Cancer incidence among Finnish seafarers, 1967–92

A cohort of 30,940 male and 11,529 female seafarers registered in the files of Seafarers' Pension Fund in Finland was followed up through the Finnish Cancer Registry for cancer in 1967–92. Among male seafarers, there were 1,199 cases of cancer, which corresponds to the average cancer incidence in Finnish men. There was a statistically significant excess of non-melanoma skin cancer (standardized incidence ratio [SIR]=1.8, 95 percent confidence interval [CI]=1.2–2.5) and mesothelioma (SIR=2.9, CI=1.2–5.6) in the follow-up category of 20 or more years since the first employment. Alcohol-related cancers were increased among seafarers (SIR for cancer of the mouth and pharynx = 1.; esophagus = 1.4; and liver = 1.5; combined CI=1.1–1.9). Deck crews had a significantly high risk of cancer of the pancreas (SIR=2.0) and also prostate after 10 years since first employment (SIR=1.6). Occupational asbestos exposure among seafarers is likely strong enough to cause excess cases of mesothelioma but not of lung cancer. Occupational exposures also may be associated with increased risk of cancers of the kidney, pancreas, prostate and old-age brain cancer in some of the main occupational categories. Cumulative ultraviolet radiation likely doubles the risk of nonmelanoma skin cancer among older men and repeated sunburns that of skin melanoma in ages below 30 (SIR among deck and engine crew = 4.6, CI=3.1–6.5). Female ship personnel had a significantly elevated total cancer risk (observed number of cases = 732) which increased over follow-up time (SIR in the category 20 years since the first employment was 1.3, CI=1.1–1.5). This excess was attributable primarily to lung cancer (SIR=2.6, CI=2.0–3.3). Also cancers of the cervix uteri, vulva, and vagina showed significant excess after 10 to 20 years since first employment aboard.Address correspondence to Dr Pukkala, Finnish Cancer Registry, Litsankatu 21 B, FIN-00170 Helsinki, Finland. The Finnish Work Environment Fund financially supported this project.Dr Pukkala is with the Finnish Cancer Registry, Helsinki, Finland. Dr Saarni is with the Regional Institute of Occupational Health, Turku, Finland.     

Incidence of cancer among Finnish patients with asbestos-related pulmonary or pleural fibrosis

Objectives: To study the asbestos-associated risk of lung cancer according to the histological type of cancer, the time of and time since diagnosis of asbestosis, the asbestos-associated risk for cancers other than lung cancer or mesothelioma, and the predictive value of asbestos-related pleural abnormalities as regards the risk of cancer.Methods: Finnish patients with asbestosis (n=1,376) or asbestos-related benign pleural disease (n=4,887) notified as an occupational disease since 1964 were followed-up through the Finnish Cancer Registry for cancer in 1967–95.Results: Compared with the total cancer incidence in Finland, men with asbestosis had a raised risk of lung cancer (standardized incidence ratio [SIR]=6.7; 95% confidence interval [CI]=5.6–7.9), mesothelioma (SIR=32, CI=14–60) and cancer of the larynx (SIR=4.2, CI=1.4–9.8). The risk of lung cancer was similarly raised for all histological types of lung cancer (the highest in insulators) and did not change markedly over time of notification or duration of follow-up. Men with benign pleural disease had a raised risk of mesothelioma (SIR=5.5, CI=1.5–14) and a slightly elevated risk of lung cancer (SIR=1.3, CI=1.0–1.8). Among women with asbestosis, significant excess was found for lung cancer and mesothelioma.Conclusion: Asbestosis and asbestos-related benign pleural disease seem to possess different predictive values as regards the risk of lung cancer.     

Relatives of Prostate Cancer Patients have an Increased Risk of Prostate and Stomach Cancers: A Population-Based, Cancer Registry study in Finland

