Microarray-based comparative genomic hybridisation of breast cancer patients receiving neoadjuvant chemotherapy

We analysed the molecular genetic profiles of breast cancer samples before and after neoadjuvant chemotherapy with combination doxorubicin and cyclophosphamide (AC). DNA was obtained from microdissected frozen breast core biopsies from 44 patients before chemotherapy. Additional samples were obtained before the second course of chemotherapy (D21) and after the completion of the treatment (surgical specimens) in 17 and 21 patients, respectively. Microarray-based comparative genome hybridisation was performed using a platform containing approximately 5800 bacterial artificial chromosome clones (genome-wide resolution: 0.9 Mb). Analysis of the 44 pretreatment biopsies revealed that losses of 4p, 4q, 5q, 12q13.11-12q13.12, 17p11.2 and 17q11.2; and gains of 1p, 2p, 7q, 9p, 11q, 19p and 19q were significantly associated with oestrogen receptor negativity. 16q21-q22.1 losses were associated with lobular and 8q24 gains with ductal types. Losses of 5q33.3-q4 and 18p11.31 and gains of 6p25.1-p25.2 and Xp11.4 were associated with HER2 amplification. No correlations between DNA copy number changes and clinical response to AC were found. Microarray-based comparative genome hybridisation analysis of matched pretreatment and D21 biopsies failed to identify statistically significant differences, whereas a comparison between matched pretreatment and surgical samples revealed a statistically significant acquired copy number gain on 11p15.2-11p15.5. The modest chemotherapy-driven genomic changes, despite profound loss of cell numbers, suggest that there is little therapeutic selection of resistant non-modal cell lineages.

Biological and clinical outcomes from a phase II placebo-controlled neoadjuvant study of anastrozole alone or with gefitinib in postmenopausal women with ER/PgR+ breast cancer (Study 223)

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Background: Gefitinib, an EGFR-tyrosine kinase inhibitor, reduces breast cancer cell growth and potentiates endocrine therapy in model systems. This double-blind multicentre study compared anastrozole 1 mg/day alone with anastrozole + gefitinib 250 mg/day as neoadjuvant therapy for breast cancer in a novel design aiming to assess additional benefit from gefitinib in individual patients. Methods: Postmenopausal women with stage I-IIIB breast cancer and ER and/or PgR+ tumours received anastrozole for 16 wks and were randomised (2:5:5 ratio) to: combination with gefitinib for 16 wks (AG); placebo for 2 wks then gefitinib for 14 wks (A:AG, to test for additional Ki67 suppression); placebo for 16 wks (A alone). Biopsies were taken at baseline, 2 and 16 wks. Primary comparison was change in Ki67 by 16 wks. Secondary comparison was objective tumour response rate (ORR) using UICC/WHO criteria at 16 wks. Results: 206 patients (pts) were randomised: (31 AG, 90 A:AG, 85 A alone); demography was well balanced between the groups. 109 pts were evaluable for Ki67: 59 AG + A:AG; 50 A alone. Change in Ki67 levels at 16 wks was not significantly different in those pts who received gefitinib + anastrozole versus anastrozole alone (p=0.257). The addition of gefitinib after 2 weeks of anastrozole did not further suppress Ki67 levels (p=0.164). 188 pts were evaluable for ORR (109 AG + A:AG; 79 A alone). The ORR was 48% in pts who received gefitinib + anastrozole and 61% in pts treated with anastrozole alone (p=0.067). Conclusions: Neither the biological nor the clinical activity of anastrozole was enhanced by the addition of gefitinib; although non-significant, both endpoints unexpectedly suggested a trend against the combination in this patient population. Molecular investigations of signal transduction pathways are underway to understand the significance of these findings.

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Benefit from adjuvant tamoxifen therapy in primary breast cancer patients according oestrogen receptor, progesterone receptor, EGF receptor and HER2 status

BACKGROUND

Most women with oestrogen receptor (ER) positive primary breast cancer receive adjuvant tamoxifen after surgery. The measurement of tumour biomarkers should allow better selection of patients for such treatment or for therapies such as aromatase inhibitors.

PATIENTS AND METHODS

Histopathological blocks of primary breast cancer patients who had been randomized to receive 2-years tamoxifen or no adjuvant therapy in two mature randomised clinical trials were retrieved. Immunohistochemical staining for ER, progesterone receptor (PgR), HER2 and epidermal growth factor receptor (EGFR) was undertaken. The primary endpoint was relapse free survival.

