Assessment of microsatellite instability in prostate tissue samples from patients with prostate cancer in Burkina Faso

A major global public health issue, particularly in sub-Saharan Africa, prostate cancer (PCa) is most often diagnosed at an advanced stage. Data on the molecular mechanisms involved in African populations remain limited. Among the genetic alterations studied, microsatellite instability (MSI) is a marker of genomic instability with diagnostic and therapeutic significance. This preliminary study aimed to assess the frequency and characteristics of MSI in patients with PCa in Burkina Faso. Eighty-four patients with histologically confirmed prostate cancer were enrolled between July 2023 and June 2024. MSI status was analyzed using five standard markers from the Bethesda panel by conventional Polymerase Chain Reaction (PCR) followed by agarose gel electrophoresis. Overall, 78.6% of tumors were microsatellite stable (MSS), while 21.4% were unstable (20.2% MSI-Low (MSI-L) and 1.2% MSI-High (MSI-H)). The most frequently unstable marker was D5S346 (14.3%), followed by BAT26 (7.1%). MSI was significantly associated with age ≥ 65 years ( p = 0.011), Prostate Specific Antigen (PSA) levels > 100 ng/mL ( p = 0.004), and Gleason score (GS) ≥ 7 ( p = 0.003). However, these associations were not confirmed by multivariate analysis. These results confirm the rarity of the MSI-H phenotype in PCa but suggest that the MSI-L phenotype may be more common in our population.