Cancer mortality in women with thyroid disease

A retrospective follow-up study of 7338 women with either nontoxic nodular goiter, thyroid adenoma, hyperthyroidism, hypothyroidism, Hashimoto's thyroiditis, or no thyroid disease was conducted. All women patients at the Massachusetts General Hospital Thyroid Clinic who were seen between 1925 and 1974 and who were treated for a minimum of 1 year were traced. A total of 2231 women (30.4%) were dead and 2012 women (27.4%) were alive as of December 31, 1978. Partial follow-up information was available for the remaining 3095 women (42.2%). The average length of follow-up was 15.2 years. When losses to follow-up were withdrawn at the time of their loss, the standardized mortality ratios (SMR) for all causes of death were 1.2 [95% confidence interval (CI), 1.1-1.3] for women with nontoxic nodular goiter, 1.2 (95% CI 1.0-1.3) for those with thyroid adenoma, 1.4 (95% CI 1.3-1.5) for women with hyperthyroidism, 1.5 (95% CI 1.3-1.7) for hypothyroid women, 1.2 (95% CI 0.9-1.5) for those with Hashimoto's thyroiditis, and 1.5 (95% CI 1.4-1.6) for those without thyroid disease. For deaths from all cancers, the standardized mortality ratios were 1.5 (95% CI 1.2-1.8) for women with nontoxic nodular goiter, 1.5 (95% CI 1.1-1.9) for those with thyroid adenoma, 1.2 (95% CI 1.0-1.4) for women with hyperthyroidism, 1.0 (95% CI 0.7-1.4) for the hypothyroid women, 1.2 (95% CI 0.7-2.1) for those with Hashimoto's thyroiditis, and 1.3 (95% CI 1.0-1.5) for those women without thyroid disease. When specific cancer sites were studied, excess numbers of deaths were observed from breast cancer in women with nontoxic nodular goiter (SMR = 1.6, 95% CI 1.0-2.6) and from lymphatic and hematopoietic cancer in women with nontoxic nodular goiter (SMR = 2.4, 95% CI 1.2-4.3) and thyroid adenoma (SMR = 2.7, 95% CI 1.1-5.2). An increase in thyroid cancer risk was observed in women with thyroid adenoma (SMR = 11.7, 95% CI 1.3-42.1) but was based on only two deaths. In hyperthyroid women, statistically significant increases in the number of deaths were observed from pancreatic cancer (SMR = 2.6, 95% CI 1.4-4.3) and respiratory cancer (SMR = 2.2, 95% CI 1.3-3.5), but not breast cancer (SMR = 1.3, 95% CI 0.8-1.8). When the data were stratified by the time between the onset of thyroid symptoms and death, a nonsignificant excess number of cancer deaths was observed in hyperthyroid women who died 20 or more years after their symptoms began.(ABSTRACT TRUNCATED AT 400 WORDS)     

Excess mortality from breast cancer 20 years after diagnosis when life expectancy is normal

In a population-based study, causes of death were traced of 418 deceased breast cancer patients diagnosed in 1960-1979 who survived at least 10 years after diagnosis. The pattern of causes of death in these patients was compared with the general female population using standardized mortality ratios (SMRs). Of 418 patients surviving at least 10 years, 196 (47%) died from breast cancer and 50 (12%) died from another cancer. The SMR for breast cancer was 15.8 (95% CI: 13.1-18.8) 10-14 years after diagnosis; it was still 4.7 (95% CI: 2.6-7.8) after 20 years. Overall mortality was higher than expected 10-14 years after diagnosis (SMR: 1.3; 95% CI: 1.1-1.5), but lower after more than 20 years (SMR: 0.6; 95% CI: 0.4-0.7). Despite a normal (or even improved) life expectancy for breast cancer patients 20 years after diagnosis the risk of dying from this disease remained elevated.     