RESULTS

813 patients were included in the study. Benefit from tamoxifen was seen in ER-positive patients [Relative risk (rr) 0.77, ci 0.63-0.93]. ER-negative patients also showed a strong trend to benefit from tamoxifen (rr 0.73, ci 0.52-1.02) which was largely confined to the PgR-positive group. Amongst the ER-positive group, PgR-positive and PgR-negative patients showed similar benefit (rr 0.81; ci 0.65-1.02 and 0.70; ci 0.49-0.99, respectively). Patients positive for HER2 did not benefit significantly (rr 1.14; ci 0.75-1.73) but this group was small.

CONCLUSIONS

Measurement of PgR status in ER-negative patients defines a group of patients that benefit from tamoxifen but would be excluded from tamoxifen therapy on the basis of ER status alone. The data are consistent with HER2 positive tumours being resistant to tamoxifen.

Growth factor signalling and response to endocrine therapy: the Royal Marsden Experience

De novo resistance to endocrine therapy is a near-universal feature of oestrogen receptor (ER)- negative breast cancer. Although many ER-positive breast cancers also show no response to tamoxifen or aromatase inhibitors on objective clinical grounds the large majority show reduced proliferation indicating that some oestrogen dependence is present in almost all ER-positive breast cancer. In neoadjuvant studies HER2 positivity is associated with poor response rates to tamoxifen but not aromatase inhibitors, consistent with preclinical models. Acquired resistance to tamoxifen is associated with decreases in ER positivity but most recurrent lesions remain ER-positive. A small proportion of these show increased HER2 expression and in these patients increased phospho-p38 may contribute to the tamoxifen-resistant phenotype. There is an unfortunate paucity of clinical and biological data on acquired resistance to aromatase inhibitors.

Influence of tegaserod on proximal gastric tone and on the perception of gastric distension

BACKGROUND

Tegaserod, a 5-hydroxytryptamine-4 receptor agonist, enhances gastric emptying, but its effects on proximal stomach function have not been studied.

AIM

To study the effect of tegaserod on gastric compliance, accommodation and perception of distension in humans.

METHODS

Nineteen healthy volunteers (10 females; mean age, 23.9 years) were studied on three separate occasions after 7 days of treatment with placebo, tegaserod 2 mg b.d. or tegaserod 6 mg b.d. in a double-blind, randomized, three-way cross-over design. After the introduction of a barostat bag, stepwise distensions were performed to determine gastric compliance and sensitivity, and a mixed liquid meal was administered in isobaric mode to assess accommodation.

RESULTS

Tegaserod had no effect on the pressures or volumes inducing first perception or discomfort. Tegaserod 6 mg b.d. enhanced fasting gastric compliance compared with placebo. Pre-prandial and post-prandial intra-balloon volumes were significantly higher after 6 mg b.d. than after placebo. Both tegaserod 2 and 6 mg b.d. shortened the time to maximum post-prandial intra-balloon volume. The amplitude of meal-induced gastric relaxation (post-prandial minus pre-prandial volumes) did not differ between the treatment arms.

CONCLUSION

In humans, tegaserod allows for larger intra-balloon volumes both before and after a meal. These findings warrant the investigation of the therapeutic potential of tegaserod in dyspeptic patients with impaired accommodation.

Studies of the Potential Utility of Ki67 as a Predictive Molecular Marker of Clinical Response in Primary Breast Cancer

INTRODUCTION

Objectives were to characterise the relationship of the proliferation marker Ki67 with response to systemic treatment in early breast cancer and to assess its clinical utility, using fine needle aspirates.

MATERIALS AND METHODS

Hundred and six women were treated with primary tamoxifen (n = 33), chemotherapy (n = 33) or chemotherapy and tamoxifen (n = 40). Treatment was not randomised and response was assessed clinically. Ki67 was evaluated prior to treatment and at Day 14 or 21 after commencing treatment. To assess reproducibility, Ki67 was evaluated in repeat FNAs taken from 37 untreated patients.

RESULTS

The percentage change in Ki67 in first 21 days was different between responders and non-responders for patients treated with tamoxifen (p = 0.007) and chemotherapy (p = 0.005) but not for chemoendocrine treatment (p = 0.062). The reproducibility study indicated that a decrease to 36% or less of the pre-treatment Ki67 value in an individual patient was required for it to be regarded as a statistically significant change. A significant decrease in Ki67 was seen in responding patients treated with chemotherapy (p = 0.026) and chemoendocrine treatment (p = 0.041). Positive and negative predictive values for response were 85 and 59% for chemotherapy patients and 88 and 54% for chemoendocrine patients, respectively.

