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Biomedical subjects

D McCready

Publications and source records attributed to D McCready.

18 recordsLinked to original sources

Evaluating the organization and delivery of breast cancer services: use of performance measures to identify knowledge gaps.

OBJECTIVES: This paper identifies gaps in our knowledge about the quality of breast cancer care in Canada to understand where programs and resources are required to enhance health services and research capacity. METHODS: A modified Delphi approach was employed involving a 15-member multidisciplinary panel of health professionals and two rounds of rating followed by deliberation to develop evidence- and consensus-based performance measures. A literature search for Canadian health services research in breast cancer was conducted based on the indicator topics. Eligible articles were identified in indexed databases of medical literature and funded research from 1995 to 2006. RESULTS: The multidisciplinary panel selected 34 indicators spanning access to services, patient outcomes, diagnosis and staging, surgery, adjuvant therapy, pathology, and follow-up care. A total of 78 articles (66 quantitative; 12 exploratory) on these topics were reviewed. Apart from two aspects of care (communication of treatment options, supportive care), the yield of Canadian breast cancer health services research did not increase subsequent to a review conducted 10 years ago which recommended greater efforts in this area. CONCLUSIONS: Research involving quantitative and qualitative methods is needed to increase our understanding about the organization and delivery of services for breast cancer diagnosis, treatment and follow-up care. Since it is unclear how to balance competing research demands, innovative strategies are required to assemble resources for health services research on breast cancer. This could include the promotion of partnerships between researchers and policy-makers across jurisdictions, and the pooling of resources between organizations, regions or networks.

Breast Neoplasms↗

The latest is the greatest? Results of a structured lecture about aromatase inhibitor use for breast cancer.

BACKGROUND: The aromatase inhibitors (AIs) are increasingly surpassing tamoxifen as the endocrine treatment of choice for postmenopausal breast cancer patients. With their increasing use, there is concern that they are being inadvertently prescribed to pre- and peri-menopausal women. METHODS: As part of a continuing medical education program for 264 practicing surgeons, a 15-min lecture was given over viewing hormone therapy for early stage breast cancer. Two multi-choice questions were asked before and after the lecture regarding the optimal hormonal treatment for pre and postmenopausal women. RESULTS: For the optimal treatment of premenopausal women, 36% of respondents chose tamoxifen before the lecture, rising to 82% after it (p<0.01). However 37% suggested an AI would be best, with a further 27% choosing either an AI or tamoxifen, falling to 7% and 11% respectively after the lecture. Before the lecture, 30% of the participants stated that any of the listed treatment options; tamoxifen alone, an AI alone or a combination of tamoxifen and an AI would be acceptable for postmenopausal women. Following the lecture, 53% chose this option (p<0.01). CONCLUSIONS: In many countries it is practicing surgeons who commence endocrine therapy for patients with breast cancer. The findings of this study are useful from two points. Firstly it is clear that many physicians feel that AIs are an effective adjuvant endocrine therapy for premenopausal breast cancer. Secondly it demonstrates the benefits of continuing medical education as a significant improvement in test scores was noted after a structured lecture.

Aromatase Inhibitors↗

A snapshot of waiting times for cancer surgery provided by surgeons affiliated with regional cancer centres in Ontario.

BACKGROUND: There is evidence that delays in treatment result in increased psychosocial morbidity for patients diagnosed with cancer. We evaluated waiting times for care among cancer patients treated by surgeons affiliated with regional cancer centres in Ontario. METHODS: Dates for 5 key events related to the surgical management of a patient with cancer were collected by a convenience sample of surgeons who treat breast, gynecologic, colorectal, head and neck, thoracic and urologic cancers. The key events were initial referral, first surgical visit, main treatment decision, major surgery and receipt of postoperative pathology report. The surgeons were also asked to judge the appropriateness of the waiting times for the intervals studied and to identify factors associated with inappropriate delays. RESULTS: A total of 62 surgeons affiliated with 8 regional cancer centres participated; data were collected for 1456 patients who underwent assessment and whose surgical visit occurred between Jan. 31 and May 31, 2000. The median waiting time from referral to first visit was 11.0 days, from first visit to treatment decision 0.0 days, from treatment decision to surgery 20.0 days and from surgery to receipt of the pathology report 8.0 days. The median waiting times for the 2 summary intervals (referral to surgery and referral to receipt of the pathology report) were 37.0 and 48.0 days respectively. The waiting times varied by cancer type; for example, the median time from referral to surgery varied from 29.0 days for colorectal cancers to 64.0 days for urologic cancers. The same interval varied from 19.0 to 43.0 days by treatment centre. The waiting times did not vary substantially by patient age. The surgeons judged that 344 (37.2%) of the 925 patients with dates for the referral-to-surgery interval had inappropriately long waiting times. They indicated that contributing factors to these inappropriate waits were shortage of operating room time (in 181 cases), lack of other resources such as diagnostic tests or allied health personnel (in 156) and patient preference or circumstance (in 28) (factors were not mutually exclusive). INTERPRETATION: Many of the patients with cancer seen by surgeons affiliated with regional cancer centres in Ontario may be experiencing significant delays in the assessment and treatment of their cancer.

