PubMed Health⌕ Search

Biomedical subjects

R K Severson

Publications and source records attributed to R K Severson.

At least 19 recordsLinked to original sources
PubMed2001

Trends in the utilization of androgen-deprivation therapy for patients with prostate carcinoma suggest an effect on mortality.

BACKGROUND: After a surge in the incidence of prostate carcinoma in the early 1990s, diminishing rates of mortality became apparent in 1993. This decrease in mortality is unlikely to be explained entirely by treatment with curative intent alone following screen-detected cases, because the time frame between detection and mortality remains relatively brief. METHODS: This study used incidence and initial treatment data from the Detroit area SEER registry between 1973 and 1998 in addition to mortality data covering the Metropolitan Detroit area obtained from the Michigan Department of Community Health. Data for Caucasian and African-American men were analyzed. The use of androgen-deprivation therapy, which evolved during the study period, was evaluated in conjunction with mortality and incidence trend data for consideration of etiologic contributions. RESULTS: The incidence of prostate carcinoma, as noted previously in national data, increased sharply in 1988, peaking in 1992 in Southeast Michigan, whereas mortality rates began to decrease in approximately 1993, with a sustained decrease to the latest recorded data in 1998. These trends were identical in Caucasians and African Americans. A sharp increase in the use of androgen-deprivation therapy began in 1990. This use of androgen-deprivation therapy is high and sustained for patients with early-stage disease, increases for several years, and then diminishes for patients with regional disease. The use also diminished through the 1990s for patients with late-stage disease, paralleling the decrease in the incidence rate for late-stage disease. CONCLUSIONS: The pattern of androgen-deprivation therapy usage was consistent with that for hormonal monotherapy and adjuvant and neoadjuvant therapy. These findings suggest that androgen-deprivation therapy may contribute, along with advances in diagnostic techniques and curative therapy with radiation or surgery, toward decreasing prostate carcinoma mortality rates in Southeast Michigan.

Adult↗
PubMed2001

Conditional median survival of patients with advanced carcinoma: surveillance, epidemiology, and end results data.

BACKGROUND: Conditional survival is clinically useful, particularly for patients with malignant disease who have a poor prognosis. However, there are no published data on the conditional median survival of patients with advanced carcinoma on a population basis. METHODS: Data on 217,573 patients with breast, colorectal, lung, or prostate carcinoma who were newly diagnosed with distant disease between 1973 and 1995 and who were followed through the end of 1997 were extracted from the Surveillance, Epidemiology, and End Results (SEER) data base of the National Cancer Institute. The Kaplan-Meier method was employed to estimate conditional median survival and 95% confidence intervals at 0-5 years after the initial diagnosis. RESULTS: The conditional median survival increased as time elapsed after the initial diagnosis. The increase was slowest and almost leveled off among patients with prostate carcinoma. The median survival of patients with breast carcinoma increased relatively linearly with time, i.e., 5-6 months per year. Conversely, there was a rapid increase in the conditional median survival according to the amount of time since diagnosis for patients with lung and colorectal carcinoma. The trend was most pronounced for patients with colorectal carcinoma. At 5 years after the initial diagnosis, the remaining median survival was longest for patients with colorectal carcinoma, almost 6 years (71.5 months), followed by patients with lung carcinoma (52.5 months), breast carcinoma (42.5 months), and prostate carcinoma (34.5 months). Although race was a correlate with initial survival, gender and age had more impact on late conditional survival. CONCLUSIONS: The conditional median survival provides useful and encouraging information for patients who survive with advanced disease and for healthcare professionals who treat these patients. However, the information should be used carefully, taking the limitations of these data into account.

Adult↗
PubMed2001

Impact of race in lung cancer: analysis of temporal trends from a surveillance, epidemiology, and end results database.

