Intentional tanning among adolescents in seven Canadian provinces: Provincial comparisons (CRAYS 2015).

This report explores intentional tanning behaviors among Canadian high school students in light of provincial restrictions on UV tanning device use among youth. Data are from the Cancer Risk Assessment in Youth Survey (CRAYS), collected from January to December 2015, at randomly selected high schools in 7 provinces. Relevant variables were: tanning methods ever used, demographics, and location and refusal of UV tanning device (beds, lamps) use in the past 12 months. Data were weighted so total survey weights by male/female, grade and province equal actual enrolments in these groups. Analyses were conducted in SAS, mostly for grades 10 and 11. Rao-Scott chi squared tests and p-values were calculated. Among 6803 grade 10 and 11 participants, 82% tanned intentionally, mostly by being/playing outside, or laying in the sun. Spray/self-tanners were used by 15% of participants. UV tanning device use was uncommon (4.4%), lowest in Ontario (2.7%) and British Columbia (3.8%), which have legislation against use among youth. Of 202 who used UV tanning devices in the past 12 months, most did at salons/studios (85%), 35% at home and 30% at a gym. Two hundred and forty-nine participants (3.4%) were refused use of UV tanning devices in the past 12 months. While legislation appears to deter UV tanning device use, it appears to have no impact on UV exposure among high school students overall. Greater prevention efforts are required to deter intentional tanning among high school students.

Tanning among Ontario adolescents pre-legislation: Prevalence and beliefs.

To establish adolescent tanning beliefs and behaviors, prevalence and location of UV tanning device (beds/lamps) use, awareness of risk and restriction signage, and frequency of tanning service refusal, noting differences by grade and sex, prior to a ban on UV tanning device use among those under 18 in Ontario, Canada. Data were collected May 5 to 20 of 2014. Children in grades 7 to 12, and under age 18 completed an on-line questionnaire that asked their age, sex, grade, methods used to tan, frequency, length and location of UV tanning device use, if services were refused and why, awareness and content of signs/warning labels, tanning beliefs and knowledge, and use of eye protection. Of 1561 participants (10% response rate), 49% were male, 51% female. There were significant differences between the sexes regarding tanning behaviors (e.g. not tanning, tanning outside). Seven percent (108) had 'ever' used UV tanning devices, females more than males (p=0.0026). Over half (57%) of the 104 using UV tanning devices in the past 12months noticed warning signs/labels, of which most noticed that UV tanning devices can cause cancer (65%), and that UV exposure can contribute to premature aging (67%). While most (66%) tanned at tanning salons/studios and beauty salons/studios, gyms/fitness clubs (35%) and home use were common (25%). A relatively low proportion of adolescents used UV tanning devices prior to the ban, with use more common among females and those in higher grades.

Cancer risk factors and screening in the off-reserve First Nations, Métis and non-Aboriginal populations of Ontario.

INTRODUCTION: This study describes the prevalence of smoking, obesity, sedentary behaviour/physical activity, fruit and vegetable consumption and alcohol use as well as the uptake of breast, cervical and colorectal cancer screening among First Nations and Métis adults in Ontario and compares these to that of the non-Aboriginal population. METHODS: We used the Canadian Community Health Survey (2007 to 2011 combined) to calculate prevalence estimates for the 3 ethnocultural populations. RESULTS: First Nations and Métis adults were significantly more likely than non-Aboriginal adults to self-report smoking and/or to be classified as obese. Alcohol use exceeding cancer prevention recommendations and inadequate fruit and vegetable consumption were more common in First Nations people than in the non-Aboriginal population. First Nations women were more likely to report having had a Fecal Occult Blood Test in the previous 2 years than non-Aboriginal women. No significant differences across the 3 ethnocultural groups were found for breast and cervical screening among women or colorectal screening among men. CONCLUSION: Without intervention, we are likely to continue to see a significant burden of smoking- and obesity-related cancers in Ontario's Aboriginal population.

