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Biomedical subjects

H H Storm

Publications and source records attributed to H H Storm.

At least 91 records · Page 5Linked to original sources

Cancer risk among staff at two radiotherapy departments in Denmark.

In comparison with the general Danish population, the relative risk (RR) for cancer among staff members employed in two radiotherapy departments in Denmark during 1954-1982 and alive on 1 April 1968 was assessed by linkage to the Danish Cancer Registry. All staff had been monitored with film dosimeters for exposure to radiation. The study cohort consisted of 4151 persons, accruing 49553 person-years at risk. The collective radiation dose was 76.54 manSv and the mean dose 18.4 mSv. A total of 163 cancer cases were observed with 152.3 expected. The risks for cancers usually considered to be radiogenic were not elevated. A significant excess of prostatic cancer was observed (five cases, relative risk, 6.02; 95% confidence interval, 1.94-14.06); this is likely to be a chance finding. No relation was observed between radiation dose or years of exposure and cancer risk, but a weak non-significant increase in risk with time since first exposure was seen.

Adult↗

Radiation dose and breast cancer risk in patients treated for cancer of the cervix.

The relationship between breast cancer and radiation treatment for cervical cancer was evaluated in an international study of 953 women who subsequently developed breast cancer and 1,806 matched controls. Radiation doses to the breast (average 0.31 Gy) and ovaries (average 32 Gy) were reconstructed for exposed subjects on the basis of their original radiotherapy records. Overall, 88% of the breast cancer cases and 89% of the controls received radiation treatment [relative risk (RR) = 0.88; 95% confidence interval (CI) = 0.7-1.2]. Among women with intact ovaries (561 cases, 1,037 controls), radiotherapy was linked to a significant 35% reduction in breast cancer risk, attributable in all likelihood to the cessation of ovarian function. Ovarian doses of 6 Gy were sufficient to reduce breast cancer risk but larger doses did not reduce risk further. This saturation-type response is probably due to the killing of a critical number of ovarian cells. Cervical cancer patients without ovaries (145 cases, 284 controls) were analyzed separately because such women are at especially low natural risk for breast cancer development. In theory, any effect of low-dose breast exposure, received incidentally during treatment for cervical cancer, should be more readily detectable. Among women without ovaries, there was a slight increase in breast cancer risk (RR = 1.07; 95% CI = 0.6-2.0), and a suggestion of a dose response with the RR being 1.0, 0.7, 1.5 and 3.1 for breast doses of 0, 0.01-0.24, 0.25-0.49 and 0.50+ Gy, respectively. However, this trend of increasing RR was not statistically significant. If low-dose radiation increases the risk of breast cancer among women over age 40 years, it appears that the risk is much lower than would be predicted from studies of younger women exposed to higher doses.

Adult↗

Multiple primary cancers of the breast, endometrium and ovary.

The association between cancers of the breast, endometrium and ovary is reviewed, using mainly population-based data from the cancer registries in Denmark and Connecticut, U.S.A. Breast cancer patients had an approximately three-fold increased risk of developing a cancer in the contralateral breast. The risk of breast cancer was also elevated following cancers of the corpus uteri and ovary, with relative risk (RR) estimates of about 1.5 from 1 to 4 years after the diagnosis of the first primary cancer. An increased risk of cancer of the corpus uteri subsequent to breast cancer was found in Connecticut, but not in Denmark. After an ovarian cancer, the risk of cancer of the corpus uteri was also elevated (RR = 1.6-2.3). An increased risk of ovarian cancer was observed subsequent to breast cancer (RR = 1.3-1.7), whereas the ovarian cancer risk decreased with time since the diagnosis of a cancer of the corpus uteri, probably reflecting treatment involving oophorectomy.

Breast Neoplasms↗

Thyroid cancer: incidence, mortality and histological pattern in Denmark.

In Denmark, as in many other countries, the incidence of thyroid cancer is increasing, while mortality from this disease is decreasing. The proportionate distribution of cell types is similar to that seen elsewhere. The increase in incidence in other countries has been attributed to the increased use of radiation for benign conditions of the head and neck. This cannot explain the increase in incidence in Denmark, and other factors may contribute importantly to the changing picture of thyroid cancer.