STUDY OBJECTIVES: We analyzed data from a community-based cancer database over a 26-year period in order to characterize clinicopathologic differences between black and white patients with lung cancer, and to identify relevant temporal trends in incidence and survival. DESIGN, SETTING, AND PATIENTS: Data on demographics, stage, histology, and survival were obtained on all black and white patients with primary bronchogenic carcinoma registered in the community-based metropolitan Detroit Surveillance, Epidemiology, and End Results database from 1973 to 1998. RESULTS: Of 48,318 eligible patients, 23% were black. Lung cancer incidence rates decreased for men of both races from 1985 to 1998, with a greater decline occurring in black men (p < 0.0001). Although incidence rates declined over time for men of both races < 50 years of age, this decrease was greater in white men, resulting in an increase in the racial differential in younger men. Temporal trends in incidence rates were similar for women of both races. The incidence of distant-stage disease was higher among blacks throughout the study period. The incidence of local-stage disease decreased for both races, though this decline was greater in blacks. A significant racial difference in 2-year and 5-year survival rates developed during the study period, due to a distinct lack of improvement in black patients. In a multivariate model, the relative risks of death for black patients, relative to white patients, were 1.24 (p < 0.0001) for local stage, 1.14 (p < 0.0001) for regional stage, and 1.03 (p = 0.045) for distant stage. CONCLUSION: Significant racial differences exist in the incidence and survival rates for lung cancer in metropolitan Detroit. Since 1973, several disturbing trends have developed, particularly with regard to the lack of improvement in overall survival in black patients. Further study is required to determine the factors responsible for these temporal trends.

Adenocarcinoma↗
PubMed2000

Paternal military service and risk for childhood leukemia in offspring.

To assess the association between paternal military service and risk for childhood leukemia, the authors analyzed data from three case-control studies conducted by the Children's Cancer Group from 1983 to 1993. A total of 605 acute myeloid leukemia (AML, age < or = 18 years) cases, 2,117 acute lymphoblastic leukemia (ALL, age < or = 14 years) cases, and 3,155 individually matched controls were included in these studies. Paternal military history and other exposure data were obtained in 2,343 matched case-control sets, including 1,805 ALL and 528 AML cases. Paternal general military service was not associated with the leukemia risk. A small, but significant, increase in the risk for AML was seen, however, among offspring of veterans who had served in Vietnam or Cambodia (odds ratio (OR) = 1.7; 95% confidence interval (CI): 1.0, 2.9), after adjustment for paternal education, race, income, smoking, X-ray exposure, and marijuana use. The risk was predominantly present in children diagnosed before the age of 2 (OR = 4.6; 95% CI: 1.3, 16.1), although there were inconsistencies in the risks associated with length of time served and interval between service and diagnosis of leukemia. Military service in Vietnam or Cambodia was unrelated to the risk for ALL. The etiologic importance, if any, of these observations has yet to be determined.

Adolescent↗
PubMed2000

Early deaths in childhood cancer.

BACKGROUND: Deaths prior to or shortly after the diagnosis of childhood cancer may reflect inadequacies in detection and appropriate referral for care. This study was performed to determine the extent of and factors associated with early death in childhood cancer. PROCEDURE: Patients with of primary cancer, aged <20 years at diagnosis, were identified from the SEER data (n = 23,470) from 1973 to 1995. Early deaths were defined as cases identified by 1) death certificate, 2) autopsy report, or 3) death within 1 month of initial diagnoses (n = 481). Cause of death was determined by ICD-8 and -9 codes. Age at diagnosis, year of diagnosis, morphology, site of disease, race, and gender were evaluated for association with early death. RESULTS: Age <1 year at diagnosis (6.2% early deaths), being diagnosed earlier in the observation period, and a diagnosis of a brain tumor, neuroblastoma, leukemia, or liver tumor were associated with increased early death. Gender and race were not associated with early death. Among the cases for whom the malignant diagnosis was made at the time of death (n = 119), the cause of death was nonmalignant for 36. For 22 of these cases the malignancy was an incidental finding and appeared not to contribute directly to the cause of death. Among these patients, 11 had neuroblastoma, 9 being <1 year of age. CONCLUSIONS: A decrease in the proportion of early deaths associated with childhood cancer has occurred during the past 2 decades. This decrease may reflect earlier diagnosis or improved imaging capabilities, surgical techniques, medical therapy, and supportive care. Awareness among pediatricians, general practitioners, and emergency physicians is warranted, with a focus on high-risk groups for early detection among childhood cancer patients.