Aged↗

Appropriate procedures for the safe handling and pathologic examination of technetium-99m-labelled specimens.

Technetium 99m may now be used to identify sentinel nodes for surgical excision in a growing number of cancer sites. The pathology specimens of these sentinel nodes and of any injected tumoural sites are radioactive. Consequently, specific clinical and laboratory procedures must be developed to handle these specimens safely. It is recommended that specimens containing the injection site should be quarantined for a period to permit decay of radioactivity. This quarantine does delay the reporting of pathology results to surgeons, oncologists and other clinicians, but it does not adversely affect final patient management.

Canada↗

Validation of a screening questionnaire for androgen deficiency in aging males.

It is now well established that testosterone levels decline with age. What has not been established is whether the decline in testosterone is associated with a symptom complex. This study examined whether certain symptoms are more commonly present in males with low bioavailable testosterone (BT) levels. These were used to evaluate a questionnaire for androgen deficiency in aging males (ADAM). The validity of the ADAM questionnaire to screen for low BT was tested in 316 Canadian physicians aged 40 to 62 years. Low BT levels were present in 25% of this population. None had elevated luteinizing hormone (LH) levels. The ADAM questionnaire had 88% sensitivity and 60% specificity. When the questionnaire was administered twice 2 to 4 weeks apart to 10 men, it was determined that the coefficient of variation was 11.5%. In a second study of 34 ADAM-positive patients, 37% of those with clearly normal BT levels demonstrated some evidence of dysphoria. Finally, in 21 patients who were treated with testosterone, improvement on the ADAM questionnaire was demonstrated in 18 (P = .002). These data support the concept of a symptom complex associated with low BT levels in aging males. In addition, the ADAM questionnaire appears to be a reasonable screening questionnaire to detect androgen deficiency in males over 40 years of age.

Adult↗

Malignant melanoma in a patient with oculocutaneous albinism.

BACKGROUND: Sun-induced malignancies (basal cell and squamous cell carcinomas) are common in oculocutaneous albinism, however, the incidence of malignant melanoma is a topic of controversy. OBJECTIVE: We have reviewed the literature and report a case of a woman with oculocutaneous albinism with an amelanotic melanoma of the anterior chest wall. RESULTS: There are only 26 previously reported cases (both case reports and African albino population studies) in 25 patients in the literature. A 27th case with immunohistochemical and ultrastructural evaluation is presented. CONCLUSIONS: It appears that melanoma, a malignancy for which sun exposure and light colouration are felt to be major risk factors, has a low incidence among a population that is both hypopigmented and often exposed to high levels of ultraviolet light. This low incidence is poorly understood and frequently disputed.

Albinism, Oculocutaneous↗

Sentinel node detection and definition may depend on the imaging agent and timing.

