Forensic short tandem repeat markers alteration in cancerous tissues: a scoping review

Short Tandem Repeats (STRs) are segments of DNA composed of a short sequence of nucleotides that repeat consecutively. These repeating sequences exhibit distinct lengths and nucleotide sequences among individuals, showcasing high variability and uniqueness. The STR profile remains consistent across all cells in an individual’s body. Nonetheless, changes in the STR profile have been documented in cancerous tissues. This scoping review aimed to investigate the occurrence and pattern of forensic STR markers alterations in cancerous tissues. We conducted a scoping review of the English-language publications published between 2002 and 2022 in the PubMed, Science Direct, and Scopus databases and a manual search of reference lists from reviewed papers. The review was carried out in compliance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews. Our search resulted in a total of 1,065 articles associating forensic STR studies with cancerous tissues. A total of 18 of these studies met our inclusion criteria. The D18S51 marker was most often found to be altered when associated with cancers such as breast, colorectal, gastric, gynaecology, and lung cancers. Following with that, FGA, VWA, D19S433, and D13S317 markers could as well be seen to have allelic alteration in cancerous tissues. Four other STR markers (TPOX, D7S820, D2S1338, and Penta D) could be potentially represented as stable STR markers in cancerous tissues. According to our review, colorectal cancer tissue has the highest level of genomic instability compared to that of other cancer types. In summary, the genetic instability caused by faulty DNA mismatch repair processes in human carcinomas can pose challenges for forensic genotyping and DNA profile matching.