Objective: Five to ten percent of prostate cancers may be caused by inherited genetic defects. In order to explore the nature of inherited cancer risks in the genetically homogeneous Finnish population, we investigated the incidence of prostate cancer and other cancers in first-degree relatives of prostate cancer patients by linking the population-based parish records on relatives with the Finnish Cancer Registry (FCR) data. Methods: The study population was composed of first-degree relatives of two groups of prostate cancer patients diagnosed in Finland during 1988–1993: (1) all early-onset (60years) patients (n=557) from the entire country, (2) a sample (n=989) of prostate cancer patients diagnosed at an age of >60years. A total of 11,427 first-degree relatives were identified through parish records, and their cancer incidence was determined based on a total of 299,970 person-years. Standardized incidence ratios (SIR) were calculated based on expected cancer rates in the general population. Results: The SIR of prostate cancer was increased in both Cohort 1 (2.5, 95% CI 1.9–3.2) and Cohort 2 (1.7, 95% CI 1.4–2.1). The risk of prostate cancer was high for relatives of patients diagnosed at an early age, and then leveled off for patients in the median age of prostate cancer diagnosis (70–79 years). However, the prostate cancer risk for relatives of patients diagnosed 80years was again statistically significantly elevated (SIR 1.8, 95% CI 1.3–2.6), suggesting a contribution of genetic factors to prostate cancer also at a late age of onset. Gastric cancer was the only other cancer type with a significantly elevated risk among the relatives. Increased risk of gastric cancer was seen only in male relatives of prostate cancer patients diagnosed at an early age, with the highest risk detected for the male relatives of prostate cancer patients diagnosed at an age of 55 years or less (SIR 5.0, 95% CI 2.8–8.2). Conclusions: Our population-based study indicates that hereditary factors may play an important role in the development of prostate cancer among the relatives of men diagnosed both at younger and older ages. This finding is relevant in the context of our observations that HPCX (hereditary prostate cancer susceptibility locus on Xq27-28) linkage in Finland is found exclusively among families with late age of onset. The association of gastric cancer with prostate cancer has not been reported previously, and may reflect the effects of a novel predisposition locus, which increases the risk to both of these common tumor types.     

Cancer incidence among marine engineers,a population-based study (Iceland)

Objectives: Marine engineers are in their occupation exposed to different chemicals, organic solvents, exhaust gases, oils, and petroleum products, and were formerly exposed to asbestos. The aim was to study the cancer pattern, with particular attention to lung and bladder cancer, in an Icelandic cohort of marine engineers, indirectly controlling for their smoking habits. Methods: A cohort of 6603 male marine engineers was followed up from 1955 to 1998, a total of 167,715 person-years. The cohort was record linked by the engineers' personal identification numbers to population-based registers containing the vital and emigration status and cancer diagnosis. Standardized incidence ratios (SIRs) were calculated for all cancers and different cancer sites in relation to different lag time and year of graduation. Information on smoking habits was obtained by administering a questionnaire to a sample of the cohort (n = 1501). Results: In the total cohort 810 cancers were observed, whereas 794 were expected (SIR 1.0, 95% CI 1.0–1.1), and significantly increased risk of stomach cancer (SIR 1.3, 95% CI 1.0–1.5) and lung cancer (SIR 1.2, 95% CI 1.0–1.5) was found. Increased risk of all cancers (SIR 1.2, 95% CI 1.1–1.3), stomach cancer (SIR 1.5, 95% CI 1.1–1.9), lung cancer (SIR 1.4, 95% CI 1.2–1.8), pleural mesothelioma (SIR 4.8, 95% CI 1.3–12.3), and urinary bladder cancer (SIR 1.3, 95% CI 1.0–1.8) were observed when a 40-year lag time was applied. The engineers' smoking habits were similar to those in a sample of the general population. The predictive value for lung cancer was 1.03. Conclusions: The increased risk for mesothelioma is possibly attributable to the previous asbestos exposure. The excess of lung cancer could also be related to asbestos exposure. The high incidence of stomach cancer, lung cancer, and bladder cancer may be related to exposure to chemical risk factors, such as oils and petroleum products, as confounding due to smoking seems to be ruled out. In the light of the limited exposure information in the present study the importance of the different occupational exposures needs to be evaluated in further studies.     

