KRAS Biology and Molecular Profiling in Pancreatic Cancer

Dr Balmaceda, a gastrointestinal medical oncologist at MD Anderson Cancer Center, opens with a patient who presented with abdominal pain, fatigue, and weight loss, and was found to have a pancreatic head mass with liver metastases and biopsy-confirmed pancreatic ductal adenocarcinoma. The patient responded to first-line combination chemotherapy before progressing, and comprehensive genomic profiling returned a KRAS mutation with a co-occurring TP53 alteration, microsatellite stable disease, and low tumor mutational burden. Dr Lee, a gastrointestinal medical oncologist at Stanford University, calls that a standard profile for the disease and notes that TP53 has no drug targeting it directly, while the microsatellite stable, low tumor mutational burden findings make immunotherapy unlikely to help. Dr Balmaceda then describes KRAS as an on and off switch that cycles between guanosine triphosphate and guanosine diphosphate bound states and stays locked on when mutated, and explains that molecular imaging revealed the pocket that finally made a long-standing undruggable target reachable.