CYP2C19*2 predicts substantial tamoxifen benefit in postmenopausal breast cancer patients randomized between adjuvant tamoxifen and no systemic treatment

Estrogen catabolism is a major function of CYP2C19. The effect of CYP2C19 polymorphisms on tamoxifen sensitivity may therefore not only be mediated by a variation in tamoxifen metabolite levels but also by an effect on breast cancer risk and molecular subtype due to variation in lifelong exposure to estrogens. We determined the association between these polymorphisms and tamoxifen sensitivity in the context of a randomized trial, which allows for the discernment of prognosis from prediction. We isolated primary tumor DNA from 535 estrogen receptor-positive, stages I–III, postmenopausal breast cancer patients who had been randomized to tamoxifen (1–3 years) or no adjuvant therapy. Recurrence-free interval improvement with tamoxifen versus control was assessed according to the presence or absence of CYP2C19*2 and CYP2C19*17. Hazard ratios and interaction terms were calculated using multivariate Cox proportional hazard models, stratified for nodal status. Tamoxifen benefit was not significantly affected by CYP2C19*17. Patients with at least one CYP2C19*2 allele derived significantly more benefit from tamoxifen (HR 0.26; p = 0.001) than patients without a CYP2C19*2 allele (HR 0.68; p = 0.18) (p for interaction 0.04). In control patients, CYP2C19*2 was an adverse prognostic factor. In conclusion, breast cancer patients carrying at least one CYP2C19*2 allele have an adverse prognosis in the absence of adjuvant systemic treatment, which can be substantially improved by adjuvant tamoxifen treatment.     

Role of Ki67 in predicting resistance to adjuvant tamoxifen in postmenopausal breast cancer patients

IntroductionBreast cancer (BC) is a major health problem in Egypt and worldwide. Its prognosis depends not only on tumor stage but also on tumor biology.AimTo correlate the expression of Ki67 with the clinical outcomes of early hormone-receptor positive postmenopausal BC patients who are receiving tamoxifen.MethodsThis cohort study included 70 patients. They were followed up for a minimum of 2 years. Ki67 was assessed on paraffin-embedded blocks using immunohistochemistry methods.ResultsThe median Ki67 value was 22.5% (IQR, 10%–50%). Ki67 was significantly higher in patients with HER2 positive tumors compared to HER2 negative tumors. After a median follow up period of 53 months, 22 patients (31%) developed disease recurrence either loco-regional or distant in 5.7% and 30%, respectively. Recurrent patients had significantly higher tumor stage, nodal stage and Ki67 values compared to non-recurrent cases. The 2-, 3- and 5-year overall survival (OS) and disease-free survival (DFS) rates were 100% & 91%, 98% & 84% and 77% & 59%, respectively. DFS was significantly worse with higher TNM stage, lower ER expression and higher Ki67 values. OS was significantly worse in patients with Ki67 values ?30%. Ki67 ?30% was an independent predictor of recurrence, poor DFS and OS.ConclusionHigh Ki67 expression is predictive of poor prognosis and of resistance to adjuvant tamoxifen therapy in postmenopausal BC. We recommend considering Ki67 as one of the risk factors that guide adjuvant treatment decisions.     

Femoral fractures in postmenopausal breast cancer patients treated with adjuvant tamoxifen

Summary The anti-estrogen tamoxifen is the prevalent endocrine treatment in postmenopausal breast cancer patients. However, nothing is known about the long-term effects of the drug on the skeleton as assessed by the occurrence of fractures.We investigated the occurrence of fractures of the femur in patients from a Danish Breast Cancer Cooperative Group (DBCG) trial initiated in 1977 by a linkage of data from the Danish National Registry of Patients with data from the DBCG registry. 1716 postmenopausal women with high-risk breast cancer were randomized to local radiotherapy with or without tamoxifen, 30 mg daily for 1 year.Fifty-one patients in the control group had one femoral fracture and 64 tamoxifen treated patients had one femoral fracture. Eleven patients in the control group had one trochanteric fracture compared to 27 patients in the tamoxifen group (logrank = 5.28, P = 0.022; hazard ratio = 2.12, 95% CL 1.12, 4.01).The results could not be explained by a longer survival in the tamoxifen group nor by bone metastases with pathological fractures.In conclusion, our study suggests that tamoxifen does not seem to offer protection against fractures in old age and may even increase the risk of fractures at particular sites. This hypothesis needs to be disproved or confirmed in other trials.     

