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Biomedical subjects

Peter Boyle

Publications and source records attributed to Peter Boyle.

At least 37 records · Page 2Linked to original sources

Meta-analysis of risk factors for cutaneous melanoma: I. Common and atypical naevi.

A systematic meta-analysis of observational studies of melanoma and one of the most important risk factors, the number of naevi, was conducted in order to clarify aspects of the aetiology of this disease. Following a systematic literature search, relative risks (RRs) were extracted from 46 studies published before September 2002. Dose-response random effects models were used to obtain pooled estimates. Sub-group analysis and meta-regression were carried out to explore sources of between-study variation and bias. Sensitivity analyses investigated the reliability of the results and any publication bias. Number of common naevi was confirmed an important risk factor with a substantially increased risk associated with the presence of 101-120 naevi compared with <15 (pooled Relative Risk (RR) = 6.89; 95% Confidential Interval (CI): 4.63, 10.25) as was the number of atypical naevi (RR = 6.36 95%; CI: 3.80, 10.33; for 5 versus 0). The type of study and source of cases and controls were two study characteristics that significantly influenced the estimates. Case-control studies, in particular when the hospital was the source for cases or controls, appeared to present much lower and more precise estimates than cohort studies.

Adult↗

Meta-analysis of risk factors for cutaneous melanoma: II. Sun exposure.

A systematic revision of the literature was conducted in order to undertake a comprehensive meta-analysis of all published observational studies on melanoma. An extensive analysis of the inconsistencies and variability in the estimates was performed to provide some clues about its Epidemiology. Following a systematic literature search, relative risks (RRs) for sun exposure were extracted from 57 studies published before September 2002. Intermittent sun exposure and sunburn history were shown to play considerable roles as risk factors for melanoma, whereas a high occupational sun exposure seemed to be inversely associated to melanoma. The country of study and adjustment of the estimates adjuste for phenotype and photo-type were significantly associated with the variability of the intermittent sun exposure estimates (P = 0.024, 0.003 and 0.030, respectively). For chronic sun exposure, inclusion of controls with dermatological diseases and latitude resulted in significantly different data (P = 0.05 and 0.031, respectively). Latitude was also shown to be important (P = 0.031) for a history of sunburn; studies conducted at higher latitudes presented higher risks for a history of sunburns. Role of country, inclusion of controls with dermatological diseases and other study features seemed to suggest that "well conducted" studies supported the intermittent sun exposure hypothesis: a positive association for intermittent sun exposure and an inverse association with a high continuous pattern of sun exposure.

Adolescent↗

Meta-analysis of risk factors for cutaneous melanoma: III. Family history, actinic damage and phenotypic factors.

A systematic meta-analysis of observational studies of melanoma and family history, actinic damage and phenotypic factors was conducted as part of a comprehensive meta-analysis of all major risk factors for melanoma. Following a systematic literature search, relative risks were extracted from 60 studies published before September 2002. Fixed and random effects models were used to obtain pooled estimates for family history (RR = 1.74, 1.41-2.14), skin type (I vs. IV: RR = 2.09, 1.67-2.58), high density of freckles (RR = 2.10, 1.80-2.45), skin colour (Fair vs. Dark: RR = 2.06, 1.68-2.52), eye colour (Blue vs. Dark: RR = 1.47, 1.28-1.69) and hair colour (Red vs. Dark: RR = 3.64, 2.56-5.37), pre-malignant and skin cancer lesions (RR = 4.28, 2.80-6.55) and actinic damage indicators (RR = 2.02, 1.24-3.29). Sub-group analysis and meta-regression were carried out to explore sources of between-study variation and bias. Sensitivity analyses investigated reliability of results and publication bias. Latitude and adjustment for phenotype were two study characteristics that significantly influenced the estimates.

Humans↗

Human papillomavirus types in head and neck squamous cell carcinomas worldwide: a systematic review.

