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Biomedical subjects

T G Hislop

Publications and source records attributed to T G Hislop.

At least 19 recordsLinked to original sources
PubMed2002

Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease.

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

Adult↗
PubMed2001

Development of scales to measure dietary acculturation among Chinese-Americans and Chinese-Canadians.

OBJECTIVE: To develop simple scales to measure a Chinese immigrant's adoption of Western eating patterns (dietary acculturation). STUDY DESIGN AND PARTICIPANTS: Data are from 244 less-acculturated women of Chinese ethnicity living in Seattle, Wash, and Vancouver, British Columbia, Canada. Interviewers collected information on sociodemographic characteristics, acculturation indices, items that reflect Western and Chinese dietary behavior, and consumption of fruits, vegetables, and fat. STATISTICAL ANALYSES: Analysis of variance and linear regression analyses examined associations among dietary measures and acculturation variables, controlling for age, education, and city of residence. RESULTS: We developed 2 scales to assess dietary acculturation: the Western Dietary Acculturation Scale and the Chinese Dietary Acculturation Scale, measuring Western and Chinese eating behavior, respectively. Although the population in this study was a less-acculturated sample, most participants reported some Western dietary practices, such as drinking milk (78%), eating cheese (78%), eating at Western fast-food restaurants (56%), and eating between meals (72%). Younger, highly educated women employed outside the home had the highest Western dietary acculturation scores (P < .001). Women with high scores on the Western scale reported higher-fat dietary behaviors and had increased fruit and vegetable intake since immigration compared to those with lower scores (P < .001). There was good agreement between the dietary acculturation scales and traditional acculturation indicators (P < .001). APPLICATIONS: Nutrition programs for immigrant/minority groups may be more effective if they are tailored to level of dietary acculturation. Therefore, the ability to accurately assess dietary acculturation is an important component of nutrition education, interventions, and counseling in these populations.

Acculturation↗
PubMed2001

A household food inventory for North American Chinese.

OBJECTIVE: To determine whether a short set of questions about foods in the household can provide information about the fat-related dietary behaviour of individual household members in less-acculturated Chinese populations. DESIGN: Cross-sectional survey. PARTICIPANTS: The study population included 244 adult females of Chinese ethnicity in Seattle, WA, and Vancouver, BC, Canada. SETTING: Bilingual interviewers collected information on the presence of 14 high-fat foods and seven reduced-fat foods in the household. Respondents were also asked about the consumption of foods and behaviour reflective of adoption of Western dietary practices, fat-related dietary behaviour, changes in consumption of high-fat foods since immigration, and sociodemographic characteristics. RESULTS: Although this was a less-acculturated sample, many households had Western foods such as butter (58%), lunchmeats (36%), snack chips (43%), and 1% or skim milk (48%). Households with respondents who were younger, married, employed outside the home, and lived with young children had significantly more high-fat foods, while high education and longer percentage of life in North America were significantly associated with having more reduced-fat foods (P , or = 0.05). Participants living in households with more high-fat foods had higher-fat dietary behaviour than those with fewer high-fat foods (fat-related dietary behaviour score, 1.54 versus 1.28; P < 0.001). Women in households with more reduced-fat foods had a significantly decreased consumption of high-fat foods since immigration compared with those in households with fewer reduced-fat foods (P < 0.001). Western dietary acculturation was higher among women in households both with more high-fat foods and more reduced-fat food counterparts (P < or = 0.05). CONCLUSIONS: Our inventory of household foods was strongly associated with current dietary behaviour, changes in food consumption, and westernization of dietary patterns. This simple, practical measure may be a useful alternative dietary assessment tool in less-acculturated Chinese populations.

Acculturation↗
PubMed2000

Premorbid diet in relation to survival from prostate cancer (Canada).

OBJECTIVES: To examine the associations between prediagnostic energy, fat, and vitamin A intake and survival from prostate cancer. METHODS: Two hundred and seven cases of prostate cancer from Toronto and 201 cases from Vancouver provided diet histories at diagnosis between 1989 and 1992 and were followed for survival from prostate cancer. After exclusions for various reasons, 263 cases (135 from Toronto, 128 from Vancouver) were analyzed in Cox proportional hazards models. RESULTS: Following adjustments for clinical stage, histologic grade, and other factors, significantly lower risks of dying from prostate cancer in the highest compared with the lowest tertiles of monounsaturated fat intakes were observed in each city and in the combined city analyses (combined cities: hazard ratio [HR] = 0.3; 95% confidence interval (CI) = 0.1-0.7). Survival from prostate cancer was significantly better for cases in the highest tertile of energy intake in Toronto (HR = 0.1; CI = 0.01-0.6) in contrast to that in Vancouver where these cases did relatively worse (HR = 2.6; CI = 0.6-10.7). Other nutrients were either not consistently or not significantly associated with prostate cancer survival in the two cities. CONCLUSIONS: This bi-center cohort study observed a consistent and significant inverse association between the premorbid intake of monounsaturated fat and risk of death from prostate cancer. The inconsistent results for energy intake between cities could potentially be attributed to non-respondent bias in Toronto.

