Two papers in this issue of the Revista Panamericana de Salud Pblica/Pan American Journal of Public Health address the problem of detection and screening strategies for cancer prevention. One paper is on the diffusion of Pap smear tests for cervical cancer prevention in a high-risk area of South America (1), and the other is on prostate-specific antigen (PSA) and digital rectal examinations in the diagnosis of prostate cancer (2). A third study in this issue analyzes the incidence of cancer among Hispanic children in the United States of America, including mainly neoplasms of the lymphoid and hematopoietic system, many of which are amenable to treatment (3). These screening and diagnostic tests, as well as modern treatments for leukemias and Hodgkin's lymphomas, are largely available in developed countries, such as those of North America (Canada and the United States) and Western Europe. As illustrated by the paper by Dzuba et al. (1), there have been some delays in the adoption of organized programs and strategies for cancer prevention and treatment in some countries of Central America and South America. Even in the United States there are racial and ethnic disparities in cancer incidence and mortality (3, 4), which suggests that not all segments of the population in the country benefit equally from progress in the prevention, early detection, and treatment of cancer.

The relation between 17 micronutrients and breast-cancer risk was analyzed in a case-control study conducted between 1993 and 1999 in the Swiss Canton of Vaud. Cases were 289 women with incident, histologically confirmed breast cancer, and controls were 442 women admitted to the same hospital for a wide spectrum of acute non-neoplastic conditions unrelated to long-term modifications of diet. Dietary habits were investigated using a validated food-frequency questionnaire. Odds ratios (ORs) were obtained after allowance for age, education, parity, menopausal status, body mass index, total energy intake and alcohol drinking. For several micronutrients, the ORs tended to decline with increasing tertile of intake, with significant inverse trends in risk for potassium (OR for the highest tertile = 0.21), total carotenoids (OR = 0.42), lycopene (OR = 0.43), folic acid (OR = 0.45), vitamin C (OR = 0.19), vitamin E (OR = 0.37) and vitamin B(6) (OR = 0.54). In a model including a continuous term for the 7 micronutrients significantly related to breast cancer, the only persisting significant inverse relations were for vitamin C (OR = 0.23) and lycopene (OR = 0.64).

A low-risk diet for cancer in the Mediterranean would imply increasing the consumption of fruit and vegetables, as well as avoiding increasing the intakes of meat and refined carbohydrates. Further, olive oil and other unsaturated fats, which are also typical aspects of the Mediterranean diet, should be preferred to saturated ones.

Abstract Prostate cancer is the fourth site for cancer incidence worldwide in men, and the third in developed countries after lung and colon-rectum (Parkin et al. 1999). Considerable changes in incidence rates from prostate carcinoma have been observed in the USA, the European Union, and in most other developed countries, suggesting that an epidemic of this neoplasm occurred in the late 1980s or early 1990s, followed by a fall in rates. A critical appraisal of the descriptive epidemiology of prostate cancer indicates, however, that most trends were likely attributable to changes in diagnostic procedures (mainly, the introduction of prostate-specific antigen-PSA-blood test), rather than substantial changes in risk-factor exposure (Levi et al. 2000).

Various aspects of the Mediterranean diet were analyzed in a series of studies conducted in Northern Italy on over 20,000 cases of several major cancers and 18,000 controls. For most digestive tract cancers, the risk decreased with increasing vegetable and fruit consumption, with relative risks between 0.3 and 0.7 for the highest level of intake, and the population attributable risks for low intake of vegetables and fruit ranged between 15 and 40%. Less strong inverse relations were observed for other (epithelial) cancers, too. A number of micronutrients contained in vegetables and fruit showed an inverse relation with cancer risk. In particular, flavones, flavonols and resveratrol were inversely related to breast cancer risk. Olive oil, which is the main common denominator of the Mediterranean diet, has also been inversely related to cancers of the colorectum and breast, and mainly of the upper digestive and respiratory tract.

Self-reported smoking prevalence is decreasing in men but not in females. There is widespread support for smoking restriction in public areas.

To provide comprehensive and quantitative information on the benefits and risks of hormone replacement therapy (HRT) on several cancer sites, we systematically examined the relation between HRT use and the risk of various cancers in women aged 45-79 by using data from a framework of case-control studies conducted in Italy between 1983 and 1999. The overall data set included the following incident, histologically confirmed neoplasms: oral cavity, pharynx, larynx and esophagus (n = 253), stomach (n = 258), colon (n = 886), rectum (n = 488), liver (n = 105), gallbladder (n = 31), pancreas (n = 122), breast (n = 4,713), endometrium (n = 704), ovary (n = 1,614), urinary bladder (n = 106), kidney (n = 102), thyroid (n = 65), Hodgkin's disease (n = 26), non-Hodgkin's lymphomas (n = 145), multiple myeloma (n = 65) and sarcomas (n = 78). The control group comprised 6,976 women aged 45-79 years, admitted for a wide spectrum of acute, nonneoplastic conditions. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) for use of HRT were derived from multiple logistic regression equations. There was an inverse association between ever use of HRT and colon (OR = 0.7), rectum (OR = 0.5) and liver cancer (OR = 0.2), with a consistent pattern of protection for duration of use. An excess risk was found for gallbladder (OR = 3.2), breast (OR = 1.1), endometrial (OR = 3.0) and urinary bladder cancer (OR = 2.0). These data from a southern European population add some useful information on the risk-benefit assessment of HRT among postmenopausal women.