Dual targeting of Src and ER prevents acquired antihormone resistance in breast cancer cells

Acquired resistance to endocrine therapies presents a major obstacle to the successful treatment of breast cancer patients. Previously, we have shown that acquisition of resistance to tamoxifen in breast cancer cells is accompanied by an elevation in Src kinase activity which promotes an aggressive, invasive phenotype in vitro. Here, we have explored the potential therapeutic effects of combining Src inhibition with anti-oestrogen treatment on the development of endocrine insensitivity in breast cancer cells. Treatment of MCF7 and T47D cells with tamoxifen alone resulted in an initial growth inhibitory phase followed by the eventual development of tamoxifen resistance together with an elevation of Src kinase activity, which was central to their increased invasive capacity. Chronic exposure of both cell types to the Src inhibitor, AZD0530, as a monotherapy resulted in outgrowth of AZD0530-resistant cells, in which Src kinase activity remained suppressed as did their in vitro invasive nature. Treatment of both MCF7 and T47D cells with AZD0530 in combination with tamoxifen resulted in a reduction of Src activity together with inhibition of focal adhesion kinase phosphorylation and a complete abrogation of their in vitro invasive behaviour. Furthermore, combination therapy significantly suppressed expression of cyclinD1 and c-myc and prevented cell proliferation and the subsequent emergence of a resistant phenotype, with total cell loss occurring by 12 weeks. These data demonstrate that pharmacological targeting of Src kinase, in conjunction with antihormone therapies, effectively prevents antihormone resistance in breast cancer cells in vitro and suggests a potential novel therapeutic benefit of Src kinase inhibitors clinically.

Clinicopathologic features of breast disease in Jamaica: findings of the Jamaican Breast Disease Study, 2000-2002

OBJECTIVE

To describe the clinicopathologic profile of breast disease in Jamaica.

METHODS

The Jamaican Breast Disease Study is an ongoing prospective, multidisciplinary investigation of breast disease at the University Hospital of the West Indies (UHWI). The initial phase was a prevalence survey comprising all consenting patients referred to the Surgical Outpatient Department (SOPD) UHWI, for breast disease. Demographic, clinical, radiologic and pathologic information were recorded for each patient and the data for the first three years (2000-2002) were analyzed.

RESULTS

A total of 1189 patients was enrolled for the study period (28.8% of all new SOPD patients). The age range was 10 to 93 years (mean/SD = 36.5 +/- 16.4 years) with a female : male ratio of 14:1. Most patients (67.8%) presented with a palpable lump and the clinical diagnosis was benign in the majority (70.4%) of patients. Fibroadenoma was the most common benign histologic result (39.4% of all biopsies) followed by non-proliferative (fibrocystic) disease (19.3% of all biopsies). Proliferative disease without atypia, complex fibroadenoma and atypical ductal hyperplasia accounted for 6.9%, 2.6% and 0.4% of biopsies respectively. Overall, 23.4% of biopsies showed malignant histology (10.8% patients); invasive ductal carcinoma accounted for the majority of these cases (69.5%).

CONCLUSIONS

The majority of patients with breast disease in Jamaica are young women with clinically benign disease. There was a low prevalence of clinically significant premalignant disease. This is the first study to prospectively describe the clinicopathologic features of breast disease in Jamaica and supports the need for advocating breast cancer screening to facilitate detection of significant premalignant disease and early stages of breast cancer.

Penetrating neck trauma and the aberrant subclavian artery

Vascular injuries from penetrating trauma to the base of the neck are accompanied by significant morbidity and potential mortality. These injuries require several diagnostic adjuncts in order to facilitate early diagnosis and appropriate treatment. Herein reported is the case of a patient who sustained penetrating injury to the thoracic inlet but had a fortuitous anomaly that prevented vascular injury and its attendant complications.

An economic evaluation of three physiotherapy treatments for non-specific neck disorders alongside a randomized trial

OBJECTIVES

Cost-effectiveness and cost-utility analyses were conducted to compare advice and exercise plus manual therapy (MT) and advice and exercise plus pulsed shortwave diathermy (PSWD) with advice and exercise alone (A&E) in the treatment of non-specific neck disorders by experienced physiotherapists.

