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Safety in Numbers: Cancer Surgeries in California Hospitals

Maryann O'Sullivan
Some hospitals perform one or two brain cancer surgeries; others do hundreds. Small volumes can mean greater risk of poor patient outcomes. See the numbers for 11 cancers at hospitals across California.
Click to View Infographic - Choosing a Hospital for Cancer Surgery Is a Delicate Operation

Despite the staggering number of Californians who are diagnosed with cancer each year — 155,920 new cases in 2014 — there is very little information to guide patient decisionmaking about where to get care. For decades research has shown that hospitals performing a low volume of surgeries are more likely to have worse patient outcomes — more complications and deaths — than hospitals with higher volumes of surgeries. But data for specific hospitals were not readily available until 2015.

Now a groundbreaking effort to address this information gap in cancer has made data on California hospital-specific cancer surgery volumes publicly available for the first time, in a report and on the consumer website

The report describes key findings from an analysis of data from the California Office of Statewide Health Planning and Development, and summarizes interviews with leaders at hospitals where these surgeries were performed infrequently to understand the factors behind the numbers.

Highlights include:

  • There is an association between low hospital surgery volume and higher mortality and complication rates for the following 11 cancers: bladder, brain, breast, colon, esophagus, liver, lung, pancreas, prostate, rectum, and stomach.
  • The majority of California's hospitals performed surgery for one or more of these 11 cancers only once or twice in 2014.
  • Of cancer patients who had surgery at a hospital that did a small number of those surgeries in 2014, more than 70% were within 50 miles of a hospital performing higher volumes.*
  • The 249 hospitals that performed only one or two of a particular procedure in 2014 are mostly urban but also rural, and they are in equal numbers small (50%) and large (50%).

These newly released data and the accompanying report, which are available as Document Downloads, can help patients, health care providers, payers, and policymakers bridge the gap between current practice and what the evidence says is best.

See How Your Hospital Compares

You can now readily look up the number of surgeries performed at California hospitals for 11 cancer types at

*Low-volume is defined as one or two of that type of cancer surgery; higher-volume is defined as the top 20% of hospitals in the state by volume for that type of cancer surgery. Fifty miles was measured from the patient's residence to the hospital as the crow flies.

The slides in the presentation above are available under Document Downloads.