Adolescent↗
PubMed2000

Patterns of infection and day care utilization and risk of childhood acute lymphoblastic leukaemia.

To investigate if decreased exposure to common childhood infections is associated with risk of childhood acute lymphoblastic leukaemia (ALL) we conducted a case-control study of 1842 newly diagnosed and immunophenotypically defined cases of ALL under age 15, and 1986 matched controls in the US. Data regarding day care, sibship size and common childhood infections were obtained through parental interviews. Data were analysed stratified by leukaemia lineage and separately for 'common' childhood ALL (age 2-5 years, CD19, CD10-positive). Neither attendance at day care nor time at day care was associated with risk of ALL overall or 'common' ALL. Ear infections during infancy were less common among cases, with odds ratios of 0.86, 0.83, 0.71 and 0.69 for 1, 2-4, 5+ episodes, and continuous infections respectively (trend P = 0.026). No effect of sibship size or birth interval was seen. With one exception (ear infections), these data do not support the hypothesis that a decrease in the occurrence of common childhood infection increases risk of ALL.

Adolescent↗
PubMed2000

Consistency of occupational exposure history from pattern and model makers.

This study investigates the consistency of occupational histories reported by the same men in 1985 and again in 1988. Detroit-area pattern and model makers participating in a colorectal cancer screening program that was offered at 3-year intervals completed a career length occupational exposure questionnaire at each screening. Analysis of the data from the 243 men who participated in both screening programs provided the opportunity to examine the consistency with which these workers reported the extent of their exposure to 13 substances commonly found in their work environment. Workers were asked to provide a work history, and for each different pattern or model maker job they had held, to estimate the percentage of time they were exposed to the 13 substances. The data indicated that over the 3-year study period, pattern and model makers were highly consistent in reporting whether or not they were exposed to the 13 substances. In addition, their first estimates of the percentage of time they were exposed to each substance were within 10% of their second estimates more than 70% of the time. This concordance was somewhat diminished after excluding those who reported no exposure. These findings suggest that skilled tradesman can provide occupational exposure information that is likely to be useful for physicians in considering an occupational cause for a presenting health concern.

Adult↗
PubMed2000

Risk of injury in African American hospital workers.

Very few data exist that describe the risk of injury in African American health care workers, who are highly represented in health care occupations. The present study examined the risk for work-related injury in African American hospital workers. Hospital Occupational Health Service medical records and a hospital human resource database were used to compare risk of injury between African American and white workers after adjusting for gender, age, physical demand of the job, and total hours worked. Risk of work-related injury was 2.3 times higher in African Americans. This difference was not explained by the other independent variables. Differences in injury reporting, intra-job workload, psychosocial factors, and organizational factors are all potential explanations for racial disparity in occupational injury. More research is needed to clarify these findings.

Accidents, Occupational↗
PubMed2000

Non-Hodgkin's lymphoma: an analysis of the Metropolitan Detroit SEER database.

We evaluated incidence and survival trends of non-Hodgkin's lymphoma (NHL) in a large population-based cancer registry. Data regarding demographics, histology, incidence, and survival were obtained on all patients with NHL registered in the Metropolitan Detroit Cancer Surveillance System, a participant in the Surveillance Epidemiology and End Results (SEER) Program of the National Cancer Institute. Incidence and survival trends from 1973 through 1995 were evaluated and stratified based on age at diagnosis, sex, race, and tumor grade. There were 11,978 patients diagnosed with NHL and recorded in the Metropolitan Detroit SEER registry from 1973 to 1995. The age-adjusted incidence rate increased from 8.6 to 15.8 per 100,000, leading to an overall increase in incidence of 83% and an average annual increase of 3.2% per year. Incidence increased significantly (p < 0.05) over time in all age groups except the youngest (ages 0-19) and in all demographic groups studied. Incidence was highest in white men and lowest in black women. The incidence of both low-grade and intermediate/high-grade NHL increased significantly for each age group (p < 0.05) except the youngest (ages 0-19). In the oldest patients (70+ years), the incidence of intermediate/high-grade NHL was almost double that of low-grade NHL. Five-year relative survival increased from 64% (1973-1983) to 68% (1984-1991) for patients with low-grade NHL and from 40% to 44% for those with intermediate/high-grade NHL. The increase in relative survival was only seen in whites, however, with 5-year relative survival in blacks decreased from 53% (1973-1983) to 45% (1984-1991). In metropolitan Detroit, the current NHL epidemic affects all age groups except the very young (ages 0-19), both sexes, and both whites and blacks and is due to increases in the incidence of both low-grade and intermediate/high-grade NHL. Five-year survival rates have increased for whites but not for blacks.