Alcoholism and cancer risk: a population-based cohort study

The incidence of cancer was studied in a population-based cohort of 9,353 individuals (8,340 men and 1,013 women) with a discharge diagnosis of alcoholism in 1965–83, followed up for 19 years (mean 7.7). After exclusion of cancers in the first year of follow-up, 491 cancers were observed cf 343.2 expected through 1984 (standardized incidence ratio [SIR] = 1.4,95 percent confidence interval [CI] = 1.3–1.6). A similar excess risk of cancer was seen among men (SIR = 1.4, CI = 1.3–1.6) and among women (SIR = 1.5, CI = 1.1–2.0). We observed the established associations with cancers of the oral cavity and pharynx (SIR = 4.1, CI = 2.9–5.7), esophagus (SIR = 6.8, CI = 4.5–9.9), larynx (SIR = 3.3, CI = 1.7–6.0), and lung (SIR = 2.1, CI = 1.7–2.6), although confounding by smoking likely increased these risk estimates. While there was evidence of increased risk for pancreatic cancer (SIR = 1.5, CI = 0.9–2.3), alcoholism did not elevate the incidence of cancer of the stomach (SIR = 0.9, CI = 6–1.4), large bowel (SIR = 1.1, CI = 0.8–1.5), prostate (SIR = 1.0, CI = 0.8–1.3), urinary bladder (SIR = 1.0, CI = 0.6–1.5), or of malignant melanoma (SIR = 0.9, CI = 0.3–1.9). Among women, the number of breast cancers observed was close to expected (SIR = 1.2, CI = 0.6–2.2), although a significant excess number of cervical cancers occurred (SIR = 4.2, CI = 1.5–9.1). The results of this study, one of the first to evaluate the incidence of cancer in a population-based cohort of alcoholics of both sexes, are consistent with smaller previous studies, which were usually limited to cancer mortality and of short follow-up.Dr Adami is with the Cancer Epidemiology Unit, University Hospital, Uppsala, Sweden. Drs McLaughlin and Hsing are with the Biostatistics Branch, National Cancer Institute, Bethesda, MD, USA. Dr Wolk is with the Cancer Epidemiology Unit, University Hospital, Uppsala, Sweden. Dr Ekbom is with the Department of Surgery and with the Cancer Epidemiology Unit, University Hospital, Uppsala, Sweden. Dr Persson is with the Department of Obstetrics and Gynaecology and with the Cancer Epidemiology Unit, University Hospital, Uppsala, Sweden. Address correspondence to Dr Adami, Cancer Epidemiology Unit, University Hospital, S-751 85 Uppsala, Sweden. The work was performed at the Cancer Epidemiology Unit, Uppsala University, Sweden; the research was supported by grants from the Swedish Cancer Society.     

Incidence of childhood cancer in twins

The incidence of childhood cancer in twins was evaluated by linking a roster of 30,925 twins born in Connecticut (United States) between 1930 and 1969 with the Connecticut Tumor Registry. Cancer, exclusive of nonmelanoma skin cancer, was identified in 19 females and 12 males under 15 years of age. The incidence rate among twins was 7.9 cancers per 100,000 person-years (PY) overall, and 9.7 and 6.1 per 100,000 PYs for females and males, respectively. Four of 13 leukemias occurred in two female twin pairs, representing concordance rates of 18 percent overall and 29 percent for like-sex pairs, which are somewhat higher than values reported previously. The number of cancers expected was computed on the assumption that twins experienced the same sex-, age-, and calendar time-specific cancer rates as recorded for all Connecticut-born children. Because active follow-up of individuals was not conducted, an adjustment to person-years of observation was made to account for childhood mortality, including the high perinatal mortality characteristie of twins. Childhood cancer was 30 percent less frequent than expected (standardized incidence ratio [SIR]=0.7; 95 percent confidence interval [CI]=0.5–0.9), a deficit that is marginally greater than those found in previous studies. Both leukemia (SIR=0.8; CI=0.4–1.4), and all other cancers combined (SIR=0.6; CI=0.3–0.9) occurred less often than expected. The deficit was greater among males (SIR=0.5; CI=0.2–0.8) than among females (SIR=0.9; CI=0.5–1.4) and was especially pronounced among males younger than five years (SIR=0.2; CI=0.0–0.7). The data support the view that twins, particularly male twins, have a lower risk of childhood cancer than single-born children. Any added risk for twins associated with their greater frequency of exposure to prenatal X-rays appears to have been insufficient to offset an effect of twinning per se. Possible explanations for this finding include (i) the low birthweight distribution of twins, or (ii) selective early mortality of twin fetuses or neonates who would otherwise have developed a clinical cancer.Drs Inskip, Boice, Stone, and Fraumeni are with the Epidemiology and Biostatistics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA. Dr Harvey was in the Epidemiology and Biostatistics Program at the time of this research and is now with Sterling Drug, Malvern, PA, USA. Dr Matanoski is in the Department of Epidemiology, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD, USA. Dr Flannery is with the Connecticut Tumor Registry, Hartford, CT, USA. Address correspondence to Dr Inskip, Radiation Epidemiology Branch, National Cancer Institute, Executive Plaza North, Room 408, Rockville, MD 20852, USA. This study was supported in part by Contract N01-CPO-1047 with the National Cancer Institute, US Public Health Service.     

