A positive predictive value (PPV) of 0.70 for a lung cancer test means that

1-If the person has lung cancer, they have a 70% chance of testing positive.

2-If the person tests positive, they have a 70% chance of having lung cancer.

3-If the person has lung cancer, they are 70% sure that they have it.

4-If the person has brain cancer, they have a 70% chance of testing positive.