Mucosal human papillomaviruses (HPV) are the cause of cervical cancer and likely a subset of head and neck squamous cell carcinomas (HNSCC), yet the global prevalence and type distribution of HPV in HNSCC remains unclear. We systematically reviewed published studies of HNSCC biopsies that employed PCR-based methods to detect and genotype HPV to describe the prevalence and type distribution of HPV by anatomic cancer site. Geographic location and study size were investigated as possible sources of variability. In the 5,046 HNSCC cancer specimens from 60 studies, the overall HPV prevalence was 25.9% [95% confidence interval (95% CI), 24.7-27.2]. HPV prevalence was significantly higher in oropharyngeal SCCs (35.6% of 969; 95% CI, 32.6-38.7) than oral SCCs (23.5% of 2,642; 95% CI, 21.9-25.1) or laryngeal SCCs (24.0% of 1,435; 95% CI, 21.8-26.3). HPV16 accounted for a larger majority of HPV-positive oropharyngeal SCCs (86.7%; 95% CI, 82.6-90.1) compared with HPV-positive oral SCCs (68.2%; 95% CI, 64.4-71.9) and laryngeal SCCs (69.2%; 95% CI, 64.0-74.0). Conversely, HPV18 was rare in HPV-positive oropharyngeal SCCs (2.8%; 95% CI, 1.3-5.3) compared with other head and neck sites [34.1% (95% CI, 30.4-38.0) of oral SCCs and 17.0% (95% CI, 13.0-21.6) of laryngeal SCCs]. Aside from HPV16 and HPV18, other oncogenic HPVs were rarely detected in HNSCC. Tumor site-specific HPV prevalence was higher among studies from North America compared with Europe and Asia. The high HPV16 prevalence and the lack of HPV18 in oropharyngeal compared with other HNSCCs may point to specific virus-tissue interactions. Small sample size and publication bias complicate the assessment of the prevalence of HPV in head and neck sites beyond the oropharynx.

Carcinoma, Squamous Cell↗

The role of the dental team in preventing and diagnosing cancer: 1. cancer in general.

Prevention and early detection are integral components of the Health Agenda and areas taking on increasing importance and emphasis. Members of the dental profession have an important role to play and, indeed, a duty to advise on the prevention of, not only oral diseases and notably oral cancer, but also on other potentially malignant conditions and their prevention. They are in a position to advise and help protect their patients, staff, colleagues, families and acquaintances. Apart from prevention, early detection and prompt referral for diagnosis offer the best hope to the patient with cancer, providing the best chance of a cure. The signs and symptoms of cancer often resemble less serious conditions and prompt referral to an appropriate specialist usually allows for the best management.

Alcohol Drinking↗

Screening for prostate cancer: updated experience from the Tyrol study.

OBJECTIVES: The aim of this study was to monitor the impact of prostate cancer screening in a natural experiment by comparing prostate cancer mortality in Tyrol, Austria, where prostate-specific antigen (PSA) testing was made available at no charge, with the rest of Austria, where this screening was not introduced. METHODS: In 1993, PSA testing was made freely available to men aged 40 to 79 years old living in the Federal State of Tyrol, Austria. In the first 10 years of this study, at least 70% of all men in this age range had PSA tests done at least once. Initially, only total PSA was measured, but free PSA measurement was added in 1995, and complexed PSA was added in 2001. Digital rectal examination (DRE) was not part of the screening examination. RESULTS: Significant migration to lower clinical as well as pathological prostate cancer stages has been observed in patients undergoing radical prostatectomy since the introduction of this screening program. A reduction in mortality rates from prostate cancer in Austria occurred from 1993 onward, with a much greater reduction in Tyrol; mortality remained fairly constant between 1993 and 1995 and subsequently fell. From 1993 to 2000 (the most recent data), there was a significantly greater decrease in the rate of prostate cancer mortality in Tyrol compared to the rest of Austria (P value = 0.006). Based on age-specific death rates for men aged 40 to 79, the difference between the number of expected and observed deaths from prostate cancer in Tyrol was 22 in 1998 (a 42% decrease), 18 in 1999 (a 33% decrease) and 25 in 2000 (a 44% decrease). CONCLUSIONS: These findings are consistent with the hypothesis that a policy of making PSA testing freely available, and wide acceptance by men in the population, is associated with a reduction in prostate cancer mortality in an area in which urology services and radiotherapy are available freely to all patients. It is our opinion that most of this decline in mortality is likely to be due to aggressive downstaging and successful treatment and that any contribution from detecting and treating early cancers will only become apparent in the years to come.

Adult↗

Serum polychlorinated biphenyls, cytochrome P-450 1A1 polymorphisms, and risk of breast cancer in Connecticut women.