Cancer risk following polymyositis and dermatomyositis: a nationwide cohort study in Denmark

Polymyositis and dermatomyositis (PM/DM) have been associated with cancer, although the long-term risks are poorly understood. To evaluate the risk of cancer by time periods subsequent to PM/DM diagnosis, a cohort of 539 patients hospitalized with PM/DM in Denmark between 1977 and 1989 was identified from the Danish Central Hospital Discharge Register. Cancer incidence among cohort members was ascertained by linkage to the Danish Cancer Registry using a unique personal-identification number. The overall cancer risk was elevated significantly among patients with DM (standardized incidence ratio [SIR]=3.8, 95 percent confidence interval [CI]=2.6–5.4) and to a lesser extent PM (SIR=1.7, CI=1.1–2.4). Significant excesses were observed for cancers of lung, ovary, and lymphatic and hematopoietic system. However, the excess cancer incidence declined steadily with increasing years since initial diagnosis of PM/DM. The cancer risk was increased about sixfold (SIR=5.9, CI=3.8–8.7) during the first year, but was lower during the second year (SIR=2.5, CI=1.1–4.8), with no significant excesses in subsequent years of follow-up. These findings confirm that PM/DM may occur as a paraneoplastic syndrome that calls for steps aimed at early cancer detection and treatment. Among long-term survivors of PM/DM, however, there is little evidence to warrant extensive preventive and screening measures beyond those recommended for the general population.Drs Chow, McLaughlin, and Fraumeni, and Ms Gridley are with the Epidemiology and Biostatistics Program, Division of Cancer Etiology, National Cancer Institute, Bethesda, MD, USA. Dr McLaughlin is currently with the International Epidemiology Institute, Rockville, MD. Ms Mellemkjær and Dr Olsen are with the Division for Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark. Address correspondence to Dr Chow, National Cancer Institute 6130 Executive Blvd, EPN/415, Rockville, MD 20852, USA.     

A prospective study of obesity and cancer risk (Sweden)

Objective: We evaluated the relation between obesity and the risks for various forms of cancer. Methods: In a population-based cohort of 28,129 hospital patients (8165 men, 19,964 women) with any discharge diagnosis of obesity (9557 only diagnosis, 5266 primary, 13,306 secondary) during 1965–1993, cancer incidence was ascertained through 1993 by record linkage to the nationwide Swedish Cancer Registry. Cancer risk was estimated using the standardized incidence ratio (SIR, with 95% confidence interval), which is the ratio of the observed number of cancers to that expected. Results: Overall, a 33% excess incidence of cancer was seen in obese persons, 25% in men and 37% in women. Significant risk elevations were observed for cancers of the small intestine (SIR = 2.8; 95% CI 1.6–4.5), colon (1.3; 1.1–1.5), gallbladder (1.6; 1.1–2.3), pancreas (1.5; 1.1–1.9), larynx (2.1; 1.1–3.5), renal parenchyma (2.3; 1.8–2.8), bladder (1.2; 1.0–1.6), cervix uteri (1.4; 1.1–1.9), endometrium (2.9; 2.5–3.4), ovary (1.2; 1.1–1.5), brain (1.5; 1.2–1.9), and connective tissue (1.9; 1.1–3.0), and for lymphomas (1.4; 1.0–1.7), with higher risk observed for Hodgkin's disease only in men (3.3; 1.4–6.5) and for non-Hodgkin's lymphoma only in women (1.6; 1.2–2.1). The association of obesity with risk of breast, prostate and pancreas cancers was modified by age. Conclusions: Obesity is associated with more forms of cancer than previously reported.     

Incidence of cancer among male waiters and cooks: two Norwegian cohorts

Previous occupational survey studies have identified waiter and cook as possible high risk occupations for cancer. However, few cohort studies have been performed among persons in the restaurant business, and we therefore have analyzed cancer incidence in two cohorts of Norwegian waiters and cooks. The cohorts consisted of skilled male workers, 1,463 waiters and 2,582 cooks, who received their craft certificate between 1958 and 1983. The cohorts were followed from 1959 through 1991. The standardized incidence ratio (SIR) for all causes of cancer was 1.4 (95 percent confidence interval [CI]=1.2–1.7] for waiters, and 1.1 (CI=0.9–1.4) for cooks. Cancers of the tongue, mouth, pharynx, larynx, esophagus, and liver were grouped together as alcohol-associated cancers. SIR for these cancers combined was 5.1 (CI=3.4–-7.4) for waiters and 4.2 (CI=2.2–7.2) for cooks. For lung cancer, SIR was 2.0 (CI=1.3–2.9) for waiters and 0.7 (CI=0.2–1.7) for cooks. For alcohol-associated cancers, the analysis carried out according to number of years since first employment showed a larger number of cases than expected for both occupations in all time-periods. The excess of lung cancer cases among waiters appeared after 30 years or more of employment. The study shows that waiters and cooks are at high risk of cancers associated with alcohol consumption, and that waiters, in addition, show high rates for lung cancer. The hypothesis of an occupational lung-cancer risk in cooks was not supported by this study.Dr Kjerheim and Mr Andersen are with The Cancer Registry of Norway. Address crrespondence to Dr Kjerheim, The Cancer Registry of Norway, Institute for Epidemiological Cancer Research, Montebello, 0310 Oslo, Norway. This project was supported by grants from the Confederation of Norwegian Business and Industry.     

