Breast Cancer and Genetic Factors
Breast cancer is a major health problem in the Western world and the leading cause of death among American women 40-55 years of age.
Although the cause of breast cancer is still unknown, it is clear that genetic factors contribute to an ill defined proportion of breast cancer incidence, estimated to be about 5-10% of all cases, but approximately 25% of cases diagnosed before age 40.
Among women born and raised in the US, Black women have a lower risk of breast cancer than White women, but the survival of Black women is poorer. It has been observed that the age distribution of disease onset as well as tumor histology is different between Black and White patients.
African-American patients have a greater incidence between 30-44 years, and medullary carcinoma is more frequent. Tumors in African-American women are more likely to be poorly differentiated, and estrogen receptor negative, and to exhibit high nuclear atypia, and higher S-phase fraction.
The greater percentage of Black women than White women diagnosed with breast cancer under age 44 suggests a genetic contribution to breast cancer in African-American women. However, very few data are available from this population to evaluate this possibility
In West Africa, the founder population of most African Americans, breast cancer has been considered to be a rare virulent disease of young women. Breast cancer in these young women is almost uniformly fatal partly because of ignorance of the disease, and lack of access to modern medical care.
In a recent review of breast cancer cases from Nigeria published by Dr Adebamaowo, the average age at diagnosis was 43 years; 10-15 years younger than in White women. Pre-menopausal women accounted for 74% of the cases and most significantly, 12% of the cases were in women younger than 30 years of age. Quite at variance with the finding in White women, breast cancer incidence in Africa does not increase with age after menopause.
While this figure may in part reflect the lower average age of the African population, the lower average age of breast cancer incidence in Blacks from all regions in North America suggest there is a strong genetic component to breast cancer susceptibility common to populations of African ancestry. Alternatively, environmental factors important in post-menopausal women may be lacking in this populations.
Only 20% European admixture exists among US Blacks, therefore the predominant genetic influences on breast cancer will be similar in Nigeria and the US. Thus, genetic analysis of breast cancer predisposition in West African populations could potentially reveal components of breast cancer susceptibility common to all Blacks in the African Diaspora. Such components should be more readily detected in West African subjects, as these populations remain relatively more genetically homogenous.
With the identification of BRCA1 and BRCA2 genes, highly penetrant genes that confer increased risk of premenopausal breast cancer, as well as a host of low penetrance genes that modify breast cancer risks, it should now be possible to systematically study the genetics of breast cancer in the African Diaspora .
The African Diaspora consists of populations which share a common genetic background, yet reside in widely varying social settings. Heritable aspects of breast cancer should be detectable in cross-cultural comparisons of Blacks in Africa, the Caribbean and North America. Potential protective factors in the environment could be identified because of the sharp contrasts in environmental exposure. However, such comparisons are extremely complex, requiring an infrastructure (accessible populations, clinical resources and processes) that can support unified assessment of exposure and disease).
We have recently established collaborations within the University of Ibadan to study the genetic and environmental factors which contribute to breast cancer in the African diaspora.
In the last four decades, there has been an increase in the prevalence of asthma and other allergic diseases. Although, there is no clear explanation for this rise, the “hygiene hypothesis” suggests that the increase is the result of improved hygiene and health care within industrialized societies.
It is believed that this decreased the incidence of childhood infections that would normally stimulate the immune system in a direction that would militate against asthma. Thus, with increasing westernization, less developed communities may follow this trend.
Factors operating very early in life may be particularly important in the acquisition of childhood asthma, whereas the development of atopic sensitization and hay fever may be affected by environmental factors occurring beyond infancy. However, environmental and lifestyle factors seem to be more important in the development of atopy and hay fever than of asthma.
In contrast to findings in industrialized countries where atopy is recognized as an important trigger and suspected in the etiology for asthma, it may be less of a factor in the expression of asthma in developing countries.
Since the relative roles of genes, sensitivity to allergens, and environmental exposures in modulating asthma course in Nigeria is unclear, and there is no credible information about asthma prevalence and its impact on quality of life in Nigeria, we are interested in understanding the impact of asthma in urban and rural areas in Nigeria while exploring the interaction between genetics and environment in the manifestation of asthma.
Health Life for All Foundation by virtue of our interest in scientific inquiry and capacity building through collaborative research that is beneficial to the health care delivery system is again positioned to improve our understanding of asthma and approach to treatment.
Sickle Cell Disease
Sickle cell disease is very prevalent in Sub Saharan Africa, especially in Nigeria. It seems to cluster in areas where malaria is endemic. While premarital counseling has the potential to decrease the prevalence of sickle cell disease, this service is not widely available. Hence, Sickle cell disease remains a significant health concern in Nigeria.
In the last decade we have witnessed improvement in the approach to management of sickle cell disease due to the effectiveness of hydroxyurea and other supportive measures in reducing the frequency of pain crisis associated with the disease.
While effective, the medications are expensive and not widely available to those likely to benefit from its use. Therefore, sickle cell disease remains a major problem affecting many Nigerians with the potential for increased morbidity and shortened life expectancy.
HLF is positioned to foster research in Sickle Cell Disease through collaboration, and strategic partnerships with support groups and organizations such as Sickle Cell Foundation of Nigeria to assist patients and relatives in dealing with this prevalent disease amongst us.”.
Malaria and HIV/AIDS
In isolation, malaria is a global threat that accounts for substantial losses both in terms of economics and lives lost in Sub-Saharan Africa and Nigeria. Malaria causes over 300 million acute cases annually with over 1 million deaths yearly in the Sub Saharan region.
The most vulnerable are the very young and pregnant women. Malaria is also a threat to people who suffer from sickle cell disease by worsening preexisting hemolysis of the red blood cells, a finding that characterize the disease.
An even greater threat to Sub-Saharan Africa, is the increasing prevalence of HIV/AIDS in the same geographical areas where malaria is endemic and sickle cell disease is rampant.
Current estimates indicate that there are over 25 million cases of HIV infection in Sub-Saharan Africa, accounting for over 60% of the global burden of HIV/AIDS. The combination is lethal because HIV infection impairs immunity to malaria, while malaria infection activates immune function, which may also promote HIV replication and infection.
Sadly, treatment directed at HIV/AIDS also has the potential to cause malaria treatment failure. Hence, we face the precarious situation where the combination of HIV/AIDS and malaria infection has potential devastating effects.
With the fragile health care delivery system and widespread poverty in Sub Saharan Africa, there is an urgent need for action to ensure that the carnage due to co-infection with HIV/AIDS and malaria is curtailed or stopped.
Health Life for all Foundation through established scientific and collaborative research; ability to educate and train medical personnel, public health practitioners and the populace through workshops and advocacy programs is well positioned to make a substantial difference in stemming the potential threat of malaria and HIV/AIDS.