Link between malaria resistance and breast cancer spread, study suggests


Scientists in South Africa have found a link between a particular type of malaria resistance and the likelihood of cancer metastasis in some patients of African descent.

Geoffrey Siwo, research scientist at IBM Research Africa and his team in Johannesburg have been aiming to predict and attempt to solve Africa’s future health issues.
Such ambitious ideals meant they had to start noticing trends in the region – one being that in some African countries the population was becoming wealthier and aging slowly, however the burden of cancer was greater.
In 2015, the older population (aged 65 and over) exceeded 1 million in 11 African countries, including Nigeria, 5.6 million; Egypt, 4.6 million; and South Africa, 3.1 million.
The team was fascinated by how cancer starts to interact with other diseases prevalent in the region, such as malaria.

Distinct gene

Using publicly available data they attempted to map how cancer spreads through the body, in what’s known as metastasis.
Among the data they stumbled upon something remarkable – a gene possibly linking people whose cancers lead to metastasis, particularly in breast cancer patients, and people showing resistance to malaria.
Many Africans have a distinct form of the Duffy Antigen Receptor (DARC) gene compared to other world populations.
A mutation of this gene, ‘makes most Africans less susceptible to a type of malaria caused by the parasite Plasmodium vivax,’ Siwo told CNN.
DARC encodes a protein that is used by the parasite to get into human red blood cells. Most Africans have a mutation of this gene that doesn’t allow it to be expressed in red blood cells, and therefore the parasite finds it difficult to get into the red blood cells of these individuals – giving those with the mutation a high level of resistance.
It’s impossible to know exact population figures for the DARC variant but frequency rates are thought to be around 95% in West Africa, and between 70 to 95% in sub-Saharan Africa.
Siwo and his team found that in some patients those with this inbuilt resistance had lower survival rates for breast cancer than those without.
The research and findings were recently presented at the American Society for Human Genetics symposium on Pharmacogenomics, and will be published next year.

Potential for personalised therapy

A mutation in the DARC gene and its potential link with cancer outcomes is ‘very interesting’ says Dr. Sarah Tishkoff, a professor of genetics and biology at the University of Pennsylvania. It is ‘of potential high significance, particularly given observed differences in cancer risk among different ethnic groups,’ she adds.
‘If this variant does play a role in cancer metastasis, it would be an example where a genetic variant which rises to high frequency due to protection from malaria may also be associated with disease risk’, she adds.
Dr. Tishkoff suggests negative outcomes have been known for other malaria resistance genes for example those associated with Sickle Cell Anaemia. But more evidence is needed she notes on whether it directly impacts cancer statistics.
Similar studies, for example research carried out in China, presumed that a lack of DARC expression predisposes African-American men to a greater incidence and mortality of prostate cancer, as well as a similar correlation between the DARC variant and breast cancer deaths.
‘It could be further explored by future studies in Africa looking for correlations between variation at this gene and the risk of cancer,’ says Dr Tishkoff.
Siwo agrees that more research is needed, which the team intends to carry out, but he’s enthusiastic on potential findings. ‘The knowledge that low expression of DARC might influence breast cancer outcomes, especially in some breast cancer patients means that in future it could potentially be used for personalising therapy or precision medicine,’ he says.

Cancer, often diagnosed late

‘The true extent of cancer [within Africa]has not been realised because it is mostly diagnosed at the late stages,’ adds Siwo.
In South Africa, there’s a five-year lag time between hospitals recording a cancer diagnosis and it being documented in annual national statistics of new cases.
‘That means, the cancer statistics we have for South Africa today is outdated by about five years, a problem that also occurs in all other countries even though with a lesser delay,’ says Siwo.
The team wants to work towards faster data collection within South Africa and more widely across the continent.
By tracking data digitally and pooling efforts across Africa, we can attempt to improve this, explains Siwo.
His team is working with the South African National Cancer Registry and the University of Witswaterand in Johannesburg to develop a system that would automatically collate the required cancer statistics in a shorter time frame.
Greater access to technology means ‘we are looking at solving problems in Africa in a way we never thought possible before,’ he says.
Siwo believes diseases such as cancer will start to impact Africa more so than elsewhere if not properly tackled.
There is a wider reach to try and get more of Africa’s budding scientists involved in targeted solutions through organised hackathons and problem-solving workshops within South Africa.
‘We are attempting to find long-term solutions,’ says Siwo. ‘New ways of addressing and treating cancer, tuberculosis, AIDS, HIV — these answers can only be found through the engagement of young scientists in Africa.’
Written by Nosmot Gbadamosi. This story was sourced from the CNN website.

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