PURPOSE: Two cases of sentinel lymph node imaging are presented in which the results are exceptions to what the literature generally defines as sentinel lymph nodes. In one case, Tc-99m antimony trisulfide colloid produced significantly different results than did Tc-99m tin colloid. In the second case, the results bring into question the definition of a sentinel node as the first in a lymphatic drainage pathway. MATERIALS AND METHODS: In one patient, lymphoscintigraphy was performed initially using Tc-99m antimony trisulfide colloid injected intradermally around a melanoma excision site. Repeated lymphoscintigraphy 1 month later, 1 hour before sentinel node excision, was done using Tc-99m tin colloid, a larger particle than antimony trisulfide colloid. The second patient, with a melanoma biopsied only, had sentinel node imaging performed using Tc-99m sulfide colloid, a particulate also larger than antimony trisulfide colloid and also 1 hour before sentinel node excision. RESULTS: In the first patient, imaging with the smaller antimony trisulfide colloid showed more lymphatic pathways and more sentinel nodes than with tin colloid. In the second patient, the first focus of retention of the imaging agent in the lymphatic pathway seen showed less intense accumulation than the next focus in the pathway, contrary to published reports that the sentinel node shows more intense accumulation than do nodes further downstream in a lymphatic pathway. CONCLUSIONS: There are exceptions to published characteristics of sentinel node lymphoscintigraphy, so care must be exercised in localizing sentinel nodes.

Antimony↗

Adjuvant treatment and onset of menopause predict weight gain after breast cancer diagnosis.

PURPOSE: Weight gain is common during the first year after breast cancer diagnosis. In this study, we examined clinical factors associated with body size at diagnosis and weight gain during the subsequent year. PATIENTS AND METHODS: An inception cohort of 535 women with newly diagnosed locoregional breast cancer underwent anthropometric measurements at baseline and 1 year. Information was collected on tumor- and treatment-related variables, as well as diet and physical activity. RESULTS: Mean age was 50.3 years; 57% of women were premenopausal. Mean baseline body mass index (weight [kg] divided by height [m] squared) was 25.5 kg/m2. Overall, 84.1% of the patients gained weight. Mean weight gain was 1.6 kg (95% confidence interval, 1.2 to 1.9 kg), 2.5 kg (95% confidence interval, 1.8 to 3.2 kg) in those receiving chemotherapy, 1.3 kg (95% confidence interval, 0.7 to 1.8 kg) in those receiving tamoxifen only, and 0.6 kg (95% confidence interval, 0.01 to 1.3 kg) in those receiving no adjuvant treatment. Menopausal status at diagnosis (P = .02), change in menopausal status over the subsequent year (P = .002), axillary nodal status (P = .009), and adjuvant treatment (P = .0002) predicted weight gain in univariate analysis. In multivariate analysis, onset of menopause and administration of chemotherapy were independent predictors of weight gain (all P < or = .05). Caloric intake decreased (P < .01) and physical activity increased (P < .05) during the year after diagnosis; these factors did not explain the observed weight gain. CONCLUSION: Weight gain is common after breast cancer diagnosis; use of adjuvant chemotherapy and onset of menopause are the strongest clinical predictors of this weight gain.

Age of Onset↗

Mastectomy or lumpectomy? Helping women make informed choices.

PURPOSE: To develop an instrument to help clinicians inform their patients about surgical treatment options for the treatment of breast cancer and to evaluate the impact of the instrument on the clinical encounter. METHODS: We developed an instrument, called the Decision Board, to present information regarding the benefits and risks of breast-conserving therapy (lumpectomy plus radiation therapy) and mastectomy to women with early-stage breast cancer to enable them to express a preference for the type of surgery. Seven surgeons from different communities in Ontario administered the instrument to women with newly diagnosed clinical stage I or II breast cancer over an 18-month period. Patients and surgeons were interviewed regarding acceptability of the instrument. The rates of breast-conserving surgery performed by surgeons before and after the introduction of the instrument were compared. RESULTS: The Decision Board was administered to 175 patients; 98% reported that the Decision Board was easy to understand, and 81% indicated that it helped them make a decision. The average score on a true/false test of comprehension was 11.8 of 14 (84%) (range, 6 to 14). Surgeons found the Decision Board to be helpful in presenting information to patients in 91% of consultations. The rate of breast-conserving surgery decreased when the Decision Board was introduced (88% v 73%, P =.001) CONCLUSION: The Decision Board is a simple method to improve communication and facilitate shared decision making. It was well accepted by patients and surgeons and easily applied in the community.

Adult↗

neu/erbB-2 amplification identifies a poor-prognosis group of women with node-negative breast cancer. Toronto Breast Cancer Study Group.

