my ob told me he saw a mass between bladder and urethra.he said he hopes it's not tumor.he referred me to urologist,check up is next week.im scared. is it possible that i have cancer? im still young.im just 31. can this be treated? can you give me some informations. thank you.

If it is cancer then it will be traeted. there are various options which will be chosen as to the type of cancer and your medical history. There is:-
Chemotherapy. Basically a drug which kills the cancer cells from inside.
Radiotherapy. using X rays to kill the cells
Surgery. Removal of the mass.

Fingers crossed that you're worrying for nothing, you do seem young to be a potential victim;