| Abbreviation | Definition |
|---|---|
| OS | Overall Survival |
| OSCR | Oncology Symptom Control Research |
| OSL | Oncology Systems Limited |
| OSM | OncoStatin M |
| OSS | Osteo Sarcoma Surgery |
| OTI | Oncology Training International |
| OTN | Oncology Therapeutics Network |
| OTRU | Ontario Tobacco Research Unit |
| OWR | One Woman's Reconstruction |
| PAC | Partners Against Cancer |
| PASRR | Pre-Admission Screening and Resident Review |
| PAT | Physical Ability Test |
| PBSC | Peripheral Blood Stem Cell |
| PBSCH | Peripheral Blood Stem Cell Harvest |
| PBSCR | Peripheral Blood Stem Cell Rescue (transplant) |
| PBSCT | Peripheral Blood Stem Cell Transplant |
| PBTR | Pediatric Brain Tumor Research |
| PBTRI | Pediatric Brain Tumor Research Institute |
| PC | Pancreas Cancer |
| PC | Prostate Cancer |