TITRE: Facteurs de risque et dépistage du cancer chez les membres des Premières Nations vivant hors réserve, chez les Métis et chez les non-Autochtones en Ontario. INTRODUCTION: Cette étude vise à décrire la prévalence du tabagisme, de l'obésité, des comportements sédentaires et de l'activité physique, de la consommation de fruits et de légumes et de la consommation d'alcool ainsi que la participation au dépistage du cancer du sein, du cancer du col de l'utérus et du cancer colorectal chez les adultes des Premières Nations et métis en Ontario, par rapport à la population non autochtone. MÉTHODOLOGIE: Nous avons utilisé les données de l'Enquête sur la santé dans les collectivités canadiennes (données de 2007 à 2011 combinées) pour calculer les estimations de la prévalence chez les trois populations ethnoculturelles. RÉSULTATS: Par rapport aux adultes non autochtones, les adultes des Premières Nations et métis étaient beaucoup plus nombreux à déclarer fumer et à être classés comme obèses. Les membres des Premières Nations étaient plus nombreux que la population non autochtone à consommer de l'alcool au-delà des recommandations en matière de prévention du cancer et à consommer insuffisamment des fruits et des légumes. Les femmes des Premières Nations étaient plus nombreuses que les femmes non autochtones à déclarer avoir fait l'objet d'un dépistage par recherche de sang occulte dans les selles au cours des deux dernières années. Aucune différence significative n'a été observée entre les membres des trois groupes ethnoculturels en ce qui concerne le dépistage du cancer du sein et du cancer du col de l'utérus chez les femmes et le dépistage du cancer colorectal chez les hommes. CONCLUSION: Si l'on intervient pas, il est probable que les cancers liés au tabagisme et à l'obésité continueront à représenter un fardeau considérable au sein de la population autochtone de l'Ontario.

Sociodemographic factors associated with cervical cancer screening coverage and follow-up of high grade abnormal results in a population-based cohort.

INTRODUCTION: A cervical cytology based screening program is effective if there is regular screening of the 'at risk' population and close follow-up of those labeled abnormal. METHODS: This is a population cohort study of women between 20-69 year old who were eligible in Ontario from 2008-2010. We used administrative data to evaluate the rates of cervical cancer screening and follow-up of high grade Pap tests. Variation in cervical cytology coverage and follow-up of high grade abnormal results are associated with age, area level income and health region. Multivariate logistic regression was used to identify independent factors associated with screening and followup. RESULTS: 3.7million women were eligible for screening of which 72% had a Pap smear in the prior 3years. These rates varied by age, income and region (p<0.0001). Women residing in the lowest income neighborhoods were half as likely to be screened (p<0.0001). 83% of those with an high grade intraepithelial lesion Pap test result had follow-up with colposcopy or treatment within 6months and this varied by year, age, income and region (p<0.0001). CONCLUSIONS: Despite universal health coverage, cervical cancer screening rates are suboptimal with older and low income women being at greatest risk. Follow-up among women with high grade abnormal tests is mediocre at 3months and acceptable at 6months. Novel models of cervical cancer screening program implementation are needed to address these inadequacies.

Priority issues in occupational cancer research: Ontario stakeholder perspectives.

INTRODUCTION: Workers are potentially exposed to known and suspected carcinogens in the workplace, many of which have not been fully evaluated. Despite persistent need, research on occupational cancer appears to have declined in recent decades. The formation of the Occupational Cancer Research Centre (OCRC) is an effort to counter this downward trend in Ontario. The OCRC conducted a survey of the broad stakeholder community to learn about priority issues on occupational cancer research. METHODS: The OCRC received 177 responses to its survey from academic, health care, policy, industry, and labour-affiliated stakeholders. Responses were analyzed based on workplace exposures, at-risk occupations and cancers by organ system, stratified by respondents' occupational role. DISCUSSION: Priority issues identified included workplace exposures such as chemicals, respirable dusts and fibres (e.g. asbestos), radiation (e.g. electromagnetic fields), pesticides, and shift work; and occupations such as miners, construction workers, and health care workers. Insufficient funding and a lack of exposure data were identified as the central barriers to conducting occupational cancer research. CONCLUSION: The results of this survey underscore the great need for occupational cancer research in Ontario and beyond. They will be very useful as the OCRC develops its research agenda.

