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John Collins

Publications and source records attributed to John Collins.

At least 19 recordsLinked to original sources
PubMed2006

Adjuvant chemotherapy followed by goserelin compared with either modality alone: the impact on amenorrhea, hot flashes, and quality of life in premenopausal patients--the International Breast Cancer Study Group Trial VIII.

PURPOSE: The purpose of this article is to compare quality of life (QOL) and menopausal symptoms among premenopausal patients with lymph node-negative breast cancer receiving chemotherapy, goserelin, or their sequential combination, and to investigate differential effects by age. PATIENTS AND METHODS: We evaluated QOL data from 874 pre- and perimenopausal women with lymph node-negative breast cancer who were randomly assigned to receive six courses of classical cyclophosphamide, methotrexate, and fluorouracil (CMF) chemotherapy, ovarian suppression with goserelin for 24 months, or six courses of classical CMF followed by 18 months of goserelin. We report QOL data collected during 3 years after random assignment in patients without disease recurrence. RESULTS: Overall, patients receiving goserelin alone showed a marked improvement or less deterioration in QOL measures over the first 6 months than those patients treated with CMF. There were no differences at 3 years after random assignment according to treatment except for hot flashes. As reflected in the hot flashes scores, patients in all three treatment groups experienced induced amenorrhea, but the onset of ovarian function suppression was slightly delayed for patients receiving chemotherapy. Younger patients (< 40 years) who received goserelin alone returned to their premenopausal status at 6 months after the cessation of therapy, while those who received CMF showed marginal changes from their baseline hot flashes scores. CONCLUSION: Age-adjusted risk profiles that consider patient-reported outcomes enable patients to adapt to their disease and treatment, such as considering the trade-offs between delayed endocrine symptoms, but higher risk of permanent menopause with chemotherapy, and immediate but reversible endocrine symptoms with goserelin, in younger premenopausal patients.

Adult↗
PubMed2006

Current and former smoking increases mortality in patients on peritoneal dialysis.

AIMS: There is limited information on the effects of smoking behaviour on mortality in patients with end-stage renal failure (ESRF). This study aimed to assess the interaction of smoking on death rate in patients with renal failure on dialysis. METHODS: All patients (n=1293) commencing peritoneal dialysis between 1985 and 1995 for renal failure in New Zealand were prospectively followed 6 monthly until 1997 and data entered on the National database. Mortality rates were calculated from the national database and rates in patients with diabetes compared with those without diabetes and in those who did or did not smoke. RESULTS: Follow-up data was available on all patients for a range of 20-40 months. 35% of the patients were clinically classified as having diabetic nephropathy as the cause of renal failure (11% type 1, 24% type 2). Seventeen percent of the total cohort were current smokers, 45% former smokers and 38% lifetime non smokers at dialysis commencement. These rates were similar between patients with diabetes (18% current, 51% former, 32% non-smoker) and those without diabetes (17% current, 42% former, 41% non-smoker). At survey end in 1997, 43% of the patients without diabetes had died compared with 59% of patients with type 1 diabetes (p<0.05) and 62% of patients with type 2 diabetes (p<0.05). The age-adjusted mortality of patients with a history of current or former smoking was higher than non-smokers. Those patients with diabetes and a history of smoking had even higher mortality. CONCLUSIONS: Patients with a current or former history of smoking on peritoneal dialysis are at greatly increased risk of death. A strategy of aggressive smoking cessation efforts should be adopted for these patients at the earliest opportunity.

Age Distribution↗
PubMed2006

The play of chance.

Most randomized controlled trials are small relative to the clinical question they address, and chance causes more variability in the results of small trials. Thus, when small studies herald new treatment interventions, clinicians might wish to wait until the body of evidence is weighty and consistent enough to be convincing.

Acupuncture↗
PubMed2006

Ocular toxicity during adjuvant chemoendocrine therapy for early breast cancer: results from International Breast Cancer Study Group trials.

