Many AI companies, including Azure with their OpenAI hosting, are more than willing to sign privacy agreements that allow processing sensitive medical data with their models.
[0] https://developers.openai.com/api/docs/guides/your-data#whic...
[1] https://developers.openai.com/api/docs/guides/your-data#stor...
[2] https://platform.claude.com/docs/en/build-with-claude/zero-d...
The models are licensed to Microsoft, and you pay them for the inference.