Cancer survival in Australia, Canada, Denmark, Norway, Sweden, and the UK, 1995-2007 (the International Cancer Benchmarking Partnership): an analysis of population-based cancer registry data.

BACKGROUND: Cancer survival is a key measure of the effectiveness of health-care systems. Persistent regional and international differences in survival represent many avoidable deaths. Differences in survival have prompted or guided cancer control strategies. This is the first study in a programme to investigate international survival disparities, with the aim of informing health policy to raise standards and reduce inequalities in survival. METHODS: Data from population-based cancer registries in 12 jurisdictions in six countries were provided for 2·4 million adults diagnosed with primary colorectal, lung, breast (women), or ovarian cancer during 1995-2007, with follow-up to Dec 31, 2007. Data quality control and analyses were done centrally with a common protocol, overseen by external experts. We estimated 1-year and 5-year relative survival, constructing 252 complete life tables to control for background mortality by age, sex, and calendar year. We report age-specific and age-standardised relative survival at 1 and 5 years, and 5-year survival conditional on survival to the first anniversary of diagnosis. We also examined incidence and mortality trends during 1985-2005. FINDINGS: Relative survival improved during 1995-2007 for all four cancers in all jurisdictions. Survival was persistently higher in Australia, Canada, and Sweden, intermediate in Norway, and lower in Denmark, England, Northern Ireland, and Wales, particularly in the first year after diagnosis and for patients aged 65 years and older. International differences narrowed at all ages for breast cancer, from about 9% to 5% at 1 year and from about 14% to 8% at 5 years, but less or not at all for the other cancers. For colorectal cancer, the international range narrowed only for patients aged 65 years and older, by 2-6% at 1 year and by 2-3% at 5 years. INTERPRETATION: Up-to-date survival trends show increases but persistent differences between countries. Trends in cancer incidence and mortality are broadly consistent with these trends in survival. Data quality and changes in classification are not likely explanations. The patterns are consistent with later diagnosis or differences in treatment, particularly in Denmark and the UK, and in patients aged 65 years and older. FUNDING: Department of Health, England; and Cancer Research UK.

Estimated ultraviolet exposure levels for a sufficient vitamin D status in North America.

Solar UV radiation is a major provider of vitamin D for humans. This study examines the distribution of solar UV radiation weighted according to the vitamin D action spectrum over the USA and Canada. Hourly and daily doses of spectrally integrated UV irradiance using the vitamin D action spectrum were estimated using a statistical relationship between UV irradiance and global solar irradiance, total ozone, and dew point temperature for 45 sites in Canada and 52 in the USA. Brewer spectrophotometer measurements at 12 sites in Canada and 21 sites in the USA were used to validate the obtained results. Different characteristics of the vitamin D action spectrum-weighted UV irradiance distribution over North America are presented in the form of monthly maps and as a data file. The time required to obtain standard vitamin D dose is also calculated for six types of skin.

On the relationship between erythemal and vitamin D action spectrum weighted ultraviolet radiation.

Erythemally weighted solar ultraviolet (UV) radiation is often used to characterize the production of vitamin D in a human body. However, the vitamin D production action spectrum is different than that for erythemal UV. The vitamin D action spectrum weighted UV is more sensitive to UV-B, while the erythemal UV action spectrum has higher weighting coefficients than the vitamin D action spectrum in the UV-A part of the spectrum. Therefore, by using the erythemal UV as an estimate for the vitamin D action spectrum weighted UV can give results that differ by up to a factor of 5. This study examines the relationship between erythemal and vitamin D action spectrum weighted UV radiation using measurements of spectral UV at the surface by Brewer spectrophotometers that are part of the US and Canadian observational networks. It is shown that the ratio of vitamin D action spectrum weighted UV to erythemal UV is nearly constant for high levels of UV (UV Index greater than 5.5) and therefore vitamin D action spectrum weighted UV can be described in terms of erythemal UV. For lower levels of UV though this relationship should not be used. A simple formula that calculates vitamin D action spectrum weighted UV from UV Index is developed. An empirical formula that expresses the ratio of vitamin D action spectrum weighted UV to erythemal UV as a function of the solar zenith angle and column ozone is also suggested. The geographical distributions of vitamin D action spectrum weighted UV in the US and Canada are discussed.