Risk of new primary cancer in patients with oropharyngeal cancer.

The relative risk of subsequent cancers was evaluated for a total of 9,092 patients with lip and oropharyngeal cancer recorded between 1953 and 1989 in the nationwide Finnish Cancer Registry. The observed numbers of patients were compared with those expected on the basis of the incidence rates in the Finnish population. There were 1,130 patients (12%) with a new cancer. The standardised incidence ratio (SIR) of contracting a new primary cancer was 1.2 for lip cancer patients (95% CI 1.1-1.3) and 1.4 for patients with oropharyngeal cancer (95% CI 1.2-1.4). Among lip cancer patients, a statistically significant excess risk was found for subsequent cancers in the oropharyngeal area (SIR 1.9, 95% CI 1.1-3.1), larynx (SIR 2.0, 95% CI 1.2-2.9) and lung (SIR 1.4, 95% CI 1.3-1.6), i.e. for cancers with tobacco aetiology. Among patients with oropharyngeal cancer there was an excess of lip cancer (SIR, 3.5, 95% CI 1.5-6.9), lung cancer (SIR 1.8, 95% CI 1.3-2.3) and leukaemia (SIR 2.3, 95% CI 1.0-4.3). Radiotherapy for the first primary did not increase the risk of new cancer.     

A cohort study of reproductive factors and family history of breast cancer in southern Sweden

Background. Studies have been contradictory regarding the hypothesis that reproductive risk factors of breast cancer as parity and age at first full-term pregnancy (AFFP) operate differently in women with and without a family history of breast cancer. Methods. The overall tumour incidence and breast cancer incidence related to fertility factors were followed in a population based cohort of 29,508 women aged 25–65 when interviewed between 1990 and 1992 in south Sweden. At the end of the follow up in December 1999, the cohort constituted 226,611 person years. The risk of breast cancer in relation to reproductive factors were studied in women with at least one first degree relative with breast cancer and compared with women without a family history. Findings. A total of 1145 malignant tumours were seen and 1166.6 were expected (SIR = 0.98, 95% CI = 0.93–1.04). Slightly more breast cancer cases were seen 434 than expected 387.69 (SIR = 1.12, 95% CI = 1.02–1.23). A family history of breast cancer among a first degree relative was present in 1615 women. Forty-five breast cancers were seen among these women while 24.27 was expectecd (SIR = 1.85, 95% CI = 1.35–2.48). Nulliparous women with a family history of breast cancer had a higher risk of breast cancer, SIR = 1.76, 95% CI = 0.64–3.82, compared with nulliparous women without a family history, SIR = 1.13, 95% CI 0.99–1.29. Similarly women with parity 1–2 with a family history had a higher SIR = 1.81, 95% CI = 1.16–2.69 compared with women without a family history having 1–2 children, SIR = 1.13, 95% CI = 0.99–1.29. In women with 3 children those with a family history continued to have a high SIR = 1.98, 95% CI = 1.11–3.27 compared with women without a family history SIR = 0.90, 95% CI = 0.73–1.09. An early full-term pregnancy was protective in both groups. A higher risk than nulliparous women were seen after age 25 in the family history group and after age 30 in the sporadic cancer group. Interpretation. Women with a first degree family history of breast cancer do not experience the same protection from a high number of pregnancies as women without a family history. However, an early first full-term pregnancy seems to offer a substantial protection in the family history group if undertaken before age 20. This suggest that reproductive factors tend to operate differently in the two groups of women.     

