Scientists in the UK have discovered that kidney cancer follows three different evolutionary “pathways” that correspond to three different forms of the disease. The discovery will help physicians make trusted conclusions about whether the tumor will be aggressive.
A second British study suggests that the first “seeds” of kidney cancer can often occur from childhood or adolescence, even 40 or 50 years before diagnosis of the disease, until then unnoticed.
Researchers from the Francis Kick Institute, Royal Marsden Hospital and UCL, headed by oncologist Shamra Turajlik, who published the journal Cell Cell Biology, analyzed more than 1,000 tumor samples from 100 patients with kidney cancer in order to reconstruct for each patient the sequence of genetic events that eventually led to cancer.
It has been established that there are three distinct evolutionary types of the disease. The first type follows a slow path of evolution and never gets aggressive. The second type, on the contrary, creates the most aggressive tumors, through rapid genetic damage from the early stages of cancer development. This allows the tumors to extend to many other parts of the body, often before even the original tumor is diagnosed.
The third type has an intermediate progression, as it acquires the ability to spread, but the genetic mutations it causes are becoming gradual and not fast. These tumors usually grow at longer intervals and often only in one area. They are composed of many different cancer cell populations, of which only some are aggressive. Scientists confirmed these findings, also analyzing samples of tumors from people who had died of kidney cancer.
“The prognosis of patients diagnosed with kidney cancer differs greatly from one another. We first showed that these differences have their root in the distinct way that these cancers are evolving. Knowing the next step in the evolutionary course of each cancer will help individualize treatment for each patient within the next decade, “said Turajlik.
So, according to the researchers, patients with less aggressive tumors will no longer perform surgery, but will simply be placed under surveillance.
Tumor analysis also revealed a series of chromosomal features that distinguish those cells in primary tumors that will lead to secondary tumors from cells that will never give up the original tumor to make metastases. The detection of two chromosomal changes that are a precursor of metastases will in future be a useful biomarker for identifying patients with the most aggressive forms of the disease.