Prevalence of BRCA1 and BRCA2 gene mutations in families with medium and high risk of breast and ovarian cancer in Brazil

Of all malignant neoplasias affecting women, breast cancer has the highest incidence rate in Brazil. The objective of the present study was to determine the frequency of genetic modifications in families with medium and high risk for breast and ovarian cancer from different regions of Brazil. An exploratory, descriptive study was carried out on the prevalence of the BRCA1 and BRCA2 mutations in case series of high-risk families for breast and/or ovarian cancer. After heredogram construction, a blood sample was taken and DNA extraction was performed in all index cases. The protein truncation test was used to screen for truncated mutations in exon 11 of the BRCA1 gene and in exons 10 and 11 of the BRCA2 gene. Of the 612 individuals submitted to genetic testing, 21 (3.4 percent), 19 women and 2 men, had mutations in the BRCA1 or BRCA2 genes. Of the 19 BRCA1 mutations found in the 18 participants, 7 consisted of ins6kb mutations, 4 were 5382insC, 3 were 2156delGinsCC, 2 were 185delAG, 1 was C1201G, 1 was C3522T, and 1 was 3450del4. With respect to the BRCA2 gene, 3 mutations were found: 5878del10, 5036delA and 4232insA (one case each). The prevalence of germline mutations in the BRCA1 and BRCA2 genes found in the present study was lower than reported by other studies on high-risk Brazilian populations. The inclusion of individuals with medium risk may have contributed to the lower prevalence observed.

Prevalence of BRCA1 and BRCA2 gene mutations in families with medium and high risk of breast and ovarian cancer in Brazil.

Of all malignant neoplasias affecting women, breast cancer has the highest incidence rate in Brazil. The objective of the present study was to determine the frequency of genetic modifications in families with medium and high risk for breast and ovarian cancer from different regions of Brazil. An exploratory, descriptive study was carried out on the prevalence of the BRCA1 and BRCA2 mutations in case series of high-risk families for breast and/or ovarian cancer. After heredogram construction, a blood sample was taken and DNA extraction was performed in all index cases. The protein truncation test was used to screen for truncated mutations in exon 11 of the BRCA1 gene and in exons 10 and 11 of the BRCA2 gene. Of the 612 individuals submitted to genetic testing, 21 (3.4%), 19 women and 2 men, had mutations in the BRCA1 or BRCA2 genes. Of the 19 BRCA1 mutations found in the 18 participants, 7 consisted of ins6kb mutations, 4 were 5382insC, 3 were 2156delGinsCC, 2 were 185delAG, 1 was C1201G, 1 was C3522T, and 1 was 3450del4. With respect to the BRCA2 gene, 3 mutations were found: 5878del10, 5036delA and 4232insA (one case each). The prevalence of germline mutations in the BRCA1 and BRCA2 genes found in the present study was lower than reported by other studies on high-risk Brazilian populations. The inclusion of individuals with medium risk may have contributed to the lower prevalence observed.

[Prevalence of risk factors for cardiovascular disease in the Guaraní-Mbyá population of the State of Rio de Janeiro]. / Prevalência de fatores de risco para doenças cardiovasculares na população Guaraní-Mbyá do Estado do Rio de Janeiro.

Social change has been involved in the unequal distribution patterns of chronic diseases in several populations. Among Indian communities experiencing life pattern changes, international studies have reported increased prevalence of hypertension and other cardiovascular risk factors. Such increased prevalence was ascertained in a survey conducted in 1999 in selected Guaraní-Mbyá communities (Sapukai, Paraty-Mirim, and Araponga) in the State of Rio de Janeiro, Brazil. A population census was carried out and interviews and clinical and biochemical evaluations were conducted with 80 men and 71 women. Observed prevalence of selected risk factors in the overall sample, including men and women, was as follows for the three communities: hypertension (4.8%, 2.6%, 7.4%); overweight (26.7%, 19.5%, 34.8%); total cholesterol levels (2.8%, 2.7%, 2.9%), and increased triglyceride levels (12.6%, 9.5%, 15.9%). All prevalence rates were higher among women and at older ages. The results suggest that the Guaraní communities have a moderate risk of chronic diseases and that measures to reduce these risk factors should be adopted.

Cancer cluster among young Indian adults living near power transmission lines in Bom Jesus do Tocantins, Pará, brazil.

A case study was carried out to explore the occurrence of a cancer cluster in 1992 among young indian adults adults living in an Amazonian village near two 500 kV power transmission lines that began operating a decade ago. Current blood levels of DDT and organophosphorus pesticides and metal levels in hair samples were measured. Extremely low magnetic field exposure was determined during current daily activities carried out by the Indian villagers. Taking into account the cancer incidence rates in different Brazilian cities, the probability of the occurrence of this cluster by chance was considered remote (p< 0.003, Poisson distribution). High blood levels of p,p'-DDT (median levels ranging from 26 to 58 ppb) were observed. As a whole, this community showed a pattern of low exposure to organophosphorus pesticides, and high recent exposure was only observed in a few blood samples. Continuous exposure to extremely low electromagnetic fields originated in the power transmission lines (which reached 95.0 mG under the lines) was observed on several opportunities during daily activities carried out by Indian villagers. Further observational studies should evaluate the interaction between exposure to extremely low electromagnetic fields and prior exposure to tumor initiators in cancer development.

Familial aggregation of breast/ovarian cancer: age of onset along subsequent generations in Brazil.

Antecedents of family aggregation of breast and ovarian cancer are observed in only 5-8% of all breast cancer cases. Nevertheless, this variable displays one of the highest risk ratios associated to breast cancer outcome. Despite recent identification of genetic mutations associated with family aggregation of these tumors, mainly at BRCA1 and BRCA2 genes, knowledge on the interaction between environmental agents in these families remains quite unclear. In this paper we ascertained the correlation among ages of the onset of breast/ovarian cancer in 260 Brazilian families with those cancer aggregations. Further we estimated the median age of the onset of breast cancer among four generations. We observed that the higher the number of family cancer cases, the highest is the correlation of ages for the onset of breast cancer. We also observed a 8-10 year decline in the mean age-of-onset of breast/ovarian cancer from one generation to another in the studied families. If these results could be confirmed elsewhere, we believe that the hypothesis of interaction between environmental risks factors in families indeed showing breast/ovarian cancer aggregation is reinforced.

[AIDS in adult women in the Municipality of Rio de Janeiro]. / AIDS em mulheres adultas no município do Rio de Janeiro.

This paper presents the main epidemiological characteristics of AIDS cases observed among adult women in Rio de Janeiro Municipality (Rio) during 1980-89. Higher incidence rates as compared to Brazilian and Canadian women, rising participation of either sexual transmission and EV drug addiction and an increasing involvement of young women were also observed. The disease does not present a random spatial distribution in Rio, and case clusters in definite high risks areas were shown. Tuberculosis was found to be the second most frequent opportunistic infection detected among cases. Finally, some of the main trends and questions related to AIDS control among women in the studied area are discussed.