My Father Had A Prostat Cancer Before 3 And Half Years. Why It Is Happening ?

my father had a prostat cancer before 3 and half years back i m writing from pakistan sir my father had a prostat cancer before 3 and half years back with the advice of dr he had surgery in good time at age 64 he dignosed cancer after surgery the radiotherphy also provide with the help of GOD every thing is done in good way my father coming into a routine life he do every thing regular check up with dr psa test check up means everuy test is on routine but sir 1month back he had bleeding with urine every test is again all is correct but we r confused y its bleeding psa is correct everything and dr also said this is sideaffescts of radiation my father dont want to do cystoscopy every test is fine than y its happening after 3 years of radiation yes one think my father is in tension hypersensitive and smoker sir help me i m waiting sir my father age is 67 when he had operation his age was 64 before 64 he is eating medicine of angina ascard loprin lexotnal ezita renitec the blood pressure control he is hypersensitive but after 64 cancer medicine also start sir pls only tell me that y bleeding is coming because every test top to tip is normal regular check up sir i cant come to america i live in pakistan sir or do mea favor my sister also doctor can u talk with her only we want to know y its happening pls answer the cause hurry i mthank ful to you regards