Aged↗
PubMed2000

Ten years of breast screening in the Screening Mammography Program of British Columbia, 1988-97.

OBJECTIVES: To evaluate 10 years outcomes of the Screening Mammography Program of British Columbia (SMPBC) and determine if breast screening targets were being achieved among women aged 40-80+ years. SETTING: Organised breast screening programme in British Columbia, Canada. METHODS: Rates of participation, abnormal referral, cancer detection, and interval cancer were calculated for asymptomatic women receiving an SMPBC mammography from 1988-97. RESULTS: 895,849 screening mammographies were provided to 335,433 women. 51.3% of women were age 50-69 years. Abnormalities were identified on 57,454 screens (6.4%) from which 3304 cancers were detected. Abnormal call rates were higher on first (9.8%), compared with subsequent screens (4.4%) and declined with age: 7.7% at age < 40 to 5.4% for age 70-79 years. Cancer detection rates were higher on first (5.0 per 1000) compared with subsequent screens (2.8 per 1000) and increased smoothly with age from 1.4 to 8.2 per 1000 from age < 40 to age 80 years and older. Twenty per cent of cancers were non-invasive. The median size of invasive cancers was 14 mm and 81% had no axillary lymph node metastases. The 12 month interval cancer rate was 0.6 per 1000 and did not vary significantly with age or screening history. The prevalence to expected incidence ratio was 3.1 for women age 50-79 years. CONCLUSION: Across a broad range of ages, surrogate indices of screening mammography success have been achieved in a population based, North American, organised breast cancer screening programme.

Adult↗
PubMed1999

Energy balance in women with breast cancer during adjuvant treatment.

OBJECTIVE: To compare weight, body composition, and major determinants of energy balance of women treated with adjuvant chemotherapy (n = 8) using Adriamycin and cyclophosphamide (AC), or radiation therapy (n = 10). DESIGN: The study used a nonrandomized prospective design. Pretreatment and posttreatment measurements, obtained at baseline and 12 weeks, respectively, included weight, body composition (determined using dual-energy x-ray absorptiometry), energy intake (determined using 3-day food records), resting energy expenditure (determined in indirect calorimetry), and physical activity (determined using 3-day physical activity records). Poststudy follow-up weights were obtained for 13 women. SUBJECTS/SETTING: Eighteen premenopausal women with breast cancer in the early stage, recruited from outpatient clinics, participated in and completed the study. STATISTICAL ANALYSES PERFORMED: Unpaired Student t tests or X2 tests were used to test for differences in baseline subject characteristics, and repeated measures analysis of variance was used to compare groups before and after treatment. RESULTS: Body weight was unchanged in both treatment groups during the study, although poststudy follow-up weights (n = 13) suggested a tendency for weight gain in both groups. Significant changes in body composition for both groups included a mean loss of 0.8 kg total lean body mass (LBM), a mean loss of 0.4 kg LBM in the leg region, and a mean 1.3% increase in percent body fat, from 40.0% to 41.3%. Overall, no between-group differences were observed in any factors associated with energy balance. APPLICATIONS: In this short-term study, AC chemotherapy using fewer antineoplastic agents and number of treatments than most chemotherapy protocols for breast cancer, did not result in weight gain during treatment. Regardless of weight gain, changes in body composition may occur in women with breast cancer during or after treatment. These potential changes have important implications for preventive nutrition counseling.

Absorptiometry, Photon↗
PubMed1998

Reducing cervical cancer among First Nations women.

First Nations women in British Columbia have a four to six times higher mortality rate from cancer of the cervix than do women in the general population. Their participation in the provincial Cervical Cytology Screening Program (CCSP) is less regular and less frequent than other women in B.C. Likewise, they have more difficulty in obtaining culturally suitable health care services from respectful and consistent professionals. These issues should be of critical concern to nurses, as nurses provide the majority of health services to First Nations people.

British Columbia↗
PubMed1997

Family history of prostate cancer: a multi-center case-control study in Canada.