Randomized trial of tamoxifen versus tamoxifen plus aminoglutethimide as adjuvant treatment in postmenopausal breast cancer patients with hormone receptor-positive disease: Austrian breast and colorectal cancer study group trial 6.

PURPOSE: To determine whether the addition of aminoglutethimide to tamoxifen is able to improve the outcome in postmenopausal patients with hormone receptor-positive, early-stage breast cancer. PATIENTS AND METHODS: A total of 2,021 postmenopausal women were randomly assigned to receive either tamoxifen for 5 years alone or tamoxifen in combination with aminoglutethimide (500 mg/d) for the first 2 years of treatment. Tamoxifen was administered at 40 mg/d for the first 2 years and at 20 mg/d for 3 years. RESULTS: All randomized and eligible patients were included in the analysis according to the intention-to-treat principle. After a median follow-up of 5.3 years, the 5-year disease-free survival in the aminoglutethimide plus tamoxifen group was 83.6% versus 83.7% in the monotherapy group (P =.89). The corresponding data for overall survival at 5 years were 91.4% and 91.2%, respectively (P =.74). More patients failed to complete combination treatment (13.7%) because of side effects as compared to tamoxifen alone (5.2%; P =.0001). CONCLUSION: Aminoglutethimide given for 2 years in addition to tamoxifen for 5 years does not improve the prognosis of postmenopausal patients with receptor-positive, lymph node-negative or lymph node-positive breast cancer.     

Idoxifene versus tamoxifen: a randomized comparison in postmenopausal patients with metastatic breast cancer.

BACKGROUND: More efficacious and safer hormonal agents are needed for breast cancer treatment and prevention. Idoxifene is a novel selective estrogen receptor modulator (SERM) that, in preclinical models, has greater antiestrogenic but lower estrogenic activity than tamoxifen. PATIENTS AND METHODS: Three hundred and twenty-one postmenopausal patients with hormone receptor-positive or -unknown metastatic breast cancer were randomized to receive either tamoxifen or idoxifene as initial endocrine therapy for advanced disease. Data were analyzed based on intention to treat and all the responses were subject to independent review. RESULTS: At the time of a second planned interim analysis, the trial was stopped for economic considerations, not for reasons related to safety or efficacy. Complete data for the 219 patients included in the second interim analysis are fully available and reported here. Median age was 59.1 years for idoxifene patients and 59.9 years for tamoxifen patients. Complete response (CR) plus partial response (PR) rates were as follows: tamoxifen, 9%; idoxifene, 13% (P = 0.39). Clinical benefit rate [CR + PR + stable disease (SD) >or=6 months] was 34.3% for idoxifene and 38.7% for tamoxifen (P = 0.31). Median time to progression and duration of response were 140 days and 151.5 days, respectively, for tamoxifen compared with 166 days and 218 days for idoxifene. None of these endpoints was significantly different for the two drugs, nor was survival. Adverse events (lethal, serious but not lethal and important but not life threatening) were similar in the two arms. CONCLUSIONS: Idoxifene was both active and well tolerated in postmenopausal women with metastatic breast cancer. Idoxifene had similar efficacy and toxicity to tamoxifen in this randomized comparison.     

Sequential tamoxifen and aminoglutethimide versus tamoxifen alone in the adjuvant treatment of postmenopausal breast cancer patients: results of an Italian cooperative study.

