- osteosarcoma
- ostomy
- OTC
- otolaryngologist
- ounce
- outcome
- outpatient
- Ovaban
- OvaRex
- ovarian
- ovarian ablation
- ovarian borderline malignant tumor
- ovarian cancer
- ovarian cancer peptide vaccine
- ovarian epithelial cancer
- ovarian germ cell tumor
- ovarian low malignant potential tumor
- ovarian suppression
- ovary
- OVax
- over-the-counter
- overactive thyroid
- overall survival rate
- overdose
- overexpress