METHODS

Between July 2000 and June 2002, 350 participants with neck disorders from 15 physiotherapy departments were randomized to: A&E (n = 115); MT (n = 114) and PSWD (n = 121). Outcome and resource-use data were collected using physiotherapist case report forms and participant self-complete questionnaires. Outcome measures were the Northwick Park Neck Pain Questionnaire (NPQ) and EuroQoL EQ-5D [used to derive quality-adjusted-life-year (QALY) utility scores]. Two economic viewpoints were considered (health care and societal). Cost-effectiveness acceptability curves were used to assess the probabilities of the interventions being cost-effective at different willingness-to-pay threshold values.

RESULTS

Mean improvement in NPQ at 6 months was 11.5 in the A&E group, 10.2 in the MT group and 10.3 in the PSWD group; mean QALY scores were 0.362, 0.342 and 0.360, respectively. Mean health care costs were pound sterling105, pound sterling119 and pound sterling123 in the A&E, MT and PSWD groups, respectively. Mean societal costs were pound sterling373, pound sterling303 and pound sterling 338 in each group, respectively. Depending on the viewpoint and the outcome measure, A&E or MT were most likely to be the cost-effective interventions. PSWD was consistently the least cost-effective intervention.

CONCLUSIONS

The cost-effective intervention is likely to be A&E or MT, depending on the economic perspective and preferred outcome, but not PSWD.

Effectiveness of the dual specific Src/Abl kinase inhibitor AZD0530 in combination with tamoxifen in preventing acquired anti-estrogen resistance in breast cancer cells

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Background: AZD0530 is a novel, orally potent, once-daily, highly selective and dual-specific Src/Abl kinase inhibitor with potential for activity in a wide range of tumors. In the context of breast cancer, where tamoxifen resistance presents a major problem, Src inhibition may be a particularly valuable therapeutic strategy since we have previously observed that elevated Src kinase activity accompanies anti-estrogen resistance in vitro, promoting an aggressive cell phenotype. Here, we have explored the potential therapeutic effects of Src inhibition with AZD0530, alone and in combination with tamoxifen, on the acquisition of endocrine resistance in breast cancer cells. Methods: MCF7 and T47D breast cancer cells were exposed to tamoxifen (10–7 M), AZD0530 (1 μM), or both agents in combination for a minimum of 10 months with passaging as necessary, or until total cell death occurred. Cells were assayed at monthly intervals for intracellular signaling pathway activity (Western Blotting) and in vitro invasive capacity (Matrigel invasion assays). Apoptosis and proliferation were assessed by ELISA and Ki67 staining, respectively. Changes in c-Myc and cyclin-D1 were measured with RT-PCR. Results: Treatment of cells with tamoxifen alone ultimately resulted in acquired resistance, elevated Src kinase activity, and a Src- dependent increase in invasive capacity. Chronic exposure to AZD0530 alone resulted in outgrowth of AZD0530 resistant cells, in which Src kinase activity remained suppressed as did their in vitro invasiveness. Treatment of MCF7 and T47D cells with AZD0530 and tamoxifen combined resulted in a reduction of Src, FAK, and Akt activity, inhibition of c-Myc gene expression, and complete abrogation of their in vitro invasive behavior. Furthermore, combination treatment completely prevented cell proliferation and the subsequent emergence of a resistant phenotype, with a total loss of cells by 12 weeks. Conclusions: Inhibition of Src kinase with AZD0530, when used in conjunction with anti-estrogen therapies, effectively prevents acquired resistance in breast cancer cells in vitro suggesting a potential novel therapeutic benefit of Src kinase inhibitors clinically.

No significant financial relationships to disclose.

Identification of transmembrane proteins as potential prognostic markers and therapeutic targets in breast cancer by a screen for signal sequence encoding transcripts

This study demonstrates, through a combination of stringent screening methods and thorough validation, that it is possible to identify transmembrane proteins preferentially expressed in primary breast tumour cells. mRNA was extracted from tumour cells isolated from invasive breast cancers and it was then subtracted against normal breast tissue mRNA prior to the generation of a signal sequence-trap library. Screening of the library identified 31 positive clones encoding 12 cell-surface and 12 secreted proteins. The expression of a subset of transmembrane genes was then interrogated using a high-throughput method (tissue microarray) coupled with cutting-edge in situ techniques in a large cohort of patients who had undergone uniform adjuvant chemotherapy. Expression of CD98 heavy chain (CD98HC) and low-level expression of the insulin-like growth factor 2 receptor/mannose-6-phosphate receptor (IGF2R/M6PR) correlated with poor patient prognosis in the whole cohort. Expression of bradykinin receptor B1 (BDKRB1) and testis enhanced gene transcript (TEGT) correlated with good prognosis in woman with oestrogen receptor (ER)-negative breast tumours. These results indicate that this combined approach of isolating primary tumour cells, generating a library to specifically isolate signal-sequence-containing transcripts, and in situ hybridization on tissue microarrays successfully identified novel prognostic markers (BDKRB1, CD98hc, and TEGT) and potential transmembrane therapeutic targets (CD98hc) in breast cancer.

