My father has lung cancer stage 3 he recently took a very hard fall that he even passed out on the side he has the cancer will it affect him?

Other than the: physical trauma of the fall this is unlikely to cause a change in the cancer issue.

Yes and No: I don't believe it's ever been reported that a recent trauma would worsen the growth or spread of a cancer tumor, (at least not in according with our present understanding, though our knowledge evolves over time). But an important question is what caused him to pass out and fall in the first place. Also the injury itself would will take some toll on his body as he heals, as it would for you or I.

Lung cancer : This question is hard to answer without more details. Most likely the fall will not affect the lung cancer or visa versa. The real question is why did he pass out? If he is getting treatment his electrolytes and blood pressure need to be checked. Good luck and feel better!

Concussion: could have its own damage and if he is on chemo he might be more likely to bleed in his brain from a fall. He needs to be seen. Good luck.