An overview of cancer survival in Africa, Asia, the Caribbean and Central America: the case for investment in cancer health services.

Population-based cancer survival data, a key indicator for monitoring progress against cancer, are reported from 27 population-based cancer registries in 14 countries in Africa, Asia, the Caribbean and Central America. In China, Singapore, the Republic of Korea, and Turkey, the 5-year age-standardized relative survival ranged from 76-82% for breast, 63-79% for cervical, 71-78% for bladder, and 44-60% for large-bowel cancer. Survival did not exceed 22% for any cancer site in The Gambia, or 13% for any cancer site except breast (46%) in Uganda. For localized cancers of the breast, large bowel, larynx, ovary, urinary bladder and for regional diseases at all sites, higher survival rates were observed in countries with more rather than less developed health services. Inter- and intra-country variations in survival imply that the levels of development of health services and their efficiency to provide early diagnosis, treatment and clinical follow-up care have a profound impact on survival from cancer. These are reliable baseline summary estimates to evaluate improvements in cancer control and emphasise the need for urgent investment to improve awareness, population-based cancer registration, early detection programmes, health-services infrastructure, and human resources in these countries in the future.

Acquisition of Helicobacter pylori infection in a high-risk population occurs within the first 2 years of life.

OBJECTIVE: To elucidate age at acquisition of Helicobacter pylori infection, we conducted a study in a population of children known to be at high risk for H pylori infection. METHOD: Children with no symptoms who were of Turkish nationality and living in the city of Ulm, Germany, and nearby communities and on whom routine health screening examinations were performed at age 1 year (56 children), 2 years (55 children), or 4 years (69 children) were included in this cross-sectional study. Stool samples were collected by the parents and sent by mail to the University of Ulm. An H pylori antigen enzyme immunoassay for the detection of H pylori in stool was used to define current infection status. Sensitivity was 84.6% (95% CI 63. 1% to 94.7%) and specificity 97.7% (95% CI 86.2% to 99.9%) in the 4-year-old children in whom the stool test was compared with the (13)C-urea breath test. RESULTS: The prevalence of infection was 8. 9% (95% CI 3.0% to 19.6%) among the 1-year-old children, 36.4% (95% CI 23.8% to 50.4%) among the 2-year-old children, and 31.9% (95% CI 21.2% to 44.2%) among the 4-year-old children. CONCLUSION: In this high-risk group of Turkish children living in Germany, H pylori acquisition seems to occur mainly between the first and the second years of life. Therefore preventive measures such as vaccination necessitate application early in infancy. Further studies are now required to ascertain the mechanisms for transmission in this age group.

Three-dimensional photon treatment planning in carcinoma of the larynx.

The role of three-dimensional (3-D) treatment planning in the definitive treatment of carcinoma of the larynx with radiation was evaluated at four institutions as part of an NCI contract. A total of 30 different treatment approaches were devised for two patients with larynx cancer. CT scans were obtained for both patients and various treatment planning tools were employed to optimize beam arrangements and to evaluate the resulting dose distribution. The effect on dose distribution of a number of factors was also examined: 1) the use of dose calculation algorithms which correct for tissue inhomogeneities, 2) the variation of the CT numbers used for inhomogeneity corrections to simulate inaccuracies in the knowledge of the CT numbers, and 3) the modification of beam energy. A multitude of data was used in plan evaluation and a numerical score was given to each plan to estimate the tumor control probability and the normal tissue complication probability. We found 3-D treatment planning to be of potential value in optimizing treatment plans in larynx cancer. Improved target coverage was achieved when complete information describing 3-D geometry of the anatomy was utilized. In some cases, the treatment planning tools employed, such as the beam's eye view, helped devise novel beam arrangements which were useful alternatives to standard techniques. We found little effect of change in CT number on dose distributions. A comparison between dose distributions calculated with tissue inhomogeneity corrections to those calculated without this correction showed little difference. We did find some improvement in the dose to the primary tumor volume at lower beam energies, but with an increased larynx volume potentially receiving doses above tolerance.