Most hospitals in the U.S. fail to check colon cancer patients thoroughly for signs their tumour is spreading, say researchers.

Checking more lymph nodes is linked to improved survival from colon cancer because it allows doctors to accurately diagnose the stage of disease and prescribe the most effective treatment, such as chemotherapy.

In the last 10 years, several oncology organizations that set guidelines in the U.S. and Canada have recommended examining at least 12 lymph nodes to determine if colon cancer has spread. Whether cancer has passed through the lymph nodes is important to long-term survival.

In Tuesday's online issue of the Journal of the National Cancer Institute, Dr. Karl Bilimoria of Northwestern University in Chicago and his team said they found more than 60 per cent of nearly 1,300 hospitals in the U.S. failed to comply with the guideline.

"Every surgeon has a story about a colon cancer patient where the pathology report showed only a few lymph nodes and no cancer was found," said Bilimoria, who also is a research fellow at the American College of Surgeons.

"Then the surgeon asks the pathologist to check six or eight more nodes, and one of those turns out to be positive for cancer. That completely changes the treatment plan."

Checking involves surgically removing fat tissue near the colon to assess the nodes, which pathologists have to painstakingly dissect, but it's a "fairly simple" way to improve care, Bilimoria said.

"Patients who could benefit from additional chemotherapy may not be getting complete treatment and have a higher chance of relapse," said Dr. Durado Brooks, of the American Cancer Society, who wasn't involved with the study. "It is something that consumers need to begin asking … Frankly, that is most likely to change medical practice."

Testing on rise

Bilimoria advised patients to protect themselves by asking their surgeon to check at least 12 nodes after surgery. If pathology reports after surgery show fewer were checked, patients should ask their surgeon about it, since more nodes can be checked from the first tissue sample.

Earlier studies estimated that up to half of colon cancer patients have at least 12 nodes checked. This study is the first to see which hospitals follow the guidelines, and the findings have been reported to each institution.

The researchers analyzed data from 74,669 colon cancer patients who underwent colectomy in those hospitals in 1996-1997 and 82,120 in 2004-2005.

The good news is that by 2004-2005, the percentage of hospitals that complied with the recommendation had climbed to 38 per cent, up from 15 per cent in the first year.

The American Joint Committee on Cancer first made the recommendation in 1987.

Colorectal cancer is the third most common cancer in Canada behind breast and lung cancer in women and prostate and lung cancer in men. About 20,000 new cases are diagnosed annually in Canada, and around 8,500 Canadians die from the disease every year.

With files from the Associated Press