CONCLUSION

Ki67 is unlikely to be useful as a predictive marker in individual patients. Further molecular markers that predict lack of response continue to be required.

Early changes in apoptosis and proliferation following primary chemotherapy for breast cancer

Patients undergoing primary chemotherapy for invasive breast cancer consented to a core biopsy of the invasive breast primary pre- and 24 h postchemotherapy. The resulting tissue was analysed for apoptosis, Ki67, ER and HER-2 using immunohistochemical techniques. These data were then used to evaluate the relationship between these biological markers and response to chemotherapy and overall survival. Response rate to chemotherapy in this group was 86%, 16 patients (25%) achieved a clinical complete response and 41 (63%) a partial response. Prechemotherapy there was a significant correlation between Ki67 and apoptotic index (AI), r=0.6, (P<0.001). A significant rise in AI (P<0.001), and fall in Ki67 (P=0.002) was seen 24 h following chemotherapy. No relationship was seen between pretreatment AI and clinical response, but higher Ki67 and growth index (Ki67/AI ratio, GI) did correlate with clinical response (both r=0.31, P<0.025). No correlation was seen between the change in AI or Ki67 at 24 h and clinical response or survival. Significant changes in apoptosis and proliferation can be demonstrated 24 h following chemotherapy, but these changes do not relate to clinical response or outcome in this study. Pretreatment proliferation and GI are however predictive of response to chemotherapy in breast cancer.

Correlation between immunohistochemistry (HercepTest) and fluorescence in situ hybridization (FISH) for HER-2 in 426 breast carcinomas from 37 centres

Accurate diagnostic assessment of HER-2 is essential for the appropriate application of the humanized anti-HER-2 monoclonal antibody trastuzumab (Herceptin) to the treatment of patients with metastatic breast cancer. The diagnostic test needs to be applicable to archival, fixed tissue removed at excision, in many cases several years earlier. We compared the assessment of HER-2 by immunohistochemistry (IHC; HercepTest) and fluorescence in situ hybridization (FISH) in 426 breast carcinomas from patients being considered for trastuzumab therapy. The tumours were tested in three reference centres having been sent in from 37 hospitals. Only 2/270 (0.7%) IHC 0/1+ tumours were FISH positive. Six of 102 (5.9%) IHC 3+ tumours were FISH negative. Five of the six had between 1.75 and 2.0 HER-2 gene copies per chromosome 17 and the sixth had multiple copies of chromosome 17. Thirteen per cent of tumours were IHC 2+ and overall 48% of these were FISH positive but this proportion varied markedly between the centres. Sixty IHC-stained slides selected to be enriched with 2+ cases were circulated between the three laboratories and scored. There were 20 cases in which there was some discordance in scoring. Consideration of the FISH score in these cases led to concordance in the designation of positivity/negativity in 19 of these 20 cases. These data support an algorithm in which FISH testing is restricted to IHC 2+ tumours in reference centres. The results may not extrapolate to laboratories with less experience or using different methodologies.

HER-2 amplification impedes the antiproliferative effects of hormone therapy in estrogen receptor-positive primary breast cancer

In experimental models, human epidermal growth factor receptor-2 (HER-2) amplification leads to estrogen independence and tamoxifen resistance in estrogen receptor (ER)-positive human breast cancer cells. Some but not all reports suggest an association between HER-2 positivity and hormone independence in breast cancer patients. This study aimed to evaluate the antiproliferative effects of endocrine therapy in HER-2-positive/ER-positive primary human breast cancer. The effect on proliferation (Ki67) of hormone therapy was assessed at 2 weeks and/or 12 weeks in biopsies from 115 primary breast cancers with ER-positive tumors. The patients took part in one of 3 neoadjuvant trials of hormonal therapy with a SERM (tamoxifen or idoxifene) or an aromatase inhibitor (anastrozole or vorozole). HER-2 status was assessed by immunocytochemistry and fluorescence in situ hybridization (FISH). Fifteen patients were defined as HER-2 positive by both immunohistochemistry and FISH, with the remaining 100 patients HER-2 negative. Geometric mean Ki67 levels were substantially higher in HER-2-positive than HER-2-negative tumors (27.7% versus 11.5%, respectively; P = 0.003). In HER-2-negative patients, Ki67 was reduced by 62 and 71% at 2 and 12 weeks, respectively (P < 0.0001 for both), but HER-2-positive patients showed no significant fall. The proportional change in Ki67 was significantly different between HER-2-positive and -negative patients (P = 0.014 at 2 weeks; P = 0.047 at 12 weeks). Mean ER levels were lower in the HER-2-positive patients (P = 0.06) but the change in Ki67 was impeded even in those with high ER. Apoptotic index was reduced by 30% at 2 weeks in the HER-2-negative group. However, there were no statistically significant differences in apoptotic index between the groups. It is concluded that ER-positive/HER-2-positive primary breast carcinomas show an impeded antiproliferative response to endocrine therapy that nonetheless may vary between individual treatments. This together with high baseline proliferation is likely to translate to poor clinical response.