Risk of second primary malignancies and causes of death in patients with adenocarcinoma and carcinoid of the small intestine

We studied risk of second malignancies and causes of death in 1829 cases of adenocarcinoma and 3055 cases of carcinoid tumours in the small bowel reported to the Swedish Cancer Registry from 1960 through to 2000. Data on causes of death were analysed as from 1966 whereas data on second tumours was available during the whole registry-period. Follow-up was available until 2001. Standard mortality ratio (SMR) and standard incidence ratio (SIR) were calculated. Female patients with adenocarcinoma had increased risk of acquiring cancer in the female genital organs (SIR 3.2; 95% confidence intervals (CI) 1.9-5.0) and breasts (SIR 2.7; 95% CI 1.1-5.4). Both sexes combined had increased risk of second tumours in the gastrointestinal tract (SIR 1.5; 95% CI 1.1-2.1) and skin (SIR 4.6; 95% CI 1.2-12). Men with carcinoid tumour had increased risk of prostate cancer (SIR 2.8; 95% CI 1.6-4.6). Increased risk was seen for both sexes with carcinoid for malignant melanoma (SIR 6.3; 95% CI 2.7-12), malignant skin tumours (SIR 3.6; 95% CI 1.7-6.7) and malignancies of endocrine organs (SIR 2.3 95% CI 1.3-3.8). Patients with adenocarcinoma had increased risk of dying from malignant diseases other than the primary cancer (SMR 9.5; 95% CI 8.6-10) and gastrointestinal disease (SMR 2.6 95% CI 1.6-4.2). The cohort with carcinoid had higher than expected risk of dying from malignant disease (SMR 4.3; 95% CI 4.0-4.6), gastrointestinal disease (SMR 2.8; 95% CI 2.1-3.6) and cardiovascular disease (SMR 1.1; 95% CI 1.0-1.3). The increased risk of second malignant tumours is an indication of common aetiology, or possibly, a general vulnerability to malignant disease for these patients. A detailed analysis of causes of death in a population-based cohort of small intestinal malignancies has not been presented before in the literature.     

Cancer mortality after nasopharyngeal radium irradiation in the Netherlands: a cohort study.

BACKGROUND: Nasopharyngeal radium irradiation (NRI) was used widely from 1940 through 1970 to treat otitis serosa in children and barotrauma in airmen and submariners. We assessed whether NRI-exposed individuals were at higher risk for cancer-related deaths than were nonexposed individuals. METHODS: We conducted a retrospective cohort study of all-cause and cancer-related mortality in 5358 NRI-exposed subjects and in 5265 frequency-matched nonexposed subjects, who as children were treated at nine ear, nose, and throat clinics in The Netherlands from 1945 through 1981. We recorded personal and medical data from original patient medical records and assessed vital status through follow-up at municipal population registries. Risk of mortality was evaluated by standardized mortality ratios (SMRs). All statistical tests were two-sided. RESULTS: The average radiation doses were 275, 10.9, 1.8, and 1.5 cGy for the nasopharynx, pituitary, brain, and thyroid, respectively. The median follow-up was 31.6 years. Three hundred two NRI-exposed subjects had died, with 269.2 deaths expected (SMR = 1.1; 95% confidence interval [CI] = 1.0 to 1.3); among nonexposed subjects, 315 died, with 283.5 deaths expected (SMR = 1.1; 95% CI = 0.99 to 1.2). Cancer-related deaths of 96 exposed subjects (SMR = 1.2; 95% CI = 0.95 to 1.4) and 87 nonexposed subjects (SMR = 1.0; 95% CI = 0.8 to 1.3) were documented. There were no excess deaths from cancers of the head and neck area among exposed subjects. However, there were excess deaths from cancers of lymphoproliferative and hematopoietic origin (SMR = 1.9; 95% CI = 1.1 to 3.0), mainly from non-Hodgkin's lymphoma (SMR = 2.6; 95% CI = 1.0 to 5.3). We found no evidence that breast cancer deaths were less than expected (SMR = 1.7; 95% CI = 0.9 to 2.8) in contrast to an earlier study. CONCLUSIONS: Our findings do not indicate an increased cancer mortality risk in a population exposed to NRI in childhood. More prolonged follow-up of this and other NRI cohorts is recommended.     

