Epidemiologic panorama of stomach cancer mortality in Mexico.

BACKGROUND: Annually, there are more than 6 million deaths from a type of malignant neoplasia worldwide. In developing countries, the highest rates of incidence of malignant neoplasias are uterine cervical cancer, stomach, lung, esophagus, pharynx, and liver cancers. Recent estimates on the incidence of cancer worldwide show that, in 1990, stomach cancer (SC) was the second most frequent type of cancer (900,000 new cases annually). Rates of incidence have decreased consistently in nearly all areas of the world. In Mexico, however, rates of incidence and mortality have increased gradually between 1980 and 1997; in 1995, 4,685 people died of SC in Mexico. This report presents a descriptive analysis of SC mortality in Mexico. METHODS: A mortality database edited from the electronic files of the National Institute of Informatics, Statistics and Geography (INEGI) in Mexico was used; population denominators were edited by the Mexican National Population Council (Conapo). Adjusted mortality rates, taking as standard of reference the population of Mexico City by sex, year, and 10-year age groups were calculated as well as the sex ratio for the 1980-1997 period. To evaluate the magnitude of risks by state, the standardized mortality ratio (SMR) was calculated; prematurity was evaluated through the potential lost-life years index (PLLYI). The analysis was carried out using the Excel and Stata 5.0 software programs. RESULTS: During the years from 1980 to 1997, in Mexico the total number of deaths from SC was 76,315. The male:female ratio was 1.2:1.0. SMR by state showed that the states of Yucatán, Sonora, Zacatecas, Michoacán, and Chiapas had higher mortality rates. The PLLYI was higher for males in the states of Chiapas, Sonora, Chihuahua, Zacatecas, and Southern Baja California, and higher for females in Chiapas, Oaxaca, Yucatán, Puebla, and Campeche. CONCLUSIONS: World statistics on mortality caused by SC suggest a decreasing trend. Findings for this study show an increase in the adjusted mortality rates by SC during the 1980-1997 period in Mexico. However, when analyzing the different indicators that reveal risks, magnitude, and prematurity of mortality, there is a differential trend in mortality by sex that includes regional patterns probably related to different socioeconomic levels.

Breast cancer in Mexican women: an epidemiological study with cervical cancer control.

INTRODUCTION: In Mexico, breast cancer (BC) is one of the main causes of cancer deaths in women, with increasing incidence and mortality in recent years. Therefore, the aim of the study is identify possible risk factors related to BC. METHODS: An epidemiological study of hospital cases of BC and controls with cervical uterine cancer (CUCA) was carried out at eight third level concentration hospitals in Mexico City. The total of 353 incident cases of BC and 630 controls with CUCA were identified among women younger than 75 years who had been residents of the metropolitan area of Mexico City for at least one year. Diagnosis was confirmed histologically in both groups. Variables were analyzed according to biological and statistical plausibility criteria. Univariate, bivariate and multivariate analyses were carried out. Cases and controls were stratified according to the menopausal hormonal status (pre and post menopause). RESULTS: The factors associated with BC were: higher socioeconomic level (OR= 2.77; 95%CI = 1.77 - 4.35); early menarche (OR= 1.32; 95%CI= 0.88 - 2.00); old age at first pregnancy (>31 years: OR= 5.49; 95%CI= 2.16 - 13.98) and a family history of BC (OR= 4.76; 95% CI= 2.10 - 10.79). In contrast, an increase in the duration of the breastfeeding period was a protective factor (>25 months: OR= 0.38; 95%CI= 0.20 - 0.70). CONCLUSIONS: This study contributes to the identification of risk factors for BC described in the international literature, in the population of Mexican women. Breastfeeding appears to play an important role in protecting women from BC. Because of changes in women's lifestyles, lactation is decreasing in Mexico, and young women tend not to breastfeed or to shorten the duration of lactation.

Prostate cancer mortality trends in Mexico, 1980-1995.

BACKGROUND: In Mexico, prostate cancer (PC) is the second highest cause of mortality by cancer in men. In 1991, there were 2,473 deaths, with a crude rate of 5.66 cases per 100,000 men age 40 or over. For this same year, the ratio of proportional mortality to the total number of malignant tumors was 12.6%. Our objectives were to determine the trends and geographic distribution of mortality for PC in Mexico for 1980-1995. METHODS: Crude and adjusted mortality rates were carried out for 1980-1995. A test for trend was done using the simple lineal regression method. The standardized mortality ratio (SMR) was calculated for 1980-1995 for each Mexican state. RESULTS: The total number of deaths by PC in Mexico for 1980-1995 was 32,349. The crude mortality rate increased during that period from 3.16 to 6.75 cases per 100,000 men over age 40. The statistical trend test with respect to time was significant (P<0.0001). The state of Southern Baja California showed a higher SMR, and a smaller SMR was shown for the state of Quintana Roo. CONCLUSIONS: The mortality trends for PC increased for the period studied. It represents a serious problem for public health. We find that the central and northern states of the country, characterized by a greater industrial and socioeconomic development, are those with a higher SMR.

