Written by Miyako Rogers, Science Writer
In a new study published in Nature, researchers developed a large prostate cancer genomics resource for sub-Saharan Africa, identifying around 2 million somatic variants. They then compared this data to patients from around the world and revealed African-specific traits such as increased tumour mutational burden, more genome alterations, specific driver genes, and more.
Lack of diversity in genomics research
While prostate cancer is a global issue, mortality rates across sub-Saharan Africa are 2.7-fold higher than global averages. Moreover, due to a lack of diversity and inclusion in genomics studies and scientific research in general, we don’t know the genetic and non-genetic factors that specifically contribute to prostate cancer in sub-Saharan Africa. Furthermore, to incorporate genomic medicine into cancer care for African patients, data specific to that population is required.
To address this issue, researchers gathered data to produce the largest cancer and prostate cancer genomics study for sub-Saharan Africa to date. Researchers used whole-genome sequencing and then used a mutation-calling and analytical framework to interpret their data and came up with some interesting findings.
African-specific findings
Researchers found that those with African ancestry had an elevated tumour burden, higher percentage of genome alteration, greater number of predicted damaging mutations, and higher total of mutational signatures compared with others. They also identified the specific driver genes NCOA2, STK19, DDX11L1, PCAT1 and SETBP1.
Researchers also defined a new prostate cancer molecular taxonomy they called “global mutational subtypes” (GMS). Investigations confirmed that GMS-B, which describes copy-number gain mutations, and GMS-D, describing “mutationally noisy” features, are specific to African populations. GMS-A, described as “mutationally quiet” was found to be universal to all ethnicities and GMS-C, which describes copy-number loss mutations, was found in African and European populations.
Future implications
This African-specific information will not only inform and improve treatment strategies for prostate cancer patients of African ancestry. It also highlights the need for diversity and inclusion in landmark studies. Moreover, the creation of GMS subtypes to describe intrinsic and extrinsic mutational processes in cancer may be a new way for researchers to describe their findings and put genomics data in a global context.