Mortality after cure of soft-tissue sarcoma treated with conservation surgery and radiotherapy

BACKGROUND: The objective of the current study was to analyze the potential treatment-related mortality in long-term survivors of soft-tissue sarcoma (STS) treated with radiotherapy (RT) and conservation surgery. METHODS: Between 1960 and 2000, 629 of 1089 patients treated with conservation surgery and RT for nonmetastatic STS at the University of Texas M. D. Anderson Cancer Center never developed disease recurrence. Long-term survival and causes of death were evaluated using the person-years method to determine the standardized mortality ratio (SMR). SMRs were calculated for death from all causes, cancer, and cardiac disease using standard U.S. data. RESULTS: The median follow-up was 13.2 years. The 10-year, 20-year, and 30-year actuarial survival rates were 88%, 69%, and 52%, respectively. The overall all-case mortality was 1.14 (95% confidence interval [95% CI], 0.98-1.33). The all-cause mortality exceeded that expected for female patients with an SMR of 1.48 (95% CI, 1.15-1.88), patients aged 相似文献   

Postmenopausal cancer risk after self-reported endometriosis diagnosis in the Iowa Women's Health Study

BACKGROUND: Endometriosis, the presence of endometrial tissue outside the uterus, has an estimated prevalence between 4% and 10%. A recent study reported that women with a hospital discharge diagnosis of endometriosis were at increased risk of cancer at any site, breast cancer, ovarian cancer, and hematopoietic malignancies, especially non-Hodgkin lymphoma (NHL). METHODS: The authors examined whether self-reported diagnosis of endometriosis was associated with increased risk of various cancers in the Iowa Women's Health Study. Incident cancer cases were identified from 1986 through 1998. Cox proportional hazards regression models were used to calculate relative risks and 95% confidence intervals for the particular cancers of interest. RESULTS: Of 37,434 participants in this analysis, 3.8% reported a history of endometriosis at baseline in 1986. After 13 years of follow-up, 1795 breast, 188 ovarian, and 243 NHL cases were detected in the cohort. Endometriosis was not associated with risk of all cancers combined (age-adjusted relative risk [RR], 0.9; 95% confidence interval [CI], 0.7-1.2), breast carcinoma (RR, 1.0; 95% CI, 0.8-1.3), or ovarian carcinoma (RR, 0.8; 95% CI, 0.2-2.4). However, endometriosis was significantly associated with risk of NHL (age-adjusted RR, 1.8; 95% CI, 1.0-3.0), especially diffuse NHL (RR, 3.2; 95% CI, 1.8-5.6). Multivariate adjustment had minimal effect on the point estimates of risk (NHL RR, 1.7; 95% CI, 0.97-2.7; diffuse NHL RR, 3.3; 95% CI, 1.9-5.9). Endometriosis was not associated with elevated risk of lung, urinary tract, endometrial, melanoma, or colorectal carcinomas (RRs, 1.2, 0.8, 1.2, 0.7, and 0.7, respectively). CONCLUSIONS: These results corroborate a previously reported association between endometriosis and increased risk of NHL but not cancer at other sites.     

Cardiotoxic effects of tangential breast irradiation in early breast cancer patients: the role of irradiated heart volume

PURPOSE: To assess the risk of cardiovascular disease (CVD) after postlumpectomy irradiation restricted to tangential fields. METHODS AND MATERIALS: We assessed the incidence of CVD in 1601 patients with T1-2N0 breast cancer (BC) treated with breast tangentials in five different hospitals between 1980 and 1993. Patients treated with radiation fields other than breast tangentials and those treated with adjuvant chemotherapy were excluded. For patients with left-sided BC, maximum heart distance (MHD) was measured on the simulator films as a proxy for irradiated heart volume. Risk of CVD by laterality and MHD categories was evaluated by Cox proportional hazards regression analysis. RESULTS: Follow-up was complete for 94% of the patients, and median follow-up was 16 years. The incidence of CVD overall was 14.1%, of ischemic heart disease 7.3%, and for other types of heart disease 9.2%, with a median time to event of 10 to 11 years. The incidence of CVD was 11.6% in patients with right-sided BC, compared with 16.0% in left-sided cases. The hazard ratio associated with left-sided vs. right-sided BC was 1.38 (95% confidence interval [CI], 1.05-1.81) for CVD overall, 1.35 (95% CI, 0.93-1.98) for ischemic heart disease , and 1.53 (95% CI, 1.09-2.15) for other heart disease, adjusted for age, diabetes, and history of CVD. The risk of CVD did not significantly increase with increasing MHD. CONCLUSIONS: Patients irradiated for left-sided BC with tangential fields have a higher incidence of CVD compared with those with right-sided cancer. However, the risk does not seem to increase with larger irradiated heart volumes.     