Dietary fibre, physicochemical properties and their relationship to health

Dietary carbohydrates that escape digestion and absorption in the small intestine include non-digestible oligosaccharides (carbohydrates with a degree of polymerisation between three and ten), resistant starch and non-starch polysaccharides. The physiological effects of this heterogeneous mixture of substrates are partly predictable on the basis of their physicochemical properties. Monosaccharide composition and chain conformation influence the rate and extent of fermentation. Water-holding capacity affects stool weight and intestinal transit time. Viscous polysaccharides can cause delayed gastric emptying and slower transit through the small bowel, resulting in the reduced rate of nutrient absorption. Polysaccharides with large hydrophobic surface areas have potentially important roles in the binding of bile acids, carcinogens and mutagens. Ispaghula is capable of binding bile acids through a large number of weak binding sites on the polysaccharide structure, and having greatest effect on the potentially more harmful secondary bile acids deoxycholic acid and lithocholic acid.

Antiproliferative effects of idoxifene in a placebo-controlled trial in primary human breast cancer

Idoxifene is a novel selective estrogen receptor modulator. It has reduced agonist activity on breast and uterine cells compared with tamoxifen and antiproliferative effects in tamoxifen-resistant breast cancer cells. Previous studies have shown that a short course of treatment with other antiestrogens prior to surgery caused a significant reduction of the growth fraction when measured by immunohistological staining using the mouse monoclonal antibody Ki67. In this study, we assessed the effect of idoxifene on biological markers of cell proliferation (Ki67) and apoptosis (TdT-mediated dUTP-biotin nick end labeling), and estrogen and progesterone receptor (ER/PR) expression was also evaluated. Core-cut biopsies were obtained in 77 postmenopausal patients with primary breast cancer at diagnosis. Patients were randomized to 40 mg/day idoxifene or placebo for 14-21 days prior to obtaining a second biopsy sample at surgical resection. The percentage of Ki67-positive cells fell from a mean 19.7 +/- 2.7% (SE) to 13.4 +/- 3.4% in idoxifene-treated ER-positive tumors (n = 30; P = 0.0043), but there was no significant effect in placebo-treated ER-positive tumors (n = 27). No effect was seen on ER-negative tumors in either group. Idoxifene had no significant effect on apoptotic index but produced a statistically significant fall in idoxifene-treated ER immunohistochemical score and a small increase in PR that did not reach statistical significance (0.05 < P < 0.10). Idoxifene was well tolerated in all patients. Idoxifene has an antiproliferative effect in ER-positive but not ER-negative breast cancers, and no significant effect on apoptosis in the short-term.

Evaluation of the role of intercellular adhesion molecule 1 in a rodent model of chronic venous hypertension

PURPOSE

To evaluate the role of intercellular adhesion molecule 1 (ICAM-1) in cutaneous leukocyte trapping in venous disease, we used our rodent model of venous hypertension (VH).

MATERIALS AND METHODS

VH was created in adult rats by ligation of the inferior vena cava, bilateral common iliac veins, and bilateral common femoral veins. In the Phase I experimental (exptl) group, anti-ICAM-1 monoclonal antibody (1A29) was given intravenously prior to venous ligations. Acute venous pressures were measured in the exptl and control (ctrl) (ligation only) groups. Bilateral forelimb and hindlimb skin specimens were harvested for myeloperoxidase (MPO) assay. In Phase II, VH was created in a chronic group; in a sham-operated group, ties were placed around the same vessels without ligations. Two weeks later, venous pressures were measured and radiolabeled ((125)I and (131)I) monoclonal antibody (mAb) to ICAM-1 was injected and allowed to circulate for 5 min before the level of radiolabeled antibody within forelimb and hindlimb specimens was measured.

