From this specific accident. However, the evidence from radiation biology in general is that there should be a certain number of cancers (and no, don't feed me anti-LNT BS.)
But, you know, probably fewer than accounted for natural variations in the background level caused by different rock types in the area or exposure to residual fly ash from thermal power plants, right?
It seems fairly obvious that if the influence of a nuclear accident on cancer rates is dominated by other factors, one should look to mitigate those other factors before worrying about the nuclear accident as a contributor.