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Population-based data from the Texas Cancer Registry were used to describe the incidence of cancer in 1990 among Texas residents younger than 20 years. A total of 788 primary malignant neoplasms were diagnosed. Higher incidence of all cancers was observed among Texas Anglo children compared with Hispanics or African-Americans, and lower rates of central nervous system (CNS) neoplasms were seen among Hispanics. Compared with national data, significantly fewer cases of all cancers combined, non-Hodgkin's lymphoma, neuroblastoma, and CNS neoplasms were seen in Texas Hispanics. The overall incidence of leukemia and acute nonlymphocytic leukemia (ANLL) was highest in Hispanics compared with other Texas children, and a three-fold statistically significant excess of ANLL was evident in Hispanic females compared with national whites. In summary, the incidence of cancer in Texas Hispanic children and adolescents differs from that seen in other racial and ethnic groups. Incidence data for Texas provide additional insight into the descriptive nature of childhood and adolescent cancers.

This study measures the validity of self-reported mammography and Pap smear usage in Mexican-American women. We compared Pap smear and mammography reports in medical records to self-reports obtained in a household survey of 450 women in El Paso, Texas. The women were generally low-income, older, and Spanish-speaking. Forty-six percent of self-reported Pap smears in the previous year were verified (60.8% within previous two years, 67.1% within previous three years). Forty-nine percent of self-reported mammograms within the previous year were verified (74.7% within previous two years). For both Pap smears and mammograms, twice as many tests in the past five years were reported as were documented. Self-reports of Pap smears at a public health clinic were more valid than those at other sites. Denials of mammography within the past five years were more accurate (97.5%) than denials of Pap smears (81.8%). We conclude that self-reports of mammograms and Pap smears in Mexican-American women greatly overestimate the prevalence of screening. Intensive cancer prevention activities in this population are needed to approach the Year 2000 Objectives set by the U.S. Department of Health and Human Services.

A death certificate case-control study of primary liver cancer and occupation was conducted to determine if the high risk of liver cancer in Mexican-Americans can be explained by farmworker exposures to pesticides. The association of liver cancer with the petroleum and chemical industry and with other potentially high-risk occupations was also examined. For the years 1969 to 1980, 1,742 deaths from primary liver cancer were identified for Texas males. Controls were randomly selected from other causes of deaths among males excluding all neoplasms, liver and gallbladder diseases, infectious hepatitis, and alcoholism, and were frequency matched to cases by age, race, ethnicity, and year of death. Risk for farmworkers based on age, race, and ethnicity-adjusted odds ratios (ORs) was not excessive (OR = 1.4, 95% confidence limits [C.L.] 0.8-2.2) but was larger than the risk for farmers (OR = 1.0, 95% C.L. 0.8-1.2). Excess risk in the petroleum and chemical manufacturing industries was confined to oil refinery workers (OR = 2.0, 95% C.L. 1.1-3.5). Other occupations with twofold risk or greater were plumbers and pipefitters (OR = 2.0, 95% C.L. 1.0-3.8), butchers and meat cutters (OR = 2.6, 95% C.L. 1.1-6.6), textile workers (OR = 3.1, 95% C.L. 1.2-7.8), cooks (OR = 2.2, 95% C.L. 1.1-4.5), and longshoremen (OR = 2.2, 95% C.L. 0.6-7.4).

The mortality experience of a large refinery cohort (1937-1978) was examined by dividing it into three subcohorts according to hire dates: those hired before 1940, those hired during the period 1940-1945, and those hired after 1945. These three periods are approximately equivalent to before, during, and after World War II and span a total hiring period of more than 75 years. The results showed that a substantial portion of the cohort (3,330 or 27%) had been recruited during 1940-1945, and they contributed 980 or 28% of the total deaths. However, their mortality experience was quite different from the rest. A series of significant increases were seen among the external causes for accidents, suicide, and homicide. In terms of overall mortality and in contrast to the rest of the cohort, no "healthy worker effect" was seen (SMR = 1.00). They also showed increases in several types of cancer including cancers of the pancreas and prostate and leukemia. These unusual experiences cannot be explained either on the basis of their war-related deaths or on their period of employment (one-half were terminated within 1 year from date of hire), and data is insufficient to separate the role of hiring practices or their socioeconomic status. However, their life-styles were probably quite different judged from the fact that alcoholism-related deaths were increased as much as fivefold. Almost two-thirds of the total deaths occurred among 4,080 workers in the before 1940 subcohort. Further, the 5,117 workers of the after-1945 subcohort contributed only 5% of the total deaths. Thus, the results of the original refinery cohort (1937-1978) primarily reflect the experience of those employees hired before 1940. Given the same cohort method (historical prospective), cohort results vary widely according to different study designs, and this has implications for "generalizable" risk assessment or risk projections. A prospective study of new hires with 30 years of follow-up is rather inefficient because it would yield only a small number of deaths, with a strong healthy worker effect. The same is true for studies based on active workers with a short period of follow-up. Studies based on time of hire, however, provide a means for controlling time-related occupational exposures.

Trends in lung cancer mortality among white and black men and women in Texas for the years 1970 to 1986 offer some measure of optimism. A decline in mortality for men and women aged 35 to 44 years and for men aged 45 to 54 years is now evident. However, the rates in older men and women continue to rise. Following a long trend of ascending death rates, a plateau in the overall age-adjusted death rates among white men is now suggested. A similar decline for women will probably not be evident until early in the next century. These patterns are consistent with profound changes that have occurred in the prevalence of cigarette smoking over the past 30 years. It is urgent to maintain the momentum by emphasizing smoking cessation and prevention programs.

The mortality and health experiences of refinery workers employed in benzene processes or operations are described. A retrospective cohort mortality study of benzene workers employed from 1952 to 1978 revealed no excess in overall general mortality or in cancer mortality compared either with the experience of the U.S. general population or with that of an internal control group. Ascertainment of vital status was accomplished for 99% of the cohort. Recent industrial hygiene data that included 1,394 personal samples indicated that 84% of all benzene exposures were less than 1 part per million (ppm), with a median exposure of 0.14 ppm for the refinery workers, and 0.53 ppm for those in the benzene-related units. Among these workers, no deaths from leukemia were observed. A medical surveillance program for benzene workers is also described, with special emphasis on the effectiveness of laboratory screening. Evaluation of data for a 21-year period showed no significant changes in the blood indices of the workers as a group. The limited value of establishing screening guidelines without the support of epidemiological studies is discussed.