Medicine (St Vincent's) - Research Publications

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    Fenofibrate, which reduces risk of sight-threatening diabetic retinopathy in type 2 diabetes, is associated with early narrowing of retinal venules: a FIELD trial substudy
    Quinn, N ; Januszewski, AS ; Brazionis, L ; O'Connell, R ; Aryal, N ; O'Day, J ; Scott, R ; Mitchell, P ; Jenkins, AJ ; Keech, AC (WILEY, 2022-04)
    Retinal vessel calibre metrics were evaluated at baseline and 2 years in a FIELD substudy (n = 208). Central retinal venule calibre was significantly reduced by fenofibrate and unchanged by placebo. Arteriole metrics did not change. Larger studies relating retinal vessel calibre to future diabetes complications and response to therapy are merited.
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    Excess mortality and undertreatment in elderly lung cancer patients: treatment nihilism in the modern era?
    Pham, J ; Conron, M ; Wright, G ; Mitchell, P ; Ball, D ; Philip, J ; Brand, M ; Zalcberg, J ; Stirling, RG (EUROPEAN RESPIRATORY SOC JOURNALS LTD, 2021-04-01)
    Treatment of elderly patients with lung cancer is significantly hindered by concerns about treatment tolerability, toxicity and limited clinical trial data in the elderly; potentially giving rise to treatment nihilism amongst clinicians. This study aims to describe survival in elderly patients with lung cancer and explore potential causes for excess mortality. Patients diagnosed with lung cancer in the Victorian Lung Cancer Registry between 2011-2018 were analysed (n=3481). Patients were age-categorised and compared using Cox-regression modelling to determine mortality risk, after adjusting for confounding. Probability of being offered cancer treatments was also determined, further stratified by disease stage. The eldest patients (≥80 years old) had significantly shorter median survival compared with younger age groups (<60 years: 2.0 years; 60-69 years: 1.5 years; 70-79 years: 1.6 years; ≥80 years: 1.0 years; p<0.001). Amongst those diagnosed with stage 1 or 2 lung cancer, there was no significant difference in adjusted-mortality between age groups. However, in those diagnosed with stage 3 or 4 disease, the eldest patients had an increased adjusted-mortality risk of 28% compared with patients younger than 60 years old (p=0.005), associated with markedly reduced probability of cancer treatment, after controlling for sex, performance status, comorbidities and histology type (OR 0.24, compared with <60 years old strata; p<0.001). Compared to younger patients, older patients with advanced-stage lung cancer have a disproportionately higher risk of mortality and lower likelihood of receiving cancer treatments, even when performance status and comorbidity are equivalent. These healthcare inequities could be indicative of widespread treatment nihilism towards elderly patients.
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    Australian experience of a modified schedule of FOLFOX with high activity and tolerability and improved convenience in untreated metastatic colorectal cancer patients
    Goldstein, D ; Mitchell, P ; Michael, M ; Beale, P ; Friedlander, M ; Zalcberg, J ; White, S ; Clarke, S (NATURE PUBLISHING GROUP, 2005-03-14)
    This study determined the efficacy and safety of a modified FOLFOX regimen that improved patient convenience without compromising oxaliplatin dose intensity. A total of 62 patients with previously untreated metastatic colorectal cancer were enrolled to receive, entirely as outpatients, 2-weekly cycles of oxaliplatin 100 mg m(-2) i.v. over 2 h, together with leucovorin 400 mg m(-2) over 2 h, 5-fluorouracil (5-FU) 400 mg m(-2), bolus, followed by a 46-h infusion of 5-FU at 2.4 g m(-2). Treatment was given until progression or unmanageable toxicity. In all, 61 patients received > or =one oxaliplatin dose and a median of 11 treatment cycles (range 1-20 cycles); 22 (36%) reported grade 3/4 neutropenia and 13 patients (21%) experienced grade 3 neurotoxicity; 16 patients (26%) discontinued treatment due to disease progression or death, 15 (25%) due to neurotoxicity and six (10%) due to haematological toxicity. Of the 56 eligible patients, complete or partial responses were observed in 29 or 52% (95% confidence interval 38-65%). Median progression-free survival was 8.2 months (7.1-9.9) and median overall survival was 18.7 months (14.0-23.4). In our experience, a modified schedule of FOLFOX improves convenience without compromising efficacy or toxicity.