Recent epidemiologic studies have suggested that genetic polymorphisms in the cytochrome P-450 1A1 gene (CYP1A1) may affect the relation between environmental exposure to polychlorinated biphenyls (PCBs) and breast cancer risk. The authors report results from a case-control study evaluating the potential effect of gene-environment interaction between CYP1A1 and serum PCB levels on breast cancer risk among Caucasian women in Connecticut. The study included 374 case women with histologically confirmed breast cancer and 406 noncancerous controls with information on both serum PCB level and CYP1A1 genotype (1999-2002). Compared with women who had the homozygous wild-type CYP1A1 m2 genotype, significantly increased risks of breast cancer were found for women with the CYP1A1 m2 variant genotype (odds ratio (OR) = 2.1, 95% confidence interval (CI): 1.1, 3.9), especially postmenopausal women (OR = 2.4, 95% CI: 1.1, 5.0). Risks associated with the CYP1A1 m2 variant genotype were highest for all women (OR = 3.6, 95% CI: 1.5, 8.2) and postmenopausal women (OR = 4.3, 95% CI: 1.6, 12.0) with higher serum PCB levels (611-2,600 ng/g). The CYP1A1 m1 and m4 genotypes were not associated with breast cancer risk independently or in combination with PCB exposure. In summary, the CYP1A1 m2 genetic polymorphism was associated with increased risk of female breast cancer and may modify the relation between PCB exposure and breast cancer risk.

Adult↗

Beyond classical meta-analysis: can inadequately reported studies be included?

Classical meta-analysis requires the same data from each clinical trial, thus data-reporting must be of a high-quality. Imputation methods are used to include studies that provide incomplete information on variability and the fixed and random effects of a drug. Regression models can be used to include studies other than randomized placebo-controlled studies. In the example outlined here, the use of non-randomized single-arm studies and studies against comparator treatments has little influence on the estimation of the treatment effect in comparison with placebo, an effect that is based on the randomized placebo-controlled studies. The inclusion of other studies serves to increase the precision of the effect of the treatment compared with baseline. Although multiple imputation techniques enable a larger number of studies to be included, which will typically increase the precision of the estimated effect, a careful sensitivity analysis is also required.

Clinical Trials as Topic↗

Menstrual and reproductive factors and risk of non-Hodgkin's lymphoma among Connecticut women.

Several recent studies have suggested a potential role of menstrual and reproductive factors in the risk of non-Hodgkin's lymphoma. To further examine the relation, the authors analyzed data from a population-based case-control study of non-Hodgkin's lymphoma in Connecticut women between 1996 and 2000. A total of 601 histologically confirmed cases and 717 randomly selected population-based controls were included in this study. An in-person interview was conducted using a standardized and structured questionnaire to collect information on menstrual and reproductive factors and potential confounding factors. Compared with nulliparous women, women who had four or more pregnancies during their lifetime were found to have a significantly reduced risk of non-Hodgkin's lymphoma (odds ratio (OR) = 0.6, 95% confidence interval (CI): 0.4, 0.9). Risk appeared to decrease with increasing number of pregnancies (p(trend) = 0.03). The authors also observed an increased risk of non-Hodgkin's lymphoma overall (OR = 1.5, 95% CI: 1.0, 2.2) and of diffuse non-Hodgkin's lymphoma (OR = 1.7, 95% CI: 1.1, 2.7) for women who started their first menstrual period at age 15 or more years compared with those who started their first menstrual period before age 12 years. These findings support a reduced risk of non-Hodgkin's lymphoma associated with multiple pregnancies and an increased risk of non-Hodgkin's lymphoma associated with later age at menarche.

Adolescent↗

Blood transfusion and risk of non-Hodgkin's lymphoma in Connecticut women.

The incidence and mortality rates of non-Hodgkin's lymphoma have been increasing worldwide. Allogeneic blood transfusion has been suggested as a risk factor for non-Hodgkin's lymphoma, but the results from epidemiologic studies have been inconsistent. Data from a population-based case-control study of Connecticut women were analyzed to evaluate this relation. A total of 601 histologically confirmed, non-Hodgkin's lymphoma incident cases identified between 1996 and 2000 and 717 randomly selected controls were included in this study. Allogeneic blood transfusion was not associated with the increased risk of non-Hodgkin's lymphoma overall (odds ratio = 1.0, 95% confidence interval: 0.7, 1.3) or by subtype of the disease. The risk also did not vary by number of allogeneic blood transfusions, age at first transfusion, or time since first transfusion. When the reason for blood transfusion was considered, an increased risk of non-Hodgkin's lymphoma was found only for allogeneic blood transfusion for reason of anemia. In summary, the authors' findings do not support the hypothesis that allogeneic blood transfusion increases the risk of non-Hodgkin's lymphoma.