Brain cancer mortality and potential occupational exposure to lead: findings from the National Longitudinal Mortality Study, 1979-1989

We evaluated the association between potential occupational lead exposure and the risk of brain cancer mortality in the National Longitudinal Mortality Study (NLMS), which is a prospective census-based cohort study of mortality among the noninstitutionalized United States population (1979-1989). The present study was limited to individuals for whom occupation and industry were available (n = 317,968). Estimates of probability and intensity of lead exposure were assigned using a job-exposure matrix (JEM). Risk estimates for the impact of lead on brain cancer mortality were computed using standardized mortality ratio (SMR) and proportional hazards and Poisson regression techniques, adjusting for the effects of age, gender and several other covariates. Brain cancer mortality rates were greater among individuals in jobs potentially involving lead exposure as compared to those unexposed (age- and gender-adjusted hazard ratio (HR) = 1.5; 95% confidence interval (CI) = 0.9-2.3) with indications of an exposure-response trend (probability: low HR = 0.7 (95% CI = 0.2-2.2), medium HR = 1.4 (95% CI = 0.8-2.5), high HR = 2.2 (95% CI = 1.2-4.0); intensity: low HR = 1.2 (95% CI = 0.7-2.1), medium/high HR = 1.9 (95% CI = 1.0-3.4)). Brain cancer risk was greatest among individuals with the highest levels of probability and intensity (HR = 2.3; 95% CI = 1.3-4.2). These findings provide further support for an association between occupational lead exposure and brain cancer mortality, but need to be interpreted cautiously due to the consideration of brain cancer as one disease entity and the absence of biological measures of lead exposure.     

Kidney cancer and occupational exposure to asbestos: a meta-analysis of occupational cohort studies

Objective: To study the risk of kidney cancer following asbestos exposure.Methods: We carried out a meta-analysis of the results of cohort studies of workers predominantly exposed to asbestos. We contacted the authors of 70 cohort studies; published results were available from the reports of 10 cohorts; we obtained the relevant information for an additional 27 cohorts.Results: The studies included in the analysis comprised a total of 169 kidney cancer deaths and 69 incident cases. The overall pooled standardized mortality ratio (SMR) of kidney cancer was 1.1, with a 95% confidence interval (95% CI) of 0.9–1.3. The pooled SMR was higher for workers with undefined asbestos exposure (SMR 1.2, 95% CI 0.9–1.6) than for workers with either predominant chrysotile (SMR 0.9, 95% CI 0.7–1.3) or some amphibole (SMR 0.96, 95% CI 0.6–1.5) exposure. Studies with published results had higher SMRs than studies for which information was obtained from the authors. Studies with high asbestos exposure and an elevated SMR of lung cancer tended to show an increased risk of kidney cancer.Conclusions: It is unlikely that asbestos exposure is responsible for an important increase in kidney cancer risk; however, high asbestos exposure might entail a small increase in risk.     

A cohort study of cancer mortality among Biology Research Laboratory workers in The Netherlands

OBJECTIVE: To examine cancer mortality among persons employed in biology research institutes. METHOD: A historical cohort study was undertaken in the Netherlands. The cohort, comprising 7307 laboratory workers employed by the four participating institutes between 1960 and 1992, was followed for mortality from 1960 to 1995 (median follow-up time 16.5 years). Causes of death were obtained for 98% of all deaths. Cancer mortality in the cohort was compared with that in the general population by computation of the standardized mortality ratio (SMR). The Cox proportional hazards model was used to compare cancer mortality among laboratory workers with that in an internal reference population consisting of unexposed research personnel (n = 2,404). RESULTS: All-cause mortality among laboratory workers was significantly lower than that in the general population. Total cancer mortality and lung cancer mortality were also significantly decreased (SMR = 0.8; 95% confidence interval CI = 0.7-0.9 and SMR = 0.7; 95% CI = 0.6-0.9), respectively. However, when compared to the internal reference population, laboratory workers had a slightly increased cancer mortality (relative risk (RR) = 1.3 95% CI = 0.9-1.9). Among men, a 2.5-fold (95% CI = 1.0-6.3) increase of lung cancer mortality was observed which could not be explained by differences in smoking habits. Lung cancer mortality increased with longer follow-up. Results with regard to a priori defined fields of research showed significantly increased cancer mortality (in particular from lung cancer) for men working in genetics (RR = 3.8), virology (RR = 4.1) and plant physiology (RR = 2.1). CONCLUSION: Laboratory workers have a favorable cancer mortality pattern as compared to the general population. However, this favorable pattern disappears when a comparison is made with a control group of unexposed research personnel. The excess lung cancer mortality among male laboratory workers was concentrated in certain fields of research, which warrants further research to identify specific exposures related to the increased risk.     