Coffee and tea consumption and cancers of the bladder, colon and rectum.

Coffee has been observed to be associated weakly or not at all with bladder cancer risk, inversely with colon cancer risk, and inconsistently with rectal cancer risk. The association between these cancers and consumption of coffee and tea was examined in a single case-control study conducted in Ontario, Canada from 1992 to 1994. A questionnaire was filled out by 927 bladder cancer cases, 991 colon cancer cases, 875 rectal cancer cases, and 2118 population controls. Although bladder cancer risk was not associated with coffee or tea, risk estimates associated with coffee among subjects who had never smoked were non-significantly increased. Colon cancer risk was inversely associated with coffee. Relative to those drinking less than 1 cup of coffee per day, the odds ratios (OR) for those drinking 1-2 cups was 0.9 (95% CI 0.8-1.1), for those drinking 3-4 cups was 0.8 (95% CI 0.7-1.0), and for those drinking 5 or more cups was 0.7 (95% CI 0.5-0.9); these ORs decreased linearly (P = 0.008). The reduced risk estimates were more pronounced with cancer of the proximal colon than the distal colon. Rectal cancer risk was not associated with either coffee or tea. Coffee consumption was observed to have a different relationship for each of the cancer sites and tea consumption was not related to any cancer site.

Predictors of sunburn among Canadian adults.

BACKGROUND: Data from the 1996 National Survey on Sun Exposure & Protective Behaviors (4,023 respondents) were analyzed to identify independent predictors of sunburn among adult Canadians. METHODS: Multivariate models predicting sunburn odds were developed using unconditional logistic regression. Backward elimination model selection was used to identify independent predictors of sunburn. RESULTS: Nonbehavioral characteristics found to predict sunburn were younger age, male sex, light skin color, nonblack hair color, and birthplace in North America or Europe. Behavioral predictors of sunburn included high awareness of the UV Index, working outdoors in the summer, longer leisure time in the sun, forgetfulness about protecting oneself from the sun, and seeking a tan. Sun avoidance between 11 AM and 4 PM was associated with lower odds of sunburn, while seeking shade when outside and use of protective clothing showed nonsignificant associations with lower sunburn odds. Sunscreen use was found to have a nonsignificant positive association with sunburn. CONCLUSIONS: These findings highlight risk factors to be considered in the targeting of sunburn reduction strategies to high-risk groups and suggest that sun avoidance, seeking shade, and use of protective clothing may be effective in preventing sunburn.

Workshop report: identification of research needs breast cancer etiology.

A workshop to evaluate the scientific evidence for the etiologic associations between modifiable lifestyle and environmental risk factors and to identify areas for future research in breast cancer etiology was sponsored jointly by the Canadian Breast Cancer Initiative and the Canadian Breast Cancer Research Initiative in May, 2001. Reviews of the scientific evidence in these topics were commissioned and an expert panel convened to consider the reviews and make recommendations for research. The panel concluded that there was substantial evidence to proceed with additional research in several areas of breast cancer etiology. Particular support for future research for several lifestyle and environmental risk factors including alcohol, diet, physical activity, anthropometric factors, hormonally active agents and occupational exposures was identified. Several emerging hypotheses for breast cancer etiology were also considered and recommendations made in these areas. Specific areas for future consideration included: insulin-like growth factors, pharmaceuticals, viruses, psychosocial factors, and functional polymorphisms. The panel also identified common themes for future research including: studies of exposures across the life cycle; research in populations with unusual exposure levels; consideration of effect modification; development of improved exposure assessment methods and use of intermediate endpoints; separation of disease subtypes by hormone receptor status, stage and tumour markers; and consideration of biological mechanisms in breast cancer etiology.

Trends in the incidence of cutaneous malignant melanoma in New South Wales, 1983-1996.

