The role of PARP inhibitors in gastrointestinal cancers

The use of BReast CAncer (BRCA) mutations as biomarkers for sensitivity to DNA damage response (DDR) targeted drugs and platinum agents is well documented in breast and gynaecological cancers. More recently the successful use DDR targeted therapies including poly (ADP-ribose) polymerases (PARP) inhibitors has been shown to extend to other germline and somatic deficiencies within the homologous recombination (HR) pathway (Farmer et al., 2005; Turner et al., 2019; Li and Heyer, 2008). Gastrointestinal (GI) cancers are lagging behind other tumour types when it comes to personalising treatment with targeted therapies. Current methods of identifying PARP-inhibitor sensitivity in gastrointestinal cancers are based on analogies from other cancer types despite there being a lack of uniformity in determining HR status between tumour types. There is an urgent clinical need to better understand the treatment implications of DDR alterations in gastrointestinal cancers. We have reviewed PARP-inhibitor use in pancreatic, gastroesophageal, hepatobiliary and colorectal cancers and explored HRD as a biomarker for sensitivity to PARP-inhibitors.

Automated summary

The use of BRCA mutations as biomarkers for sensitivity to targeted drugs and platinum agents is well documented in breast and gynecological cancers. Recent studies have shown that DDR targeted therapies extend to other deficiencies within the HR pathway. However, gastrointestinal cancers lag behind in personalized treatment and current methods for determining PARP-inhibitor sensitivity are based on analogies from other cancer types. Therefore, it is important to better understand the implications of DDR alterations in gastrointestinal cancers.