Impact of radiation therapy and/or chemotherapy on the risk for a second malignancy after breast cancer

The risk of any second malignancy was determined for all patients treated for a primary cancer of the breast without evidence of distant metastasis at Duke University Medical Center between 1970 and 1981. The incidence, 10-year actuarial risk (AR), and relative risk (RR) of a second malignancy developing were calculated for the 407 patients who were treated with surgery alone, 226 who were treated with surgery followed by adjuvant chemotherapy (CT), 140 who were treated with surgery plus adjuvant radiation therapy (RT), and 308 who received all three modalities (CRT). The AR of a subsequent cancer (8.4% for CRT, 8.7% for CT, 8.7% for RT, and 11.7% for surgery only patients) did not differ significantly between treatment groups. The overall second cancer RR was 1.0% after CRT (95% confidence interval [CI], 0.4 to 2.0), 1.3% after RT (95% CI, 0.6 to 2.5), 1.6% after CT (95% CI, 0.9 to 2.6), and 1.7% after surgery alone (95% CI, 1.2 to 2.4). Contralateral breast cancers (RR of 4.2%; 95% CI, 2.7 to 6.3) account for the statistically significant excess of second malignancies among the surgery alone patients. The AR for contralateral breast cancer in the surgery group was higher than in either group receiving CT (P less than 0.01), but was not significantly different from the RT group. The RR for solid tumors other than breast cancer was not significantly different from unity in any of the treatment groups. The RR for acute leukemia was 16.7% in the CRT group (95% CI, 0.2 to 92.7), 11.1% in the CT group (95% CI, 0.1 to 61.8), 10.0% in the surgery alone group (95% CI, 1.1 to 36.1), and 0.0% in the RT group (95% CI, 0.0 to 61.1). This study indicated that inclusion of RT and/or CT in the initial treatment of breast cancer did not impact negatively on patients' overall risk for a subsequent malignancy during the first decade after therapy, and that adjuvant CT with or without RT may decrease their risk of a contralateral breast cancer.     

The relationship between alcohol use and risk of breast cancer by histology and hormone receptor status among women 65-79 years of age.

Alcohol consumption is associated with a moderate increase in breast cancer risk, possibly because alcohol increases estrogen levels in blood. Certain types of breast carcinomas are more hormonally responsive than others, including those that have a lobular histology or are hormone receptor positive, but few studies evaluating alcohol use and breast cancer risk have stratified results by histology or estrogen receptor (ER)/progesterone receptor (PR) status. We conducted a population-based case-control study of women 65-79 years of age in western Washington State. Women (975) diagnosed with invasive breast cancer during 1997-1999 were compared with 1007 controls. Ever-use of alcohol over the past 20 years was associated with a 1.3-fold [95% confidence interval (CI), 1.0-1.5] increased risk of breast cancer, although this increase was primarily limited to women who consumed > or =30.0 g/day of alcohol [odds ratio (OR), 1.7; 95% CI, 1.1-2.6]. Differences in risk by histology were observed: ever-use of alcohol was associated with a 1.8-fold (95% CI, 1.3-2.5) increased risk of lobular cancer but only a 1.2-fold (95% CI, 0.9-1.4) increased risk of ductal cancer. Ever-users of alcohol had an increase in risk of ER+/PR+ tumors (OR, 1.3; 95% CI, 1.1-1.7), but no change in their risks of ER+/PR- or ER-/PR- tumors. Alcohol use appears to be more strongly associated with risk of lobular carcinomas and hormone receptor-positive tumors than it is with other types of breast cancer. These results are consistent with there being an underlying hormonal basis for the known association between alcohol use and breast cancer incidence.     