Acromegaly and cancer risk: a cohort study in Sweden and Denmark

Objective: Several studies have suggested that patients with acromegaly have an increased risk of benign and malignant neoplasms, especially of the colon. To further investigate this relationship we evaluated cancer risk in population-based cohorts of acromegaly patients in Sweden and Denmark. Methods: Nationwide registry-based cohorts of patients hospitalized for acromegaly (Denmark 1977–1993; Sweden 1965–1993) were linked to tumor registry data for up to 15–28 years of follow-up, respectively. Standardized incidence ratios (SIR) and 95% confidence intervals (CI) were calculated to estimate cancer risk among 1634 patients with acromegaly. Results: The patterns of cancer risk in Sweden and Denmark were similar. After excluding the first year of follow-up, 177 patients with acromegaly had a diagnosis of cancer compared with an expected number of 116.5 (SIR = 1.5, 95% CI = 1.3–1.8). Increased risks were found for digestive system cancers (SIR = 2.1, 95% CI = 1.6–2.7), notably of the small intestine (SIR = 6.0, 95% CI = 1.2–17.4), colon (SIR = 2.6, 95% CI = 1.6–3.8), and rectum (SIR = 2.5, 95% CI = 1.3–4.2). Risks were also elevated for cancers of the brain (SIR = 2.7, 95% CI = 1.2–5.0), thyroid (SIR = 3.7, 95% CI = 1.8–10.9), kidney (SIR = 3.2, 95% CI = 1.6–5.5), and bone (SIR = 13.8, 95% CI = 1.7–50.0). Conclusions: The increased risk for several cancer sites among acromegaly patients may be due to the elevated proliferative and anti-apoptotic activity associated with increased circulating levels of insulin-like growth factor-1 (IGF-1). Pituitary irradiation given to some patients may have contributed to the excess risks of brain tumors and thyroid cancer. Our findings indicate the need for close medical surveillance of patients with acromegaly, and further studies of the IGF-1 system in the etiology of various cancers.     

Increased incidence of bowel cancer after non-surgical treatment of appendicitis

Background

There is an ongoing debate on the use of antibiotics instead of appendectomy for treating appendicitis but diagnostic difficulties and longstanding inflammation might lead to increased incidence of bowel cancer in these patients. The aim of this population-based study was to investigate the incidence of bowel cancer after non-surgical treatment of appendicitis.

Are Coffee, Tea, and Total Fluid Consumption associated with Bladder Cancer Risk? Results from the Netherlands Cohort Study

Objectives: Coffee, tea, and fluid consumption have been thought to influence bladder cancer incidence. In a large prospective study, these associations were investigated. Methods: In 1986, cohort members (55–69 years) completed a questionnaire on cancer risk factors. Follow-up was established by linkage to cancer registries until 1992. The multivariable case–cohort analysis was based on 569 bladder cancer cases and 3123 subcohort members. Results: The incidence rate ratios (RR) for men consuming <2 cups of coffee/day was 0.89 (95% CI 0.51–1.5) using the median consumption category (4–<5 cups/day) as reference. This RR increased to 1.3 (95% CI 0.94–1.9) for men consuming 7 cups/day, although no clear dose–response association was found. The RRs decreased from 1.2 (95% CI 0.56–2.7) for women consuming <2 cups of coffee/day to 0.36 (95% CI 0.18–0.72) for women consuming 5 cups/day compared to the median consumption category (3–<4 cups/day). Men and women who abstained from drinking tea had a RR of 1.3 (95% CI 0.97–1.8) compared to those consuming 2–<3 cups of tea per day (median consumption category). The RR for men and women comparing highest to lowest quintile of total fluid consumption was 0.87 (95% CI 0.63–1.2). Conclusion: The data suggest a possible positive association between coffee consumption and bladder cancer risk in men and a probable inverse association in women. Tea consumption was inversely associated with bladder cancer. Total fluid consumption did not appear to be associated with bladder cancer.     

Occupational Exposure to Diesel Engine Emissions and Risk of Cancer in Swedish Men and Women