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    Molecular markers of response and toxicity to FOLFOX chemotherapy in metastatic colorectal cancer
    Chua, W ; Goldstein, D ; Lee, CK ; Dhillon, H ; Michael, M ; Mitchell, P ; Clarke, SJ ; Iacopetta, B (NATURE PUBLISHING GROUP, 2009-09-08)
    BACKGROUND: To investigate three genetic alterations (TP53 mutation, Kras mutation and microsatellite instability (MSI)) and three polymorphisms (methylene tetrahydrofolate reductase (MTHFR) C677T, excision repair cross complementing group 1 (ERCC1)-118 and X-ray repair cross complementing group 1 (XRCC1)-399) for their ability to predict response, survival and toxicity to FOLFOX first line chemotherapy in the treatment of metastatic colorectal cancer (mCRC). METHODS: Tumour tissues from 118 mCRC patients who underwent FOLFOX treatment from three successive phase II trials were evaluated for mutations in TP53 (exons 5-8) and Kras (codons 12 and 13) and for MSI using PCR-based analysis. Genotyping for common single nucleotide polymorphisms in the MTHFR (codon 677), ERCC1 (codon 118) and XRCC1 (codon 399) genes was also carried out using PCR techniques. These genetic markers were correlated with clinical response, survival and toxicity to treatment. RESULTS: Patients with the T allele of ERCC1-118 showed significantly worse progression-free survival in univariate analysis (HR=2.62; 95% CI=1.14-6.02; P=0.02). None of the genetic alterations or polymorphisms showed significant association with clinical response to FOLFOX. The MTHFR, ERCC1 and XRCC1 polymorphisms showed no associations with overall haematological, gastrointestinal or neurological toxicity to FOLFOX, although MTHFR 677 TT genotype patients showed a significantly higher incidence of grade 3 or 4 diarrhoea (26%) compared with CC or CT genotype patients (6%, P=0.02). CONCLUSIONS: The ERCC1-118 and MTHFR C677T polymorphisms were associated with progression and severe diarrhoea, respectively, after FOLFOX treatment in mCRC. Although our findings require confirmation in large prospective studies, they reinforce the concept that individual genetic variation may allow personalized selection of chemotherapy to optimize clinical outcomes.
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    Lack of evidence of disease contamination in ovarian tissue harvested for cryopreservation from patients with Hodgkin lymphoma and analysis of factors predictive of oocyte yield
    Seshadri, T ; Gook, D ; Lade, S ; Spencer, A ; Grigg, A ; Tiedemann, K ; McKendrick, J ; Mitchell, P ; Stern, C ; Seymour, JF (NATURE PUBLISHING GROUP, 2006-04-10)
    Ovarian cryopreservation is a promising technique to preserve fertility in women with Hodgkin lymphoma (HL) treated with chemotherapy. Thus, the aim of this study was to examine harvested ovarian tissue for subclinical involvement by HL by morphology/immunohistochemistry, and to define patient and treatment factors predictive of oocyte yield. This was a retrospective analysis of 26 ovarian tissue samples harvested for cryopreservation from women with HL. Histology, immunohistochemistry and follicle density (number mm(-3)) was examined. Disease status and preharvest chemotherapy details were obtained on 24 patients. The median age was 22 years (range 13-29). Seven of 24 patients had infradiaphragmatic disease at time of harvest. Nine of 20 patients had received chemotherapy preharvest (ABVD (Adriamycin), Bleomycin, Vinblastine and Dacarbazine) = 7, other regimens = 2). The seven receiving ABVD showed no difference in follicle density compared to patients not receiving treatment (n = 14); (median = 1555 vs 1620 mm3 P = 0.97). Follicle density measurement showed no correlation with patient age (R2 = 0.0001, P = 0.99). There was no evidence of HL involvement in the 26 samples examined (95% CI = 0-11%). In conclusion, subclinical involvement of HL has not been identified in ovarian tissue, even when patients have infradiaphragmatic disease. Furthermore, the quality of tissue harvested does not appear to be adversely affected by patient's age or prior ABVD chemotherapy.