Adolescent↗

Second primary cancer after treatment for cervical cancer. Late effects after radiotherapy.

Using data from the population-based Danish Cancer Registry, the relative risk (RR) of second primary cancer was assessed among 24,970 women with invasive cervical cancer (1943-1982) and 19,470 women with carcinoma in situ of the cervix. The analysis was stratified according to treatment with (+) and without (-) radiation. For all second primaries combined, a RR+ = 1.1 (95% confidence interval (CI) = 1.06-1.18) and a RR- = 1.3 (95% CI = 1.13-1.40) was observed after invasive cervical cancers and a RR+ = 3.5 (95% CI = 1.4-7.2) and RR- = 1.1 (95% CI = 0.7-1.6) following in situ cancer. The small overall excess of second primary cancer is accounted for by an increase of some cancers such as lung, bladder, and a concurrent decrease in others such as breast. Although not statistically different from nonirradiated, the RR increased with time since treatment among irradiated invasive cervical cancer patients in organs close to and at intermediate distance from the cervix, reaching a maximum after 30 or more years of follow-up (RR = 1.9; 95% CI = 1.4-2.5). Altogether, for these sites an excess of 64 cases per 10,000 women per year were attributable to radiation among survivors of 30+ years. The highest risks among long-term survivors were observed for the following: other genital organs (RR = 5.8; 95% CI = 1.8-13.0) bladder (RR = 5.5; 95% CI = 2.8-9.5), connective tissue (RR = 3.3; 95% CI = 0.4-12.0), stomach (RR = 2.5; 95% CI = 1.1-4.7) and rectum (RR = 2.4; 95% CI = 1.1-4.6). A significant deficit of risk for breast cancer (RR = 0.7, 95% CI = 0.6-0.8) was observed for 10+ years, may be attributable to the effect of ovarian ablation by radiotherapy. It is speculated that the same effect also may explain the observed deficits of brain tumors (RR = 0.6; 95% CI = 0.4-1.0) and skin melanomas (RR = 0.6; 95% CI = 0.3-1.0). It is concluded that cancers attributable to radiation, apart from acute nonlymphocytic leukemias, tend to appear late (10 or more years after radiotherapy), and that the risk remains elevated for more than 30 years.

Carcinoma in Situ↗

Completeness of cancer registration in Denmark 1943-1966 and efficacy of record linkage procedures.

The completeness of registration in the national, population based cancer registry in Denmark was evaluated for the first 23 years (1943-1966) of operation. The registry was linked to a complementary data file on 5674 Danish invasive cervical cancer patients enrolled in an international, clinical follow-up study on the basis of identifying information including name, month and year of birth and date of cervical cancer diagnosis. The cancer register had a deficit of 2.2% (95% confidence interval, 1.8-2.6) cervical cancer patients; this figure is low compared to those of other cancer registers. Some 80% of the identified cases were retrieved by computerized matching alone, and an additional 15% were identified by combining computerized and visual matching procedures. Scrutiny of non-retrieved case records revealed that major errors in the identifiers of the cohort used for linkage were responsible for inability to identify an additional 1.7%. The presents study underlines the importance of meticulously recorded, high quality key identifiers in registers, and linkage of cohorts to establish the presence or absence of disease.

Denmark↗

Radiation dose and second cancer risk in patients treated for cancer of the cervix.

The risk of cancer associated with a broad range of organ doses was estimated in an international study of women with cervical cancer. Among 150,000 patients reported to one of 19 population-based cancer registries or treated in any of 20 oncology clinics, 4188 women with second cancers and 6880 matched controls were selected for detailed study. Radiation doses for selected organs were reconstructed for each patient on the basis of her original radiotherapy records. Very high doses, on the order of several hundred gray, were found to increase the risk of cancers of the bladder [relative risk (RR) = 4.0], rectum (RR = 1.8), vagina (RR = 2.7), and possibly bone (RR = 1.3), uterine corpus (RR = 1.3), cecum (RR = 1.5), and non-Hodgkin's lymphoma (RR = 2.5). For all female genital cancers taken together, a sharp dose-response gradient was observed, reaching fivefold for doses more than 150 Gy. Several gray increased the risk of stomach cancer (RR = 2.1) and leukemia (RR = 2.0). Although cancer of the pancreas was elevated, there was no evidence of a dose-dependent risk. Cancer of the kidney was significantly increased among 15-year survivors. A nonsignificant twofold risk of radiogenic thyroid cancer was observed following an average dose of only 0.11 Gy. Breast cancer was not increased overall, despite an average dose of 0.31 Gy and 953 cases available for evaluation (RR = 0.9); there was, however, a weak suggestion of a dose response among women whose ovaries had been surgically removed. Doses greater than 6 Gy to the ovaries reduced breast cancer risk by 44%. A significant deficit of ovarian cancer was observed within 5 years of radiotherapy; in contrast, a dose response was suggested among 10-year survivors. Radiation was not found to increase the overall risk of cancers of the small intestine, colon, ovary, vulva, connective tissue, breast, Hodgkin's disease, multiple myeloma, or chronic lymphocytic leukemia. For most cancers associated with radiation, risks were highest among long-term survivors and appeared concentrated among women irradiated at relatively younger ages.