PURPOSE: To determine whether switching patients from tamoxifen to antiaromatase treatment would prevent some of the relapses or deaths that we assume would occur if tamoxifen were continued. PATIENTS AND METHODS: Three hundred eighty postmenopausal breast cancer patients receiving adjuvant tamoxifen treatment for 3 years were randomized to either continue tamoxifen for 2 more years or to switch to low-dose aminoglutethimide (250 mg daily) for 2 years. RESULTS: At a median follow-up of 61 months (range, 5 to 94 months), 59 events occurred in the tamoxifen group, and 55 occurred in the aminoglutethimide group. More treatment failures at distant sites, such as viscera (P =.02), were observed in the tamoxifen group. Although no differences in disease-free survival between the two groups have emerged so far, a significant trend favors aminoglutethimide in overall survival (P =.005) and breast cancer-specific survival (P =.06). Even if more patients in the antiaromatase group complained of drug-related side effects and more of them discontinued treatment (P =.0001), the number of cardiovascular events and, in general, of life-threatening adverse events was higher in the tamoxifen arm. CONCLUSION: Switching patients from tamoxifen to aminoglutethimide treatment resulted in comparable event-free survival, but longer overall survival was achieved in patients who were switched to aminoglutethimide as compared with those who continued to receive tamoxifen. Should these preliminary results be confirmed by larger studies with a similar design, which are now testing the effectiveness of the new, more active, and tolerable aromatase inhibitors, sequencing tamoxifen with an aromatase inhibitor could become a preferable alternative to tamoxifen alone in early breast cancer patients.     

Phase III randomized trial of toremifene versus tamoxifen for Japanese postmenopausal patients with early breast cancer

Background

Toremifene, a selective estrogen receptor modulator, is used as adjuvant therapy for postmenopausal patients with breast cancer in Japan. For Japanese patients, however, only limited data are available on the efficacy and safety profile of toremifene. To establish the long term efficacy and safety of toremifene for Japanese patients, we conducted a prospective, multicenter, randomized phase III trial comparing toremifene and tamoxifen.

Patients and methods

The subjects were postmenopausal Japanese patients who had undergone surgery for node-negative breast cancer. Toremifene or tamoxifen was administered for 2 years. The primary endpoint was demonstration of the non-inferiority of toremifene compared with tamoxifen in respect of 5-year survival. Secondary endpoints were cumulative overall survival, cumulative disease-free survival, effects on lipid profiles, and adverse events.

Results

A total of 253 patients were enrolled. The baseline characteristics of the two treatment groups were well-balanced. Median follow-up was 66.5 months. Five-year survival was similar for toremifene and tamoxifen (97.0 vs. 96.9 %; 90 % confidence interval ?3.9 to 4.1), indicating that toremifene is not inferior to tamoxifen for postmenopausal Japanese patients with early breast cancer. Cumulative overall survival and cumulative disease-free survival were also very similar for toremifene and tamoxifen (97.5 vs. 97.3 %, log-rank test P = 0.9458; 88.4 vs. 90.6 %, log-rank test P = 0.3359, respectively). Adverse events in both groups were similar and mostly mild or moderate. Thus, both are equally effective and well tolerated.

Conclusion

Our results suggest that the efficacy and safety of toremifene and tamoxifen are equivalent for postmenopausal Japanese patients with early breast cancer.     

Long-term follow-up of the randomized Stockholm trial on adjuvant tamoxifen among postmenopausal patients with early stage breast cancer