The incidence of cutaneous malignant melanoma (CMM) has been rising in fair-skinned populations throughout the world for decades. The upward trend may, however, finally be slowing in some of these populations. Recent (1983-1996) CMM incidence trends for a high incidence area (New South Wales, Australia) have been examined according to gender, age group, body site and tumour thickness. Despite continuing upward trends in older age groups, particularly among men (e.g., 7.20% increase per year in men aged 75+), incidence for younger ages is stabilizing (in men) or declining (in women): average annual percentage changes of -3.03 and -0.88 were observed for women aged 15-34 and 35-54, respectively. Patterns suggest a birth-cohort effect, with those born since 1945 or 1950 having lower (females) or similar (males) rates to those born earlier. For each gender, all-ages incidence rose by a similar amount for each of the main body sites except the leg in women, where incidence fell by 0.49% per year. In men, the incidence of both thin (75 mm) melanomas increased (significantly, by 2.63% per year and non-significantly, by 0.93% per year, respectively) between 1989 and 1996. In women, incidence remained stable for both thickness subgroups. These data are consistent with a stabilization or reduction in either total sun exposure or intermittency of exposure among New South Wales cohorts born since about 1950. Because incidence rates are still much higher than they were a few decades ago, however, efforts to reduce sun exposure, particularly in children and youth, must continue.

Association of perforation of the appendix with female tubal infertility.

Although perforation of the appendix is considered a risk factor for female tubal infertility, the epidemiologic evidence supporting this relation is inconsistent. Risk factors for tubal infertility were compared for 121 women with documented primary tubal infertility attending in vitro fertilization clinics in Toronto, Canada, from July to December 1998 and 490 controls who were pregnant during the same time period. Self-administered questionnaires and review of medical records were used to assess exposures. The authors found that neither history of acute appendicitis nor perforation of the appendix was a statistically significant risk factor for tubal infertility. The crude odds ratio for perforated appendicitis was 3.4 (95% confidence interval (CI): 0.9, 12.9), and the adjusted odds ratio was 1.4 (95% CI: 0.3, 6.2). In addition to increased age and annual income, cigarette smoking (odds ratio (OR) = 2.0, 95% CI: 1.2, 3.2), history of endometriosis (OR = 6.0, 95% CI: 2.8,12.8), and history of pelvic inflammatory disease (OR = 6.0, 95% CI: 2.8, 12.8) were significantly associated with tubal infertility in multivariate analysis. These data do not provide substantial evidence that perforation of the appendix is an important risk factor for female tubal infertility.

Do larger people have more naevi? Naevus frequency versus naevus density.

BACKGROUND: It is unclear which of the number or the density of naevi on the skin is the more appropriate measure of risk of melanoma. Furthermore, the relationship between the number of naevi and their density in an individual has not been explored. Thus, for example, it is unknown if larger people tend to have more naevi by virtue of having a larger skin area, or if the density of naevi is similar in people of different body sizes. In this study, we explored the relationship between the number and the density of naevi in a sample of adolescents. SUBJECTS AND METHODS: A sample survey of naevi in 472 grade 9 secondary school students (aged 14-15 years) was conducted in Tasmania, Australia during 1992, and a subset of these individuals was followed up in 1997. Counts of naevi of various sizes were taken on the arm, leg, and back. Naevus density was estimated by using an algorithm to estimate body surface area from the height and weight of an individual. More general relationships of the naevus counts to height and weight were also explored. Finally, we considered whether the relationship between naevus density and the anthropometric variables could be confounded by exposure to ultraviolet radiation. RESULTS: The mean number of naevi was very similar in the two samples. Naevus density was slightly lower in the 1997 sample, mainly because of increasing body size in the cohort. The numbers of naevi were only weakly related to height and weight in males, and there was essentially no relationship in females. Regression analysis showed significant relationships of weight to the back naevus counts in males in 1992 and 1997, and to the arm naevus count in males in 1997; otherwise, none of the regression coefficients for height and weight were statistically significant. This picture did not change following adjustment for potentially confounding variables indicating time spent outdoors or in the sun. Furthermore, there was no evidence that time spent in the sun was related to the body mass index. CONCLUSIONS: It appears that the number and density of naevi in an individual are unrelated. Accordingly, with the present state of knowledge concerning the risk of melanoma, both the number and density of naevi should be considered as equally valid in future studies as markers of the risk of melanoma, and in studies on the natural history of naevi. If the disease mechanism is systemic, and not related to particular naevi, naevus density might form the better marker of risk. However, if the disease mechanism is related to effects on particular naevi, then the risk would vary in proportion to the number of naevi.