In a population-based case-control study of prostate cancer conducted in Montreal, Toronto and Vancouver between 1989 and 1993, a total of 640 newly incident cases and 639 aged-matched population controls were interviewed as to their family history of prostate cancer as well as nutritional and other lifestyle and environmental factors. In total, 94 cases (15%) reported at least one blood relative with a family history, as compared with 32 (5%) of controls, giving a relative risk of 3.32 (95% confidence interval 2.18-5.05). The association was very consistent across all 3 centers, and was similar for each specific type of relative considered (fathers or brothers). Thus, this study provides further evidence of familial aggregation of prostate cancer, and suggests the possibility that part or all of such clustering could be related to inherited genetic patterns; if so, the availability of screening procedures for the disease offers the possibility of useful early intervention in individuals with such inherited susceptibility.

Aged↗
PubMed1997

Patterns of initial management of node-negative breast cancer in two Canadian provinces. British Columbia/Ontario Working Group.

OBJECTIVE: To describe the patterns of initial management of node-negative breast cancer in Ontario and British Columbia and to compare the characteristics of the patients and tumours and of the physicians and hospitals involved in management. DESIGN: Retrospective, population-based, cohort study. PARTICIPANTS: All 942 newly diagnosed cases of node-negative breast cancer in 1991 in British Columbia and a random sample of 938 newly diagnosed cases in Ontario in the same year. OUTCOME MEASURES: Number and proportion of patients with newly diagnosed node-negative breast cancer who received breast-conserving surgery (BCS) or mastectomy and who received radiation therapy after BCS. RESULTS: BCS was used in 413 cases (43.8%) in British Columbia and in 634 cases (67.6%) in Ontario (p < 0.001). After BCS, radiation therapy was received by 378 patients (91.5% of those who had undergone BCS) in British Columbia and 479 patients (75.6% of those who had undergone BCS) in Ontario (p < 0.001). In both provinces, lower patient age, smaller tumour size, a noncentral unifocal tumour, absence of extensive ductal carcinoma in situ and initial surgery by a surgeon with an academic affiliation were associated with greater use of BCS. Lower patient age and larger tumour size were associated with greater use of radiation therapy after BCS in both provinces. CONCLUSION: Patient, tumour and physician factors are associated with the choice of initial management of breast cancer in these two Canadian provinces. However, the differences in management between the two provinces are only partly explained by these factors. Other possible explanations, such as the presence of provincial guidelines, differences in the organization of the health care system or differences in patient preference, require further research.

Age Distribution↗
PubMed1997

Post screen-detected breast cancer within the Screening Mammography Program of British Columbia.

The histological characteristics and extent of mammographic density were compared between 170 post screen-detected (PSD) breast cancers and 466 screen-detected (SD) breast cancers in women attending the Screening Mammography Program of British Columbia. In addition, methods of detection and clinical presentation for the PSD cancers were examined. Invasive ductal, comedo, and medullary carcinoma were significantly more common in PSD cancer in women under age 50 years, and invasive ductal carcinoma in women over age 50 years. Mammographic density was more common in PSD cancers for all age groups under 70 years. The majority of PSD cancers were node negative with no evidence of metastases; however, they tended to be of more advanced stage than SD cancer. Most PSD cancers regardless of age were initially found by the woman herself, presenting as a palpable mass, and the likelihood of being detected within 12 months of the last screening mammogram was higher at younger ages.

Age Factors↗
PubMed1997

The association between population-based treatment guidelines and adjuvant therapy for node-negative breast cancer. British Columbia/Ontario Working Group.

This study evaluated the impact of province-wide treatment guidelines on consistency of adjuvant therapy for node-negative breast cancer. A retrospective population-based cohort study was conducted in the Canadian provinces of British Columbia, which has province-wide guidelines, and Ontario, which does not. All eligible 1991 incident cases of node-negative breast cancer in British Columbia (n = 942) and a similar number of randomly selected 1991 incident cases in Ontario (n = 938) were reviewed. Consistency of adjuvant therapy received was evaluated by stratifying cases into discrete diagnostic groups using several grouping systems, and by then comparing the distribution of treatments received within each diagnostic group in the two provinces. Recursive partitioning was also performed. We observed that patterns of pathology reporting were consistent with awareness of the factors used in the British Columbia guidelines to define indications for adjuvant therapy. Consistency of care was greater in British Columbia than in Ontario by all diagnostic grouping systems and by recursive partitioning (P < 0.001), and the observed patterns in British Columbia corresponded to the British Columbia guidelines. We conclude that population-based treatment guidelines can play a role in promoting consistent patterns of adjuvant therapy for women with node-negative breast cancer.

