Purpose
This case–control study assesses the independent roles of reproductive history, postmenopausal hormonal therapy (HT), socioeconomic status (SES), and occupational physical activity on the ...risk of breast cancer (BC).
Methods
Odds ratios (OR) were estimated from conditional logistic multivariate regression model in a data set of 19,253 Finnish women diagnosed with BC between 1994 and 2013 and 96,265 age-matched population controls.
Results
Both pre- and postmenopausal white-collar workers had significantly increased risk of ductal and lobular BC as compared to manual workers. Moderate occupational physical activity reduced risk of lobular BC by 14%. There was a transient increase in the risk of BC observed after each birth followed by a protective effect starting some years after the delivery. As the number of children increased, the short-term excess risk was lower and protective effect was observed earlier. Continuous estrogen-progestin therapy (EPT) significantly increased the risk of both ductal and lobular BC and the magnitude of risk was directly proportional to duration of use (OR for 5+ years of use 2.26, 95% confidence interval 2.12–2.42). Monthly EPT for 5+ years increased the risk (OR 1.32, 95% CI 1.20–1.45). Users of estradiol plus levonorgestrel intrauterine system devices showed ORs of 1.56 (95% CI 1.45–1.69) and 2.18 (95% CI 1.81–2.64) for ductal and lobular BC, respectively.
Conclusion
This study concludes that pregnancy has a dual effect on BC risk, with a transient increase in risk followed by a long-term protective effect. The SES and HT have a large effect on BC risk while occupational physical activity has only a small independent effect.
Abstract Background Systematic reviews on the association between statin therapy and cancer have focused on randomised trials without assessing the quality of evidence. We aimed to review the overall ...evidence taking study quality into consideration. Methods Publications of original studies on the effect of statin treatment on cancer in adult patients were searched on MEDLINE, EMBASE and CENTRAL databases upto October 2007. Our search yielded 37 eligible original studies out of 3607 references. Five studies were additionally found through manual search. Thus, 42 studies were included in the analyses: 17 randomised controlled trials, 10 cohort studies, and 15 case-control studies. Findings Statins had no effect on the overall incidence of cancer (median risk ratio (RR) 0.96, range 0.72 to 1.2), or on the incidence of lung (median RR 0.92, range 0.83 to 3.0), breast (median RR 1.04, range 0.74 to 19) or prostate cancer (median RR 0.96, range 0.33 to 1.7). They seemed to protect from stomach (median RR 0.59, range 0.40 to 0.88) and liver cancer (median RR 0.62, range 0.33 to 1.2), and from lymphoma (median RR 0.74, range 0.28 to 2.2). They increased the incidence of both melanoma (median RR 1.5, range 1.3 to 1.7) and non-melanoma skin cancer (median RR 1.6, range 1.2 to 2.2). The effect varied, yet inconsistently, by statin type. The median follow-up time was 4 years. The strength of evidence was mostly weak. Interpretation The evidence suggests that statins do not have short-term effects on cancer risk. The evidence on potentially protective or harmful effects is inconclusive. High quality cohort studies with long follow-up are needed to resolve the issue.
Lichen sclerosus and risk of cancer Halonen, Pia; Jakobsson, Maija; Heikinheimo, Oskari ...
International journal of cancer,
1 May 2017, Letnik:
140, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Malignant potential of lichen sclerosus (LS) has been suspected, but evidence is sparse. We used the population‐based Finnish Cancer Registry data to further study this connection.
We identified all ...women with the diagnosis of LS (n = 7,616) listed in the Finnish Hospital Discharge Registry from 1970 to 2012. The cohort was followed through the Finnish Cancer Registry for subsequent cancer diagnoses until 2014. Standardized incidence ratios (SIRs) were calculated for different cancers by dividing the observed numbers of cancers by expected ones. The expected numbers were based on national cancer incidence rates.
During the follow‐up period, we found 812 cancers among patients with LS (SIR: 1.13, 95% CI 1.05–1.21). LS was associated with an increased risk of vulvar (182 cases, SIR: 33.6, 95% CI 28.9–38.6) and vaginal cancer (4 cases, SIR: 3.69, 95% CI 1.01–9.44). The risk of cancers of the uterine cervix and lung was significantly decreased.
LS is associated with an increased risk for vulvar and vaginal cancer. These data are important when designing the care of women diagnosed with LS.
What's new?