Buckle-related complications following surgical repair of retinal dialysis

AIM

To describe buckle-related complications following surgical repair of retinal dialysis.

METHODS

A retrospective study of 28 consecutive cryobuckle procedures for retinal detachments secondary to retinal dialysis is reported, with particular attention directed towards postoperative complications relating to the buckle. Stata 8 statistical software and Fisher's exact test were used to analyse the data.

RESULTS

Of the 28 cases, anatomic success was achieved with a single procedure in 26 cases (92.9%). Postoperative complications were seen in 20 cases (71.4%), with complications attributable to the buckle noted in 19 (67.9%). Buckle-related complications included exposure (7; 25%), strabismus (5; 17.9%), and infection (3; 10.7%). Surgical removal of the buckle was indicated in 13 cases (46.4%), typically within the first 6 postoperative months. Of these, the retina remained flat following removal of buckle in 12 cases (92.3%), whereas the retina redetached in one case (7.7%).

CONCLUSION

Cryotherapy with explant is an effective primary procedure for the surgical repair of retinal detachment secondary to retinal dialysis. However, there is a high rate of postoperative complications relating to the buckle following this surgical approach, although the buckle can be safely removed without compromising the anatomic success of the primary surgery in the vast majority of cases.

Sorafenib in advanced melanoma: a Phase II randomised discontinuation trial analysis

The effects of sorafenib – an oral multikinase inhibitor targeting the tumour and tumour vasculature – were evaluated in patients with advanced melanoma enrolled in a large multidisease Phase II randomised discontinuation trial (RDT). Enrolled patients received a 12-week run-in of sorafenib 400 mg twice daily (b.i.d.). Patients with changes in bi-dimensional tumour measurements <25% from baseline were then randomised to sorafenib or placebo for a further 12 weeks (ie to week 24). Patients with ⩾25% tumour shrinkage after the run-in continued on open-label sorafenib, whereas those with ⩾25% tumour growth discontinued treatment. This analysis focussed on secondary RDT end points: changes in bi-dimensional tumour measurements from baseline after 12 weeks and overall tumour responses (WHO criteria) at week 24, progression-free survival (PFS), safety and biomarkers (BRAF, KRAS and NRAS mutational status). Of 37 melanoma patients treated during the run-in phase, 34 were evaluable for response: one had ⩾25% tumour shrinkage and remained on open-label sorafenib; six (16%) had <25% tumour growth and were randomised (placebo, n=3; sorafenib, n=3); and 27 had ⩾25% tumour growth and discontinued. All three randomised sorafenib patients progressed by week 24; one remained on sorafenib for symptomatic relief. All three placebo patients progressed by week-24 and were re-started on sorafenib; one experienced disease re-stabilisation. Overall, the confirmed best responses for each of the 37 melanoma patients who received sorafenib were 19% stable disease (SD) (ie n=1 open-label; n=6 randomised), 62% (n=23) progressive disease (PD) and 19% (n=7) unevaluable. The overall median PFS was 11 weeks. The six randomised patients with SD had overall PFS values ranging from 16 to 34 weeks. The most common drug-related adverse events were dermatological (eg rash/desquamation, 51%; hand-foot skin reaction, 35%). There was no relationship between V600E BRAF status and disease stability. DNA was extracted from the biopsies of 17/22 patients. Six had V600E-positive tumours (n=4 had PD; n=1 had SD; n=1 unevaluable for response), and 11 had tumours containing wild-type BRAF (n=9 PD; n=1 SD; n=1 unevaluable for response). In conclusion, sorafenib is well tolerated but has little or no antitumour activity in advanced melanoma patients as a single agent at the dose evaluated (400 mg b.i.d.). Ongoing trials in advanced melanoma are evaluating sorafenib combination therapies.