Female↗

The evaluation of trends in soft tissue sarcoma according to diagnostic criteria and consumption of phenoxy herbicides.

The possible association between exposure to phenoxy herbicides and development of soft tissue sarcomas has been studied in both case-control and cohort studies. In these studies soft tissue sarcoma cases have been identified from either deaths with malignant neoplasms of the connective tissue (ICD-8 171) as the underlying cause of death, from incident cancer cases with the same topography code, or from incident cases of extraskeletal sarcomas, excluding lympho and reticulosarcomas. The current study shows that the choice of source material has a considerable influence on the registered occurrence of soft tissue sarcomas in a well defined population. In 1978 to 1982 an annual number of 33 deaths from ICD-8 171 was registered in Denmark, whereas the annual number of diagnosed extraskeletal sarcomas was 231. The distribution over histologic types differed between tumours coded to the connective tissue and extraskeletal sarcomas coded to specific organs. Furthermore, during the period 1943 to 1982 the mortality from ICD-8 171 increased slightly, whereas the incidence from all extraskeletal sarcomas decreased slightly, except for males since 1970. Time trends based on any of the three source materials should, however, be interpreted with caution.

2,4,5-Trichlorophenoxyacetic Acid↗

Radiation dose and leukemia risk in patients treated for cancer of the cervix.

To quantify the risk of radiation-induced leukemia and provide further information on the nature of the relationship between dose and response, a case-control study was undertaken in a cohort of over 150,000 women with invasive cancer of the uterine cervix. The cases either were reported to one of 17 population-based cancer registries or were treated in any of 16 oncologic clinics in Canada, Europe, and the United States. Four controls were individually matched to each of 195 cases of leukemia on the basis of age and calendar year when diagnosed with cervical cancer and survival time. Leukemia diagnoses were verified by one hematologist. Radiation dose to active bone marrow was estimated by medical physicists on the basis of the original radiotherapy records of study subjects. The risk of chronic lymphocytic leukemia, one of the few malignancies without evidence for an association with ionizing radiation, was not increased [relative risk (RR) = 1.03; n = 52]. However, for all other forms of leukemia taken together (n = 143), a twofold risk was evident (RR = 2.0; 90% confidence interval = 1.0-4.2). Risk increased with increasing radiation dose until average doses of about 400 rad (4 Gy) were reached and then decreased at higher doses. This pattern is consistent with experimental data for which the down-turn in risk at high doses has been interpreted as due to killing of potentially leukemic cells. The dose-response information was modeled with various RR functions, accounting for the nonhomogeneous distribution of radiation dose during radiotherapy. The local radiation doses to each of 14 bone marrow compartments for each patient were incorporated in the models, and the corresponding risks were summed. A good fit to the observed data was obtained with a linear-exponential function, which included a positive linear induction term and a negative exponential term. The estimate of the excess RR per rad was 0.9%, and the estimated RR at 100 rad (1 Gy) was 1.7. The model proposed in this study of risk proportional to mass exposed and of risk to an individual given by the sum of incremental risks to anatomic sites appears to be applicable to a wide range of dose distributions. Furthermore, the pattern of leukemia incidence associated with different levels of radiation dose is consistent with a model postulating increasing risk with increasing exposure, modified at high doses by increased frequency of cell death, which reduces risk.

Adult↗