Adolescent↗
PubMed1999

Axillary lymph node metastases associated with small invasive breast carcinomas.

BACKGROUND: Over the past 20 years the proportion of invasive breast carcinomas measuring < or = 1 cm has increased progressively. Information regarding the effect of clinical and histologic characteristics on the frequency of lymph node metastases associated with small invasive breast carcinomas is limited. METHODS: A review of Surveillance, Epidemiology, and End Results data was performed using cases diagnosed between January 1988 through December 1993. A total of 12,950 patients with invasive breast carcinomas measuring < or = 1 cm undergoing a resection of the primary tumor and an axillary lymph node dissection were included in this study. The effect of clinical and histologic characteristics on the frequency of lymph node metastases was reviewed. RESULTS: The frequency of lymph node metastases associated with T1a tumors was less than that observed from T1b tumors (9.6% vs. 14.3%; P < 0.001). Tumors with favorable histology (mucinous, papillary, and tubular carcinomas) had a lower frequency of lymph node metastases compared with all other histologic types (3.9% vs. 13.9%; P < 0.001). Increasing histologic grade was associated with an increased risk of lymph node metastases ranging from 7.8% in Grade 1 tumors to 21.0% in Grade 4 tumors (P < 0.001). Increasing patient age was associated with a progressively decreasing frequency of associated axillary lymph node metastases ranging from 22.6% in women age < 40 years to 10.2% in women age > or = 70 years (P < 0.001). CONCLUSIONS: Cases in which an axillary lymph node dissection can be avoided are those with an associated frequency of lymph node metastases < or = 5%, including T1a and T1b mucinous and tubular carcinomas, T1a papillary carcinomas, and T1a Grade 1 carcinomas.

Adenocarcinoma↗
PubMed1999

Parental cigarette smoking and the risk of acute leukemia in children.

BACKGROUND: Studies of the relation between parental smoking and childhood leukemia have produced inconsistent results. In the largest case-control studies of childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) conducted to date, the authors evaluated leukemia risk relative to parental self-report of cigarette smoking. METHODS: In telephone interviews in which a structured questionnaire was used, parents of 1842 ALL patients, 517 AML patients, and their matched controls were asked about their cigarette smoking habits before, during, and after the pregnancy with the index child. Risk of leukemia was examined by histologic type, age of the child at diagnosis, immunophenotype (for ALL), and French-American-British morphology group (for AML). RESULTS: The risk of ALL was not associated with the father's ever having smoked (odds ratio [OR] = 1.04, 95% confidence interval [CI] 0.90-1.20) or the mother's ever having smoked (OR = 1.04, 95% CI 0.91-1.19). Similarly, no significant risk of AML was observed for paternal (OR = 0.88, 95% CI 0.67-1.16) or maternal smoking (OR = 0.95, 95% CI 0.74-1.22). The relative risk of leukemia was not significantly different from the null for parental smoking in any time period during or around the index pregnancy, nor was it related to the number of cigarettes, the number of years of smoking, or the number of pack-years. A small number of sporadic, statistically significant associations were found, but overall there appeared to be no association between parental cigarette smoking and ALL or AML, or any subgroup of leukemia. CONCLUSIONS: Parental smoking while pregnant or exposure to cigarette smoke shortly after birth is unlikely to contribute substantially to the risk of childhood leukemia in North America.

Acute Disease↗
PubMed1999

Seasonal variations in the diagnosis of childhood cancer in the United States.

