Opportunities and challenges for the implementation of pharmacogenomics in supportive care for gastrointestinal cancer patients in Zimbabwe

Supportive care in oncology aims to prevent and manage cancer-related side effects. This study reviews supportive medications for gastrointestinal cancer patients, analyzes usage patterns, biomarker frequencies, and feasibility of dose adjustments.

A 10-year retrospective study was performed at Parirenyatwa group of Hospitals, Radiotherapy & Oncology Center evaluating the supportive care medicines prescribed for all gastrointestinal cancer patients.

A total of 607 patients were analyzed, 42% receiving cancer-specific treatment and 58% best supportive care. Patients who receive cancer-specific treatment, 200 participants (78%) received at least one supportive care medicine compared to 250 (71%) in the best supportive care group (OR 1.4; 95% CI 0.96–2; p = 0.08).Seventeen different supportive care medications were prescribed, seven (41%) of these have pharmacogenomic biomarkers testing recommendation. More patients in the cancer-treated group received medicines with actionable pharmacogenomic biomarkers than in the best supportive care group (56% versus 40%; OR 1.9; 95% CI 1.38–2.66; p = 0.0001). PGX guidelines were fully implemented for tramadol, codeine, omeprazole, and ondansetron; partially for ibuprofen and celecoxib; and unimplementable for amitriptyline.

There is an opportunity to improve supportive care in gastrointestinal cancer patients through pharmacogenomics though some specific medicines challenges to full implementations are due to limited registered medicines.