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Biomedical subjects

N F Boyd

Publications and source records attributed to N F Boyd.

At least 91 records · Page 5Linked to original sources
PubMed1988

Measurement of the clinical status of patients with breast cancer: evidence for the validity of self assessment with linear analogue scales.

We have assessed the validity of a method of measurement for describing the clinical status of patients with breast cancer. One hundred and nine patients with breast cancer assigned numerical values to their own state of health using linear analogue scales. We have shown previously that this method of measurement is reliable and corresponds well with other methods of assessment. Validity was assessed in this study by examining the ability of measurements to distinguish between groups of patients who differed either in the presence of metastatic disease or in the treatments they were receiving. All patients completed the same set of 29 linear analogue scales that enquired about the severity of health related problems and symptoms. In general, patients with metastatic disease were clearly distinguished from patients without metastases by their scores on items related to physical function. Patients receiving chemotherapy were distinguished from those not receiving chemotherapy by their scores on treatment related toxicities. Measures of psychological and social health were similar in patients receiving chemotherapy regardless of disease status. These results provide further support for the validity of measurement of clinical status with linear analogue scales scored by patients.

Breast Neoplasms↗
PubMed1988

The association of histological and radiological indicators of breast cancer risk.

Previous work has shown that extensive mammographic dysplasia in women aged less than 50 was strongly associated with breast cancer but that the radiological appearance of ductal prominence was not associated with risk. In the present paper we examine the association between these mammographic signs in the breast and histological patterns in the terminal ductal lobular unit (TDLU), the region of the breast where breast cancer is believed to originate. Surgical biopsies from a consecutive series of women aged less than 50 were reviewed and classified according to the histopathology of the epithelium in the TDLU. Mammograms from the same subjects were independently classified according to the extent of the radiological signs of dysplasia and ductal prominence. Degree of histopathology and the extent of mammographic dysplasia were associated and atypia of the ductal type was found more frequently in patients with extensive dysplasia. However, the strength and statistical significance of the association varied according to the radiologist who classified the mammograms. No association was found between degree of histopathology and ductal prominence. These results add to the evidence that extensive mammographic dysplasia in women aged less than 50 is a risk factor for breast cancer. They do not indicate that the radiological signs of dysplasia are caused by histological changes in the TDLU.

Adult↗
PubMed1988

A randomized trial of two dose levels of cyclophosphamide, methotrexate, and fluorouracil chemotherapy for patients with metastatic breast cancer.

This study was designed to assess the role of dosage of chemotherapy for treatment of metastatic breast cancer. One hundred thirty-three patients without prior chemotherapy for metastatic disease were randomly allocated to receive two different dose levels of cyclophosphamide (C), methotrexate (M), and fluorouracil (F), administered intravenously (IV) every 3 weeks. Patients were stratified by sites of disease (visceral, bone, or soft-tissue dominant) and by interval from primary surgery to first recurrence. Doses on the higher-dose arm were 600 mg/m2 (C,F) and 40 mg/m2 (M) with escalation if possible; doses on the lower-dose arm were 300 mg/m2 (C,F) and 20 mg/m2 (M) without escalation. Patients who failed to respond to lower-dose CMF were crossed over to the higher-dose arm. Patients randomized to the higher-dose arm had longer survival measured from initiation of chemotherapy (median survival, 15.6 months v 12.8 months, P = .026 by log-rank test), but the effect of dose was of borderline significance (P approximately 0.12) when adjusted for a chance imbalance between the two arms in the time from first relapse to randomization, using the Cox proportional hazards model. Response rates (International Union Against Cancer [UICC] criteria) for patients with measurable disease were higher-dose arm: 16/53 (30%) and lower-dose arm: 6/53 (11%), (P = .03). Only one of 37 patients responded on crossover from the lower- to the higher-dose arm. Patients experienced more vomiting, myelosuppression, conjunctivitis, and alopecia when receiving higher doses of chemotherapy. A series of 34 linear analogue self-assessment scales were used to make detailed quality of life assessments on a subset of 49 patients. These scales confirmed greater toxicity in the immediate posttreatment period, but also a trend to improvement in general health and some disease-related indices, in patients receiving higher-dose chemotherapy. This trial suggests that better palliation is achieved by using full-dose chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Ultrasonographically defined parenchymal patterns of the breast: relationship to mammographic patterns and other risk factors for breast cancer.

We have used ultrasound of the breast to define four parenchymal patterns in which increasing proportions of the breast are replaced by densely echogenic tissue. A series of 452 symptomatic women examined by both ultrasound and conventional X-ray mammography was reviewed to determine whether these ultrasonographic images could predict the breast parenchymal pattern defined mammographically. A very strong correlation was demonstrated between the breast pattern on ultrasound and the volume of the breast replaced by either dysplasia (Kendall's tau-b = 0.731 +/- 0.026, p less than 0.0001) or ductal prominence (Kendall's tau-b = 0.641 +/- 0.049, p less than 0.0001). This was seen both on initial reporting and on a blind re-reading of a random sample of 100 cases. The strength of correlation was similar for subgroups defined by family history of breast cancer, age, menopausal status, and history of benign breast disease, and the breast parenchymal pattern assessed by mammography or ultrasound showed similar associations with these variables. Ultrasonographic parenchymal patterns of the breast can predict the tissue patterns defined mammographically and may therefore be useful as a marker of breast cancer risk.

