| 1. |
- Eriksson, Mikael, 1951-
(författare)
-
Epidemiological studies on multiple myeloma
- 1992
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Multiple myeloma is a painful and uncurable malignant disease with an increasing incidence and mortality in several countries, e.g., Sweden. Some factors are suspected to be of aetiological significance, such as ionising radiation and chronic antigenic stimulation in certain inflammatory diseases. A familial factor has also been indicated. Furthermore, some studies have demonstrated farming as an occupation entailing an increased risk for the disease.The aim of this investigation was to further elucidate the impact of different aetiological factors in relation to multiple myeloma. The knowledge of aetiology is always a prerequisite for prevention.A case-control study on multiple myeloma was performed in a high-inddence area, the northern part of Sweden. One part of this study dealt with occupations and different exposures. The results supported farming as being an occupation with an increased risk. Within farming two kinds of pesticides, phenoxyacetic adds and DDT, and contact with certain domestic animals, i.e., cattle, horses and goats, were assodated with multiple myeloma.Farming as a risk factor was also confirmed by a register-based linkage study using the Swedish Cancer Environment Register. In this study a time trend was indicated, with increasing standardized inddence ratios over the different time periods studied.Another part of the case-control study showed that rheumatoid arthritis entailed an increased risk for multiple myeloma, a finding earlier suggested from register-based linkage studies, but not from any çase-control study.A third part of the case-control study indicated an increased risk for multiple myeloma if any first-degree relative had a history of haematological malignancy, or other malignant tumour, espedally prostatic cancer, brain tumour, and renal cancer.A case study encompassing 942 patients with haematological malignandes in the county of Jämtland, Sweden, during a 22-year period showed that about 5% of the patients had at least one relative who also suffered from such a disease. An espedally strong familial occurrence was found in the group of chronic lymphoprohferative diseases, including multiple myeloma.
|
|
| 2. |
- Hallquist, Arne, 1948-
(författare)
-
Thyroid cancer : studies on etiology and prognosis
- 1994
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Thyroid cancer constitutes about 1% of all malignant tumours and the incidence is increasing in Sweden. It is rare in children before the age of 10. During puberty the female to male ratio increases to be two to three times more common in females. The ratio remains constant until menopause and thereafter declines. The etiology of this gender-dependent incidence difference is unclear. Ionizing radiation is the only well-established risk factor for the disease, while the impact of other etiological factors is not clear.A retrospective study based upon medical records of 218 females and 91 males with papillary, mixed or follicular types of thyroid cancer was conducted. Prognostic factors were compared by multivariate analysis using Cox's semiparametric hazard model. Differences in prognosis between women and men were found. There was a higher relapse rate and mortality risk among men. Distant metastasis, age >50 years, regional lymph node metastasis, low or moderate differentiation, and tumour related symptoms at diagnosis were also independent factors related to increased tumour mortality risk.A population-based case-control study including 180 cases and 360 controls was carried out to identify risk factors for thyroid cancer. Information on exposure was obtained by mailed questionnaires. The first part of the study investigated connections between medical ionizing radiation and thyroid cancer. The results showed that diagnostic X rays were a significant risk factor for papillary thyroid cancer in women between 20 and 50 years at diagnosis. Exposure to iodine-131 caused no increased risk for thyroid cancer. The result supports that external radiotherapy is a risk factor for thyroid cancer in women.The second part of the case-control study dealt with occupation and different exposures. Work with diagnostic X-ray investigations and work as a lineman was associated with thyroid cancer. Exposure to impregnating agents increased the risk.The third part of this study showed that one pregnancy increased the risk for papillary thyroid cancer. A medical history of asthma or allergy decreased the risk.Another case-control study using medical records as the source for assessment of exposure gave a non significantly increased risk for thyroid cancer in patients who had been treated with external radiotherapy including the thyroid gland.
|
|
