did not significantly impact breast cancer or other cause mortality, although different baseline factors influenced type of death.     

Effect of local therapy on locoregional recurrence in postmenopausal women with breast cancer in the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial

Background and purpose

The TEAM trial investigated the efficacy and safety of adjuvant endocrine therapy consisting of either exemestane or the sequence of tamoxifen followed by exemestane in postmenopausal hormone-sensitive breast cancer. The present analyses explored the association between locoregional therapy and recurrence (LRR) in this population.

Material and methods

Between 2001 and 2006, 9779 patients were randomized. Local treatment was breast conserving surgery plus radiotherapy (BCS + RT), mastectomy without radiotherapy (MST-only), or mastectomy plus radiotherapy (MST + RT). Patients with unknown data on surgery, radiotherapy, tumor or nodal stage (n = 199), and patients treated by lumpectomy without radiotherapy (n = 349) were excluded.

Results

After a median follow-up of 5.2 years, 270 LRRs occurred (2.9%) among 9231 patients. The 5-years actuarial incidence of LRR was 4.2% (95% CI 3.3–4.9%) for MST-only, 3.4% (95% CI 2.4–4.2%) for MST + RT and 1.9% (95% CI 1.5–2.3%) for BCS + RT. After adjustment for prognostic factors, the hazard ratio (HR, reference BCS + RT) for LRR remained significantly higher for MST-only (HR 1.53; 95% CI 1.10–2.11), not for MST + RT (HR 0.78; 95% CI 0.50–1.22).

Conclusion

This explorative analysis showed a higher LRR risk after MST-only than after BCS + RT, even after adjustment for prognostic factors. As this effect was not seen for MST + RT versus BCS + RT, it might be explained by the beneficial effects of radiation treatment.     

氟维司群治疗绝经后激素受体阳性晚期乳腺癌的研究进展

以阻断雌激素作用通路为目的的内分泌治疗是晚期乳腺癌的一线治疗选择之一。氟维司群作为雌激素拮抗剂,可通过阻断并降解雌激素受体起作用。目前,临床上使用氟维司群每月250 mg作为一线内分泌治疗后疾病进展或复发的绝经后激素受体阳性晚期乳腺癌的二线治疗方案。相比之下,氟维司群每月500 mg可获得更好的疗效,且不增加新的安全性问题。目前对于氟维司群的研究更多地集中在一线治疗以及与其他药物联用来治疗晚期乳腺癌。该文对氟维司群在激素受体阳性晚期乳腺癌中的研究进展进行了综述。     

Preclinical and clinical experience with fulvestrant (Faslodex) in postmenopausal women with hormone receptor-positive advanced breast cancer

Fulvestrant (Faslodex) is a new type of estrogen receptor (ER) antagonist that binds, blocks, and degrades the ER, leading to reduced expression of the progesterone receptor (PgR). Unlike the selective ER modulator tamoxifen, fulvestrant is devoid of any known agonist activity. Fulvestrant has a steroidal structure that competitively binds to the ER with an affinity much greater than that of tamoxifen. After binding to fulvestrant, degradation of the ER is accelerated, ultimately resulting in a reduction in cellular ER. Immunohistochemical studies have demonstrated that a single intramuscular injection of fulvestrant results in a dose-dependent decrease in ER and PgR indices and in Ki-67 expression. At the approved 250 mg dose, the decrease in receptor positivity with fulvestrant treatment was greater than that with tamoxifen. Phase III clinical trials have demonstrated the clinical benefit of fulvestrant in the endocrine treatment of breast cancer. Among patients who progressed during adjuvant or first-line endocrine therapy, fulvestrant was at least as effective as anastrozole as second-line treatment for the primary endpoints of objective response and time to progression, and was well tolerated. After a median follow-up of 24.5 months, a combined survival analysis from two Phase III studies has shown that fulvestrant may be considered similar to anastrozole for time to death (27.4 months versus 27.7 months, respectively). For the first-line therapy of advanced breast cancer in postmenopausal women, fulvestrant was shown to be active and well tolerated in a trial that compared fulvestrant 250 mg once monthly and tamoxifen 20 mg once daily. Treatment with fulvestrant has also demonstrated clinical efficacy among patients who progressed following treatment with tamoxifen followed by nonsteroidal aromatase inhibitors. The efficacy of fulvestrant in sequential endocrine therapy and in combination with other agents appears promising and active investigations are ongoing to explore the clinical potential of this novel antiestrogen.     