Pregnancy outcomes in females after treatment for childhood cancer.

This Ontario province-wide cohort study was conducted to compare the risk of adverse pregnancy outcomes in female childhood cancer survivors who received abdominal-pelvic radiation and/or chemotherapy with alkylating agents with the risk among those who were treated by non-sterilizing alkylating agents with the risk among those who were treated by non-sterilizing surgery only. Females in Ontario, Canada, diagnosed in 1964-1988 before age 20 with a histologically confirmed malignancy and who had survived for at least 5 years, attained age 18, and were alive at the time of study, were identified through the Ontario Cancer Registry. We ascertained pregnancy outcomes by a telephone-administered questionnaire. Treatment data were abstracted from medical records for 830 subjects 18-49 years of age, the analysis comprised 340 survivors who had one or more pregnancies after treatment. There was no evidence of an increased risk of having a spontaneous abortion or an infant with a birth defect. Survivors receiving abdominal-pelvic radiation were more likely to have a low birth weight infant (odds ratio estimate [OR] = 3.64; 95% confidence interval [CI] = 1.33-9.96), a premature low birth weight infant (OR = 3.29; 95% CI = 0.97-11.1), or an infant who died in the perinatal period (OR = 2.41; 95% CI = 0.50-11.5), compared with those receiving surgery. Risks of perinatal death and having a low birth weight infant increased with dose of radiotherapy directed to the abdomen.

Methodological issues in the development of the Canadian Cancer Incidence Atlas.

The Canadian Cancer Incidence Atlas is among recent national atlases using incidence rather than mortality data. Methods used to assess the significance and spatial correlation of the age-standardized rates (ASIRs) for the 290 census divisions are described. The expected number of cases by area was used to determine cancer sites with sufficient cases to be mapped. ASIR significance was assessed using a simulation based on a Poisson distribution. The consistency of the observed case distributions with the Poisson distribution was examined. The bootstrap confidence interval (CI) for the ASIR developed by Swift was used in the atlas. Spatial correlation was assessed with Moran's I/I(max) and the significance determined by a simulation in order to allow for area population variation. Data quality indicators typically used for cancer registries were presented, supplemented by a registry questionnaire.

Case-control study of colon and rectal cancers and chlorination by-products in treated water.

This population-based case-control study was conducted in southern Ontario, Canada from 1992 to 1994 to assess the relationship between chlorination by-products in public water supplies and cancers of the colon and rectum. Interviews providing residence and water source histories were completed by 76% of eligible cancer cases and 72% of eligible controls. Supplemental data from municipal water supplies were used to estimate individual exposure to water source, chlorination status, and by-product levels as represented by trihalomethanes (THMs) during the 40-year period before the interview. The analyses included 767 colon cases, 661 rectal cases, and 1545 controls with exposure information for at least 30 of these years (75% of subjects with completed interviews). Among males, colon cancer risk was associated with cumulative exposure to THMs, duration of exposure to chlorinated surface water, and duration of exposure to a THM level > or = 50 microg/liter and 75 microg/liter. Males exposed to chlorinated surface water for 35-40 years had an increased risk of colon cancer compared with those exposed for < 10 years (odds ratio, 1.53; 95% confidence interval, 1.13-2.09). Males exposed to an estimated THM level of 75 microg/liter for > or = 35 years had double the risk of those exposed for < 10 years (odds ratio, 2.10; 95% confidence interval, 1.21-3.66). In contrast, these relationships were not observed among females. No relationship was observed between rectal cancer risk and any of the measures of exposure to chlorination by-products. The results of this study should be interpreted with caution because they are only partially congruent with the limited amount of literature addressing this issue.

Pre-natal and peri-natal exposures and risk of testicular germ-cell cancer.

