Philip J. Drew

The analysis of doxorubicin resistance in human breast cancer cells using antibody microarrays

Doxorubicin is considered to be the most effective agent in the treatment of breast cancer patients. Unfortunately, resistance to this agent is common, representing a major obstacle to successful treatment. The identification of novel biomarkers that are able to predict treatment response may allow therapy to be tailored to individual patients. Antibody microarrays provide a powerful new technique, enabling the global comparative analysis of many proteins simultaneously. This technology may identify a panel of proteins to discriminate between drug-resistant and drug-sensitive samples. The Panorama Cell Signaling Antibody Microarray was exploited to analyze the MDA-MB-231 breast cancer cell line and a novel derivative, which displays significant resistance to doxorubicin at clinically relevant concentrations. The microarray comprised 224 antibodies selected from a variety of pathways, including apoptotic and cell signaling pathways. A standard ≥2.0-fold cutoff value was used to determine differentially expressed proteins. A decrease in the expression of mitogen-activated protein kinase–activated monophosphotyrosine (phosphorylated extracellular signal-regulated kinase; 2.8-fold decrease), cyclin D2 (2.5-fold decrease), cytokeratin 18 (2.5-fold decrease), cyclin B1 (2.4-fold decrease), and heterogeneous nuclear ribonucleoprotein m3-m4 (2.0-fold decrease) was associated with doxorubicin resistance. Western blotting was exploited to confirm results from the antibody microarray experiment. These results suggest that antibody microarrays can be used to identify novel biomarkers and further validation may reveal mechanisms of chemotherapy resistance and identify potential therapeutic targets. [Mol Cancer Ther 2006;5(8):2115–20]

Artificial neural networks applied to outcome prediction for colorectal cancer patients in separate institutions

BACKGROUND Artificial neural networks are computer programs that can be used to discover complex relations within data sets. They permit the recognition of patterns in complex biological data sets that cannot be detected with conventional linear statistical analysis. One such complex problem is the prediction of outcome for individual patients treated for colorectal cancer. Predictions of outcome in such patients have traditionally been based on population statistics. However, these predictions have little meaning for the individual patient. We report the training of neural networks to predict outcome for individual patients from one institution and their predictive performance on data from a different institution in another region. METHODS 5-year follow-up data from 334 patients treated for colorectal cancer were used to train and validate six neural networks designed for the prediction of death within 9, 12, 15, 18, 21, and 24 months. The previously trained 12-month neural network was then applied to 2-year follow-up data from patients from a second institution; outcome was concealed. No further training of the neural network was undertaken. The networks predictions were compared with those of two consultant colorectal surgeons supplied with the same data. FINDINGS All six neural networks were able to achieve overall accuracy greater than 80% for the prediction of death for individual patients at institution 1 within 9, 12, 15, 18, 21, and 24 months. The mean sensitivity and specificity were 60% and 88%. When the neural network trained to predict death within 12 months was applied to data from the second institution, overall accuracy of 90% (95% CI 84-96) was achieved, compared with the overall accuracy of the colorectal surgeons of 79% (71-87) and 75% (66-84). INTERPRETATION The neural networks were able to predict outcome for individual patients with colorectal cancer much more accurately than the currently available clinicopathological methods. Once trained on data from one institution, the neural networks were able to predict outcome for patients from an unrelated institution.

Dynamic Contrast Enhanced Magnetic Resonance Imaging of the Breast Is Superior to Triple Assessment for the Pre-Operative Detection of Multifocal Breast Cancer