The Stockholm Breast Cancer Study Group conducted a randomized trial during 1976 through 1990 comparing adjuvant tamoxifen versus control. A total of 2,738 postmenopausal women with invasive, early stage disease were randomised between tamoxifen for 2 or 5 years, or no adjuvant endocrine therapy. Among high-risk patients the treatment was given against a background of either postoperative, locoregional radiation or CMF-type chemotherapy. The median follow up was 18 years (range 11-25 years). There was a statistically significant (p =0.001) interaction between ER status and tamoxifen with no treatment benefit among receptor negatives. PgR-status had little additional predictive value. Among ER-positive patients tamoxifen reduced locoregional recurrences by 48%, contralateral breast cancers by 54%, distant metastases by 28%, and all events by 24% (p <0.001). On the other hand, there was a substantial increase of endometrial cancer associated with tamoxifen. There was no effect of tamoxifen on intercurrent mortality whereas breast cancer deaths were reduced by 31% (p <0.001) and overall mortality by 15% (p =0.01). Tamoxifen produced long-term benefits among estrogen receptor positive patients in terms of breast cancer-related events, but also an increased incidence of endometrial cancer. Despite long-term follow-up we observed no benefit with tamoxifen in terms of cardiovascular mortality.     

Carcinoembryonic antigen cell adhesion molecule 6 predicts breast cancer recurrence following adjuvant tamoxifen.

PURPOSE: Tamoxifen remains therapy of choice for premenopausal estrogen receptor alpha-positive breast cancer. However, resistance and recurrence are serious problems. Our previous work indicated that carcinoembryonic antigen cell adhesion molecule 6 (CEACAM6) was significantly up-regulated in tamoxifen-resistant (TAMr) MCF-7 derivatives. The aim of this study was to determine the functional role of CEACAM6 in endocrine-resistant breast cancer and to retrospectively test whether it was predictive of resistance in a large cohort of breast cancers with long-term follow-up. EXPERIMENTAL DESIGN: siRNA silencing of CEACAM6 was done in TAMr cells and effects on clonogenicity and endocrine sensitivity were determined. CEACAM6 immunohistochemistry was done on a tissue microarray comprising 108 relapsed primary human breast cancers and 243 tamoxifen-sensitive controls. RESULTS: siRNA-mediated silencing of CEACAM6 reduced both clonogenicity and anchorage-dependent and anchorage-independent growth of TAMr cells. Importantly, CEACAM6 silencing restored sensitivity of TAMr cells to 4-hydroxytamoxifen and proliferative response to 17beta-estradiol. Immunohistochemistry showed significantly more CEACAM expression in the relapsed group compared with nonrelapsed controls [35 of 108 (33.3%) and 32 of 243 (13.2%), respectively; odds ratio, 3.16 (95% confidence interval, 1.83-5.47); P < 0.0001]. Additionally, we derived an outcome predictor model based on CEACAM expression that restratified patients in the Nottingham prognostic index intermediate-risk group into either higher-risk or lower-risk group. CONCLUSIONS: Our data support an important role for CEACAM6 in endocrine resistance, which can serve as a powerful predictor of future recurrence.     

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.     

Quality of life and adjuvant tamoxifen treatment in breast cancer patients

About two-thirds of all breast cancer patients are treated with adjuvant hormonal therapy. Side effects of tamoxifen and their effects on physical, emotional and social functioning have been shown to impair the quality of life. Aim of this paper was to evaluate the side effects and level of influence on the physical, emotional and social functioning caused by tamoxifen treatment. For assessment of quality of life an own questionnaire was designed. Between January 2001 and December 2003, 136 women with breast cancer and adjuvant tamoxifen therapy were included in this study. Data of side effects, physical and mental health and patients' self-evaluation identified detrimental effects on patients' quality of life. Prevalence and severity of symptoms were not influenced by length of tamoxifen treatment. Patients were damaged in their constitution in respect to previous chemotherapy and pre-existing diseases; no influence was found by age or histopathological tumour characteristics. Our survey determines that breast cancer patients experience significant influence on quality of life by the negative impact on the physical, emotional and social functioning caused by tamoxifen treatment. Explicit attention to changes in quality of life should be considered as part of the standard care for women receiving adjuvant tamoxifen treatment.     