BACKGROUND: Others have reported ocular toxicity after adjuvant chemoendocrine therapy, but this study looked at ocular toxicity in similarly treated patients from large randomized clinical trials. METHODS: Information was retrieved on incidence and timing of ocular toxicity from the International Breast Cancer Study Group (IBCSG) database of 4948 eligible patients randomized to receive tamoxifen or toremifene alone or in combination with chemotherapy (either concurrently or sequentially). Case reports of patients with ocular toxicity were evaluated to determine whether ocular toxicity occurred during chemotherapy and/or hormonal therapy. Additional information was obtained from participating institutions for patients in whom ocular toxicity occurred after chemotherapy but during administration of tamoxifen or toremifene. RESULTS: Ocular toxicity was reported in 538 of 4948 (10.9%) patients during adjuvant treatment, mainly during chemotherapy. Forty-five of 4948 (0.9%) patients had ocular toxicity during hormone therapy alone, but only 30 (0.6%) patients had ocular toxicity reported either without receiving any chemotherapy or beyond 3 months after completing chemotherapy and, thus, possibly related to tamoxifen or toremifene. In 3 cases, retinal alterations, without typical aspects of tamoxifen toxicity, were reported; 4 patients had cataract (2 bilateral), 12 impaired visual acuity, 10 ocular irritation, 1 optical neuritis, and the rest had other symptoms. CONCLUSION: Ocular toxicity during adjuvant therapy is a common side effect mainly represented by irritative symptoms due to chemotherapy. By contrast, ocular toxicity during hormonal therapy is rare and does not appear to justify a regular program of ocular examination. However, patients should be informed of this rare side effect so that they may seek prompt ophthalmic evaluation for ocular complaints.

Aged↗
PubMed2005

Prognostic value of extracapsular tumor spread for locoregional control in premenopausal patients with node-positive breast cancer treated with classical cyclophosphamide, methotrexate, and fluorouracil: long-term observations from International Breast Cancer Study Group Trial VI.

PURPOSE: We sought to determine retrospectively whether extracapsular spread (ECS) might identify a subgroup that could benefit from radiotherapy after mastectomy, especially patients with 1 to 3 positive lymph nodes (LN1-3+). PATIENTS AND METHODS: We randomized 1,475 premenopausal women with node-positive breast cancer to three, six, or nine courses of "classical" CMF (cyclophosphamide, methotrexate, and fluorouracil). After a review of all pathology forms, 933 patients (63%) had information on the presence or absence of ECS. ECS was present in 49.5%. The median follow-up was 10 years. RESULTS: In univariate analyses, ECS was associated with worse disease-free survival (DFS) and overall survival (OS). In multivariate analyses adjusting for tumor size, vessel invasion, surgery type, and age group, ECS remained significant (DFS: hazard ratio, 1.61; 95% CI, 1.34 to 1.93; P < .0001; OS: 1.67; 95% CI, 1.34 to 2.08; P < .0001). However, ECS was not significant when the number of positive nodes was added. The locoregional failure rate +/- distant failure (LRF +/- distant failure) within 10 years was estimated at 19% (+/- 2%) without ECS, versus 27% (+/- 2%) with ECS. The difference was statistically significant in univariate analyses, but not after adjusting for the number of positive nodes. No independent effect of ECS on DFS, OS, or LRF could be confirmed within the subgroup of 382 patients with LN1-3+ treated with mastectomy without radiotherapy. CONCLUSION: Our results do not support an independent prognostic value of ECS, nor its use as an indication for irradiation in premenopausal patients with LN1-3+ treated with classical CMF. However, we could not examine whether extensive ECS is of prognostic importance.

Adult↗
PubMed2005

Site of primary tumor has a prognostic role in operable breast cancer: the international breast cancer study group experience.