Objective: To investigate the risk of cancer among workers exposed to diesel emissions in a large record-linkage study from Sweden. Methods: The Swedish Cancer Environment Register III contains nationwide data on cancer incidence during 1971–1989, by occupation and industry of employment as reported in the 1960 and 1970 censuses. After excluding farmers, we classified job and industry titles according to estimated probability and intensity of exposure to diesel emissions. Exposed men in the 1960 census contributed over 7,400,000 person-years, and exposed women contributed over 240,000. We compared them to the remainder of the employed population, using indirect standardization and multivariate Poisson regression analysis. Results: Men exposed in the 1960 census experienced an increased risk of lung cancer: the relative risks (RRs) were 0.95 (95% confidence interval [CI] 0.9–1.0), 1.1 (1.1–1.2) and 1.3 (1.3–1.4) for low, medium, and high intensity of exposure. Corresponding results for probability of exposure were 1.1 (1.0–1.1), 0.9 (0.86–0.94) and 1.2 (1.1–1.2). The risk was higher for squamous cell carcinoma of the lung than for other histological types. Results in women were not suggestive of an effect (RR in the category of medium or high intensity of exposure 1.1, 95% CI 0.6–1.8). A small but significant increase in risk of cancers of the stomach (SIR 1.06), pancreas (SIR 1.05), larynx (SIR 1.09), and the kidney (SIR 1.06) was present among men exposed to diesel emissions, without a clear trend according to either probability or intensity of exposure. The SIR among women was non-significantly increased for stomach, pancreatic, and laryngeal cancers, but not for kidney cancer. Furthermore, a significantly increased risk of oral/pharyngeal (SIR 1.64) and cervical (SIR 1.48) cancers was present among women, with a suggestion of a dose–response relationship. There was no increased risk of bladder cancer in either gender. Conclusions: The results of this study provide evidence of a positive exposure–response relationship between exposure to diesel emissions and lung cancer risk among men. The positive results for other neoplasms, such as stomach, pancreatic, oral/pharyngeal, and cervical cancers, cannot be attributed to diesel exposure, but they deserve attention in future investigations.     

Testicular cancer,occupation and exposure to chemical agents among Finnish men in 1971–1995

Objective: To find associations between testicular cancer, occupation and chemical exposure.Methods: A cohort of all economically active Finnish men born between 1906 and 1945 was followed-up for 19.7 million person-years during 1971–1995. Incident cases of testicular cancer (n=387) were identified in a record linkage with the Finnish Cancer Registry. The Census occupations in 1970 were converted to chemical exposures with a job-exposure matrix (FINJEM). Cumulative exposure (CE) was calculated as the product of prevalence, level, and duration of the exposure. Standardised incidence ratio (SIR) was calculated for each of the 393 occupations, and for CE categories of the 43 chemical agents, using average male population as reference. Relative risks (RR) comparing various CE-categories with unexposed ones were defined for selected agents by Poisson regression analysis.Results: Elevated SIRs were observed among railway traffic supervisors (5.8, 95% CI 1.6–14.7), programmers (4.3, 1.4–9.9), university teachers (4.1, 1.3–9.5) and electrical engineers (3.9, 1.1–10.1). A significant exposure-response trend (mainly contributed by seminoma) was observed for pesticides, textile dust, aliphatic and alicyclic hydrocarbons, and some other organic solvents.Conclusions: Risk of testicular cancer increased only in four occupations. Pesticides, textile dust, and some organic solvents may be related to an excess risk of seminoma.     

Increased risk of second cancers following breast cancer: Role of the initial treatment

Objectives and methods.The risk of second primary malignancies (SMN) was studied in a cohort of 4,416 one-year survivors of a breast cancer. The role of the menopausal status and of the initial treatment modalities (surgery, radiotherapy, and chemotherapy) was investigated. Results.Excluding second primary breast cancer and non-melanoma skin cancer, a total of 193 (4.4%) patients developed a SMN between 1973 and 1992, compared with 136 expected (Standardised Incidence Ratio, SIR=1.4, 95% CI (1.2–1.6)). No trend towards either an increase or a decrease was noted in the SIR with time after treatment (p=0.2). The greatest increase in the relative risk concerned soft tissue cancers (SIR=13.0, 95% CI: 6.8–22.3), followed by leukaemia (SIR=3.1, 95% CI: 1.7–5.0), melanoma (SIR = 2.7, 95% CI: 1.4–4.8), kidney (SIR=2.5, 95% CI: 1.2–4.5), ovary (SIR=2.0, 95% CI: 1.2–3.1) and uterine tumours (SIR=1.9, 95% CI: 1.4–2.5). The SIR was 3.0 (95% CI 1.8–4.7) in women under 40 at the time of the breast cancer, 1.9 (95% CI : 1.4 – 2.4) in those aged 40–49 and 1.2 (95% CI 1.0–1.4) in those aged 50 or more. In the 2,514 women who had received radiotherapy as initial treatment without chemotherapy, the SIR for all SMN was 1.6 (95% CI: 1.1–2.3) fold higher than in those who had not received radiotherapy as initial treatment. Conclusion.In conclusion, this study confirms the increased risk of second malignancies in women treated for a breast cancer, and particularly in those who were younger at the time of treatment for breast cancer. Our results also suggest that radiotherapy may play a role in the onset of these second lesions.     

Second cancer risk and mortality in men treated with radiotherapy for stage I seminoma

Background:

Patients with stage I testicular seminoma are typically diagnosed at a young age and treatment is associated with low relapse and mortality rates. The long-term risks of adjuvant radiotherapy in this patient group are therefore particularly relevant.

