HHS OCR report · 2021
Cancer Centers of Southwest Oklahoma, LLC data breach
OCR report facts
- Covered entity
- Cancer Centers of Southwest Oklahoma, LLC
- Entity type
- Healthcare Provider
- State
- Oklahoma
- Individuals affected
- 8,000
- Submission date
- Jun 4, 2021
- Type of breach
- Hacking/IT Incident
- Location of breached information
- Electronic Medical Record, Network Server
- Business associate present
- Yes
- Status
- Archive (closed)
OCR description
The covered entity (CE), Cancer Centers of Southwest Oklahoma, LLC, reported that its business associate (BA) experienced a ransomware attack that compromised the electronic protected health information (ePHI) of 6,253 individuals. The ePHI involved included names, addresses, dates of birth, driver’s license numbers, Social Security numbers, medications prescribed, lab results, and diagnoses/conditions. The CE notified HHS, affected individuals, and the media.
Text as published on the HHS OCR breach portal.
Frequently asked questions
How many people were affected by the Cancer Centers of Southwest Oklahoma, LLC data breach?
The report to HHS OCR lists 8,000 individuals affected.
When was it reported to HHS?
It was submitted to HHS OCR on Jun 4, 2021.
What type of breach was it?
The OCR portal lists the type of breach as Hacking/IT Incident, with the breached information located in: Electronic Medical Record, Network Server.
Is the investigation still open?
No. The report is in the OCR portal archive, which holds reports where OCR has closed its review.
Is a breach notice letter from Cancer Centers of Southwest Oklahoma, LLC legitimate?
This site cannot verify letters. Check the sender against the organisation's official website and the HHS OCR breach portal, and avoid calling numbers or clicking links only listed in an unexpected message. See our guide on what to do after a data breach notice.
Source: HHS OCR Breach Portal, OCR export October 2026. Network USA is not affiliated with HHS or Cancer Centers of Southwest Oklahoma, LLC.