Does it or doesn't it? Evidence is scant on whether the skin condition lichen sclerosus leads to cancer. These authors conducted the largest study to date, looking at 7,600 patients for nearly a decade. Among these patients, 800 cancer cases arose. Analysis showed that lichen sclerosus does increase one's risk of developing vulvar or vaginal cancer, but decreases the risk of cervical cancer, although the numbers were few due to the rarity of LS and these cancers.
Recent studies have suggested that statins, an established drug group in the prevention of cardiovascular mortality, could delay or prevent breast cancer recurrence but the effect on disease-specific ...mortality remains unclear. We evaluated risk of breast cancer death among statin users in a population-based cohort of breast cancer patients. The study cohort included all newly diagnosed breast cancer patients in Finland during 1995-2003 (31,236 cases), identified from the Finnish Cancer Registry. Information on statin use before and after the diagnosis was obtained from a national prescription database. We used the Cox proportional hazards regression method to estimate mortality among statin users with statin use as time-dependent variable. A total of 4,151 participants had used statins. During the median follow-up of 3.25 years after the diagnosis (range 0.08-9.0 years) 6,011 participants died, of which 3,619 (60.2%) was due to breast cancer. After adjustment for age, tumor characteristics, and treatment selection, both post-diagnostic and pre-diagnostic statin use were associated with lowered risk of breast cancer death (HR 0.46, 95% CI 0.38-0.55 and HR 0.54, 95% CI 0.44-0.67, respectively). The risk decrease by post-diagnostic statin use was likely affected by healthy adherer bias; that is, the greater likelihood of dying cancer patients to discontinue statin use as the association was not clearly dose-dependent and observed already at low-dose/short-term use. The dose- and time-dependence of the survival benefit among pre-diagnostic statin users suggests a possible causal effect that should be evaluated further in a clinical trial testing statins' effect on survival in breast cancer patients.
To estimate the risk for breast cancer in Finnish women using postmenopausal estradiol (E2)-progestogen therapy.
All Finnish women over 50 years using E2-progestogen therapy for at least 6 months in ...1994-2005 (N=221,551) were identified from the national medical reimbursement register and followed up for breast cancer incidence (n=6,211 cases) through the Finnish Cancer Registry to the end of 2005. The risk for breast cancer in E2-progestogen therapy users was compared with that in the general population.
The standardized incidence ratio for all types of breast cancer was not elevated within the first 3 years of use, but it rose to 1.31 (95% confidence interval 1.20-1.42) for the use from 3-5 years and to 2.07 (1.84-2.30) with 10 or more years of use. Exposure to sequential progestogen for 5 years or more was accompanied with a lower risk elevation (1.78, 1.64-1.90) than exposure to continuous use (2.44, 2.17-2.72). Oral and transdermal use of E2-progestogen therapy was associated with comparable risk elevations for breast cancer. The use of norethisterone acetate was accompanied with a higher risk after 5 years of use (2.03, 1.88-2.18) than that of medroxyprogesterone acetate (1.64, 1.49-1.79). The risk of lobular breast cancer increased sooner than that for ductal cancer and was detectable for E2-progestogen therapy use less than 3 years (1.35, 1.18-1.53). There was no excess risk of breast cancer with distant metastases among E2-progestogen therapy users.
The use of E2-progestogen therapy is associated with an increased risk for breast cancer after 3 years of use. The risk is lower for sequential than for continuous use, but comparable for oral and transdermal use. The risk elevation may not be uniform for all progestogens.
II.
Narrow-band TL-01 ultraviolet B phototherapy (TL-01) is an effective and widely used treatment for many skin diseases. The purpose of the investigation was to assess the risk of skin cancers in ...patients treated with TL-01 phototherapy who have not received any other phototherapy modalities. This cohort study included 4,815 TL-01 treated patients in Finland with psoriasis or atopic dermatitis. Clinical information was collected from the hospital records and linked with Finnish Cancer Registry data. The follow-up started from the first TL-01 treatment and the mean follow-up time was 8.4 years. Standardized incidence ratios were calculated for basal cell carcinoma, cutaneous melanoma, and squamous cell carcinoma. The standardized incidence ratio for basal cell carcinoma was 2.5 (95% confidence interval 1.8-3.5), for cutaneous melanoma 4.0 (95% confidence interval 2.1-6.8) and for squamous cell carcinoma 3.7 (95% confidence interval 1.7-7.0). For basal cell carcinoma and squamous cell carcinoma, the standardized incidence ratios remained similar during the whole follow-up time while the standardized incidence ratio for cutaneous melanoma was markedly higher during the first 5 years of follow-up. In conclusion, an increased incidence of skin cancers was observed among TL-01 treated patients. It should be confirmed in the future whether the skin cancer risk of TL-01 phototherapy will remain high in a longer follow-up.