Oral high-dose medroxyprogesterone acetate versus tamoxifen. A randomized crossover trial in postmenopausal patients with advanced breast cancer

In a prospective randomized multicenter study in previously untreated postmenopausal patients with advanced breast cancer, the response to treatment with oral medroxyprogesterone acetate (MPA) 300 mg three times daily was compared with tamoxifen (TAM) 20 mg twice daily. Of 61 patients treated with MPA, 27 (44%) had a partial or complete remission, 6 showed no change, and 28 had progressive disease. Of 68 patients treated with TAM, 24 (35%) showed a remission, 15 no change, and 29 progression. The difference in response rate is not significant. However, 11 of 25 patients with osseous metastases as predominant site, responded to MPA and 7 of 31 to TAM (P = 0.05). Moreover, in patients older than age 70 years, 13 of 26 responded to MPA and 6 of 31 to TAM (P less than 0.05). Median duration of remission of all patients in the MPA arm was 17 months and in the TAM arm, 23 months (not significant). Median survival was 20 months for MPA and 26 months for TAM (not significant). After cross-over from TAM to MPA 8 of 31 patients responded and after cross-over from MPA to TAM, no response was seen in 27 patients. These data indicate that the response rate and duration to MPA and TAM are comparable, except in patients with osseous metastases and in patients older than age 70 years. MPA has more side effects, but seems to be more effective after cross-over, and may thus be reserved for second-line treatment.     

One year of adjuvant tamoxifen compared with chemotherapy and tamoxifen in postmenopausal patients with stage II breast cancer

PurposeWe report the long-term results of a randomised trial comparing tamoxifen with tamoxifen plus cyclophosphamide, methotrexate and fluorouracil (CMF) in postmenopausal high-risk breast cancer patients. In addition, we analyse the prognostic and predictive value of centrally assessed subtypes.MethodsPostmenopausal patients with breast cancer and positive nodes, deep invasion or size exceeding 5 cm were randomly assigned to 1 year of tamoxifen, or cyclophosphamide 600 mg/m², methotrexate 40 mg/m² and fluorouracil 600 mg/m² intravenously on day 1 every 4 weeks for nine cycles plus tamoxifen (CMFT). Tissue microarrays were constructed retrospectively and oestrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), and proliferation-related Ki-67 antigen (Ki67) status were assessed.ResultsFrom October 1982 through March 1990 we randomised 1445 patients and 969 (67%) were eligible for the biomarker analysis. At 10-years 936 women had suffered a disease-free survival (DFS) event (tamoxifen, 495 events in 686 patients; CMFT, 441 events in 642 patients). The addition of CMF to tamoxifen significantly improved DFS (adjusted hazard ratio 0.82; 95% confidence interval (CI) 0.71–0.93; P = 0.003) but not overall survival (adjusted hazard ratio 0.95; 95% CI 0.85–1.08; P = 0.44). DFS was superior in Luminal A tumours (ER or PgR positive, HER2 negative and Ki67 ?14%) when compared to Luminal B or non-luminal (ER and PgR negative) tumours. There was no statistical evidence of heterogeneity by subtype in the benefit from CMF (P_interaction = 0.45).ConclusionCMF added to 1 year of tamoxifen reduces the risk of a DFS event. The benefit from CMF was not significantly different in Luminal A and B subtypes.     

