It is important to consider what sort of things can affect the sample collection rate or the results of the DNA testing. Unfortunately, there is not a simple black and white answer to this.
Our bodies are fantastic things and it's difficult to say exactly what the effects of specific drugs or treatment can have on them. We know that different people can have the same treatment and experience different side effects and also the severity of those effects will vary.
With chemotherapy and radiotherapy treatments in particular, what we do know is that this has the ability to affect the results. It can damage some of the cells, or even the DNA itself that we look at in order to provide you with results. In this case, we recommend that you allow 6 months from the date of your last treatment to take your DNA sample.
If you have any further concerns about past, present, or future treatment and your results with us your healthcare provider is the best most qualified person to answer these, they will have far greater knowledge than ours about the specific treatment you are receiving, and will, therefore, be able to give you advice that's correct for you.