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Biomedical subjects

J D Boice

Publications and source records attributed to J D Boice.

At least 127 records · Page 7Linked to original sources
PubMed1992

Cancer mortality after iodine-131 therapy for hyperthyroidism.

Cancer mortality was studied in 10,552 Swedish hyperthyroid patients treated with 131I between 1950 and 1975. The patients were matched with the Swedish Cause-of-Death Register and the cases of 977 patients who died from cancer or leukemia were studied. The patients had been followed up for an average of 15 years (range 0 to 35 years), and the overall standardized mortality ratio (SMR) was 1.09 [95% confidence interval (CI) = 1.03 to 1.16], with a higher risk for women. The highest mortality was seen during the first year after exposure (SMR = 1.15) and decreased for the following 9 years (SMR = 1.04). The risk of dying from a cancer in the digestive tract and respiratory organs was significantly elevated more than 10 years after exposure, as was the overall cancer mortality (SMR = 1.14). No increased risk was seen for leukemia, bladder cancer or breast cancer. Younger patients and those receiving 131I at higher activity had higher SMRs than older patients and those receiving lower activity. Patients with toxic nodular goiter had higher risk than those with Graves' disease. The lack of increasing mortality over time and with increasing activity of 131I administered argues against a carcinogenic effect of 131I. However, in the case of cancers of the stomach, the 131I exposure could have contributed to the excess mortality from these cancers.

Age Factors↗
PubMed1992

Cancer in the contralateral breast after radiotherapy for breast cancer.

BACKGROUND: Patients with breast cancer have a threefold increase in the risk that a second breast cancer will develop. Radiation treatment for the initial cancer can result in moderately high doses to the contralateral breast, possibly contributing to this heightened risk. METHODS: We conducted a case-control study in a cohort of 41,109 women diagnosed with breast cancer between 1935 and 1982 in Connecticut. We reviewed the medical records of 655 women in whom a second breast cancer developed five or more years after the initial tumor and compared their radiation exposure with that of 1189 matched controls from the cohort who did not have a second cancer. The dose of radiation to the contralateral breast was estimated from the original radiotherapy records. Among the exposed women, the average radiation dose to the contralateral breast was 2.82 Gy (maximum, 7.10). RESULTS: Overall, 23 percent of the women who had a second breast cancer and 20 percent of the controls had received radiotherapy (relative risk of a second breast cancer associated with radiotherapy, 1.19). Among women who survived for at least 10 years, radiation treatment was associated with a small but marginally significant elevation in the risk of a second breast cancer (relative risk, 1.33); the risk increased significantly with the dose of radiation. An increase in risk in association with radiotherapy was evident only among women who were under 45 years of age when they were treated (relative risk, 1.59) and not among older women (relative risk, 1.01). CONCLUSIONS: Radiotherapy for breast cancer contributes little to the already high risk of a second cancer in the opposite breast. Fewer than 3 percent of all second breast cancers in this study could be attributed to previous radiation treatment; the risk, however, was significantly increased among women who underwent irradiation at a relatively young age (less than 45 years). Radiation exposure after the age of 45 entails little, if any, risk of radiation-induced breast cancer.

Adult↗
PubMed1992

A health survey of radiologic technologists.

A health survey of more than 143,000 radiologic technologists is described. The population was identified from the 1982 computerized files of the American Registry of Radiologic Technologists, which was established in 1926. Inactive members were traced to obtain current addresses or death notifications. More than 6000 technologists were reported to have died. For all registrants who were alive when located, a detailed 16-page questionnaire was sent, covering occupational histories, medical conditions, and other personal and lifestyle characteristics. Nonrespondents were contacted by telephone to complete an abbreviated questionnaire. More than 104,000 responses were obtained. The overall response rate was 79%. Most technologists were female (76%), white (93%), and employed for an average of 12 years; 37% attended college, and approximately 50% never smoked cigarettes. Radiation exposure information was sought from employer records and commercial dosimetry companies. Technologists employed for the longest times had the highest estimated cumulative exposures, with approximately 9% with exposures greater than 5 cGy. There was a high correlation between cumulative occupational exposure and personal exposure to medical radiographs, related, in part, to the association of both factors with attained age. It is interesting that 10% of all technologists allowed others to practice taking radiographs on them during their training. Nearly 4% of the respondents reported having some type of cancer, mainly of the skin (1517), breast (665), and cervix (726). Prospective surveys will monitor cancer mortality rates through use of the National Death Index and cancer incidence through periodic mailings of questionnaires. This is the only occupational study of radiation employees who are primarily women and should provide new information on the possible risks associated with relatively low levels of exposure.

