Preoperative treatment of postmenopausal breast cancer patients with letrozole: A randomized double-blind multicenter study

BACKGROUND

A randomized, double-blind, multicenter study was conducted to compare the anti-tumor activity of letrozole vs. tamoxifen in postmenopausal women with ER and/or PgR positive primary untreated breast cancer.

PATIENTS AND METHODS

Three hundred thirty-seven postmenopausal women with ER and/or PgR positive primary untreated breast cancer were randomly assigned once daily treatment with either letrozole 2.5 mg or tamoxifen 20 mg for four months. At baseline none of the patients were considered to be candidates for breast-conserving surgery (BCS) and 14% of the patients were considered inoperable. The primary endpoint was to compare overall objective response (CR + PR) determined by clinical palpation. Secondary endpoints included overall objective response on ultrasound and mammography and the number of patients who qualified for BCS.

RESULTS

Overall objective response rate (clinical palpation) was statistically significantly superior in the letrozole group, 55% compared to tamoxifen, 36% (P < 0.001). Secondary endpoints of ultrasound response, 35% vs. 25% (P = 0.042), mammographic response, 34% vs. 16% (P < 0.001), and BCS, 45% vs. 35% (P = 0.022) between the letrozole and tamoxifen groups, respectively, showed letrozole to be significantly superior. Both treatments were well tolerated.

CONCLUSIONS

This study shows that letrozole is more effective than tamoxifen as preoperative therapy in postmenopausal patients with ER and/or PgR positive primary untreated breast cancer and is at least as well tolerated.

Letrozole is more effective neoadjuvant endocrine therapy than tamoxifen for ErbB-1- and/or ErbB-2-positive, estrogen receptor-positive primary breast cancer: evidence from a phase III randomized trial

PURPOSE

Expression of ErbB-1 and ErbB-2 (epidermal growth factor receptor and HER2/neu) in breast cancer may cause tamoxifen resistance, but not all studies concur. Additionally, the relationship between ErbB-1 and ErbB-2 expression and response to selective aromatase inhibitors is unknown. A neoadjuvant study for primary breast cancer that randomized treatment between letrozole and tamoxifen provided a context within which these issues could be addressed prospectively.

PATIENTS AND METHODS

Postmenopausal patients with estrogen- and/or progesterone receptor-positive (ER+ and/or PgR+) primary breast cancer ineligible for breast-conserving surgery were randomly assigned to 4 months of neoadjuvant letrozole 2.5 mg daily or tamoxifen 20 mg daily in a double-blinded study. Immunohistochemistry (IHC) for ER and PgR was conducted on pretreatment biopsies and assessed by the Allred score. ErbB-1 and ErbB-2 IHC were assessed by intensity and completeness of membranous staining according to published criteria.

RESULTS

For study biopsy-confirmed ER+ and/or PgR+ cases that received letrozole, 60% responded and 48% underwent successful breast-conserving surgery. The response to tamoxifen was inferior (41%, P =.004), and fewer patients underwent breast conservation (36%, P =.036). Differences in response rates between letrozole and tamoxifen were most marked for tumors that were positive for ErbB-1 and/or ErbB-2 and ER (88% v 21%, P =.0004).

CONCLUSION

ER+, ErbB-1+, and/or ErbB-2+ primary breast cancer responded well to letrozole, but responses to tamoxifen were infrequent. This suggests that ErbB-1 and ErbB-2 signaling through ER is ligand-dependent and that the growth-promoting effects of these receptor tyrosine kinases on ER+ breast cancer can be inhibited by potent estrogen deprivation therapy.

[Promoting health in health care organizations and hospitals? A survey of the French community in Belgium]

Health promotion concept and practices have brought many significant changes even in disease management and care settings. In the Ottawa charter, health promotion is defined as "the process of enabling people to increase control over, and to improve, their health". However, care settings are in contradiction with this process on several levels (focus on disease and not enough on health, concern more on cure than on care, etc.). The emergence of health promotion practices has been deeply questioning these features. Care institutions start to reconsider their role and missions. However, changes are slow and there has been much resistance. What is the current situation of health promotion in French speaking Belgian care institutions in 1998? The WHO EUROPE HEALTH PROMOTING HOSPITALS' (HPH) project, which officially started in 1991, aims at "promoting positive health and well-being in hospitals and beyond that, in the community". For each participating hospital, the implications of membership have an important influence on the institution and care project, because it implies adherence to the principles of the Ottawa charter on health promotion, and to the philosophy and objectives of HPH. Belgium joined the WHO project and the HPH network in 1996. It was necessary to review the situation of health care institutions in the French speaking community of Belgium in order to understand the evolution over the last years, to assess health professionals expectations and the feasibility of some actions, and to provide political decision makers with information likely to influence future decisions and choices in a positive way. This article presents the descriptive results of a survey carried out on nursing and patient education departments in health care institutions. Half of 105 hospitals answered the questionnaires sent. Out of these answers, 150 projects and actions were identified and briefly described by the institutions, which had the possibility to present a maximum of five actions. The main topics addressed were chronic diseases, psychology (conflict management, aggressiveness, ill-treatment), maternity, screening, prevention and vaccination. Regarding perspectives, 78% of actions concern disease and/or risks of disease (therapeutic or preventive perspectives) and 22% concern the maintenance or improvement of health. 90% of listed and described actions are permanent, and only 10% are selective (limited), which suggests an evolution of projects and their integration in practices. Concerning the number of projects, two aspects were analysed: the number by institution and the evolution over the last twenty years. On average, there are 3.2 actions per institution. As for the evolution, 7% of hospitals said they had at least one education action/project in 1980, 60% in 1990 and 98% in 1998. This amazing and remarkable evolution occurred simultaneously to the development of education committees, of patient education co-ordinators and/or resource persons. In this field, there was also a remarkable evolution since the creation of the first committees in 1983. Amongst the elements encouraging the development of information and health education initiatives and actions mentioned by hospital managers, the first one is a demand from the public (and patients). It is the first time, since the existence of such surveys that this factor is mentioned as the most important.

