My friends lungs are full of tumers from forth stage breast cancer, she is having coughing fits and her docs haven't given her oxygen therapy, why not?

O2 won't stop cough: Oxygen will not stop the cough.It may help her feel a bit better but a strong cough med is probably indicated.Is hospice needed?They do a wonderful job of helping when conditions seem bleak or unsolvable to usual care.

Her oxygen level OK?: It sounds like your friend is quite ill, but she may not oxygen yet. This is quite easily determined in an office setting with a pulse-oximetry meter. If she is having shortness of breath, easy fatigue etc..It is reasonable to check her oxygen status. Treating her coughs may make her more comfortable. Advise her to consult her docs... Wish her luck for me...

Possibly...: Oxygen can only be prescribed if her oxygen level is low enough to warrant this therapy. So, your friend's oxygen level is likely not low enough. Her doctors will likely monitor this and prescribe it if/when necessary (her pulse ox needs to be below 88% on room air to qualify). I am very sorry about your friend's illness. Best of luck to both of you!

Oxygen therapy: Oxygen is only needed if a persons blood oxygen is below a certain level the treatment of symptoms is not oxygen unless a person is not able to keep a good level of oxygen without supplement so if your friend has a po2 of >90 without oxygen he may not need any.