Aged↗
PubMed1997

Cigarette smoking and risk of prostate cancer: a population-based case-control study in Ontario and British Columbia, Canada.

The relationship between cigarette smoking and risk of prostate cancer was examined in a case-control study conducted in Ontario and British Columbia, Canada. In each centre, cases were men with a histologically confirmed diagnosis of adenocarcinoma of the prostate notified to the provincial cancer registry. In Ontario, controls were selected randomly from assessment lists maintained by the Ontario Ministry of Revenue and were frequency matched to the cases on age. In British Columbia, controls were also frequency matched to the cases on age and were selected randomly from a roster maintained by the Medical Services Plan of British Columbia. The study in Ontario was conducted between April 1990 and April 1992, and that in British Columbia was conducted between January 1989 and December 1991. In all, the study included 408 cases (207 in Ontario and 201 in British Columbia) and 407 controls (207 in Toronto and 200 in British Columbia (one case was unmatched). Overall, there was little variation in risk of prostate cancer with pack-years of cigarette consumption (filter and non-filter cigarettes combined), and there was no evidence for an effect confined to filter or non-filter cigarettes. There was some evidence for a positive association with non-filter cigarettes in British Columbia, but on formal testing for heterogeneity, this finding was not inconsistent with the absence of an association in Ontario. There was also little variation in risk by years since first smoked or (for ex-smokers) by years since quitting. These data provide little support for an association between cigarette smoking and prostate cancer risk.

Adenocarcinoma↗
PubMed1997

Compliance with practice guidelines for node-negative breast cancer.

PURPOSE: Practice guidelines for cancer management have been in use in the province of British Columbia (BC), Canada, since the mid 1970s. To evaluate practice guideline compliance, treatment received was compared with treatment recommended in a population-based cohort of women with breast cancer. METHODS: All incident cases (n = 939) of invasive, pathologically node-negative breast cancer diagnosed in 1991 were identified from the BC Cancer Registry. Treatment details were abstracted from cancer clinic records for cases referred to the BC Cancer Agency (BCCA) (n = 661) and original source documents for nonreferred cases. Management decisions were considered compliant if the patient received the recommended treatment or was entered onto a randomized trial of the modality being assessed. RESULTS: Overall compliance with adjuvant therapy guidelines was 97% for radiotherapy, 96% for chemotherapy, and 89% for tamoxifen. An oncology specialist was consulted by 94% of patients with an indication for adjuvant treatment and by 58% of those without an indication (odds ratio [OR] = 10.7; 95% confidence interval, 7.0 to 16.4). Compliance with a guideline to deliver radiotherapy was 95%; with chemotherapy, 77%; and with tamoxifen, 68%. Compliance with a guideline that stated no adjuvant treatment was indicated was 99% for radiotherapy, 98% for chemotherapy, and 92% for tamoxifen. Noncompliance among patients with an indication for treatment was related to nonreferral to an oncology specialist and less complete implementation of guideline changes in the community as compared with cancer center practices. CONCLUSION: Compliance was high, but scheduled updating and more effective community implementation could further improve consistency of care.

Aged↗
PubMed1996

Cervical cytology screening. How can we improve rates among First Nations women in urban British Columbia?

OBJECTIVE: To determine Pap smear screening rates among urban First Nations women in British Columbia; to identify facilitators and barriers; and to develop, implement, and evaluate specific interventions to improve Pap smear screening in Vancouver. DESIGN: Computer records of band membership lists and the Cervical Cytology Screening Program registry were compared to determine screening rates; personal interviews and community meetings identified facilitators and barriers to urban screening programs. A community advisory committee and the project team collaborated on developing specific interventions. SETTING AND PARTICIPANTS: Purposive sample of British Columbia First Nations women, focusing on women living in Vancouver. INTERVENTIONS: Poster, art card, and follow-up pamphlet campaign; articles in First Nations community papers; community meetings; and Pap smear screening clinics for First Nations women. MAIN OUTCOME MEASURES: Pap smear screening rates among BC First Nations women according to residence and reasons for not receiving Pap smears. RESULTS: Pap smear screening rates were substantially lower among First Nations women than among other British Columbia women; older women had even lower rates. No clear differences were found among First Nations women residing on reserves, residing in Vancouver, or residing off reserves elsewhere in British Columbia. Facilitators and barriers to screening were similar among women residing on reserves and in Vancouver. Many First Nations women are greatly affected by health care providers' attitudes, abilities to provide clear information, and abilities to establish trusting relationships. CONCLUSIONS: Family physicians are an important source of information and motivation for Pap smear screening among First Nations women.