Toremifene in the treatment of breast cancer

Although more widespread screening and routine adjuvant therapy has improved the outcome for breast cancer patients in recent years, there remains considerable scope for improving the efficacy, safety and tolerability of adjuvant therapy in the early stage disease and the treatment of advanced disease. Toremifene is a selective estrogen receptor modifier (SERM) that has been widely used for decades in hormone receptor positive breast cancer both in early and late stage disease. Its efficacy has been well established in nine prospective randomized phase III trials compared to tamoxifen involving more than 5500 patients, as well as in several large uncontrolled and non-randomized studies. Although most studies show therapeutic equivalence between the two SERMs, some show an advantage for toremifene. Several meta-analyses have also confirmed that the efficacy of toremifene is at least as good as that of tamoxifen. In terms of safety and tolerability toremifene is broadly similar to tamoxifen although there is some evidence that toremifene is less likely to cause uterine neoplasms, serious vascular events and it has a more positive effect on serum lipids than does tamoxifen. Toremifene is therefore effective and safe in the treatment of breast cancer. It provides not only a useful therapeutic alternative to tamoxifen, but may bring specific benefits.     

Endogenous estrogen and postmenopausal breast cancer: a quantitative review

This paper systematically reviews the results from epidemiologic studies investigating the hypothesis that breast cancer risk inpostmenopausal women increases with increasing concentrations of estradiol in blood and with increasing urinary estrogen excretion rates. Data from 29epidemiologic studies of endogenous hormones and postmenopausal breast cancer were used. The ratio of the average estrogen concentration in the women with breast cancer to that in the women without breast cancer (and its 95 percent confidence interval [CI]) was calculated for each study, and the results were summarized by calculating weighted averages of the log ratios. In six prospective studies of serum estradiol concentration, 329 women who subsequently developed breast cancer had, overall, a 15 percent (CI = 6-24percent, P = 0.0003) higher mean concentration of estradiol in their blood than the 1,105 women who remained free of cancer. The results of these prospective studies did not differ significantly from each other(chi-squared for heterogeneity = 8.7; degrees of freedom = 5; P > 0.1).Similar differences in mean estrogen levels were seen in the case-control studies which reported either estradiol concentrations in the blood or urinary estrogen excretion. However, the case-control studies showed significant heterogeneity among their results. The data from the prospective studies strongly suggest that breast cancer risk in postmenopausal women is associated with relatively high concentrations of endogenous estradiol. This revised version was published online in July 2006 with corrections to the Cover Date.     

A randomised study of the effects of letrozole and anastrozole on oestrogen receptor positive breast cancers in postmenopausal women

Introduction Changes in proliferation as measured by Ki67 occur within 14 days of starting treatment with an aromatase inhibitor and these changes have been shown to be predictors of long term outcome. This study aimed to compare changes in proliferation following 14 days of treatment with anastrozole and letrozole. Methods Two hundred and six women with 209 estrogen receptor (ER) positive operable breast cancers (three bilateral) were randomly allocated to receive either 14 days treatment with 2.5 mg of letrozole or 1 mg of anastrozole prior to surgery. Changes in expression of estrogen (ER) and progesterone receptors (PgR) as assessed by ALLRED scores and proliferation as assessed by Ki67 were analysed. The HER2 status of each tumour was also assessed using a combination of the Hercept test and FISH. Results Both letrozole and anastrozole reduced ER expression (ALLRED score) by a mean of 0.32 (0.20–0.44), P < 0.001 and PgR fell by a mean of 2.54 (2.20–2.89) P < 0.0001. Letrozole reduced proliferation from a geometric mean of 6.37% to 0.81%, P < 0.0001 and anastrozole reduced proliferation from 5.81% to 0.77%, P < 0.0001. There was no differences between drugs in the fall in ER, PgR or proliferation. Both letrozole and anastrozole produced significant falls in proliferation in both HER2 positive and HER2 negative cancers, all P < 0.001. Discussion 14 days of both letrozole and anastrozole reduces proliferation, ER and PgR expression. No significant difference between these two drugs was identified. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.