Adult↗
PubMed1992

Leukemia, lymphoma, and multiple myeloma following selected medical conditions.

The role of selected prior medical conditions in the etiology of hematopoietic malignancies was examined in a case-control study of members of two regional branches of the Kaiser Permanente Medical Care Program (USA). Past history of chronic infectious, autoimmune, allergic, and musculoskeletal disorders was abstracted from medical records for leukemia (n = 299), non-Hodgkin's lymphoma (NHL, n = 100), and multiple myeloma (n = 175) cases and matched controls (n = 787). Little difference was found between cases and controls for most of the chronic conditions evaluated, including sinusitis, carbuncles, urinary tract infections, pelvic infections, herpes zoster, asthma, rheumatoid arthritis, psoriasis, bursitis, and gout. Only three statistically significant elevated risks were found, i.e., with combined disc disease myeloma among patients with prior eczema and disk and other musculoskeletal conditions, and NHL following tuberculosis. Only two of these associations showed consistent patterns by sex and geographic region (myeloma with eczema and with musculoskeletal conditions). While prior history of eczema and musculoskeletal conditions may slightly increase risk of myeloma, this study provided little if any support for an association of chronic infectious, autoimmune, allergic, and musculoskeletal conditions with subsequent occurrence of the leukemias or NHL. Additionally, these data did not support a role for chronic antigenic stimulation, as defined in previous epidemiologic studies, in the etiology of hematopoietic malignancies.

Aged↗
PubMed1992

Childhood cancer among Swedish twins.

The risk of childhood cancer was evaluated among 35,582 twins born in Sweden between 1952 and 1967. Cancers were identified through linkage with national cancer and mortality registries. Overall, 59 childhood cancers and 41 deaths from cancer occurred before the age of 16. For both sexes combined, the cancer incidence was similar to that in the general population of primarily single-born children (number observed/number expected [O/E] = 1.0, 95 percent confidence interval [CI] = 0.7-1.2). For males under age five, cancer incidence was reduced significantly (O/E = 0.3, CI = 0.1-0.7). There was a substantial increase in all-cause mortality among twins (O/E = 3.7), attributable to a high mortality during the first year of life. Excluding this first year, the O/E for death (all causes) was 1.1 (CI = 1.0-1.3). For cancer mortality of both sexes, the O/E was 0.9 (CI = 0.6-1.2), with no significant reduction of risk in any sex-age group. We conclude that with the possible exception of males aged 0-4 years, the childhood cancer risk of twins appears similar to that of singletons.

Adolescent↗
PubMed1992

Cancer risk following exposure to Thorotrast: overview in relation to a case report.

Radioactive measurements and histopathologic findings are described in a patient administered Thorotrast, a radiographic contrast agent, 36 y prior to death and compared with cancer risks noted in epidemiologic studies. This person [designated as U.S. Uranium Registry (USUR) Case 1001] had prearranged for donation of her body to the USUR and the National Cancer Institute for study. Elevated levels of radioactivity were noted in those organs in which excess cancers have been reported in epidemiologic surveys of Thorotrast-exposed subjects. Hepatic tissue in USUR Case 1001 was estimated to have received an average lifetime absorbed dose of 16.2 Gy, based on radiochemical analyses, consistent with the high risks for liver tumors reported in all studied populations. Thorotrast was present throughout the bone marrow of USUR Case 1001, who died secondary to complications of refractory anemia with excess blasts (RAEB). Elevated risks for acute myeloid leukemia have been noted in Thorotrast patients, and more recently, cases of RAEB and RAEB in transformation have been reported. The thorium decay series includes the bone-seeking radionuclides 224Ra and 228Ra, which have been associated with high risks for osteosarcomas, although the association between Thorotrast and bone cancer is not as convincing. The skeleton of USUR Case 1001, however, contained significant levels of radioactivity. Other tissues evaluated in USUR Case 1001 included lung, eye, kidney, and breast, which did not contain elevated levels of radioactivity.