乳腺癌辅助他莫昔芬治疗与后续白内障发生的相关性分析

背景与目的：他莫昔芬是绝经前激素受体阳性乳腺癌辅助内分泌治疗的标准药物,也是绝经后患者的重要选择。目前,他莫昔芬治疗与后续白内障发生的相关性争议较大,需进一步证实。方法：分析复旦大学附属肿瘤医院乳腺外科前瞻性维护的病例数据库中的相关信息,结合门诊随诊数据,共纳入3 034例可用患者。其中无内分泌治疗患者806例,含他莫昔芬治疗1 065例,仅接受芳香化酶抑制剂治疗1 163例。对无内分泌治疗与含他莫昔芬治疗两组,根据后续发生白内障与否进行关联分析,并进行年龄（≤40岁、40~50岁、＞50岁）与他莫昔芬用药时长（用药5年内、超过5年）的亚组研究。结果：无内分泌治疗组（806例）与含他莫昔芬治疗组（1 065例）两组间白内障发生率没有显著差异（HR=1.1,95% CI：0.8~1.5;P=0.70）。但在不同年龄亚组中有不同情况：≤40岁组与40~50岁组,他莫昔芬的使用与白内障发病没有显著关联;在＞50岁组,使用他莫昔芬后发生白内障的概率（15.4%）是未使用组（9.0%）的1.8倍（95% CI：1.1~3.1;P=0.024）。不仅如此,多因素分析揭示,长期使用他莫昔芬（超过5年）的患者也相对于5年内使用患者有更高的白内障发生风险。结论：虽然在整体人群中白内障与他莫昔芬无显著相关,但在中老年等绝经后患者及长时间他莫昔芬用药患者中,白内障的发病风险显著提高。提示选择他莫昔芬治疗时,要重视各类不良反应风险的评估和白内障高危人群的鉴别。     

Phase III randomized adjuvant study of tamoxifen alone versus sequential tamoxifen and anastrozole in Japanese postmenopausal women with hormone-responsive breast cancer: N-SAS BC03 study

Clinical trials conducted in Western countries have shown that aromatase inhibitors are associated with better disease-free survival (DFS) than tamoxifen in postmenopausal early breast cancer. Because pharmacogenetic differences in drug-metabolizing genes may cause ethnic differences, assessment of the efficacy and tolerability of aromatase inhibitors in non-white women is warranted. This open-label, randomized clinical trial included 706 postmenopausal Japanese women with hormone-receptor-positive breast cancer, who had received tamoxifen for 1 to 4 years as adjuvant therapy. This study was closed early after entry of ~28% of the initially planned patients. They were randomly assigned to either switch to anastrozole or to continue tamoxifen for total treatment duration of 5 years. Primary endpoints were DFS and adverse events. At a median follow-up of 42 months, the unadjusted hazard ratio was 0.69 (95% confidence interval, 0.42–1.14; P = 0.14) for DFS and 0.54 (95% CI, 0.29–1.02; P = 0.06) for relapse-free survival (RFS), both in favor of anastrozole. The incidence of thromboembolic events in the tamoxifen group and bone fractures in the anastrozole group was not excessively high. Switching from tamoxifen to anastrozole was likely to decrease disease recurrence in postmenopausal Japanese breast cancer patients. Ethnic differences in major adverse events may be attributable to a low baseline risk of these events in Japanese.     

Phosphorylated S6K1 is a possible marker for endocrine therapy resistance in hormone receptor-positive breast cancer

Cross-talk between the estrogen receptor and the mammalian target of rapamycin (mTOR) pathway is one of the mechanisms of endocrine therapy resistance, and the phosphorylated S6 kinase 1(p-S6K1) is known to be a marker of the mTOR pathway activation. The authors assessed the prognostic significance of p-S6K1 according to the hormone receptor (HR) status. The expression of p-S6K1 was evaluated in 304 breast cancer tissues, and the association between its expression and patient outcomes was investigated. Among 197 cases with the HR (+) tumor, 70 (35.5%) were positive for p-S6K1. Most of the patients (97.5%) with the HR (+) tumor received adjuvant endocrine therapy. The expression of p-S6K1 was found to be an independent worse prognosticator affecting overall survival (OS) and breast cancer-specific survival (BCSS) in the HR (+) group (hazard ratio, 2.62; 95% confidence interval [CI], 1.19–5.76; P = 0.017 and hazard ratio, 3.25; 95% CI, 1.20–8.82; P = 0.020, respectively). In the HR (−) group, however, the p-S6K1 expression was not associated with patients’ survival. The expression of p-S6K1 is a worse prognostic factor in patients with HR (+) tumors. These results suggest that the p-S6K1 expression might be a marker for endocrine therapy resistance in patients with HR (+) tumors.     