Adult↗

Leveling of prostate cancer mortality in Western Europe.

BACKGROUND: Mortality from prostate cancer (CaP) has increased throughout Europe until the early 1990s. Trends in 24 European countries, the European Union (EU), six selected Central and Eastern European countries, and the Russian Federation have been updated to 1999. METHODS: Cancer death certification data for CaP were abstracted from the World Health Organization database. RESULTS: In the EU, the peak rate (15.7/100,000) was reached in 1993, followed by a leveling off and a decline to 14.1/100,000 in 1999. Age-standardized analysis for each subsequent age group of men aged 50 or over showed larger absolute falls in the elderly. CaP rates were lower in Central and Eastern European countries providing data, but showed a rise from 9.7/100,000 in 1980 to 11.3 in 1996, and leveled off thereafter. Rates were originally lower, but the rises larger in the Russian Federation (from 5.1/100,000 in 1980 to 8.1/100,000 in 1999). In the late 1990s, there was a threefold difference between the highest rates of 22/100,000 in Norway and those of 7.7 in Russia or 7.3 in Ukraine. Such a difference was, however, restricted to the elderly, since at age 35-64 the Russian rate (6.7/100,000) was the same as that of Norway, and only Greece and Italy had appreciably lower rates. CONCLUSION: The pattern of trends in CaP rates observed across Europe is consistent with a favorable role of improved diagnosis, but mainly of advancements of therapy (including more widespread adoption of radical prostatectomy and androgen blockage) on CaP mortality in Western Europe.

Adolescent↗

Cancer mortality in Europe, 1995-1999, and an overview of trends since 1960.

Mortality data, abstracted from the World Health Organization database, are presented in tabular form for 26 cancer sites or groups of sites, plus total cancer mortality, in 36 European countries during the period 1995-1999. Trends in mortality are also given in graphic form for 23 major countries plus the European Union as a whole over the period 1960-1999. In the European Union, total cancer mortality declined by 7% for both sexes over the last 5 years considered. The fall since the late 1980s was 10% in both sexes, corresponding to the avoidance of over 90000 deaths per year, as compared to the rates of the late 1980s. For the first time, over the last few years, some leveling of mortality was reported also in the Russian Federation, the Czech Republic, Poland, Hungary and other Eastern European countries, although cancer rates in those areas remain exceedingly high. The overall favorable pattern of cancer mortality over recent years is largely driven by the decline of tobacco-related cancer mortality in men. However, important components of the trends are also the persistence of substantial falls in gastric cancer, mainly in Russia and Eastern Europe, the recent decline in intestinal cancer in both sexes and of breast cancer in women, together with the long-term falls in uterine (cervical) cancer, leukemias, Hodgkin's disease and other neoplasms amenable to advancements in diagnosis and treatment. Female lung cancer mortality has been declining in the Russian Federation, but is still rising in other areas of the continent. Thus, urgent intervention is needed to bring under control the tobacco-related lung cancer epidemic in European women before it reaches the high level observed in North America. Supplementary material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020-7136/suppmat/index.html

Europe↗

Diet and nutrient intakes and risk of non-Hodgkin's lymphoma in Connecticut women.

A population-based case-control study (601 cases and 717 controls) was conducted in 1995-2001 among Connecticut women to evaluate the relation between diet and nutrient intakes and the risk of non-Hodgkin's lymphoma (NHL). When the highest quartile of intake was compared with the lowest, the authors found an increased risk of NHL associated with animal protein (odds ratio = 1.7, 95% confidence interval: 1.2, 2.4) and saturated fat (odds ratio = 1.9, 95% confidence interval: 1.1, 2.3) but a reduced risk for polyunsaturated fat (odds ratio = 0.6, 95% confidence interval: 0.4, 0.9) and no relation for vegetable protein and monounsaturated fat. An increased risk was also observed for higher intakes of retinol, eggs, and dairy products. On the other hand, a reduced risk was found for higher intakes of dietary fiber and for several fruit and vegetable items. Risk of NHL associated with diet and nutrient intakes appeared to vary based on NHL subtype. An association between dietary intake and NHL risk is biologically plausible because diets high in protein and fat may lead to altered immunocompetence, resulting in an increased risk of NHL. The antioxidant or inhibiting nitrosation reaction properties of vegetables and fruits may result in a reduced risk. Further investigation of the role of dietary intakes on the risk of NHL is warranted.