Seasonal trends in month of diagnosis have been reported for childhood acute lymphoblastic leukaemia (ALL) and non-Hodgkin's lymphoma (NHL). This seasonal variation has been suggested to represent an underlying viral aetiology for these malignancies. Some studies have shown the highest frequency of diagnoses in the summer months, although this has been inconsistent. Data from the Children's Cancer Group and the Pediatric Oncology Group were analysed for seasonal incidence patterns. A total of 20,949 incident cancer cases diagnosed in the USA from 1 January 1989 through 31 December 1991 were available for analyses. Diagnosis-specific malignancies available for evaluation included ALL, acute myeloid leukaemia (AML), Hodgkin's disease, NHL, rhabdomyosarcoma, neuroblastoma, retinoblastoma, osteosarcoma, Wilms' tumour, retinoblastoma, Ewings' sarcoma, central nervous system (CNS) tumours and hepatoblastoma. Overall, there was no statistically significant seasonal variation in the month of diagnosis for all childhood cancers combined. For diagnosis-specific malignancies, there was a statistically significant seasonal variation for ALL (P = 0.01; peak in summer), rhabdomyosarcoma (P = 0.03; spring/summer) and hepatoblastoma (P = 0.01; summer); there was no seasonal variation in the diagnosis of NHL. When cases were restricted to latitudes greater than 40 degrees ('north'), seasonal patterns were apparent only for ALL and hepatoblastoma. Notably, 33% of hepatoblastoma cases were diagnosed in the summer months. In contrast, for latitudes less than 40 degrees ('south'), only CNS tumours demonstrated a seasonal pattern (P = 0.002; winter). Although these data provide modest support for a summer peak in the diagnosis of childhood ALL, any underlying biological mechanisms that account for these seasonal patterns are likely complex and in need of more definitive studies.

Adolescent↗
PubMed1999

The causes of acute leukemia.

Although impressive biologic advances have increased understanding of leukemogenesis, we know little about the causes of the acute leukemias. Epidemiologic studies have focused primarily on children. Higher birth weight is associated with an increased risk of childhood acute leukemia. Several theories have been advanced that may account for these observations, and additional biologic studies are needed. Some epidemiologic studies suggest that the acute leukemias in children may have an infectious component. Again, further work, especially in the area of specific causative agents, is necessary. Another area for future epidemiologic study includes investigation of exposure to natural and synthetic DNA topoisomerase II inhibitors. Preliminary evidence suggests that exposure to these agents, which are found in certain foods and medications, may be related to the subsequent development of acute leukemia in infants.

Acute Disease↗
PubMed1998

The risk of subsequent primary carcinoma of the pancreas in patients with cutaneous malignant melanoma.

BACKGROUND: Carcinoma of the pancreas is the fifth leading cancer in the U.S. and has the poorest survival rate of the major malignancies. Recent studies have reported an increased risk of carcinoma of the pancreas in malignant melanoma-prone kindreds and have suggested a link between malignant melanoma and pancreas carcinoma and mutations in the p16INK4 gene. This study evaluates the risk of carcinoma of the pancreas in a population-based cohort of patients with malignant melanoma. METHODS: The malignant melanoma patients were identified from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute. The cohort was followed within the SEER system to ascertain the occurrence of subsequent microscopically confirmed primary carcinoma of the pancreas from January 1973 through December 1993. The time of follow-up was expressed as person-years of observation. Standardized incidence ratios (SIR) and 95% confidence intervals (95% CI) were calculated. RESULTS: There were 43,781 malignant melanoma patients providing 263,528 person-years of follow-up. A nearly 2-fold increased risk of subsequent carcinoma of the pancreas in patients diagnosed with malignant melanoma before age 50 years was observed (SIR = 1.76; 95% CI = 0.80-3.34) and the greatest estimated risk occurred in young white females (SIR = 2.27; 95% CI = 0.73-5.30). CONCLUSIONS: These results provide some evidence in support of observations in recent studies that not only a family history of malignant melanoma but also malignant melanoma diagnosed at an early age may be associated with the subsequent development of carcinoma of the pancreas. Further research with larger numbers of melanoma patients is necessary to explore these potential associations.

Adolescent↗
PubMed1998

Association between childhood acute lymphoblastic leukemia and use of electrical appliances during pregnancy and childhood.