Acetic acid-enhanced magnification endoscopy in the diagnosis of specialized intestinal metaplasia, dysplasia and early cancer in Barrett's oesophagus

BACKGROUND

Barrett's surveillance is prone to sampling error. Aim To determine whether enhanced magnification endoscopy using acetic acid instillation improves diagnostic accuracy of specialized intestinal metaplasia/dysplasia in Barrett's oesophagus.

METHODS

We examined the detection rate of the specialized intestinal metaplasia/dysplasia in 64 consecutive patients with Barrett's oesophagus using acetic acid to enhance mucosal pit patterns. Histology was compared with the previous findings at recent conventional surveillance in 62 patients. We also examined the inter-/intra-observer agreement in the assessment of the enhanced magnification endoscopy pit pattern findings.

RESULTS

Histology revealed columnar-lined oesophagus in six (9%) patients, specialized intestinal metaplasia in 49 (77%), low-grade dysplasia in five (8%), high-grade dysplasia in one (2%), and adenocarcinoma in three (5%). There was discordance between the histologic findings from conventional surveillance with random biopsy. Fifteen patients (24%) had a histological upgrade with enhanced magnification endoscopy. There was a high detection rate of specialized intestinal metaplasia even in short segment Barrett's oesophagus (74%), and additionally, there were two cancers, one with 2-cm Barrett's oesophagus and one ultra-short (1 cm). The mean kappa values for inter- and intra-observer agreement in assessing the pit patterns were 0.571 (0.041) and 0.709 (0.038), respectively.

CONCLUSIONS

Enhanced magnification endoscopy allows clear visualization of the epithelial pit patterns within Barrett's oesophagus, and targeted biopsy results in a high yield of specialized intestinal metaplasia and dysplasia.

Ovarian cancer death reduction for women at high risk: workload implications for gynaecology services

Ovarian cancer spreads early, presents late and is difficult to cure. Reducing death rates from ovarian malignancy has focussed on the unaffected females of families with a high chance of a mutant gene such as BRCA1 and BRCA2. We set up a familial ovarian cancer service in a district general hospital in the UK, serving a population of 330,000. The clinical genetics team acted as gatekeepers to the service. Risk assessment, ultrasound and biochemical screening and prophylactic oophorectomy were discussed. Gene testing was offered when appropriate. This study reviews the levels of activity for the first 8 years of the service. In all, 153 women were referred, of whom 34 (16%) did not have significant clinical histories. Of the 114 who fulfilled the UKFOCSS criteria for family history and age, four were quickly found to be gene mutation negative and 20 (17%) declined intervention. A total of 29 (25%) chose prophylactic oophorectomy and 61 (54%) chose ultrasound screening.

A cost consequences analysis of local corticosteroid injection and physiotherapy for the treatment of new episodes of unilateral shoulder pain in primary care

OBJECTIVE

Local steroid injections and community-based physiotherapy have been shown to be of similar benefit for treating shoulder pain presenting to primary care. This paper presents a cost consequences analysis of a prospective economic evaluation, conducted alongside a randomized clinical trial (RCT) of corticosteroid injections versus physiotherapy for new episodes of unilateral shoulder pain, to determine the economic implications of injection versus physiotherapy.

METHODS

A pragmatic RCT with 207 patients randomized to either physiotherapy (n = 103) or local steroid injection (n = 104) was conducted. The resource inputs required were identified for each treatment arm in terms of capital, staff and consumables. These were measured for the period up to 6 months post-randomization. Outcome measures included shoulder disability, shoulder pain, global assessment of health change and the EQ5D, all at 6 months. A sensitivity analysis was performed around the general practitioner minor surgical fee.

RESULTS

Analysis is presented on the 199 patients for which the general practice record review (101 physiotherapy, 98 injection) was available. The total mean costs, per patient, were 71.28 pound sterling for the injection group and 114.60 pound sterling for the physiotherapy group. The difference in average total cost per patient was 43.32 pound sterling (95% bootstrap confidence interval: 16.21 pound sterling, 68.03 pound sterling ). This is a statistically significant difference in cost. Outcome was similar in both groups across all measures following intervention. Smaller mean differences in cost were observed between the treatment groups in the sensitivity analysis, but the difference remained in favour of injection over physiotherapy.

CONCLUSIONS

This study has shown, given similar clinical outcomes across the treatment groups, that corticosteroid injections were the cost-effective option for patients presenting with new episodes of unilateral shoulder pain in primary care.