Women and low income individuals more likely to have dangerous colorectal cancer complications at time of diagnosis

A new study from the Institute for Clinical Evaluative Sciences (ICES) shows that women and low income individuals are more likely to have serious complications at the time they are diagnosed with colorectal cancer (CRC), despite the fact that early detection through regular screening can greatly reduce the burden of this disease.

“Although elective surgical resection is the treatment for CRC, a proportion of patients are only diagnosed once they experience an acute bowel obstruction, a perforation at the site of the tumour, or an emergency admission to hospital, all of which signal more advanced disease,” said lead author and ICES senior scientist Dr. Linda Rabeneck.

“However, up until now, no studies have evaluated what factors put CRC patients at greater risk for these adverse events. Identifying these factors could be useful to better target screening and diagnostic services.”

To investigate this issue, ICES scientists tracked Ontario adults 20 years of age and older who were newly diagnosed with CRC between 1996 and 2001. The proportions that had acute bowel obstruction, a perforation at the site of the tumour, or who required emergency admission to hospital were calculated, and factors associated with these poor outcomes were identified.

During the study period, 41,356 people were diagnosed with CRC and 7,739 (19%) of these patients were diagnosed because they experienced these dangerous complications. Women had 7% higher odds compared with men, and low income individuals had 22% higher odds compared with the higher income group for experiencing these complications.

“There are several potential explanations for our findings,” said Dr. Rabeneck. “Lower income people may have a harder time accessing colonoscopy services to be screened for CRC. Women may tend to be averse to colonoscopy because of a reluctance to undergo procedures performed by a male physician, largely related to a sense of embarrassment.

“Nevertheless, it is encouraging to hear that the Ontario government intends to implement a CRC screening program later this year, becoming the first province in Canada to do so, because organized population-based CRC screening is the best way for us to prevent the disease or catch more cases early on when the cancer is easier to treat.”

The study, “Risk factors for obstruction, perforation or emergency admission at presentation in patients with colorectal cancer: a population-based study”, is in the May 2006 issue of the American Journal of Gastroenterology.

Author affiliations: ICES (all authors); Toronto Sunnybrook Regional Cancer Centre (Drs. Rabeneck and Paszat); Departments of Medicine (Dr. Rabeneck), Radiation Oncology (Dr. Paszat), and Health Policy, Management and Evaluation (Drs. Rabeneck and Paszat), University of Toronto.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

FOR FURTHER INFORMATION, PLEASE CONTACT:

• Julie Dowdie,
• Media Relations Officer. ICES
• (416) 480-4780 or cell (416) 432-8143