PURPOSE: Cancer presenting at the medial site of the breast may have a worse prognosis compared with tumors located in external quadrants. For medial tumors, axillary lymph node staging may not accurately reflect the metastatic potential of the disease. PATIENTS AND METHODS: Eight-thousand four-hundred twenty-two patients randomly assigned to International Breast Cancer Study Group clinical trials between 1978 and 1999 were classified as medial site (1,622; 19%) or lateral, central, and other sites (6,800; 81%). Median follow-up was 11 years. RESULTS: A statistically significant difference was observed for patients with medial tumors versus those with nonmedial tumors in disease-free survival (DFS; 10-year DFS, 46% v 48%; HR, 1.10; 95% CI, 1.02 to 1.18; P = .01) and overall survival (10-year OS 59% v 61%; HR, 1.09; 1.01 to 1.19; P = .04). This difference increased after adjustment for other prognostic factors (HR, 1.22; 95% CI, 1.13 to 1.32 for DFS; and HR, 1.24; 95% CI, 1.14 to 1.35 for OS; both P = .0001). The risk of relapse for patients with medial presentation was largest for the node-negative cohort and for patients with tumors larger than 2 cm. In the subgroup of 2,931 patients with negative axillary lymph nodes, 10-year DFS was 61% v 67%, and OS was 73% v 80% for medial versus nonmedial sites, respectively (HR 1.33; 95% CI, 1.15 to 1.54; P = .0001 for DFS; and HR 1.40; 95% CI, 1.17 to 1.67; P = .0003 for OS). CONCLUSION: Tumor site has a significant prognostic utility, especially for axillary lymph node-negative disease, that should be considered in therapeutic algorithms. New staging procedures such as biopsy of the sentinel internal mammary nodes or novel imaging methods should be further studied in patients with medial tumors.

Adult↗
PubMed2005

An update on master's degrees in medical education.

Planning and implementing educational programs in medicine optimally requires a background in educational theory and practice. An avenue of training open to such practitioners is a master's degree in medical education. A single 1998 report lists the programs known at that time and information about them remains scarce. The authors have re-examined all current programs offering master's degrees in medical or health sciences education in the English-speaking world, including the Netherlands. The authors contacted the programs identified in the 1998 report to establish how many were still in operation. The search was extended using Pubmed and other search engines. A further verification targeted a selected sample of 10 prominent US medical schools. Twenty-one currently operating programs were identified: six in the US, eight in the UK, three in Canada, three in Australia and one in Holland. Seven of nine original master's programs were still in existence. URLs, website and other logistical information about each program are tabled. A master's degree in medical or health sciences education is the most specific method for medical faculty to obtain a credentialed grounding in educational theory and practice. The authors provide up-to-date contact information for current programs and summarize other related essential logistical data.

Curriculum↗
PubMed2005

Rebecca's story.

Explore the source record for details and available documents.

Adult↗
PubMed2005

Participation in the RACS sentinel node biopsy versus axillary clearance trial.

BACKGROUND: The Royal Australasian College of Surgeons (RACS) SNAC trial is a randomized controlled trial of sentinel node biopsy (SNB) versus axillary clearance (AC). It opened in May 2001 and is recruiting rapidly with good acceptance by consumers. METHODS: A study of eligibility and treatment choices was conducted between November 2001 and September 2002 for women presenting with early breast cancer to 10 centres participating in the trial. RESULTS: More than half of the 622 women (54%) were ineligible for trial entry because they had large (> 3 cm) or multicentric cancers. Participation was offered to 92% of eligible women and was taken up by 63%. The commonest reason for not participating was the desire to choose treatment rather than have it randomly allocated. Despite this there is a great acceptance of clinical trials because very few women (4% of those eligible) gave 'lack of interest in clinical trials' as the reason for non-participation. Few women who declined trial participation chose to have SNB alone (4.5% of those eligible). CONCLUSION: Sentinel node biopsy may become the standard of care for managing small breast cancers, but a significant number of patients will still require or choose axillary dissection. Results from large randomized trials are needed to determine the relative benefits and harms of SNB compared with AC. Surgeons must carefully discuss options for management with their patients.

Axilla↗
PubMed2005

Magnetic resonance imaging of changes in muscle tissues after membrane trauma.

