Biomedical subjects

S J Cleator

Publications and source records attributed to S J Cleator.

4 recordsLinked to original sources

PubMed2006

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.

Adult↗

PubMed2005

Good clinical response of breast cancers to neoadjuvant chemoendocrine therapy is associated with improved overall survival.

BACKGROUND: We present extended follow-up from a prospective randomised trial evaluating the role of neoadjuvant chemoendocrine therapy in the treatment of operable breast cancer. PATIENTS AND METHODS: 309 women were randomised to primary surgery followed by eight cycles of adjuvant mitoxantrone, methotrexate with tamoxifen (2MT) or 2MT with mitomycin-C (3MT) versus the same regimen for four cycles before followed by four cycles after surgery. For this analysis the median follow-up of patients was 112 months. RESULTS: After 10 years follow-up there is still no statistically significant difference in disease-free survival (DFS) (71% versus 71%) or overall survival (OS) (63% versus 70%) when comparing adjuvant versus neoadjuvant treatment, respectively. Of 144 evaluable patients in the neoadjuvant arm, 74 achieved a good clinical response and 70 patients achieved a poor clinical response. Good responders had a superior DFS (80% versus 64%, P=0.01) and OS (77% versus 63%, P=0.03) compared to poor responders. CONCLUSIONS: At 10 years, neoadjuvant and adjuvant treatment continue to have equivalent OS and DFS. Good clinical response to neoadjuvant chemotherapy is associated with superior DFS and OS. This supports the use of clinical response of primary breast cancer to neoadjuvant therapy as a surrogate marker of survival benefit.

Adult↗

PubMed2000

Management problems in oncology.

Man has evolved sophisticated defence mechanisms over millions of years to combat insertion of foreign DNA into his cells. However, gene therapy carries huge potential for the treatment of cancer. The challenge is therefore to translate our scientific knowledge into a clinical reality.

Animals↗

PubMed1992

An examination of needlestick injury rates, hepatitis B vaccination uptake and instruction on 'sharps' technique among medical students.

A 12-question survey designed to examine venepuncture techniques and instruction and uptake of hepatitis B vaccination was completed by 172 of the 275 medical students to whom it was distributed (a response rate of 62.5%). Seventy-five injuries were reported, at an average of 0.3 per student per year. Of the respondents, 63% resheathed needles after use, a practice frequently cited as a cause of needlestick injury. However, in this sample resheathing was not significantly associated with a higher or lower injury rate (chi 2 = 2.07, P > 0.1). Of the respondents from the most recent intake, only 20 out of 57 had completed a course of hepatitis B vaccinations prior to the commencement of venepuncture duties. There was almost universal ignorance concerning the correct course of action following 'sharps' injury. Recommendations are made concerning hepatitis B vaccination and teaching strategies for medical students.

Bloodletting↗