Background: Inadequately treated multifocal and multicentric disease results in increased local recurrence following breast-conserving surgery. The accurate preoperative diagnosis of multifocal/centric breast cancer would facilitate the planning of appropriate surgery and prevent reoperation for residual disease. While triple assessment remains the established diagnostic technique, its sensitivity for the diagnosis of multifocal disease remains poor. Dynamic contrast enhanced Magnetic Resonance Imaging (DCE-MRI) of the breast represents an alternative emerging diagnostic modality that has been shown to be highly sensitive for the delineation of primary breast cancer. The aim of this study was to prospectively compare the diagnostic accuracy of DCE-MRI of the breast with conventional triple assessment for the preoperative diagnosis of multifocal/centric breast cancer.Methods: Patients were recruited from the symptomatic breast clinics. All patients underwent standard triple assessment and DCE-MRI. The MRI scans were reported by a single radiologist blinded to the results of the triple assessment. Surgery was then planned accordingly to all available scan results and the specimens examined by a single pathologist. All patients who did not undergo surgery have been followed up for a minimum of 18 months.Results: A total of 334 women were recruited. There were 178 (52%) cancers that were histologically confirmed and multifocal/centric breast cancer was diagnosed provisionally by the preoperative investigations in 68 (38%); multifocal n = 33, multicentric n = 35, of these patients. In this group, subsequent histology confirmed multifocal/centric disease in 50 (73.5%): multifocal n = 15, multicentric n = 35. Unifocal cancer was found in 15 (22%) and benign disease in 3 (4.4%). The resultant sensitivity, specificity, positive, and negative predictive values were 18%, 100%, 100%, and 76% for triple assessment and 100%, 86%, 73%, and 100% for DCE-MRI.Conclusion: DCE-MRI identified a subgroup of breast cancer patients with multifocal/centric disease not evident on standard triple assessment. MRI of the breast should be considered for the preoperative planning of surgery for primary breast cancer.

Enhanced recovery in colorectal resections: a systematic review and meta-analysis.

Objective  The study aimed to produce a comprehensive up‐to‐date meta‐analysis exploring the safety and efficacy of enhanced recovery (ER) programmes after colorectal resection.

Genetic changes in breast cancer detected by comparative genomic hybridisation

Breast cancer is characterised by a number of genetic aberrations. Our purpose was to use comparative genomic hybridisation (CGH) to screen breast carcinomas for copy number changes: 44 ductal and 8 lobular carcinomas were studied and a large number of genetic aberrations identified. Many of these showed similarity to previous CGH results, however, a number of loci not previously shown to have undergone frequent change were identified. This included copy number gains affecting chromosomes 1p, 4q, 5q, 6q and 13q. Furthermore, we have identified 2 regions of copy number change, the gain on 5p and deletion of 16q, which correlated with lobular carcinomas. Our results highlight several areas of the genome that may be important in the molecular genetics of breast cancer. Int. J. Cancer 86:494–500, 2000.

Routine screening for local recurrence following breast-conserving therapy for cancer with dynamic contrast-enhanced magnetic resonance imaging of the breast

AbstractBackground: Dynamic contrast-enhanced magnetic resonance imaging (MRI) of the breast is highly sensitive for the diagnosis of primary breast malignancy. We investigated the clinical application of dedicated dynamic breast MR for routine screening for local recurrence following breast-conserving therapy. Methods: Patients underwent a single dynamic MR of the breast routinely in the period 1 to 2 years following treatment, or earlier if recurrence was suspected. A biopsy was performed if there was suspicion of recurrence on MR. Results: One hundred and five patients with a median age of 58 years (range 50 to 65 years) were recruited for the study. Sixteen biopsies were performed and nine recurrences were confirmed histologically. Patients not undergoing biopsy have been followed up for a median of 341 days (range 168 to 451 days) following the MR. The sensitivity for clinical examination, mammography, examination combined with mammography, and MRI alone for the detection of recurrent cancer were 89%, 67%, 100%, and 100%, respectively, and the specificity was 76%, 85%, 67%, and 93%. Conclusion: Combined clinical examination and mammography are as sensitive as dedicated dynamic MR of the breast for the detection of locoregional recurrence, but breast MRI is associated with a far greater specificity. Therefore, dedicated dynamic breast MRI should be used when there is clinical or mammographic suspicion of recurrence to confirm or refute its presence.

Preliminary experience with butyl-2-cyanoacrylate adhesive in tension-free inguinal hernia repair

Sir We read with interest the paper by Dr Shifrin et al. (Br J Sue 1996; 83: 1107-9) regarding carotid endarterectomy without preoperative angiography using Duplex ultrasonography as the sole investigative technique. They concluded that it was safe to omit angiography in preoperative assessment (in patients selected on surgeon’s preference) as they found no difference in postoperative complications compared with patients who had also undergone conventional angiography. We do not consider that this conclusion can be drawn from their results. Following the North American Symptomatic Carotid Endarterectomy Trial study’ a clearly defined group of patients with more than 70 per cent stenosis of the internal carotid artery were demonstrated to receive benefit from surgery compared with medical therapy. An important role of preoperative investigation in carotid disease is to assess accurately the degree of stenosis to define those patients who will benefit from surgery. The authors do not state how they assessed the stenosis found at operation and how closely it agreed with the Duplex findings. How do the authors know that they have not operated on a number of patients with a 50 per cent stenosis who did not require surgery? Such a group of patients would be exposed to the risks of surgery unnecessarily. From the data provided in this paper we would therefore still be reticent to perform endarterectomy on patients based on a single preoperative investigation such as duplex ultrasonography.