Adult↗
PubMed1987

Age as a confounding factor in the association of mammographic dysplasia and estrogen receptor concentration in breast cancer.

We have examined the association between hormone receptor concentration in primary breast cancer and the mammographic pattern of the breast in which the cancer arose. A significant association was found between the concentration of estrogen receptor and the proportion of the breast volume occupied by the radiological signs of dysplasia. Both estrogen receptor concentration and dysplasia were found to be strongly associated with age. Estrogen receptor concentration rose with increasing age, while the age of patients with extensive dysplasia was substantially less than that of patients with no dysplasia. After taking age into account, no association remained between estrogen receptor concentration and mammographic dysplasia. Age is therefore a confounding factor in this association.

Adult↗
PubMed1987

Eliciting preferences for alternative drug therapies in oncology: influence of treatment outcome description, elicitation technique and treatment experience on preferences.

Several methodologic issues arise in eliciting preferences for therapy. Examples are the selection of appropriate descriptions of treatment outcomes and of elicitation techniques. Of particular importance is the correspondence of patients' anticipated preferences for treatment to actual preferences once they have experienced treatment. Treatment outcome descriptions and elicitation techniques were compared for a hypothetical drug decision problem involving trade-offs between quality and quantity of life. Preferences of 54 cancer patients were elicited before, and 6 weeks following initiation of chemotherapy treatment. Patients' preferences were not influenced by the way information about side effects was presented, nor the stated probability of survival at high and moderate levels. A riskless rating technique produced different preferences from those of a risky treatment choice method. Although patients experienced significant toxicity following initiation of treatment, their preferences remained stable on retest. The results raise questions about the extent to which patients are willing, at the time of decision making, to trade off survival rate for improved quality of life.

Antineoplastic Agents↗
PubMed1987

Computed tomography in advanced ovarian cancer: an evaluation of diagnostic accuracy.

The authors have investigated the diagnostic accuracy of computed tomography (CT) of the abdomen and pelvis in the assessment of patients prior to second-look laparotomy for advanced ovarian cancer. CT studies (read independently by three radiologists) and laparotomy findings were analyzed in 50 patients. Sensitivity varied from 0.30 to 0.65 among the radiologists, specificity from 0.44 to 0.89, positive predictive value from 0.50 to 0.73, and negative predictive value from 0.60 to 0.70. Receiver operator curve analysis of the data indicated poor performance of CT as a diagnostic test. The authors also examined some problems in interpreting their data and that of others in the literature, in particular, the influence of potential sources of bias.

Evaluation Studies as Topic↗
PubMed1987

Critical appraisal of the evidence that dietary fat intake is related to breast cancer risk in humans.

A critical appraisal was undertaken of the evidence that dietary fat intake is related to breast cancer risk by application of the criteria for causal inference proposed by Bradford Hill to the published evidence that relates dietary fat to breast cancer risk in humans. These criteria concern the consistency, strength, and temporal relationships of possible causative associations and also require the existence of a biologic gradient and examine the extent to which the proposed causal association is in keeping with other biological and epidemiological knowledge. The published reports were inconsistent in their ability to detect a significant association between dietary fat and breast cancer risk, correlation studies that examined the effect of fat over large ranges being largely positive, and studies with stronger designs (case-control, cohort) that examined fat intake over much smaller ranges being largely negative. It was postulated that methodologic limitations associated with the design of the latter studies, in particular the small ranges of fat intake examined and inaccuracies in the measurement of fat intake, may have obscured any relationships between dietary fat and breast cancer that did exist. The remaining criteria, with the exception of temporality and epidemiological coherence, were not satisfied. Insufficient evidence existed to conclude a causal association existed between dietary fat and breast cancer risk in humans. A need for further study was identified in several areas, and it was concluded that intervention studies that examined the effect of fat over large ranges were most likely to yield the information required to determine whether dietary fat intake was causally related to breast cancer risk.

Animals↗
PubMed1986

Observer variation in the classification of mammographic parenchymal patterns.

Wolfe has described different cancer risks associated with a classification of four patterns of the breast parenchyma on mammography, but there is however little information available on the ability of radiologists to agree on the classification of the different patterns. We have assessed inter-rater agreement on the assignment of films to one of the four mammographic patterns described by Wolfe. One hundred xeromammograms were selected, copied and distributed to 10 radiologists who were experts in mammography. Films were classified according to the presence or absence of several radiological signs, according to diagnosis and recommendation, and according to mammographic pattern. Agreement was assessed after correction for agreement expected by chance, using the Kappa statistic. In general, high levels of agreement were found for the classification of mammographic pattern. Agreement on the classification of mammographic pattern was substantially greater than agreement for any other feature of mammographic interpretation, including diagnosis and recommendation.

