May 27 (HealthDay News) -- Over the past 15 years, the average survival rate for patients battling advanced colorectal cancer has increased dramatically, new research indicates, due in equal measure to the advent of new, powerful drugs and more frequent surgical interventions.
While in the early- to mid-1990s, the average patient would have survived about 14 months post-diagnosis, by the late 90s that figure began a rapid ascent, the study revealed. The result: The average life expectancy for a newly diagnosed patient today has doubled, to just shy of 30 months post-diagnosis.
Longer-range survival prospects also improved. Where fewer than 10 percent of patients could expect to live five years post-diagnosis in the early to mid-90s, a projected 30 percent of patients can now look forward to that prospect.
"What we're seeing is that over the past several years both an increase in the use of new chemotherapies and a more aggressive use of surgery for removing cancer that has spread to the liver has resulted in very significant increases in longer survival for patients," said study lead author Dr. Scott Kopetz, an assistant professor in the department of gastrointestinal medical oncology at the University of Texas M.D. Anderson Cancer Center in Houston. "And this increase is of a magnitude that is rarely seen in the treatment of cancer," he said.
The findings appear in the May 26 issue of the Journal of Clinical Oncology.
Colorectal cancer is the fourth most common cancer in the United States, with nearly 150,000 patients diagnosed in 2008 alone, according to the American Cancer Society.
In their effort to gauge patient survival trends, the authors first reviewed data regarding nearly 2,500 colorectal cancer patients who had treatments at either M.D. Anderson or at the Mayo Clinic between 1990 and 2006.
In that time, overall average survival rates went up, from about 14 months post-diagnosis between 1990 and 1997 to almost 19 months between 1998 and 2003. By the end of the study in 2006, that figure had shot up to just over 29 months.
Five-year survival rates also increased, from just over 9 percent between 1990 and 1997 to 13 percent between 1998 and 2000; and then again to just over 19 percent between 2001 and 2003. The authors now estimate that nearly 30 percent of patients diagnosed between 2004 and 2006 will ultimately have survived five years post-diagnosis.
These trends were confirmed by a secondary analysis of U.S. National Cancer Institute data on 50,000 patients with metastatic colon cancer between 1990 and 2005.
The researchers noted that although less than 10 percent of the patients had undergone a surgical procedure known as hepatic resection (to deal with the spread of disease to the liver), the intervention started to be performed with greater frequency beginning in 2000.
Even more impressive survival rates would be possible down the road, Kopetz suggested, if more patients who could benefit from surgery were encouraged to have it.
"Our best estimates are that 20 to 30 percent of metastatic colon cancer patients would be eligible for surgery for their disease," he noted. "But the data indicates that only about 5 percent of patients are currently undergoing these surgeries.
Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, said the findings need to be interpreted with caution.
"We have certainly made advances in treatment as a result of chemotherapy, compared to where we were 10, 15, 30 years ago, he noted. And we've also learned that there is a group of patients where we can do something with surgical techniques, and they can often go on to do very well. And yes, the results, in terms of improved survival trends, are important. But the question is, does this trend these improvements-- really apply to every institution across the U.S.?" he said.
"The answer is probably not," he added, "because the treatment opportunities and technical know-how differs from institution to institution, and even the types of patients who get seen are different. Those patients reflected in this study have, for example, come to the two places included in this analysis and sought out the very best high-quality care. And this kind of care is not always available across the country. So, this does indicate what is possible to achieve. But we have to be careful about drawing too broad a conclusion."
SOURCE: Scott Kopetz, M.D., assistant professor, gastrointestinal medical oncology, department of gastrointestinal medical oncology, University of Texas M.D. Anderson Cancer Center, Houston; Len Lichtenfeld, M.D., deputy chief medical officer, American Cancer Society, Atlanta; May 26, 2009, Journal of Clinical Oncology