Purpose
Obesity increases the risk of several cancers, but the influence of bariatric surgery on the risk of individual obesity-related cancers is unclear. This study aimed to assess the impact of ...bariatric surgery on cancer risk in a multi-national setting.
Materials and Methods
This cohort study included all adults with an obesity diagnosis identified from national patient registries in all Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) from 1980 to 2012. Cancer risk in bariatric surgery patients was compared with non-operated patients with obesity. Multivariable Cox regression provided adjusted hazard ratios (HRs) with 95% confidence intervals (CIs). Age, sex, calendar year, country, length of follow-up, diabetes, chronic obstructive pulmonary disease and alcohol-related diseases were evaluated as confounders.
Results
Among 482,572 participants with obesity, 49,096 underwent bariatric surgery. Bariatric surgery was followed by a decreased overall cancer risk in women (HR 0.86, 95% CI 0.80–0.92), but not in men (HR 0.98, 95% CI 0.95–1.01). The risk reduction was observed only within the first five post-operative years. Among specific tumours, HRs decreased for breast cancer (HR 0.81, 95% CI 0.69–0.95), endometrial cancer (HR 0.69, 95% CI 0.56–0.84) and non-Hodgkin lymphoma (HR 0.64, 95% CI 0.42–0.97) in female bariatric surgery patients, while the risk of kidney cancer increased in both sexes (HR 1.44, 95% CI 1.13–1.84).
Conclusion
Bariatric surgery may decrease overall cancer risk in women within the first five years after surgery. This decrease may be explained by a decreased risk of breast and endometrial cancer and non-Hodgkin lymphoma in women.
We present up to 45 years of cancer incidence data by occupational category for the Nordic populations. The study covers the 15 million people aged 30-64 years in the 1960, 1970, 1980/1981 and/or ...1990 censuses in Denmark, Finland, Iceland, Norway and Sweden, and the 2.8 million incident cancer cases diagnosed in these people in a follow-up until about 2005. The study was undertaken as a cohort study with linkage of individual records based on the personal identity codes used in all the Nordic countries.
In the censuses, information on occupation for each person was provided through free text in self-administered questionnaires. The data were centrally coded and computerised in the statistical offices. For the present study, the original occupational codes were reclassified into 53 occupational categories and one group of economically inactive persons.
All Nordic countries have a nation-wide registration of incident cancer cases during the entire study period. For the present study the incident cancer cases were classified into 49 primary diagnostic categories. Some categories have been further divided according to sub-site or morphological type. The observed number of cancer cases in each group of persons defined by country, sex, age, period and occupation was compared with the expected number calculated from the stratum specific person years and the incidence rates for the national population. The result was presented as a standardised incidence ratio, SIR, defined as the observed number of cases divided by the expected number. For all cancers combined (excluding non-melanoma skin cancer), the study showed a wide variation among men from an SIR of 0.79 (95% confidence interval 0.66-0.95) in domestic assistants to 1.48 (1.43-1.54) in waiters. The occupations with the highest SIRs also included workers producing beverage and tobacco, seamen and chimney sweeps. Among women, the SIRs varied from 0.58 (0.37-0.87) in seafarers to 1.27 (1.19-1.35) in tobacco workers. Low SIRs were found for farmers, gardeners and teachers.
Our study was able to repeat most of the confirmed associations between occupations and cancers. It is known that almost all mesotheliomas are associated with asbestos exposure. Accordingly, plumbers, seamen and mechanics were the occupations with the highest risk in the present study. Mesothelioma was the cancer type showing the largest relative differences between the occupations. Outdoor workers such as fishermen, gardeners and farmers had the highest risk of lip cancer, while the lowest risk was found among indoor workers such as physicians and artistic workers.
Studies of nasal cancer have shown increased risks associated with exposure to wood dust, both for those in furniture making and for those exposed exclusively to soft wood like the majority of Nordic woodworkers. We observed an SIR of 1.84 (1.66-2.04) in male and 1.88 (0.90-3.46) in female woodworkers. For nasal adenocarcinoma, the SIR in males was as high as 5.50 (4.60-6.56).