Epidemiologic panorama of colorectal cancer in Mexico, 1980-1993.

INTRODUCTION: Colorectal cancer is the third cause of cancer-related death in the world, with 468,000 estimated deaths in 1993. In some countries mortality rates have started to decline, and survival rates have increased. In this study performed in Mexico, information is presented on the increase in mortality from this form of cancer, especially in more economically developed areas. METHODS: The mortality trend for colorectal cancer was evaluated and standardized by five-year age groups in the period 1980 to 1993. Also, the standardized mortality ratio was calculated for Mexico's 32 states, as was the possible association between mortality and indicators of rurality level and fertility rates in the different regions of Mexico. RESULTS: In the period studied, 18,962 deaths were officially reported. The average age of death was 66 years. The mortality rate among women (1.8) was significantly higher than among men (1.55 per 100,000 inhabitants). Mortality from colorectal cancer grew by 100 percent in both genders (beta = 0.089; P < 0.001), especially in the age group 34 and younger, in the 45 to 49 age group, and in the older than 75 age group (P < 0.05). The standardized mortality ratio was greater in the states in the north of Mexico. Finally, an inverse correlation was observed throughout Mexico between the rurality index (r = -0.60; P < 0.001) and the fertility rates (r = -0.43; P < 0.05) and mortality from colorectal cancer. CONCLUSIONS: In this study, there is evidence that mortality from this cancer is higher in geographic areas with greater socioeconomic development, similar to regional patterns observed in other countries. In Mexico, the coming years will see a serious epidemic in mortality from this disease; therefore, immediate attention must be given to identifying the profile of high-risk subjects and implementing early cancer detection measures.

[Epidemiology of cancer of the breast in Mexico. Consequences of demography transition]. / La epidemia de cáncer de mama en México. Consecuencia de la transición demográfica?

OBJECTIVE: Analyze the relation between reductions in fertility and the inverse en breast cancer mortality in the different states of Mexico for the period 1979-1994. MATERIALS AND METHODS: Fertility rates and beast cancer mortality rates were utilized to analyze the proposed relationship in the states of the country. Principal component analysis and classification analysis were then used in the confirmatory analysis of this relationship. RESULTS: There is an important decrease in fertility trends overall with regional differences: the northern states of Mexico have lowest then the southern states. These regional differences are inversely related to the observed differences in breast cancer mortality within the states: the northern states have levels of breast cancer mortality much higher than the southern states. CONCLUSIONS: The increase in mortality due to breast cancer and its relation to the decrease in fertility illustrates the importance that must be given to the preventive aspect of health services since in the near future Mexican women will exhibit reproductive behaviors similar to women in developed countries.

Trends of lung cancer mortality in Mexico.

Lung cancer (LC) is one of the most important public health problems in the world; 1,035,000 annual deaths are estimated each year and more than 80% of these are attributed to tobacco. The trend of lung cancer mortality in Mexico City from 1979 - 1993 was determined, as was the rate ratio of lung cancer mortality in 31 states in Mexico, taking Mexico City as a reference by means of a Poisson model. A strong linear regression model was used to evaluate the rate, where the dependent variable was LC mortality rate and the independent variable the year observed. In 15 years, 73,807 deaths from LC were reported, with an increase in mortality from 5.01 - 7.25 per 100,000 inhabitants. Mortality increases significantly after 60 years of age (B not equal to 0), p<.05) in men and in women. Mortality from LC was 70% in men, and more than 60% of deaths were reported after 65 years of age. Mortality risk is higher in the northern states of the country (e.g., Sonora, RR=2.40) than in the southern region (e.g., Oaxaca RR=0.40). In Mexico, almost 10,000 deaths by LC are estimated for the year 2010. Therefore, changes in lifestyle should be encouraged in order to decrease the smoking habit. The governmental tax on cigarettes should be increased, smoking restricted in squares and public spaces, and the risks should be announced on cigarette packages, among other measures. With respect to other emergent risk factors, the sources of industrial pollution and toxic emissions should be regulated.

[Breast cancer. A historical account, present and future]. / Cáncer de mama. Un hilo conductor histórico, presente y futuro.

This essay describes the different theoretical constructions of breast cancer models, such as the biological, hygienist-preventive and epidemiological. An anecdotal account of the Hippocratic model is also presented. This disease will be one of the major challenges posed by noncommunicable diseases in coming years, due to a significant increase of life expectancy and to a decrease of the overall annual growth rate-resulting in the ageing of the population-, as well as to lifestyle changes-particularly the considerable decrease of fertility rates and breastfeeding practices-, and to the poor efficiency and effectiveness of breast cancer screening programs. In this context, one of the main challenges for breast cancer control is to secure the multidisciplinary approach offered by public health. After analyzing the different models, we favor the sociomedical model as the one that incorporates several areas of knowledge to formulate an effective response to breast cancer.