I would like to know how deadly is "wilms tumor?

The Staging of Wilms: Dictates survival, as well as whether hitology is favorable or not. Stg i-iii carries only 5% lethality with favorable histology, but that figure is 15-30% less with unfavorable histology. Stage IV and v have about 15% mortality with favorale histology, but unfav stage v has55% surv, stage IV only 40%. This is of course with treatment, mostly surgery and chemo.

Depends: The prognosis for wilms tumor really depends on the stage of disease and how it looks under the microscope. Generally patients with localized disease and favorable histology wilms tumor do very well while the prognosis for metastatic wilms tumor is not as good.