PURPOSE: It remains a challenge to predict which women with axillary node-negative (ANN) breast cancer at greatest risk of relapse may benefit most from adjuvant therapy. Increases in neu/erbB-2 have been implicated in breast cancer prognosis. Although overexpression has been investigated extensively, this study represents the first prospective assessment of the prognostic value of neu/erbB-2 DNA amplification in a cohort of women with newly diagnosed ANN. METHODS: A consecutive series of women was monitored for recurrence (median follow-up duration, 36 months) and tumors from 580 individuals were analyzed for amplification. The association of amplification with risk of recurrence was examined in survival analyses with traditional and histologic markers as prognostic factors. RESULTS: Neu/erbB-2 was amplified in 20% of cases. We found an increased risk of disease recurrence when neu/erbB-2 was amplified > or = twofold that persisted with adjustment for other prognostic factors (relative risk, 2.36; P = .002). We found some evidence that amplification was more important in patients who received chemotherapy compared with untreated patients. CONCLUSION: neu/erbB-2 amplification is an independent prognostic factor for risk of recurrence in ANN breast cancer. Women with tumors without neu/erbB-2 amplification have a good prognosis; aggressive therapy in this group is therefore difficult to justify. On the other hand, even with adjuvant chemotherapeutic treatment, women whose tumors exhibit neu/erbB-2 amplification have an increased risk of recurrence. We encourage a randomized trial to compare more aggressive adjuvant chemotherapy versus standard chemotherapy for ANN women whose tumors exhibit neu/erbB-2 amplification.

Axilla↗

Elevated levels of plasma triglycerides are associated with histologically defined premenopausal breast cancer risk.

Lipids and lipoproteins have been associated with breast cancer risk; however, published results have been inconsistent. To clarify these associations, we measured fasting lipids in women undergoing breast biopsies. A case-control study examined the association of fasting levels of lipids with histologically defined breast cancer risk. Four groups of premenopausal women were assembled on the basis of histological appearance of breast tissue: 1) no epithelial proliferation (n = 102), 2) proliferation without atypia (n = 53), 3) atypical hyperplasia or carcinoma in situ (n = 53), and 4) node-negative invasive cancer (n = 102). A postoperative fasting blood specimen was analyzed for cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. Demographics, risk factors, diet, physical activity, fasting weight, and skin-fold thickness were measured. Triglyceride levels were significantly higher in women with node-negative invasive cancer (0.94 +/- 1.04 mg/ml) than in those with no epithelial proliferation (0.83 +/- 1.04 mg/ml, p = 0.03). This association persisted after adjustment for age, body size, lipids, reproductive and familial risk factors, and previous benign breast problems (p < 0.01), in keeping with an independent association of elevated triglycerides with breast cancer risk.

Adult↗

Clinical behavior of untreated axillary nodes after local treatment for primary breast cancer.

BACKGROUND: The purpose of this study was to examine the rate of axillary failure in patients with primary breast cancer treated without axillary dissection or radiation and to determine what factors may be associated with axillary failure. METHODS: We studied 112 patients with invasive breast cancer treated for primary disease with breast-conserving surgery without axillary dissection or radiation to the breast or axilla, accrued between 1977 and 1986. Data for these patients were prospectively gathered for a research database and reviewed retrospectively to determine axillary failure. The effects of age, tumor size, estrogen receptor (ER) status, progesterone receptor (PgR) status, histologic grade, nuclear grade, and tumor emboli on time to axillary failure were examined. RESULTS: The median follow-up was 9.6 years. There were 26 axillary recurrences, resulting in a 10-year actuarial nodal control rate of 72%. Patients with nodal failure proceeded to axillary dissection with minimal morbidity. In both univariate and multivariate analyses, only tumor size was significantly associated with axillary failure (p = 0.04 and p = 0.06, respectively). CONCLUSIONS: This study demonstrates a significant effect of tumor size on axillary failure and a reasonable rate of local control in small tumors. Further research should examine the utility of axillary dissection in women with small breast cancers.

Actuarial Analysis↗

A case-control comparison of durability and cost between implanted reservoir and percutaneous catheters in cancer patients.

