Determinants of black/white differences in colon cancer survival.

BACKGROUND: Blacks have lower survival rates for colon cancer than whites, possibly related to more advanced stages of disease at diagnosis and to socioeconomic differences between blacks and whites. While the black/white difference in colon cancer survival is well documented, the few studies that have investigated this difference have been limited by the modest number and type of explanatory factors that were considered. PURPOSE: We analyzed data from the National Cancer Institute Black/White Cancer Survival Study to determine 1) what characteristics might contribute to the racial difference in colon cancer survival and 2) if a survival disparity remained between black and white patients after adjustment was made for these characteristics. METHODS: This prospective study included 454 blacks and a stratified random sample of 521 whites, aged 20-79 years, with cancer of the colon diagnosed from January 1, 1985, through December 31, 1986, and who were residents of the metropolitan areas of Atlanta, New Orleans, and San Francisco/Oakland. Follow-up was truncated on December 31, 1990. Cox proportional hazards regression was used to estimate the death rate among blacks relative to that among whites after adjustment for potential explanatory factors, including sociodemographic factors, concurrent (comorbid) medical conditions, stage at diagnosis, tumor characteristics, and treatment. All P values were calculated from two-tailed tests of statistical significance. RESULTS: After adjustment for age, sex, and geographic area, the black-to-white mortality hazard ratio (HR) was 1.5 (95% confidence interval [CI] = 1.2-1.9), indicating that the risk of death among black patients was 50% higher than that among white patients. Further adjustment for stage reduced the excess cancer mortality to 20% (HR = 1.2; 95% CI = 1.0-1.5), decreasing the overall racial difference in excess mortality from 50% to 20% or to a 60% reduction in excess mortality. Although adjustment for poverty reduced the excess mortality by 20%, adjusting for both stage and poverty did not further reduce the racial difference. Among patients with stages II and III disease, blacks had lower survival rates than whites (HR = 1.8; 95% CI = 1.0-3.1 and HR - 1.5; 95% CI = 1.0-2.3, respectively). Among those patients with metastatic disease (stage IV), survival was similar for whites and blacks. CONCLUSIONS: Stage at diagnosis accounted for more than half of the excess colon cancer mortality observed among blacks. Poverty and other socioeconomic conditions, general health status, tumor characteristics, and general patterns of treatment did not further explain the remaining survival disadvantage among blacks. IMPLICATIONS: Because the racial disparity was confined to earlier stages, future studies should investigate whether blacks have more advanced disease at diagnosis and whether less aggressive treatment is provided because of understanding.

Increased chromosome damage in pediatric heart catheterization patients after diagnostic fluoroscopy and cineangiography.

Chromosome damage (CD) and sister chromatid exchange (SCE) levels were studied in lymphocytes from 30 pediatric heart catheterization patients receiving radiation during diagnostic fluoroscopy and cineangiography procedures. Forty-eight-hour CD and 72-hr SCE cultures were prepared from sequential samples taken from each patient: samples 1-3 via the catheter the same day (1) before exposure, (2) after fluoroscopy, and (3) after cineangiography; and sample 4 by venipuncture the next morning. Significant increases in CD (dicentrics, rings, and fragments), but not SCE, were observed. From a mean base level of 0.4% cells with CD, the CD levels increased 2-3-fold in samples 3 and 4 (p = .001). Rings only occurred in samples 3 and 4. While increased CD levels also correlated with increasing age, body surface area, and weight, partial correlations controlling for these factors clearly indicate that the CD effects are principally attributable to the radiological procedures (p = .001). Increased CD levels correlated with both the roentgen dose of cineangiography exposure (p = .002) and the volume of contrast medium (p = .000); however, partial correlations, controlling for either factor, indicate that the contrast medium was the principal factor (p = .006).

The cardiovascular abnormalities associated with duplicated segments of chromosome 7.

Congenital heart disease is an integral part of many genetic syndromes such as the major trisomies 13, 18, and 21. Little information, however, is available with reference to the incidence of cardiac anomalies in the trisomy 7 syndromes. Two patients with partial trisomy 7q, one of whom had congenital heart disease, are presented. A review of the literature reveals incomplete description of the cardiovascular abnormalities in the majority of case reports of patients with this syndrome, however, when described it appears that there are no specific defects associated with trisomy 7p and 7q, but only an increased frequency of occurrence. Further clinical and postmortem data regarding details of the congenital heart defects associated with trisomy 7 is required to confirm this preliminary observation.

Differences between black and white patients with cancer of the uterine corpus in interval from symptom recognition to initial medical consultation (United States).

To determine whether Black women with symptoms of uterine corpus cancer had longer times from symptom recognition to initial medical consultation than did White women in the United States, 331 newly diagnosed patients living in Atlanta (GA), New Orleans (LA), and San Francisco/Oakland (CA) during 1985-87 were interviewed to collect information on symptoms, dates of recognition and consultation, and other factors that might affect the interval. Data were analyzed to estimate medical consultation rates and rate ratios following symptom recognition. Median recalled times between symptom recognition and consultation were 16 days for Black women and 14 days for White women. Although poverty, having no usual source of healthcare, and other factors were associated with lower consultation rates, the adjusted rate among Black women was only somewhat lower (0.87) than among White women, and the 95 percent confidence interval (CI = 0.58-1.31) was consistent with no true difference between the races. In addition, the median time to consultation for women with stage IV cancer was only 15 days longer than the time (14 days) for the women with stage I cancer. These results suggest that time from symptom recognition to initial medical consultation does not contribute importantly to the more advanced stage cancer of the uterine corpus commonly found among Black women.

Racial differences in tumor grade among women with endometrial cancer.

Black women with endometrial cancer have more advanced disease and less favorable tumor grade than do white women. This study evaluated whether racial differences in tumor grade could be explained by hormone-related factors and other putative determinants of grade. Subjects included 207 white and 81 black postmenopausal women diagnosed with primary cancer of the uterine corpus between 1985 and 1987. Blacks had poorer tumor grade than whites (odds ratio for FIGO grade 2 versus grade 1 is 1.8; odds ratio for grade 3 versus grade 1 is 2.8). Over 75% of the excess of poorly differentiated tumors versus well-differentiated tumors among blacks could be explained by racial differences in use of replacement estrogens, age at first pregnancy, history of oophorectomy, poverty, stage of disease, use of screening, and access to health care. The most prominent factor was estrogen therapy, which was associated with favorable tumor grade and was used much less frequently by blacks. Although not statistically significant, a moderate racial difference in tumor grade remained after control of the potential explanatory explanatory variables. This may reflect true biologic variation between blacks and whites and may explain, in part, the observation that blacks with endometrial cancer have a worse prognosis.