Methods:

We identified patients and obtained treatment details from 12 cancer centres (11 United Kingdom, 1 Norway) and ascertained second cancers and mortality through national registries. Data from 2629 seminoma patients treated with radiotherapy between 1960 and 1992 were available, contributing 51 151 person-years of follow-up.

Results:

Four hundred and sixty-eight second cancers (excluding non-melanoma skin cancers) were identified. The standardised incidence ratio (SIR) was 1.61 (95% confidence interval (CI): 1.47–1.76, P<0.0001). The SIR was 1.53 (95% CI: 1.39–1.68, P<0.0001) when the 32 second testicular cancers were also excluded. This increase was largely due to an excess risk to organs in the radiation field; for pelvic–abdominal sites the SIR was 1.62 (95% CI: 1.43–1.83), with no significant elevated risk of cancers in organs elsewhere. There was no overall increase in mortality with a standardised mortality ratio (SMR) of 1.06 (95% CI: 0.98–1.14), despite an increase in the cancer-specific mortality (excluding testicular cancer deaths) SMR of 1.46 (95% CI: 1.30–1.65, P<0.0001).

Conclusion:

The prognosis of stage I seminoma is excellent and it is important to avoid conferring long-term increased risk of iatrogenic disease such as radiation-associated second cancers.     

Secondary cancers after a childhood cancer diagnosis: a nationwide hospital-based retrospective cohort study in Japan

Background

The epidemiology of secondary cancers in childhood cancer survivors has been unknown in Asian countries. Our aim is to assess the incidence and risk factors for secondary cancers through a nationwide survey in Japan.

Methods

A retrospective cohort study comprising 10,069 children who were diagnosed with cancer between 1980 and 2009 was conducted in 15 Japanese hospitals. The cumulative incidence rate was calculated using death as the competing risk and compared by the Gray method. The standardized incidence ratio (SIR) was defined as the ratio of the number of observed cancers divided by the number of expected cancers. The risk factors were analyzed using Cox regression analysis.

Results

One hundred and twenty-eight patients (1.3 %) developed secondary cancers within a median follow-up of 8.4 years. The cumulative incidence rate was 1.1 % (95 % confidence interval [CI] 0.9–1.4) at 10 years and 2.6 % (95 % CI 2.1–3.3) at 20 years after primary cancer diagnosis. Sensitivity analysis, limited to 5-year survivors (n = 5,387), confirmed these low incidence rates. The SIR of secondary cancers was 12.1 (95 % CI 10.1–14.4). In the Cox analysis, the hazard ratios for secondary cancers were 3.81 (95 % CI 1.53–9.47) for retinoblastoma, 2.78 (95 % CI 1.44–5.38) for bone/soft tissue sarcomas, and 1.81 (95 % CI 1.16–2.83) for allogeneic stem cell transplantation.

Conclusions

The cumulative incidence of secondary cancers in children in Japan was not high; however, the SIR was relatively high. Retinoblastoma or sarcoma in addition to allogeneic stem cell transplantation were significant risk factors for secondary cancers.

     

Cancer in phenoxy herbicide manufacturing workers in Denmark, 1947–87—an update

This report is an update of a cohort study from the two Danish phenoxy herbicide manufacturing plants. The study originally covered the period 1947–82. Data now have been added for the period 1983–87. In 1943–87, the 940 phenoxy herbicide manufacturing and packaging workers experienced the same overall cancer incidence as the Danish population (observed [Obs]=66; expected [Exp]=64.27; standardized incidence ratio [SIR]=1.0; 95 percent confidence interval [CI]=0.8–1.3). The same was true for the 1,179 workers employed in manual service functions. The data for 1947–82 included five cases of soft tissue sarcoma (STS). One of these patients had his diagnosis changed when he died in 1985. One new STS case was diagnosed during the period 1983–87. This updated study thus includes a total of five STS cases. Four of the STS cases were observed among persons potentially exposed to phenoxy herbicide (Exp=1.76; SIR=2.3; CI=0.6–5.8). Three of the cases occurred among men employed for at least one year in one factory. In this subgroup, an SIR of 6.4 (CI=1.3–18.7) was observed when a 10-year latency period was taken into account. Based on small numbers, this Danish study thus continues to add to the evidence for a possible association between phenoxy herbicide exposure and risk of STS. Persons potentially exposed to phenoxy herbicide had an incidence of non-Hodgkin's lymphoma close to that of the Danish population (Obs=4; Exp=3.08; SIR=1.3; CI=0.4–3.3).