Majority of kidney cancer cases diagnosed at earliest stage

Individuals with kidney cancer in the United States now are more likely to have their tumor diagnosed in the most treatable stage than they were a decade ago, leading to a slightly higher survival rate, according to a study published in the May 19 online edition of Cancer.

The national study, led by Christopher J. Kane, MD, of the University of California, San Diego Medical Center and the Moores UCSD Cancer Center, analyzed records of more than 200,000 kidney cancer patients described in the National Cancer Data Base to determine how kidney cancer presentation has changed over a 12-year period.

“The changes in kidney cancer presentation are visible nationally and quite dramatic,” Dr. Kane said. “If you are diagnosed with kidney cancer today, it is more likely to be at the earliest stage I level as opposed to more advanced stage II, III, or IV just a decade ago. The study also reveals a small but significantly higher survival rate for recently diagnosed kidney cancers. This is good news for the more than 50,000 kidney cancer patients who will be identified this year.”

The analysis looked at kidney cancer data between 1993 and 2004 and revealed that stage I kidney cancers increased from approximately 43% in 1993 to 57% in 2004, but decreased in stages II to IV of the disease. The average size of the stage I tumors decreased from 4.1 cm in 1993 to 3.6 cm in 2003. Overall survival for all patients with kidney cancer increased 3.3% between 1993 and 2003. The 5-year survival rate for people with stage I kidney cancer is now 88% or better.

While the reason for the downward trend is not known with certainty, the low stage presentation of tumors appears to be due to more widespread use of medical imaging such as ultrasound, CT scans, and MRIs to evaluate other medical conditions.