A case-control study was performed to compare the durability and cost of implanted reservoir catheter systems with percutaneous central venous catheters. Twenty cancer patients had reservoir systems placed in 1985 for chemotherapy delivery. The control group consisted of 60 cancer patients, matched according to age, sex, and diagnosis who were part of a group of more than 700 patients with percutaneous catheters inserted during the same period. The reservoir catheters were found to function for a significantly (P less than 0.0001) longer time (495 +/- 54 days) compared to the percutaneous catheters (197 +/- 22 days). The total cost for each system was calculated by adding the charges for an average insertion (reservoir = $1738, percutaneous = $562) to the maintenance charges accumulated over the catheters' lifespan. Reservoir catheters were associated with a significantly greater total cost than percutaneous catheters ($2233 +/- 54, $1453 +/- 102, respectively) but, if the total cost was spread out over the lifespan of the catheter by dividing the total cost by duration of use, reservoir catheters can be less expensive on a per diem basis. The break point occurs at approximately 6 months. For use less than 6 months, percutaneous catheters are cheaper primarily because of their lower insertion costs, but, for longer periods, reservoir catheters become cheaper because of lower maintenance costs and because a second percutaneous catheterization would likely be necessary.

Adult↗

Neostigmine, pyridostigmine and edrophonium as antagonists of deep pancuronium blockade.

To compare the ability of equipotent doses of neostigmine, pyridostigmine and edrophonium to antagonize intense pancuronium neuromuscular blockade, one hundred and twenty ASA physical status I or II patients scheduled for elective surgery received 0.06 mg.kg-1 pancuronium during a thiopentone nitrous oxide-enflurane anaesthetic. Train-of-four stimulation was applied every 12 s and the force of contraction of the adductor pollicis muscle was recorded. In the first 60 patients, spontaneous recovery was allowed until ten per cent of initial first twitch height. Then neostigmine (0.005, 0.01, 0.02 or 0.05 mg.kg-1), pyridostigmine (0.02, 0.04, 0.1 or 0.2 mg.kg-1), or edrophonium (0.1, 0.2, 0.4 or 1 mg.kg-1) was injected by random allocation. Dose-response relationships were established from the measurement of first twitch height (T1) ten minutes later. From these, neostigmine, 0.04 and 0.08 mg.kg-1 was found to be equipotent to pyridostigmine, 0.2 and 0.38 mg.kg-1, and edrophonium, 0.54 and 1.15 mg.kg-1, respectively. These doses were given by random allocation to the next 60 patients, but at one per cent spontaneous recovery. Neostigmine, 0.04 mg.kg-1, produced a T1 of 73 +/- 4 per cent (mean +/- SEM), and a train-of-four ratio (TOF) of 39 +/- 3 per cent. This was significantly greater than with pyridostigmine, 0.2 mg.kg-1 (T1 = 50 +/- 6 per cent; TOF = 25 +/- 3 per cent), and edrophonium, 0.54 mg.kg-1 (T1 = 54 +/- 3 per cent; TOF = 17 +/- 2 per cent).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Dose-response curves for edrophonium, neostigmine, and pyridostigmine after pancuronium and d-tubocurarine.

To determine the potencies of neostigmine, pyridostigmine, and edrophonium in reversing pancuronium and d-tubocurarine blockade, dose-response curves were established for first twitch height recovery and train-of-four ratio. One hundred and twenty ASA physical status I or II patients scheduled for elective surgery received either 0.06 mg/kg pancuronium or 0.36 mg/kg d-tubocurarine during a thiopental-nitrous oxide-enflurane anesthetic. Train-of-four stimulation was applied every 12 s, and the force of contraction of the adductor pollicis muscle was recorded. When first twitch height had recovered spontaneously to 10% of its initial value, neostigmine (0.005, 0.01, 0.02 or 0.05 mg/kg), pyridostigmine (0.02, 0.04, 0.1, or 0.2 mg/kg), or edrophonium (0.1, 0.2, 0.4 or 1 mg/kg) was injected by random allocation. Recovery was measured 10 min after the injection of the antagonist. First twitch ED50's were 0.013, 0.085, and 0.17 mg/kg after pancuronium, and 0.017, 0.11, and 0.27 mg/kg after d-tubocurarine, for neostigmine, pyridostigmine, and edrophonium, respectively. The ED50 for pyridostigmine and edrophonium obtained after d-tubocurarine was significantly larger (P less than 0.05) than that after pancuronium. The train-of-four dose-response curves were significantly flatter for edrophonium than for the other two agents, indicating a greater ability of edrophonium to antagonize fade at low doses. It is concluded that the potency of reversal agents may be different for different relaxants, and that potency ratios might depend upon the end-point chosen as full neuromuscular recovery.

Adult↗