Researchers looking at multiple different levels of changes in clear cell renal cell carcinoma (ccRCC) are closer to determining how these tumors grow and survive. RCC is the most common neoplasm of the kidney.

According to a statement from St. Michael’s Hospital in Toronto, Ontario, Canada, where investigator George M. Yousef serves as a laboratory pathologist, scientists have been seeking to learn how different people have kidney tumors with the same histology despite the fact that the genetic changes within individual tumors can vary. Such knowledge could improve the diagnosis and treatment of ccRCC.

As Yousef and colleagues reported in Cancer Research (2012;72[20]:5273-5284), they looked at three different ways in which cancer cells can grow and survive:

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  • The tumor can amplify (or replicate) its chromosomes.
  • The tumor can alter a process that controls the on/off switch for genes needed for cell growth and differentiation, known as methylation.
  • The tumor can drive gene activation through another gene.

Evaluating all these changes simultaneously in the same setting improved the group’s understanding of tumor behavior and how the apparently different changes can produce the same results. By using a high-resolution microarray, Yousef’s team also was able to identify very specific regions of the chromosomes where genetic alterations take place in RCC to a much higher resolution than previously. Combined information from chromosomal changes, methylation, and gene expression provided a much clearer picture of the mechanism of kidney cancer development.

“Now we look at the mechanism rather than the individual change,” explained Yousef in the St. Michael’s statement. “Regardless of the apparent differences in the tumor, the outcome will be the same. Eventually, we may be able to target treatment based on the mechanism that is affected rather than on the individual genes that are changed.”