Switching trial of adjuvant tamoxifen with an aromatase inhibitor in postmenopausal patients with breast cancer

Tamoxifen is currently a standard of care for postmenopausal patients with breast cancer with hormone receptor-positive tumors who are candidates for adjuvant endocrine therapy. This treatment is highly effective and relatively safe. However, a significant proportion of women are constitutively resistant or become resistant to tamoxifen, despite having hormone receptor-positive tumors. Moreover, the prolonged exposure to tamoxifen can produce severe and life-threatening side effects like endometrial carcinoma or thromboembolic disease. Aromatase inhibitors (AI) have been shown to be quite effective in advanced disease, and also have promising efficacy in early-stage breast cancer as alternatives to tamoxifen. This article reviews the results achieved by AI following 2-3 years or 5 years of tamoxifen. At least 3 trials indicate that switching to an AI following 2-3 years of tamoxifen can produce a substantial benefit. A fourth trial indicates that additional benefit can be achieved by a few years of treatment with an AI after 5 years of tamoxifen. The updated results of previous trials and ongoing trials will soon establish criteria for selecting patients who might be better candidates for sequencing, and to fine tune strategies that are more appropriate.     

Patterns of failure in a randomized trial of adjuvant chemotherapy in postmenopausal patients with early breast cancer treated with tamoxifen.

BACKGROUND: We studied the effect of adjuvant anthracycline-based chemotherapy in postmenopausal patients with resected early breast cancer treated with adjuvant tamoxifen. PATIENTS AND METHODS: The trial included 835 patients with either axillary lymph node involvement, or tumors with histological grade II or III. They were randomized after local surgery to receive either tamoxifen (TAM group) or tamoxifen plus chemotherapy (TAM-CT group) consisting of six courses of 5-fluorouracil, doxorubicin and cyclophosphamide (FAC), or 5-fluorouracil, epidoxorubicin and cyclophosphamide (FEC). Radiotherapy was given after completion of adjuvant chemotherapy in the TAM-CT group and after surgery in the TAM group. RESULTS: The 5-year disease-free survival (DFS) rates were 73% in the TAM group and 79% in the TAM-CT group (log-rank test, P = 0.06). The 5-year overall survival rates were 82% and 87%, respectively (P = 0.06). The 5-year distant metastasis rates were 22% and 16% (P = 0.02), and the 5-year local recurrence rates were 6% and 4%, respectively (P = 0.23). There were no significant differences for contralateral breast cancer or other new primary malignancies. Chemotherapy tended to be more effective for patients who had tumors without estrogen receptors (trend test, P = 0.05). CONCLUSIONS: Anthracycline-based chemotherapy administered to postmenopausal patients receiving adjuvant tamoxifen gave a borderline significant benefit on overall and DFS, mainly by a reduction in distant metastases. Delaying radiotherapy after six courses of chemotherapy did not affect local control after up to 10 years of follow-up.     

Late treatment-related morbidity in breast cancer patients randomized to postmastectomy radiotherapy and systemic treatment versus systemic treatment alone

Late treatment-related morbidity after mastectomy and adjuvant systemic treatment with and without postoperative irradiation was assessed in 84 patients randomized in the Danish Breast Cancer Cooperative Group Trials 82b and c. A structured interview and physical examination, using a standardized assessment sheet, constructed on the basis of the late effects normal tissues (LENT) scoring system, was used. The median length of follow-up from mastectomy was 9 years (range 6-13 years). Lymphedema was measured in 14% of the irradiated patients versus 3% of the non-irradiated patients (NS). Slightly decreased shoulder morbidity was measured in 45% of the irradiated women versus 15% of the non-irradiated patients, but moderate or more severe impairment was seen in only 5% of the irradiated patients and in none of the non-irradiated patients (p=0.004). Seventeen percent of the irradiated patients and 2% of the non-irradiated patients found that impairment of shoulder movement caused symptoms (p=0.001).