The highest class-specific risks were neutropenia grade 3-4 for CDK4/6 inhibitors (OR 40.77; 95% CI 19.52-85.19), stomatitis grade 3-4 for mTOR inhibitors (OR 11.92; 95% CI 3.68-38.57), hyperglycemia grade 3-4 for PI3K inhibitors (OR 40.93; 95% CI 10.08-166.22) and diarrhea for anti-HER2 agents (OR 9.93; 95% CI 4.71-20.95).