Modulation of basal hepatic glycogenolysis by nitric oxide

We perfused livers from fed rats with a balanced salt solution containing 1 mmol/L glucose. Under these conditions a low steady rate of glycogenolysis was observed (approximately 1.7 micromol glucose equivalents/g/min; 20% of the maximal glycogenolytic activity). Nitric oxide (NO) transiently stimulated hepatic glucose production. A maximal response (on average doubling basal glucose output) was observed with 34 micromol/L NO. The same concentration of nitrite (NO2-) was ineffective. Half-maximal effects were seen at 8 to 10 micromol/L NO, irrespective of the flow direction (portocaval or retrograde). This glycogenolytic response to NO corresponded to a partial activation of phosphorylase. The NO effect was not additive to maximal stimulation of glycogenolysis (7.7 +/- 0.2 micromol hexose equivalents/g/min; n = 4) by 100 micromol/L dibutyryl cyclic adenosine monophosphate (Bt2cAMP). The requirement for activation of phosphorylase was also evidenced by the ineffectiveness of NO in phosphorylase-kinase-deficient livers of gsd/gsd rats. The NO effect was blocked by co-administration of cyclooxygenase inhibitors (50 micromol/L ibuprofen, 50 micromol/L indomethacin, or 2 mmol/L aspirin), suggesting a mediatory role of prostanoids from nonparenchymal cells. This conclusion was confirmed by the fact that NO did not activate phosphorylase in isolated hepatocytes. Moreover, NO was no longer glycogenolytic in livers perfused with Ca2+-free medium, in agreement with the known mediatory role of Ca2+ in prostanoid-mediated responses. Surprisingly, in Ca2+-free medium NO inhibited the basal glucose production. This coincided with an increased elution of cyclic guanosine monophosphate (cGMP). Inhibition of glycogenolysis by NO under these conditions was blocked by 1 mmol/L theophylline, suggestive for involvement of cGMP-stimulated cAMP phosphodiesterase. However, we could not confirm that an increase in cGMP resulted in a drop in cAMP. In conclusion, NO recruits opposing mechanisms with respect to modulation of basal hepatic glycogenolysis. In the presence of Ca2+, activation of phosphorylase with stimulation of glycogenolysis dominates. Cyclooxygenase inhibitors abolish this effect. Activation by NO of the cyclooxygenase in nonparenchymal cells is a distinct possibility. In the absence of Ca2+, inhibition of basal glycogenolysis becomes observable. It remains to be established whether this results from cGMP-mediated stimulation of hydrolysis of cAMP.

In situ 13C NMR quantification of hepatic glycogen

We report on the 13C NMR visibility of the C-1 glycosidic carbon of alpha-particulate glycogen in perfused rat liver. We used rats fed ad libitum, animals refed after a 48 h fast with a sucrose supplement with or without glucocorticoid treatment, and gsd/gsd rats with a hepatic glycogen storage disease due to phosphorylase kinase deficiency. Thus we studied a wide range of glycogen levels (25-140 mg/g liver). All livers were perfused with 15 mM glucose, to maintain constant glycogen levels. Failure to activate glycogen phosphorylase ensures stable glycogen levels in gsd/gsd livers. Natural abundance 13C NMR signals were calibrated against a phantom containing a fixed amount of glycogen. Accumulated free induction decays were analysed after Fourier transformation by numerical integration, or by direct analysis of the signal in the time domain using a non-iterative method based on singular value decomposition. NMR quantification of the glycogen correlated well with the chemical determination over the whole concentration range. However, the precision (reproducibility) of glycogen determinations (be it by chemical methods or by NMR spectroscopy) may pose problems. Authors should be encouraged to report systematically on the precision of their methods.