Adult↗

Hair-coloring product use and risk of non-Hodgkin's lymphoma: a population-based case-control study in Connecticut.

A population-based case-control study was conducted in Connecticut in 1996-2002 to test the hypothesis that lifetime hair-coloring product use increases non-Hodgkin's lymphoma risk. A total of 601 histologically confirmed incident female cases and 717 population-based controls were included in the study. An increased risk of non-Hodgkin's lymphoma was observed among women who reported use of hair-coloring products before 1980 (odds ratio = 1.3, 95% confidence interval (CI): 1.0, 1.8). The odds ratios were 2.1 (95% CI: 1.0, 4.0) for those using darker permanent hair-coloring products for more than 25 years and 1.7 (95% CI: 1.0, 2.8) for those who had more than 200 applications. Follicular type, B-cell, and low-grade lymphoma generally showed an increased risk. On the other hand, the authors found no increased risk of non-Hodgkin's lymphoma overall and by subtype of exposure and disease among women who started using hair-coloring products in 1980 or later. It is currently unknown why an increased risk of non-Hodgkin's lymphoma was found only among women who started using hair-coloring products before 1980. Further studies are warranted to show whether the observed association reflects the change in hair dye formula contents during the past two decades or indicates that recent users are still in their induction and latent periods.

Adult↗

Screening for prostate cancer: updated experience from the Tyrol study.

The aim of the Tyrol study was to monitor the impact of screening in a natural experiment by comparing prostate cancer mortality in Tyrol, where prostate-specific antigen (PSA) testing was introduced at no charge, with the rest of Austria, where it was not strictly organized and not free of charge. In 1993, PSA testing was made freely available to men between the ages of 45 and 75 years in the Federal State of Tyrol, Austria. At least 70% of all of the men in this age range have been tested at least once during the first 10 years of the study. Initially, only total PSA was measured, but free PSA measurement was added in 1995. Since 2001, complexed PSA also has been measured. Digital rectal examination was not part of the screening examination. Significant migration to lower clinical and pathological stages has been observed since the introduction of this screening program. These findings are consistent with the hypothesis that the policy of making PSA testing freely available, and the wide acceptance by men in the population, is associated with a reduction in prostate cancer mortality in an area in which urology services and radiotherapy are available freely to all patients. It is our opinion that most of this decline is likely a result of aggressive downstaging and successful treatment and that any contribution from detecting and treating early cancers will become apparent in the years to come.

Aged↗

Evaluation of the clinical benefit of permixon and tamsulosin in severe BPH patients-PERMAL study subset analysis.

OBJECTIVE: To compare the efficacy of the lipido-sterolic extract of Serenoa repens, Permixon, to that of the alpha-blocker, tamsulosin, in the treatment of severe low urinary tract symptoms (LUTS) of benign prostatic hyperplasia (BPH). METHODS: In a 12-month, double-blind, randomized study that showed equivalent efficacy of Permixon 320 mg/day and tamsulosin 0.4 mg/day ("PERMAL study"), 685 BPH patients with IPSS > or =10 had been analyzed for efficacy. Of these, the 124 patients with severe LUTS (IPSS >19) at randomization were retained for this subset analysis. After a 4-week run-in period, 59 and 65 patients had been randomized to tamsulosin and Permixon groups, respectively. Both treatment groups were compared regarding the evolution from baseline of total IPSS and its irritative and obstructive subscores, LUTS-related QoL, prostate volume, Q(max) and MSF-4 (sexual activity questionnaire) at different time points over 1 year. An analysis of variance of changes from baseline to end point was performed for all the parameters. The over-time evolutions of total, irritative and obstructive IPSS were further compared using a variance analysis for repeated measurements. RESULTS: At 12 months, total IPSS decreased by 7.8 with Permixon and 5.8 with tamsulosin (p=0.051); the irritative symptoms improved significantly more (p=0.049) with Permixon (-2.9 versus -1.9 with tamsulosin). The superiority of Permixon in reducing irritative symptoms appeared as soon as month 3 and was maintained up to month 12 (p=0.03). CONCLUSION: Permixon 320 mg/day was shown to be slightly superior to tamsulosin 0.4 mg/day in reducing LUTS in severe BPH patients after 3 months and up to 12 months of treatment.

Adrenergic alpha-Antagonists↗