RESULTS

In the acute study with 1A29, hindlimb pressures were significantly elevated in both the ctrl (n = 4) and exptl (n = 4) hindlimbs (15.4 +/- 0.239 and 13.8 +/- 1.89 mm Hg, respectively) compared with ctrl and exptl forelimbs (1.38 +/- 0.554 and 1.50 +/- 0.612 mm Hg, respectively). However, MPO activity was significantly elevated in the hindlimbs of the ctrl group compared with the hindlimbs of the exptl animals (19.8 +/- 1.54 U vs 6.71 +/- 2.46 U). In the chronic VH rats (n = 5) given radiolabeled anti-ICAM-1 mAb, the hindlimb pressures (10.1 +/- 4.52 mm Hg) were significantly elevated (P < 0.05) compared with forelimb pressures (1 +/- 0.447 mm Hg) and compared with the forelimb and hindlimb pressures in the sham-operated animals (n = 4) (1.63 +/- 0.813 and 4.25 +/- 2.13 mm Hg, respectively). However, there was not a significant difference in the quantity of ICAM-1-hindlimb versus forelimb or chronic VH versus sham.

CONCLUSIONS

Anti-ICAM-1 mAb decreased MPO activity in hypertensive hindlimb skin, supporting the instrumental role of ICAM-1 in cutaneous leukocyte trapping. However, the constituent endothelial ICAM-1 is not elevated by VH.

Prognostic relevance of cerbB2 expression following neoadjuvant chemotherapy in patients in a randomised trial of neoadjuvant versus adjuvant chemoendocrine therapy

Recent advances in the detection and treatment of breast cancer have led to an intensive search for new markers of both prognosis and chemoresponsiveness. The oncogene cerbB2 has proved to be one of the most promising markers currently under study, both as a predictor of chemoresponsiveness and as a marker of poor prognosis. In addition the increasing use of neoadjuvant chemotherapy has led to the loss of standard prognostic criteria. In order to study the potential role of cerbB2 expression as an indicator of chemoendocrine resistance and poor prognosis, both before and after chemotherapy, we obtained tumour sections from 283 women enrolled onto a neoadjuvant trial. In this trial patients were randomised to receive either primary surgery followed by adjuvant chemoendocrine treatment or neoadjuvant chemoendocrine therapy followed by surgery. CerbB2 status was determined immunohistochemically on all of these patients. Thirty-eight percent of the tumours were cerbB2 positive. There was no significant difference in expression between the adjuvant (41%) and neoadjuvant arms (35%). CerbB2 positive patients were much more likely to have shown non-response to chemoendocrine therapy (p < 0.001) and had a worse DES (p < 0.05). The best prognosis was seen in cerbB2 negative patients receiving neoadjuvant chemoendocrine therapy who showed a significantly better DFS (p < 0.05), than the cerbB2 negative patients receiving adjuvant therapy.

Time-related effects of estrogen withdrawal on proliferation- and cell death-related events in MCF-7 xenografts

Endocrine treatments for human breast cancer have been based largely upon the removal of estrogenic stimuli. The regression of tumors after estrogen deprivation has generally been characterized as being due to reduced proliferation but more recently has been recognized to also involve increased apoptosis. The aim of our experiments was to define the associated changes in certain proliferation- and cell death-related biological parameters after hormone withdrawal from estrogen-dependent MCF-7 xenografts in athymic nude mice using immunohistochemical techniques. The baseline estrogen receptor (ER) level of this MCF-7 xenograft was relatively low (average H score 23) but it was strongly Bcl-2-, PgR- and pS2-positive, indicating the functional integrity of estrogen signaling. Changes in proliferation (Ki-67), apoptosis, ER, progesterone receptor (PgR), cyclin D1, p27kip1, Bcl-2 and Bax expression were assessed during the 2 weeks after estrogen deprivation. ER levels rose markedly after estrogen ablation, whereas PgR levels fell to about 10% of baseline and pS2 levels halved. The proportion of Ki-67-positive cells was unchanged after 24 hr but by day 14 had reduced by about 80%. The normal levels of cyclin D1 also reduced after estrogen withdrawal in contrast to the rapid increase in levels of cyclin-dependent kinase inhibitor p27kip1. This latter increase appeared to occur in advance of the changes in Ki-67. The proportion of apoptotic cells increased from a mean 1.5% at baseline to 2.9% after 3 days and 4.7% after 14 days. There were reductions in both Bcl-2 and Bax staining but these appeared to be greater for Bcl-2, effectively decreasing the Bcl-2/Bax ratio. Our results provide a framework for the use of these parameters as intermediate markers in comparisons of hormonal agents for human breast cancer treatment.