Male waiters and tobacco workers had the highest risk of lung cancer, probably attributable to active and passive smoking. Miners and quarry workers also had a high risk, which might be related to their exposure to silica dust and radon daughters. Among women, tobacco workers and engine operators had a more than fourfold risk as compared with the lung cancer risk among farmers, gardeners and teachers. The occupational risk patterns were quite similar in all main histological subtypes of lung cancer.
Bladder cancer is considered as one of the cancer types most likely to be related to occupational carcinogens. Waiters had the highest risk of bladder cancer in men and tobacco workers in women, and the low-risk categories were the same ones as for lung cancer. All this can be accounted for by smoking. The second-highest SIRs were among chimney sweeps and hairdressers. Chimney sweeps are exposed to carcinogens such as polycyclic aromatic hydrocarbons from the chimney soot, and hairdressers' work environment is also rich in chemical agents.
Exposure to the known hepatocarcinogens, the Hepatitis B virus and aflatoxin, is rare in the Nordic countries, and a large proportion of primary liver cancers can therefore be attributed to alcohol consumption. The highest risks of liver cancer were seen in occupational categories with easy access to alcohol at the work place or with cultural traditions of high alcohol consumption, such as waiters, cooks, beverage workers, journalists and seamen.
The risk of colon cancer has been related to sedentary work. The findings in the present study did not strongly indicate any protective role of physical activity. Colon cancer was one of the cancer types showing the smallest relative variation in incidence between occupational categories. The occupational variation in the risk of female breast cancer (the most common cancer type in the present series, 373 361 cases) was larger, and there was a tendency of physically demanding occupations to show SIRs below unity. Women in occupations which require a high level of education have, on average, a higher age at first child-birth and elevated breast cancer incidence. Women in occupational categories with the highest average number of children had markedly lower incidence. In male breast cancer (2 336 cases), which is not affected by the dominating reproductive factors, there was a suggestion of an increase in risk in occupations characterised by shift work. Night-shift work was recently classified as probably carcinogenic, with human evidence based on breast cancer research.
The most common cancer among men in the present cohort was prostate cancer (339 973 cases). Despite the huge number of cases, we were unable to demonstrate any occupation-related risks. The observed small occupational variation could be easily explained by varying PSA test frequency.
The Nordic countries are known for equity and free and equal access to health care for all citizens. The present study shows that the risk of cancer, even under these circumstances, is highly dependent on the person's position in the society. Direct occupational hazards seem to explain only a small percentage of the observed variation - but still a large number of cases - while indirect factors such as life style changes related to longer education and decreasing physical activity become more important.
This publication is the first one from the extensive Nordic Occupational Cancer (NOCCA) project. Subsequent studies will focus on associations between specific work-related factors and cancer diseases with the aim to identify exposure-response patterns. In addition to the cancer data demonstrated in the present publication, the NOCCA project produced Nordic Job Exposure Matrix (described in separate articles in this issue of Acta Oncologica) that transforms information about occupational title histories to quantitative estimates of specific exposures. The third essential component is methodological development related to analysis and interpretation of results based on averaged information of exposures and co-factors in the occupational categories.
Prostate cancer is thought to be the most heritable cancer, although little is known about how this genetic contribution varies across age.
To address this question, we undertook the world's largest ...prospective study in the Nordic Twin Study of Cancer cohort, including 18,680 monozygotic (MZ) and 30,054 dizygotic (DZ) same-sex male twin pairs. We incorporated time-to-event analyses to estimate the risk concordance and heritability while accounting for censoring and competing risks of death, essential sources of biases that have not been accounted for in previous twin studies modeling cancer risk and liability.
The cumulative risk of prostate cancer was similar to that of the background population. The cumulative risk for twins whose co-twin was diagnosed with prostate cancer was greater for MZ than for DZ twins across all ages. Among concordantly affected pairs, the time between diagnoses was significantly shorter for MZ than DZ pairs (median, 3.8 versus 6.5 years, respectively). Genetic differences contributed substantially to variation in both the risk and the liability heritability = 58% (95% confidence interval, 52%-63%) of developing prostate cancer. The relative contribution of genetic factors was constant across age through late life with substantial genetic heterogeneity even when diagnosis and screening procedures vary.
Results from the population-based twin cohort indicate a greater genetic contribution to the risk of developing prostate cancer when addressing sources of bias. The role of genetic factors is consistently high across age.
Findings affect the search for genetic and epigenetic markers and frame prevention efforts.
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