The immunological status of breast cancer patients during treatment with a new antiestrogen, toremifene

Understanding sex biases in immunity: effects of estrogen on the differentiation and function of antigen-presenting cells

The initiation and perpetuation of innate and adaptive immunity is dependent on the ability of professional antigen-presenting cells (APCs) to sense inflammatory stimuli; produce cytokines; and internalize, degrade, and present antigens via surface major histocompatibility complex (MHC) molecules. Dendritic cells (DCs), macrophages, and B lymphocytes express estrogen receptors, indicating that the steroid sex hormone estrogen might directly modulate the function of these cells during immune responses. Sex-specific parameters of immune function have been identified during autoimmunity and the pathogenesis of infectious disease, which show sex biases in their incidence and manifestation; female immunity also varies as estrogen levels change. In this article, we summarize studies that demonstrate effects of estrogen on the differentiation or function of APCs in model in vitro systems, or under circumstances of natural or imposed variation in estrogen levels in vivo.

Immune function and adjustment style: do they predict survival in breast cancer?

The aim of this study was to investigate the role of immune status and psychosocial factors in survival from early breast cancer (N=61). Baseline assessments included lymphocyte number and function, natural killer cell activity (NKA), plasma cortisol and prolactin level. Psychosocial measures included anxiety, depression and mental adjustment to cancer and social support. Length of follow-up was 6.1-7.9 years with 14 (23%) breast cancer deaths. In Cox proportional hazards models adjusting for lymph node status two parameters predicted longer survival, low NKA (HR 29 per LLU, p=0.003) and minimizing the illness adjustment (HR 0.64 per scale point, p=0.012). These data provide little evidence for a psychoneuroimmunological mechanism in the survival from breast cancer. While this study is limited due to small sample size, and therefore the possibility of inflated estimates, longer survival in those minimizing the illness is a finding consistent with recent studies; however, the counter-intuitive finding that high NKA predicts shorter survival may be a marker for current disease or response to treatments.

Toremifene. A review of its pharmacological properties and clinical efficacy in the management of advanced breast cancer

The triphenylethylene antiestrogen toremifene is a chlorinated derivative of the antiestrogen tamoxifen, an agent which has been widely and successfully used in the treatment of breast cancer. Clinical trials investigating the efficacy of toremifene as first-line endocrine therapy in postmenopausal women with advanced breast cancer (estrogen receptor status positive or unknown) have shown this drug to have similar antitumour activity to that of tamoxifen. In multicentre comparative trials, objective responses (complete and partial) occurred in 20 to 29% of patients treated with toremifene (60 to 240 mg/day) and in 19 to 37.5% of tamoxifen (20 or 40 mg/day) recipients. The duration of response, time to disease progression and median overall survival time were generally similar in both treatment groups. Toremifene is well tolerated. Most drug-related adverse effects are mild or moderate in severity and rarely necessitate discontinuation of therapy. The tolerability profile of toremifene is similar to that reported for tamoxifen, the most common adverse effects being hot flushes, sweating, nausea and/or vomiting, dizziness, oedema, and vaginal discharge and/or bleeding. Thus, toremifene provides an equally effective and well tolerated alternative to tamoxifen for the first-line endocrine therapy of postmenopausal advanced breast cancer. Preclinical studies showing toremifene to have a lower carcinogenic potential than tamoxifen indicate that toremifene may be a preferable agent for long term treatment regimens; however, these findings require confirmation in the clinical setting.

Natural immunity in breast cancer patients during neoadjuvant chemotherapy and after surgery

Breast cancer is the most common cancer in women. Surgery, and more recently neoadjuvant chemotherapy, are being utilized as the initial treatment for breast cancer; however little is known about their effects on the natural immune system. The natural immune system (natural killer [NK] cells) is thought to be important in immune surveillance, including protection from metastasis during the intravascular tumour seeding that occurs during surgery. To investigate the effects of surgery on the natural immune system, we studied the pre-operative and post-operative peripheral blood lymphocytes (PBL) of 10 patients with stage I or II breast cancer: there was a 71.6 +/- 25.3% post-operative reduction in NK cell function (P < 0.005, Student's paired t-test). To investigate the effects of neoadjuvant chemotherapy and surgery, we examined PBL from five patients with stage III breast cancer: NK cell function dropped 95.7 +/- 1.9% after neoadjuvant chemotherapy, and there was a further 51.0 +/- 23.4% decrease after surgery (P < 0.05, Student's paired t-test). Neither group of patients had decreased numbers of NK cells, changes in the percentage of T helper or suppressor cells, or alterations in the production of cytotoxic factor by NK cells. These findings suggest that the impairment in NK cell function reflects a defect in the ability of NK cells to recognize and/or bind to tumour target cells. We conclude that the initial treatment of breast cancer patients, whether it involves surgery alone or with neoadjuvant chemotherapy, profoundly impairs their natural immune system and could increase the risk of metastasis. Further studies are needed to delineate the mechanism of this derangement in natural immunity and possibly alter its course.

Agonistic and antagonistic effects of antiestrogens in different target organs

Antiestrogens block by definition specifically the actions of estrogens. In the classical uterotropic assay in immature rodents, where estrogens cause fluid retention and cell proliferation, triphenylethylenes have also species-specific estrogen-like (agonistic) effects. 4-hydroxylated triphenylethylenes have in general less estrogenic properties than unhydroxylated ones, and ICI 164,384 has no estrogenic activity in this model. Uterus responds to estrogens by stimulation of cell proliferation. Some other tissues, like breast, liver, and bone respond by regulation of specific protein synthesis. Some of the proteins act as growth factors, and some have unknown functions. The regulation of gene expression is a complex phenomenon: estrogens may turn the responsive gene on or off. Similarly antiestrogens may participate in the gene regulation by mimicking or antagonising estrogen-like actions. This paper summarizes the estrogenic and antiestrogenic effects of classical and new antiestrogens in different tissues.