Aged↗
PubMed1992

Residential radon exposure and lung cancer in Swedish women.

A case-control study was undertaken to investigate the role of residential radon exposure for lung cancer. The study included 210 women with lung cancer diagnosed from 1983-1986 in the county of Stockholm and 191 hospital and 209 population controls. Interviews provided information on lifetime residences and smoking. Radon concentrations measured in 1,573 residences of the study subjects showed a lognormal distribution with arithmetic and geometric means of 127.7 and 96.0 Bq m-3, respectively. Lung cancer risks tended to increase with estimated radon exposure, reaching a relative risk of 1.7 (95% confidence interval: 1.0-2.9) in women having an average radon level exceeding 150 Bq m-3 (4 pCi L-1). Stronger associations were suggested in younger persons and risk estimates appeared to be within the same range as those projected for miners. However, further studies are needed to clarify the level of risk associated with exposure to residential radon.

Air Pollution, Indoor↗
PubMed1991

Thyroid cancer: a lethal endocrine neoplasm.

This conference focuses on the controversies about managing thyroid cancer, emphasizing the possibility that the treatment of patients with potentially fatal thyroid cancer may be improved. Although the mortality rate from thyroid cancer is low, it is the highest among cancers affecting the endocrine glands (excluding the ovary). Exposure to radiation during childhood in the 1930s and 1940s increased the incidence of but not the mortality from thyroid cancer, because these tumors are mainly papillary cancers developing in young adults. These rates may change as the exposed cohort ages. Risk factors that increase mortality include older patient age and the growth characteristics of the tumor at diagnosis, the presence of distant metastases, and cell type (for example, the tall-cell variants of papillary cancer, follicular cancer [to be distinguished from the more benign follicular variant of papillary cancer], medullary cancer, and anaplastic cancer). Local metastases in lymph nodes do not seem to increase the risk for death from papillary cancer, but they do increase the risk for death from follicular and medullary cancer. In the latter, mortality is decreased by the early detection and treatment of patients with the familial multiple endocrine neoplasia syndrome 2a. There are excellent tumor markers for differentiated cancer of the parafollicular and of the follicular cells (serum calcitonin and serum thyroglobulin levels, respectively). Measuring the calcitonin level allows early diagnosis of familial medullary cancer, whereas measuring the thyroglobulin level, although useful only after total thyroidectomy, allows early recognition of recurrence or metastases of papillary or follicular cancer. Initial surgery, protocols for follow-up, and the use of radioiodine for the ablation of any residual thyroid and the treatment of metastatic cancer are discussed. Because these tumors resist currently available chemotherapy regimens, possible ways to increase the effectiveness of radioiodine therapy are considered as are new approaches to treatment.

Carcinoma↗
PubMed1991

Therapeutic radiation at a young age is linked to secondary thyroid cancer. The Late Effects Study Group.

We estimated the risk of thyroid cancer among 9170 patients who had survived 2 or more years after the diagnosis of a cancer in childhood. As compared with the general population, patients had a 53-fold increased risk (95% confidence interval, 34-80). Risk increased significantly with time since treatment for the initial cancer (P = 0.03). Detailed treatment data were obtained for 23 cases and 89 matched controls from the childhood cancer cohort. Sixty-eight % of the thyroid cancers arose within the field of radiation. Radiation doses to the thyroid of greater than 200 cGy were associated with a 13-fold increased risk (95% confidence interval, 1.7-104). The risk of thyroid cancer rose with increasing dose (P less than 0.001), but this was derived almost entirely from the increase from less than 200 to greater than 200 cGy. The risk of thyroid cancer did not decrease, however, at radiation doses as high as 6000 cGy.

Adolescent↗
PubMed1991

Second cancers following non-Hodgkin's lymphoma.