Cancer risk after radiotherapy for breast cancer

Among women with breast cancer, we compared the relative and absolute rates of subsequent cancers in 1541 women treated with radiotherapy (RT) to 4570 women not so treated (NRT), using all registered in the Swiss Vaud Cancer Registry in the period between 1978 and 1998, and followed up to December 2002. Standardised incidence ratios (SIRs) and the corresponding 95% confidence intervals (CIs) were based on age- and calendar year-specific incidence rates in the Vaud general population. There were 11 lung cancers in RT (SIR = 1.40; 95% CI: 0.70-2.51) and 17 in NRT women (SIR = 0.76; 95% CI: 0.44-1.22), 72 contralateral breast cancers in RT (SIR = 1.85; 95% CI: 1.45-2.33) and 150 in NRT women (SIR = 1.38; 95% CI: 1.16-1.61), and 90 other neoplasms in RT (SIR = 1.37; 95% CI: 1.10-1.68) and 224 in NRT women (SIR = 1.05; 95% CI: 0.91-1.19). Overall, there were 173 second neoplasms in RT women (SIR = 1.54, 95% CI: 1.32-1.78) and 391 among NRT women (SIR = 1.13, 95% CI: 1.02-1.25). The estimates were significantly heterogeneous. After 15 years, 20% of RT cases vs 16% of NRT cases had developed a second neoplasm. The appreciable excess risk of subsequent neoplasms after RT for breast cancer must be weighed against the approximately 5% reduction of breast cancer mortality at 15 years after RT.     

Cancer mortality after kidney transplantation: A multicenter cohort study in Italy

Kidney transplant (KT) recipients are known to be at risk of developing several cancer types; however, cancer mortality in this population is underinvestigated. Our study aimed to assess the risk of cancer death among Italian KT recipients compared to the corresponding general population. A cohort study was conducted among 7373 individuals who underwent KT between 2003 and 2020 in 17 Italian centers. Date and cause of death were retrieved until 31 December 2020. Indirect standardization was used to estimate standardized mortality ratios (SMRs) and corresponding 95% confidence intervals (CIs). Cancer was the most common cause of death among the 7373 KT recipients, constituting 32.4% of all deaths. A 1.8-fold excess mortality (95% CI: 1.59-2.09) was observed for all cancers combined. Lymphomas (SMR = 6.17, 95% CI: 3.81-9.25), kidney cancer (SMR = 5.44, 95% CI: 2.97-8.88) and skin melanoma (SMR = 3.19, 95% CI: 1.03-6.98) showed the highest excess death risks. In addition, SMRs were increased about 1.6 to 3.0 times for cancers of lung, breast, bladder and other hematopoietic and lymphoid tissues. As compared to the general population, relative cancer mortality risk remained significantly elevated in all age groups though it decreased with increasing age. A linear temporal increase in SMR over time was documented for all cancers combined (P < .01). Our study documented significantly higher risks of cancer death in KT recipients than in the corresponding general population. Such results support further investigation into the prevention and early detection of cancer in KT recipients.     

Mortality from cancer and other causes in parents of children with cancer: a population-based study in Piedmont, Italy.

This population-based study (the largest on this issue conducted in Southern Europe) has examined mortality among the parents of 2622 children diagnosed with cancer in Piedmont during 1967-1994. Parents were followed up from the date of the index child's birth until the end of 2000, yielding a total of 118 090.7 person-years of observation. Standardized mortality ratios (SMRs) were estimated using mortality rates for the whole population of Piedmont as the reference. Among mothers, total mortality was similar to that expected [SMR 1.02, 95% confidence interval (CI) 0.85-1.23, 117 cases]. A reduced risk of mortality was seen in fathers (SMR 0.91, 95% CI 0.81-1.02, 293 cases); this was largely due to causes other than cancer and the reduction in risk disappeared after the index child's death (SMR 0.98, 95% CI 0.84-1.15, 168 cases). Deaths from cancers of the lymphohaematopoietic system were in excess among mothers (SMR=2.13, 95% CI 1.02-3.92, 10 cases) and breast cancer deaths were in excess specifically among mothers of leukaemic children (SMR 2.32, 95% CI 1.16-4.14, 11 cases). Three mothers dying with breast cancer had index children who had been diagnosed with a bone sarcoma. Parental cancer of the respiratory tract was significantly associated with both tumours of the central nervous system and Hodgkin's lymphoma in the index child. The excess risks identified here may be due to genetic factors or due to parental psychological stress consequent to cancer in a child that may lead to increased mortality either through the direct effects of stress or through consequent changes in lifestyle.     

