RE:RE:How many patients required...Randomization of the patients at baseline (before study begins) should ensure that baseline characteristics between the two arms are similar and representative of the population as a whole.
i.e. number of patients between 50 and 70 y.o should be similar, number of patients at CIS tumour stage should be similar, number of patients of certain ethnicities should be similar etc. between the two arms.
Now of course randomization does not always ensure these variables are similar - especially in smaller sample sizes.
However, the baseline charadcteristics of the MCNA Ph III are public and are as we would expect - so while there is a theoretical possibility this process is not perfect, we know the facts in relation to this case.