The present case-control study was undertaken to investigate the association between exposure to maternal hormones and risk of testicular germ-cell cancer by histologic subgroups. Cases were males, aged 16 to 59 years, diagnosed with testicular germ-cell cancer in Ontario between 1987 and 1989. Histologic review was performed on all eligible cases for the purpose of categorizing cases as seminoma or non-seminoma (the latter classified 2 ways, with and without tumors containing seminoma). Risk factor data were collected on 502 cases, 346 case mothers, 975 age-matched controls, and 522 control mothers. Exogenous hormone exposure was associated with elevated risk (OR = 4.9, 95% CI 1.7-13.9). Several additional risk factors were associated with risk of testicular cancer: bleeding and threatened miscarriage (OR = 0.6, 95% CI 0.3-1.0), maternal cigarette smoking (12+ cigarettes/day OR = 0.6, 95% CI 0. 4-1.0). pre-term birth (OR = 1.6, 95% CI 1.0-2.5), and treatment for undescended testicle (OR = 8.0, 95% CI 3.2-20.0). First births were associated with elevated risk (OR = 1.7, 95% CI 1.0-2.8) among mothers below the age of 24 years at conception. There was little evidence that risk factors differed by histologic subgroup. We found evidence that exposure to maternal hormones, particularly estrogens, is associated with testicular germ-cell cancer risk. Not only does exposure to elevated levels (exogenous hormone use, pre-term birth, and first births among young mothers) increase risk but also exposure to relatively lower levels (heavy cigarette consumption and, perhaps, bleeding and threatened miscarriage) may decrease cancer risk.

Efficacy of neomycin sulfate water medication on the control of mortality associated with colibacillosis in growing turkeys.

The objective of this investigation was to evaluate the efficacy, safety, and toxicity of neomycin sulfate (Neomix 325) water medication to control mortality associated with colibacillosis (Escherichia coli) in growing turkeys. One efficacy trial was conducted at five locations; each location included 2,880 sexed 21-d-old turkey poults that were naturally challenged with litter from turkey flocks that had colibacillosis. Between 5 and 7 d after challenge, and when mortality had reached 0.5%, poults were randomized within sex into three treatment groups of 0, 11, or 22 mg neomycin sulfate/kg body weight. In each location, each treatment was replicated 12 times with 40 poults per sex per replicate. All treatments were administered in the drinking water for 5 d. The pivotal decision criterion was mortality. Mortality was defined as 1) supported mortality (SM): positive microbial culture for E. coli and gross lesions, 2) diagnosed mortality (DM): diagnosed as associated with E. coli but not supported by lesions or positive microbiological cultures, 3) overall mortality (OM): mortality associated with E. coli or other microorganisms and miscellaneous reasons such as accidents (trampling or suffocations). Performance data (growth and feed utilization) also were measured and are reported without statistical analysis. Results from this efficacy study clearly demonstrated the effectiveness of neomycin sulfate against E. coli as measured by a reduction in mortality. In the target animal safety and toxicity study (done in conjunction with the efficacy study), neomycin sulfate in the drinking water at 66, 110, or 220 mg/kg per d for 15 d had no observable adverse effects on poult performance, as measured by feed or water consumption, body weight, gross pathology, or mortality.

Workshop report: physical activity and cancer prevention.

A workshop to evaluate the evidence for the role of physical activity in cancer prevention and to identify priorities for action, particularly in relation to the primary prevention of cancer, was held by Cancer Care Ontario in March 2000. A review of the scientific evidence was commissioned and an expert panel convened to consider the review report and to make recommendations for public health, research and intervention. The panel concluded that evidence was convincing for the role of physical activity in preventing colon cancer; probable for breast cancer; possible for prostate cancer and insufficient for other sites. It is recommended that physical activity messages promoting at least 30 45 minutes of moderate to vigorous activity on most days of the week be included in primary prevention interventions for cancer. The panel recommended that future research on physical activity incorporate comprehensive assessments, including measures of the multiple dimensions and types of physical activity; biological mechanisms; and behavioural and population factors. Cancer Care Ontario will incorporate physical activity messages in its primary prevention programming around nutrition and health body weight.