How to deal with child has had cancer and language delay afterward?

Be grateful: When i was a kid in the 1950's, childhood cancer was a death sentence. Nowadays, the cure rate is high. I have physician-colleagues who were cured. Whether chemotherapeutic agents may cause language delay or whether it just happens, and whether intensive treatment is evidence-based / justifiable, i can't address -- ask your oncologist. Is junior deaf? Dr. Feynman didn't speak until he was 4.