Vascular endothelial growth factor in premenopausal women - indicator of the best time for breast cancer surgery?

Timing of surgery in premenopausal patients with breast cancer remains controversial. Angiogenesis is essential for tumour growth and vascular endothelial growth factor (VEGF) is one of the most potent angiogenic cytokines. We aimed to determine whether the study of VEGF in relation to the menstrual cycle could help further the understanding of this issue of surgical intervention. Fourteen premenopausal women were recruited, along with three post-menopausal women, a woman on an oral contraceptive pill and a single male subject. Between eight and 11 samples were taken per person, over one menstrual cycle (over 1 month in the five controls) and analysed for sex hormones and VEGF165. Serum VEGF was significantly lower in the luteal phase and showed a significant negative correlation with progesterone in all 14 premenopausal women. No inter-sample variations of VEGF were noted in the controls. Serum from both phases of the cycle from one subject was added to MCF-7 breast cancer cells; VEGF expression in the supernatant was lower in the cells to which the luteal phase serum was added. The lowering of a potent angiogenic cytokine in the luteal phase suggests a possible decreased potential for micrometastasis establishment in that phase. This fall in VEGF may be an effect of progesterone and should be the focus of future studies.

Current applications and future direction of MR mammography

Compared with triple assessment for symptomatic and occult breast disease, magnetic resonance mammography (MRM) offers higher sensitivity for the detection of multifocal cancer, which is important in selecting patients appropriately for breast-conserving surgery. It is an ideal tool for the screening of patients with a high risk of breast cancer or where there is axillary disease or nipple discharge and conventional imaging has not revealed the primary focus. Techniques are now available to biopsy lesions only apparent on MRM. MRM can differentiate scar tissue from tumour; therefore, it is useful in patients in which there is possible recurrent disease. Clinical and X-ray mammographic assessment of response to neoadjuvant chemotherapy may be unreliable because of replacement of the tumour with scar tissue. MRM can identify responders and nonresponders with more accuracy. It is the modality of choice for the assessment of breast implants for rupture with accuracy higher than X-ray mammography and ultrasound. Advances in both spatial and temporal resolutions, the imaging sequences employed, pharmacokinetic modelling of contrast uptake, the use of dedicated and now phased-array breast coils, and gadolinium-based contrast agents have all played their part in the advancement of this imaging technique. Despite the limitations of patient compliance, scan-time and cost, this review describes how MRM has become a valuable tool in breast disease, especially in cases of diagnostic uncertainty. However, MRM must make the transition from research institutions into routine clinical practice.

A UK training programme for nurse practitioner flexible sigmoidoscopy and a prospective evaluation of the practice of the first UK trained nurse flexible sigmoidoscopist

Background—Flexible sigmoidoscopy is a technical skill that has been successfully performed by suitably trained colorectal nurse practitioners in the USA. However, no recognised training course exists for nurse practitioners in the UK. Aims—To design and evaluate a training programme for nurse endoscopists. Methods—A multidisciplinary committee of nurses and clinicians developed a structured programme of study and practice. This involved a staged process of observations, withdrawals, and ultimately, full procedures. Once training had been completed the nurse practitioner was permitted to practice independently. Patients with colorectal symptoms referred for flexible sigmoidoscopy were examined for the final stages of training and independent practice. A prospective evaluation of the training and practice of the first trained nurse flexible sigmoidoscopist was performed. Barium enema, video, clinical follow up, and histology were used to validate the results of the flexible sigmoidoscopies. Results—The training programme required that 35 observations, 35 withdrawals, and 35 supervised full procedures were performed prior to the development of independent practice. Subsequent to the completion of this programme 215 patients have been examined independently by the nurse practitioner. Ninety three per cent of the examinations were judged successful and pathology was identified in 51%. The nurse endoscopist successfully identified all “significant” pathology whereas barium enema failed to identify pathology in 12.5%. There were no complications. Conclusion—With suitable training nurse endosocopists are able to perform flexible sigmoidoscopy safely and effectively.