Adolescent↗
PubMed1996

Clinical determinants of mammographic dysplasia patterns.

The association between the clinical manifestations of benign breast disease (BBD) and mammographic patterns was investigated among 1394 women (923 pre-menopausal and 471 post-menopausal) participating to the Canadian National Breast Screening Study in Vancouver, who completed a questionnaire designed to collect detailed information on the symptoms and signs of BBD, hormonal, reproductive and dietary factors. Mastalgia was present in 637 (46%) women and was cyclical in 505 (79%). Breast swelling was noted in 331 women (23%) and mammary dysplasia involving 50% or more of the breast parenchyma in 733 (43%). Mastalgia was highly associated with breast swelling (odds ratios [OR] = 29.9, 95% confidence interval [CI] = 21.3-41.8), particularly when cyclical and characterized by tenderness with pain (OR = 58.4, 95% CI = 39.1-87.0). The relative risk for mammary dysplasia involving 50% or over of the breast parenchyma was significant in pre-menopausal women having breast swelling (OR = 2.96, 95% CI = 1.81-4.83), being highest in women with cyclical mastalgia associated with tenderness and pain (OR = 3.43, 95% CI = 1.49-7.92); similar associations were noted in post-menopausal women. This study indicates that mastalgia is strongly related to breast swelling, especially when tenderness is associated with pain. Furthermore, mastalgia associated with breast swelling is highly related to the presence of mammary dysplasia involving 50% or more of the breast parenchyma in both pre- and post-menopausal women, suggesting that cyclical tenderness and breast swelling may carry an increased breast cancer risk.

Adult↗
PubMed1995

Vasectomy and prostate cancer: results from a multiethnic case-control study.

BACKGROUND: Vasectomy, a widely used form of contraception, has been associated in some studies with increased prostate cancer risk. PURPOSE: We assessed this association on the basis of data collected in a large multiethnic case-control study of prostate cancer that was conducted in the United States (Los Angeles, San Francisco, and Hawaii) and Canada (Toronto and Vancouver). METHODS: In home interviews conducted with newly diagnosed prostate cancer case patients and population control subjects, we obtained information on the participants' medical history, including a history of vasectomy and the age at which the procedure was performed, as well as other potential risk factors. Blood samples were collected from control subjects only and were assayed for concentration of sex hormones and sex hormone-binding globulin. RESULTS: The present analysis was based on 1642 prostate cancer patients and 1636 control subjects. A history of vasectomy was not significantly associated with prostate cancer risk among all racial/ethnic groups combined (odds ratio [OR] = 1.1; 95% confidence interval [CI] = 0.83-1.3), whites (OR = 0.94; 95% CI = 0.69-1.3), blacks (OR = 1.0; 95% CI = 0.59-1.8), or Chinese-Americans (OR = 0.96; 95% CI = 0.42-2.2). Among Japanese-Americans, the OR was 1.8 (95% CI = 0.97-3.4), but the statistically nonsignificant elevation in risk was limited to more educated men and those with localized cancers. ORs did not vary significantly by age at vasectomy or years since vasectomy. We found a lower serum concentration of sex hormone-binding globulin and a higher ratio of dihydrotestosterone to testosterone among vasectomized control subjects than among nonvasectomized control subjects. CONCLUSIONS: The findings of this study do not support previous reports of increased prostate cancer risk associated with vasectomy. However, the altered endocrine profiles of vasectomized control subjects seen in this cross-sectional comparison warrant further evaluation in longitudinal studies.

Aged↗
PubMed1994

Screening mammography in British Columbia: 1988-1993.

Breast carcinoma continues to be the most common cause of death due to malignancy for women in Canada. The Screening Mammography Program of British Columbia, the first provincial screening program in Canada, was established in 1988 with funding from the Ministry of Health to diagnose the disease as early as possible. The program has grown rapidly, increasing from 7,100 examinations in a pilot project in 1988 to 89,390 examinations between April 1, 1992 and March 31, 1993 for a cumulative total of 201,937 examinations of 128,325 women, and it now offers free screening mammography throughout the province. The program has maintained quality control standards and low cost per mammogram while developing different operational models for the differing requirements of the various areas of the province. Similar proportions of women older or younger than age 50 have favourable characteristics such as small size of tumor (median: 15 to 16 mm) and negative lymph nodes (86% to 89%).

Breast Neoplasms↗