As part of a comprehensive study of residential magnetic field exposure in nine midwestern and mid-Atlantic states, we evaluated the use of appliances by 640 patients with acute lymphoblastic leukemia, 0-14 years of age, diagnosed between 1989 and 1993, and 640 matched control children. Mothers were interviewed regarding use of electrical appliances during their pregnancy with the subject and the child's postnatal use. The risk of acute lymphoblastic leukemia was elevated in children whose mothers reported use of an electric blanket or mattress pad during pregnancy [odds ratio (OR) = 1.59; 95% confidence interval (CI) = 1.11-2.29] but was reduced for use of sewing machines during pregnancy (OR = 0.76; 95% CI = 0.59-0.98). The risk of acute lymphoblastic leukemia was increased with children's use of electric blankets or mattress pads (OR = 2.75; 95% CI = 1.52-4.98) and three other electrical appliances (hair dryers, video machines in arcades, and video games connected to a television), but the patterns of risk for duration in years of use and frequency of use were inconsistent for most appliances used by children. Risks rose with increasing number of hours per day children spent watching television, but risks were similar regardless of the usual distance from the television. The inconsistency in the dose-response patterns for many appliances, reporting and selection bias, and the lack of an effect for measured 60 Hertz magnetic fields or wire codes in our companion study must be considered before ascribing these associations to exposures from magnetic fields.

Case-Control Studies↗
PubMed1997

A case-control study of self-reported exposures to pesticides and pancreas cancer in southeastern Michigan.

A case-control study of pancreas cancer in residents, aged 30-79 years, of 18 counties in southeastern Michigan was conducted to investigate the risks of exposure to DDT and related materials in the general population. Sixty-six people with cytologically diagnosed pancreas cancer were identified using 7 participating hospitals in metropolitan Detroit and Ann Arbor. One hundred and thirty-one controls were frequency-matched to the cases on age, sex, ethicity and county of residence by random-digit dialing. All study participants were administered a questionnaire to assess life-time exposure to pesticides from both environmental and occupational sources, family history of cancer, past medical history, smoking history and demographic information. A statistically significant increased risk was found for self-reported exposure to ethylan (1,1-dichloro-2,2-bis(4-methoxyphenyl) ethane). Increased odds ratios were observed for self-reported exposures to chloropropylate and DDT, as well as for the summary group of organochlorine pesticides which included all of these materials, though these associations were not significant.

Adult↗
PubMed1997

Residential exposure to magnetic fields and acute lymphoblastic leukemia in children.

BACKGROUND: Previous studies found associations between childhood leukemia and surrogate indicators of exposure to magnetic fields (the power-line classification since known as "wire coding"), but not between childhood leukemia and measurements of 60-Hz residential magnetic fields. METHODS: We enrolled 638 children with acute lymphoblastic leukemia (ALL) who were under 15 years of age and were registered with the Children's Cancer Group and 620 controls in a study of residential exposure to magnetic fields generated by nearby power lines. In the subjects' current and former homes, data collectors measured magnetic fields for 24 hours in the child's bedroom and for 30 seconds in three or four other rooms and outside the front door. A computer algorithm assigned wire-code categories; based on the distance and configuration of nearby power lines, to the subjects' main residences (for 416 case patients and 416 controls) and to those where the family had lived during the mother's pregnancy with the subject (for 230 case patients and 230 controls). RESULTS: The risk of childhood ALL was not linked to summary time-weighted average residential magnetic-field levels, categorized according to a priori criteria. The odds ratio for ALL was 1.24 (95 percent confidence interval, 0.86 to 1.79) at exposures of 0.200 mu T or greater as compared with less than 0.065 mu T. The risk of ALL was not increased among children whose main residences were in the highest wire-code category (odds ratio as compared with the lowest category, 0.88; 95 percent confidence interval, 0.48 to 1.63). Furthermore, the risk was not significantly associated with either residential magnetic-field levels or the wire codes of the homes mothers resided in when pregnant with the subjects. CONCLUSIONS: Our results provide little evidence that living in homes characterized by high measured time-weighted average magnetic-field levels or by the highest wire-code category increases the risk of ALL in children.

Case-Control Studies↗