The study by Deborah Schrag, MD, and her team at Memorial Sloan-Kettering Cancer Center in New York City, evaluated outcomes for almost 28,000 patients who had colon cancer surgery within six months of diagnosis. They looked at whether patients had died within 30 days after surgery (known as the postoperative death rate) and studied long-term survival. Statistical analyses were done to look for associations between hospital procedure volume and short-term or long-term survival rates.

The researchers found a 3.5% postoperative death rate among patients treated at hospitals that performed the most colon cancer surgeries, compared to 5.5% for those treated at the lowest volume hospitals. Patients treated at the high-volume hospitals also had better five-year survival rates. About 50% of patients treated at the highest volume hospitals were alive five years after surgery, compared to 45.2% of those treated at hospitals performing lower volumes.

This 2% difference in the 30-day postoperative death rate contrasts with the findings of earlier research involving other kinds of cancer surgery. Those studies found patients are up to 15% more likely to survive complicated, high-risk cancer surgeries – such as those for pancreatic and esophageal cancer – when they are performed at high-volume hospitals.

In the colon cancer study, the link between a high volume of operations and better survival persisted after taking into account the patients’ age at diagnosis, sex, race, cancer stage, presence of other serious health problems, whether or not chemotherapy was given after surgery, and other variables. Although the research does not include patients younger than 65, people older than 65 are the most likely to get colon cancer.

Michael Thun, MD, Vice President of Epidemiology and Surveillance Research for the American Cancer Society (ACS), says, "The question of where to receive health care is important, and this well-conducted study shows how important experience is in cancer care."

The study is also "very good news for small hospitals that these differences were small," Schrag says. It is also reassuring for patients who prefer to have surgery at familiar hospitals in their own communities that do not perform a high volume of surgeries. But, Schrag adds, "It would be even better if the differences [between the categories of hospitals] were still smaller."

The researchers say more study is needed to find the underlying factors – such as care during and after the operation and access to a multi-disciplinary team of health care professionals – that may explain the relationship between hospital volume and outcomes. Further study also should focus on how those factors interact with the skill of the surgeon.

Schrag recommends that colon cancer patients ask about a hospital's case volume and consider it as one of several factors in deciding where to seek treatment. The ACS estimates 135,400 new cases of colorectal cancer will be diagnosed in 2001, and 56,700 people are expected to die of the disease this year.