Mortality among United States radiologic technologists, 1926-90

The possible mortality risk from low level chronic exposures to ionizing radiation was evaluated among 143,517 United States radiologic technologists certified by the American Registry of Radiologic Technologists between 1926-80. This is one of the few occupational studies of primarily women (73 percent) exposed to radiation during their employment. More than 2.8 million person-years of follow-up were accrued through 1990, and 7,345 deaths were identified. A strong healthy-worker effect was observed (standardized mortality ratios [SMR] for all causes and all cancers were 0.69 and 0.79, respectively). Lung cancer (429 deaths) was not increased with available measures of radiation exposure and no significant associations were observed for acute, myelogenous, and monocytic leukemia (74 deaths). Relative to the general population, the standardized mortality ratio (SMR) for female breast cancer was 0.99 (based on 425 deaths); however, breast cancer was significantly elevated relative to all other cancers in a test of homogeneity of SMRs (ratio of SMRs = 1.3, P < 0.0001). Significant risks were correlated with employment before 1940 (SMR = 1.5; 95 percent confidence interval [CI] = 1.2-1.9), when radiation doses were likely highest, and among women certified for more than 30 years (SMR = 1.4, CI = 1.2-1.7) for whom the cumulative exposure was likely greatest. Using an internal referent group, risk increased with duration of certification among the 1,890 women certified before 1940 (P-trend < 0.001). While the findings for breast cancer are consistent with a radiation effect, possible misclassification in exposure (based on number of years certified) and potential confounding associated with reproductive histories preclude a causal conclusion.     

Risk of mortality and cancer incidence in Barrett's esophagus.

BACKGROUND: There are very few prospective follow-up studies of Barrett esophagus (BE) cohorts assessing the risk of extraesophageal cancer incidence or mortality. Such studies are necessary in order to understand the overall risks of cancer and death experienced by patients with BE. METHODS: A cohort of 502 patients with BE were identified at Leeds General Infirmary, England. Mortality and cancer incidence information were provided by the Office for National Statistics. Standardized mortality ratios (SMR) and standardized incidence ratios (SIR) were calculated using indirect standardization. RESULTS: All-cause mortality was found to be elevated in patients with BE [SMR, 1.21; 95% confidence interval (95% CI), 1.06, 1.37] and remained so after esophageal cancers were excluded (SMR, 1.16; 95% CI, 1.01-1.32). Increased mortality risks were also found for malignant neoplasms of the esophagus (SMR, 7.26; 95% CI, 3.87-12.42) and diseases of the digestive system (SMR, 2.03; 95% CI, 1.11-3.40). The remaining disease categories produced no altered risk estimates. Circulatory disease mortality was borderline statistically significant (SMR, 1.24; 95% CI, 1.00-1.52; P = 0.053) for those with a specialized intestinal metaplasia diagnosis of BE. In the cancer incidence analyses, esophageal malignancies (SIR, 8.66; 95% CI, 4.73-14.53) and esophageal adenocarcinomas (SIR, 14.29; 95% CI, 7.13-22.56) were found to be increased in BE. All remaining analyses provided unaltered risks, including that of colorectal cancer. CONCLUSIONS: This study has shown evidence of an increased risk of esophageal cancer incidence and mortality in BE. It has also shown that those who have a histologic BE diagnosis may also have an increased risk of circulatory disease mortality.     

Population-density and county-level variation in breast cancer mortality rates among white women residing in the Northeastern and Southern United States

OBJECTIVE: We assessed the contribution of variation in risk factor prevalence to population-density and county-level variation in breast cancer mortality rates. METHODS: In 1995 we collected risk factor information in a telephone interview of a random digit dialed sample of: (1) 1241 women from counties in the upper and lower tertiles of population density as of 1970 in the Northeast and South of the United States (Design A); (2) 2492 women from counties in the upper and lower tertiles of 1970-1979 breast cancer mortality rates in the four populations from Design A, and; (3) 276 women in Nassau County in New York State. We calculated 1990-94 mortality ratios (MRs) adjusted for breast cancer risk factors. RESULTS: The high/low population-density fully-adjusted MRs in women > or = 55 years were 1.01 (95% CI 0.9-1.2) and 1.00 (95% CI 0.8-1.2). The fully-adjusted MRs for high versus low mortality counties ranged from 0.95 (95% CI 0.8-1.2) to 1.29 (95% CI 1.0-1.6) in women > or = 55 years. CONCLUSIONS: Differences in risk factor prevalence explained higher rates in high-density versus low-density areas in older women. Modest elevations in the adjusted high/low breast cancer MRs among older women in certain groups of counties may reflect unidentified risk factors but more likely are due to chance.     