Clinical studies of apoptosis and proliferation in breast cancer

The interaction between cell death and cell proliferation determines the growth dynamics of all tissues. Studies are described here which relate the changes in proliferation and apoptosis that occur in human breast cancer during medical therapeutic manoeuvres. Xenograft studies strongly support the involvement of increased apoptosis as well as decreased proliferation after oestrogen withdrawal, and limited studies in clinical samples confirm the involvement of both processes. Cytotoxic chemotherapy induces increases in apoptosis within 24 h of starting treatment. However, after 3 months therapy the residual cell population shows apoptotic and proliferation indices much below pretreatment levels. Further molecular studies of this "dormant" population are important to characterise the mechanism of their resistance to drug therapy. The early changes in proliferation and apoptosis may provide useful intermediate response indices.

Reduced apoptosis and proliferation and increased Bcl-2 in residual breast cancer following preoperative chemotherapy

Experimental laboratory data suggest that tumour growth is a balance between apoptosis and proliferation and that suppression of drug-induced apoptosis by oncogenes such as bcl-2 may be an important cause of intrinsic chemoresistance. The aims of this study were to assess the in vivo relationship of apoptosis to proliferation and Bcl-2 protein in human breast tumours both prior to chemotherapy and in the residual resistant cell population at the completion of treatment. We examined apoptotic index (AI), Ki67 and Bcl-2 protein expression in the tissue of 40 patients with operable breast cancer immediately before ECF preoperative chemotherapy, and in 20 of these patients with residual tumour, at the completion of treatment. There was a significant positive association between AI and Ki67 both before and after chemotherapy, and in their percentage change with treatment. In the residual specimens AI and Ki67 were significantly reduced compared with pre-treatment biopsies, while Bcl-2 expression showed a significant increase. No differences were seen in the pre-treatment levels of any of the variables measured between patients obtaining pathological complete response and those who did not, although numbers were small. These data suggest that apoptosis and proliferation are closely related in vivo. It is possible that the phenotype of reduced apoptosis and proliferation, and increased Bcl-2 may be associated with breast cancer cells resistant to cytotoxic chemotherapy, although this can only be proven by assessing larger numbers of patients in relation to pathological response.

Induction of apoptosis by tamoxifen and ICI 182780 in primary breast cancer

Hormonal breast cancer therapies have traditionally been considered cytostatic, but recent pre-clinical data suggest that anti-oestrogens can induce apoptosis. The aim of this study was to assess whether tamoxifen (TAM) and ICI 182780 (ICI) could induce apoptosis in human breast cancer, and whether this was related to oestrogen receptor status. We measured apoptosis in primary breast cancer patients before and after pre-surgical treatment with 20 mg/day TAM (study 1) or 6 or 18 mg/day ICI (study 2). In each study there was a randomised non-treatment (NT) control group. TAM significantly increased apoptotic index (AI) in ER+ but not in ER- tumours. There was a significant increase in AI following treatment with ICI. Insufficient pairs of samples were available to determine whether this change was confined to ER+ tumours, but in a cross-sectional analysis AI was significantly higher in excision biopsies for ICI-treated than NT patients for ER+ but not ER- tumours. Our results provide clinical evidence that apoptosis may be induced in ER+ primary breast cancer by both non-steroidal and steroidal anti-oestrogens.

Clinical nursing judgment related to reducing the incidence of falls by elderly patients

The incidence of falls among elderly patients has been and continues to be a major challenge for nurses. Falls add physical injury and mental stress to patients' existing health problems, are a deterrent to rehabilitation, and increase healthcare costs. This study describes the variables that nurses identify as influencing their clinical decision making and the nursing behaviors associated with preventing patient falls. The study was grounded in the theory that discretionary nursing behaviors are related to nursing expertise, and the study was guided by the assumption that such behaviors are proactive and anticipatory. An analysis of interviews of registered nurses (n = 14) working on a geriatric rehabilitation unit in a medical center in Ohio focused on the zones of association and the contextual meanings of language used by the nurses when discussing patient falls. Four themes emerged: the reasons for patient falls, identifying patients who are likely to fall, preventing falls, and nurses' feelings when patients fall.