The risk of second malignancies following non-Hodgkin's lymphoma (NHL) was estimated in 29,153 patients diagnosed with NHL between 1973 and 1987 in one of nine areas participating in the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. Compared with the general population, NHL patients were at a significantly increased risk of developing second cancers (observed/expected [O/E] = 1.18; O = 1231). The O/E ratio increased significantly with time to reach 1.77 in 10-year survivors. Significant excesses were noted for acute nonlymphocytic leukemia (O/E = 2.88), cancers of the bladder (O/E = 1.30), kidney (O/E = 1.47), and lung (O/E = 1.57), malignant melanoma (O/E = 2.44), and Hodgkin's disease (O/E = 4.16). Chemotherapy appeared related to subsequent acute nonlymphocytic leukemia (ANLL) and bladder cancer. Radiation therapy was associated with ANLL and possibly cancers of the lung, bladder, and bone. Malignant melanoma was not clearly related to initial NHL treatment.

Antineoplastic Agents↗
PubMed1991

Cancer in populations living near nuclear facilities. A survey of mortality nationwide and incidence in two states.

Reports from the United Kingdom have described increases in leukemia and lymphoma among young persons living near certain nuclear installations. Because of concerns raised by these reports, a mortality survey was conducted in populations living near nuclear facilities in the United States. All facilities began service before 1982. Over 900,000 cancer deaths occurred from 1950 through 1984 in 107 counties with or near nuclear installations. Each study county was matched for comparison to three "control counties" in the same region. There were 1.8 million cancer deaths in the 292 control counties during the 35 years studied. Deaths due to leukemia or other cancers were not more frequent in the study counties than in the control counties. For childhood leukemia mortality, the relative risk comparing the study counties with their controls before plant start-up was 1.08, while after start-up it was 1.03. For leukemia mortality at all ages, the relative risks were 1.02 before start-up and 0.98 after. For counties in two states, cancer incidence data were also available. For one facility, the standardized registration ratio for childhood leukemia was increased significantly after start-up. However, the increase also antedated the operation of this facility. The study is limited by the correlational approach and the large size of the geographic areas (counties) used. It does not prove the absence of any effect. If, however, any excess cancer risk was present in US counties with nuclear facilities, it was too small to be detected with the methods employed.

Adult↗
PubMed1991

Diagnostic x-ray procedures and risk of leukemia, lymphoma, and multiple myeloma.

Exposure to diagnostic x-rays and the risk of leukemia, non-Hodgkin's lymphoma (NHL), and multiple myeloma were studied within two prepaid health plans. Adult patients with leukemia (n = 565), NHL (n = 318), and multiple myeloma (n = 208) were matched to controls (n = 1390), and over 25,000 x-ray procedures were abstracted from medical records. Dose response was evaluated by assigning each x-ray procedure a score based on estimated bone marrow dose. X-ray exposure was not associated with chronic lymphocytic leukemia, one of the few malignant conditions never linked to radiation (relative risk [RR], 0.66). For all other forms of leukemia combined (n = 358), there was a slight elevation in risk (RR, 1.17) but no evidence of a dose-response relationship when x-ray procedures near the time of diagnosis were excluded. Similarly, patients with NHL were exposed to diagnostic x-ray procedures more often than controls (RR, 1.32), but the RR fell to 0.99 when the exposure to diagnostic x-ray procedures within 2 years of diagnosis was ignored. For multiple myeloma, overall risk was not significantly high (RR, 1.14), but there was consistent evidence of increasing risk with increasing numbers of diagnostic x-ray procedures. These data suggest that persons with leukemia and NHL undergo x-ray procedures frequently just prior to diagnosis for conditions related to the development or natural history of their disease. There was little evidence that diagnostic x-ray procedures were causally associated with leukemia or NHL. The risk for multiple myeloma, however, was increased among those patients who were frequently exposed to x-rays.

Adult↗
PubMed1991

Radiation dose and leukaemia risk: general relative risk techniques for dose-response models in a matched case-control study.

Generalized relative risk functions were used to model radiation dose-response information from a large matched case-control study of leukaemia occurring after treatment for cervical cancer. Models suggested by radiobiological theory were investigated and compared to standard analyses of categorical dose-response to the linear model. Local radiation doses to each of fourteen bone marrow compartments for each patient were incorporated into the models, and the corresponding risks were summed. Conditional maximum likelihood methods were used to estimate risk parameters. Unique features of the analysis include modelling both induction and reduction of risk as a function of radiation dose absorbed by different parts of the body within individuals. Detailed statistical aspects of these analyses are presented and discussed.

Adult↗
PubMed1991

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 characteristic 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.

Adolescent↗