Breast Neoplasms↗
PubMed1986

Computed tomography in advanced ovarian cancer. Inter- and intraobserver reliability.

We have examined the reliability of computed tomography (CT) in the assessment of patients with advanced ovarian cancer. Three radiologists independently read the same set of 140 CT scans. Fifty percent of the films were reread by the same radiologist to assess intraobserver agreement. In addition we assessed variability among radiologists in reporting signs of disease such as a mass and ascites and the variability in reporting a change in signs in response to therapy. Intraobserver agreement on the identification of signs such as a mass and ascites and on overall response to therapy was moderate to excellent (Kappa 0.52-0.84). Agreement among observers on the same signs was not as good (Kappa 0.36-0.79).

Adult↗
PubMed1985

Weight gain during adjuvant chemotherapy for breast cancer.

Weight gain during adjuvant chemotherapy has been reported by several authors. Because increased body weight at diagnosis is associated with an increased risk of disease recurrence, we have assessed the prevalence of weight gain in a series of patients receiving adjuvant treatment, as well as the association of weight gain with type of treatment and risk of recurrence. We first assembled an inception cohort of 237 patients who had all undergone pretreatment evaluation and treatment at one institution, and had already been followed for at least 12 months. Body weight at the start and completion of treatment was recorded, as was type of treatment and status at last followup. Ninety-six percent of patients gained weight during treatment and none lost weight (mean increase 4.3 kg). Weight gain was strongly associated with treatment, and was least in patients receiving single agent chemotherapy, greatest in patients treated with ovarian ablation and prednisone, and intermediate in those receiving combination chemotherapy. There was no association between weight gain and disease recurrence.

Adult↗
PubMed1985

Eliciting preferences for alternative cancer drug treatments. The influence of framing, medium, and rater variables.

In oncology there is increasing interest in the development of techniques to help patients choose between alternative therapies in ways that are consistent with their preferences. The purpose of this study was to examine some methodological problems associated with the elicitation of preferences. Preferences for alternative drug therapies were sought from 208 visitors to an open house at the Ontario Cancer Institute and from 216 university nursing students. Preferences were not significantly dependent on the sex, age or professional status of the respondents, nor on the medium used for elicitation of preferences (computer terminal versus pencil-and-paper questionnaire). In contrast, the importance of the way decision problems are framed was confirmed. Comparison of a positive frame (outcomes expressed as the probability of surviving) with a negative frame (outcomes expressed as the probability of dying) and a mixed frame (probabilities of surviving and dying were both given) pointed to the presence or absence of the word "survive" in the outcome description as the main source of framing bias. The framing effect was in the opposite direction to that hypothesized.

Adolescent↗
PubMed1985

The frequency of malignant neoplasms in patients with polymyositis-dermatomyositis. A controlled study.

Seventy-one patients with polymyositis-dermatomyositis (PM/DM) admitted to the Wellesley Hospital Rheumatic Disease Unit (RDU) in Toronto between 1965 and 1980 were followed up to 1981. The frequencies of malignant neoplasms occurring prior to or concurrent with initial RDU admission were compared, using case-control methods, with age- and sex-matched control groups with a diagnosis of any non-PM/DM rheumatic disease (rheumatic disease controls) or osteoarthritis, fibrositis, or fracture (noninflammatory musculoskeletal controls). In a cohort analysis, the incidence of malignant neoplasm subsequent to initial RDU admission in patients with PM/DM was compared with the expected incidence in the Canadian population. Fifteen of 71 patients with PM/DM had an antecedent or concurrent cancer compared with four of 71 rheumatic disease controls and one of 71 noninflammatory musculoskeletal controls. Cohort analysis showed no increase in the number of subsequent malignant neoplasms in patients with PM/DM compared with the age- and sex-matched Canadian population.

Adolescent↗
PubMed1984

Linear analogue self-assessment of voice quality in laryngeal cancer.

This study evaluated the reliability and sensitivity of laryngeal cancer patients' linear analogue self-assessments (LASA) of voice quality. Thirty patients completed LASA scales for a number of voice-related symptoms and abilities several times during a standard treatment programme. The study design allowed evaluation of the scales' reliability, both early and late in treatment, and sensitivity to the changes expected during irradiation. Another 29 post-treatment patients completed the same scales in interviews separated by several weeks. Results indicate that LASA scores were generally reliable, sensitive to clinical change, yet stable when clinical status is unaltered. Though further demonstrations of the validity of these scales are required, their possible use as outcome measures in future clinical trials comparing treatments for laryngeal cancer is feasible.

Adult↗