A pure electroporation injury leads to cell membrane disruption and subsequent osmotic swelling of the tissue. The state of water in the injured area of a tissue is changed and differs from a healthy tissue. Magnetic resonance imaging (MRI), which is very sensitive to the quality of the interaction between mobile (water) protons and a restricted (protein) proton pool, is therefore a useful tool to characterize this injury. Here, we present a protocol designed to measure the difference between the values of the transverse magnetic relaxation time (T2) in MRIs of healthy and electrically injured tissue. In addition, we present a method to evaluate the two main contributions to the MRI contrast, the degree of structural alteration of the cellular components (including a major contribution from membrane pores), and edema. The approach is useful in assessing the level of damage that electric shocks produce in muscle tissues, in that edema will resolve in time whereas structural changes require active repair mechanisms.

Animals↗
PubMed2004

Lorentz invariance and quantum gravity: an additional fine-tuning problem?

Trying to combine standard quantum field theories with gravity leads to a breakdown of the usual structure of space time at around the Planck length, 1.6x10(-35) m, with possible violations of Lorentz invariance. Calculations of preferred-frame effects in quantum gravity have further motivated high precision searches for Lorentz violation. Here, we explain that combining known elementary particle interactions with a Planck-scale preferred frame gives rise to Lorentz violation at the percent level, some 20 orders of magnitude higher than earlier estimates, unless the bare parameters of the theory are unnaturally strongly fine tuned. Therefore an important task is not just the improvement of the precision of searches for violations of Lorentz invariance, but also the search for theoretical mechanisms for automatically preserving Lorentz invariance.

Journal Article↗
PubMed2004

The management of early breast carcinoma before and after the introduction of clinical practice guidelines.

BACKGROUND: Clinical practice guidelines for the management of breast carcinoma were introduced in Australia in October, 1995. This article describes the management of early-stage breast carcinoma both before and after the introduction of these guidelines. METHODS: All cases of early breast carcinoma that were diagnosed over the same 6-month period in 1995 and 1999 and registered with a state-based cancer registry were identified. Treating surgeons completed a survey assessing tumor characteristics and primary treatment. In 1995, 95% of 188 surgeons who were approached participated and 96% of the surveys were returned. In 1999, 92% of 159 surgeons who were approached participated and 91% of the surveys were returned. Analyses are based on 1066 cases from 1995 and 1001 cases from 1999. RESULTS: The pathologic disease stage of the patients was similar in both study years. The proportion of patients who underwent breast-conserving therapy (BCT) increased from 54% in 1995 to 69% in 1999. This increase was noted across most levels of disease characteristics but was not evident among those patients treated by the least active surgeons. The proportion of patients treated with BCT who received radiotherapy increased from 59% in 1995 to 80% in 1999. This trend was observed across most levels of tumor characteristics and surgeon caseload. The proportion of women with receptor-positive tumors who were treated with endocrine therapy increased, whereas the proportion of patients with receptor-negative tumors who received this therapy decreased from 39% in 1995 to 17% in 1999. CONCLUSIONS: The management of early breast carcinoma in the state of Victoria appeared to change between 1995 and 1999 in the direction expected if the national guidelines had been incorporated into the practice patterns of surgeons treating breast carcinoma patients.

Adult↗
PubMed2004

Towards less confusing terminology in reproductive medicine: a proposal.

The use of the term 'infertility' and related terms in reproductive medicine is reviewed. Current terminology is found to be ambiguous, confusing, and misleading. We recommend that the fertility investigation report of a couple should consist of statements concerning description, diagnosis, and prognosis. The description concerns the duration of nonpregnancy before consulting the clinician. A system for prognostic grading is proposed. The fertility investigation report forms the basis for further action, including the possibility of waiting with treatment in case of almost normal or only slightly reduced fertility. The use of the terms 'infertility', 'subfertility', and 'fecundity' is not necessary, and it is recommended to avoid them.

Humans↗
PubMed2004

RETIRED: Canadian contraception consensus.

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

Canada↗
PubMed2004

RETIRED: Canadian contraception consensus.

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

Canada↗