Mortality after exposure to polychlorinated biphenyls and polychlorinated dibenzofurans: A meta‐analysis of two highly exposed cohorts

Both Yucheng and Yusho were events of accidental exposure to highly doses of polychlorinated biphenyls and dibenzofurans in Asian people. Mortality experiences caused by various diseases were reported in both cohorts with similar and dissimilar findings. We thus conducted a meta‐analysis of two cohorts to reevaluate the effects of PCBs and PCDFs on major causes of mortalities. Two recently updated Yucheng and Yusho mortality studies were included. For selected diseases, standardized mortality ratios (SMR) and 95% confidence intervals (95% CI) were extracted. Meta‐analyses were conducted using a random‐effects model only when heterogeneity (I² > 50% and/or p value <0.10 by the Q test) was not found. A total of 1,803 Yucheng subjects (male, N = 830; female, N = 973) with 48,751 person‐years of follow‐up and 1,664 Yusho subjects (male, N = 860; female, N = 804) with 50,773 person‐years are included. An increase in all‐cause mortality (pooled SMR=1.2, 95% CI: 1.1–1.3, I² = 0.0%), all cancers (pooled SMR=1.3, 95% CI: 1.1–1.6, I² = 0.0%), lung cancer (pooled SMR=1.7, 95% CI: 1.2–2.3, I² =0.0%), heart disease (pooled SMR=1.3, 95% CI: 1.0–1.7, I² = 43.4%) and hepatic disease (pooled SMR=1.9, 95% CI: 1.3–2.8, I² = 0.0%) were found in pooled males. Significant elevation from liver cancer was found in pooled females (pooled SMR=2.0, 95% CI: 1.1–3.6, I² = 0.0%). This meta‐analysis of Yucheng and Yusho cohorts showed similar elevation from all cancer, lung cancer, heart disease and hepatic disease mortalities in exposed men. Furthermore, a new finding of elevated liver cancer mortality in exposed women was identified.     

Incidence of malignant tumours in relatives of BRCA1 and BRCA2 germline mutation carriers

We investigated cancer incidence between 1958 and 1995 in 1873 individuals belonging to 29 consecutively identified BRCA1 and 20 BRCA2 associated families from Southern Sweden using data from parish and local tax authorities, as well as the Swedish Cancer Registry, Cause of Death Registry and Census Registry. 150 malignant tumours were analysed from 1145 relatives in the BRCA1 families and 87 tumours were analysed from 728 relatives in the BRCA2 families. After excluding index cases which led to the mutation analysis, the incidence for all malignant tumours was significantly increased for both BRCA1- standardised morbidity rate, SMR, 1.98, 95% confidence interval (CI) 1.59-2.45; P < 0.0001 and BRCA2- (SMR 1.79, 95% CI 1.35-2.31; P < 0.0001) associated family members. For women in BRCA1-associated families, the incidence of breast cancer (SMR 3.76, 95% CI 2.29-5.80, P < 0.0001), ovarian cancer (SMR 15.49, 95% CI 9.46-23.92, P < 0.0001), stomach cancer (SMR 5.86, 95% CI 1.60-15.01, P = 0.005) were significantly increased. Amongst men only invasive squamous cell cancer of the skin was significantly increased (SMR 6.02, 95% CI 1.96-14.05, P = 0.002). In BRCA2 associated families, female breast cancer (SMR 3.03, 95% CI 1.61-5.18, P = 0.0005) was increased after exclusion of index cases. If these were included, ovarian cancer (SMR 5.16, 95% CI 1.89-11.24, P = 0.001), invasive cervical cancer (SMR 4.21, 95% CI 1.15-10.79, P = 0.016), male breast cancer (SMR 290.52, 95% CI 125.42-572.43, P < 0.0001), and prostate cancer (SMR 2.21, 95% CI 0.89-4.56, P = 0.042) were significantly increased. The increased risk for ovarian cancer in BRCA2 related families were limited to the cases leading to mutation analysis. Our data suggest that apart from breast and ovarian cancer, the incidence of other cancer types do not appear to be greatly increased in BRCA1- and BRCA2-associated families and does not warrant specific clinical follow-up in carriers.