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    Oxaliplatin combined with infusional 5-fluorouracil and concomitant radiotherapy in inoperable and metastatic rectal cancer: a phase I trial
    Loi, S ; Ngan, SYK ; Hicks, RJ ; Mukesh, B ; Mitchell, P ; Michael, M ; Zalcberg, J ; Leong, T ; Lim-Joon, D ; Mackay, J ; Rischin, D (NATURE PUBLISHING GROUP, 2005-02-28)
    The aim of this study was to define the recommended dose of oxaliplatin when combined with infusional 5-fluorouracil (5-FU) and concurrent pelvic radiotherapy. Eligible patients had inoperable rectal cancer, or symptomatic primary rectal cancer with metastasis. Oxaliplatin was given on day 1 of weeks 1, 3 and 5 of radiotherapy. Dose level 1 was oxaliplatin 70 mg m(-2) with 5-FU 200 mg m(-2) day(-1) continuous infusion 96 h week(-1). On dose level 2, the oxaliplatin dose was increased to 85 mg m(-2). On dose level 3, the duration of the 5-FU was increased to 168 h per week. Pelvic radiotherapy was 45 Gray (Gy) in 25 fractions over 5 weeks with a boost of 5.4 Gy. Fluorine-18 fluoro deoxyglucose and Fluorine-18 fluoro misonidazole positron emission tomography (FDG-PET and FMISO-PET) were used to assess metabolic tumour response and hypoxia. In all, 16 patients were accrued. Dose-limiting toxicities occurred in one patient at level 2 (grade 3 chest infection), and two patients at level 3 (grade 3 diarrhoea). Dose level 2 was declared the recommended dose level. FDG-PET imaging showed metabolic responses in 11 of the 12 primary tumours assessed. Four of six tumours had detectable hypoxia on FMISO-PET scans. The addition of oxaliplatin to infusional 5-FU chemoradiotherapy was feasible and generally well tolerated. For future trials, oxaliplatin 85 mg m(-2) and 5-FU 200 mg m(-2) day(-1) continuous infusion 96 h week(-1) is the recommended dose when combined with 50.4 Gy of pelvic radiotherapy.
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    Pharmacodynamic analysis of tumour perfusion assessed by 15O-water-PET imaging during treatment with sunitinib malate in patients with advanced malignancies
    Scott, AM ; Mitchell, PL ; O'Keefe, G ; Saunder, T ; Hicks, RJ ; Poon, A ; Baum, C ; Brega, N ; McCarthy, TJ ; Toner, GC (SPRINGEROPEN, 2012)
    BACKGROUND: We evaluated pharmacodynamic changes in tumour perfusion using positron emission tomography (PET) imaging with 15O-water to assess biological response to sunitinib, a multitargeted tyrosine kinase inhibitor. METHODS: Patients with advanced malignancies received sunitinib 50 mg/day orally, once daily for 4 weeks on treatment, followed by 2 weeks off treatment, in repeated 6-week cycles. Quantitative measurement of tumour perfusion was assessed using 15O-water-PET at baseline and after 2 weeks of treatment. At least one reference tumour lesion was included in the fields of view and assessed at both time points. Patients also underwent 18 F-fluorodeoxyglucose (FDG)-PET imaging at baseline and after 2 and 4 weeks of treatment. Radiological response of the reference tumour lesion and overall radiological response were assessed at week 12. Serum pharmacokinetic and biomarker analyses were also performed. RESULTS: Data were available for seven patients. Compared with baseline, all patients experienced a decrease in reference tumour blood flow ranging from 20 % to 85 % and also a reduction in the FDG standard uptake value ranging from 29 % to 67 %. Six patients experienced a partial metabolic response based on FDG-PET criteria. Four patients had stable disease defined by radiological response (Response Evaluation Criteria in Solid Tumors) lasting between 4 and 12 cycles. An association between perfusion change and clinical benefit, and biomarker levels including vascular endothelial growth factor was observed. CONCLUSION: Administering sunitinib to patients with advanced malignancies is associated with early biological responses, including decreased blood flow in secondary tumour deposits.