Hello dear student, 

We all know it's difficult to crack exams for masters and it's even not that difficult if you know your interest already. And if you have studied those subjects already in your b.sc . Now considering how you should study . So I would suggest you to go through previous year's of the university you want to take admission in . Paper's must be available online and cover the major part of cancer biology. But first you need to check for the pattern of the paper , the syllabus comes in the entrance. Only that can help you to score good in entrance 

I hope this was helpful

Best wishes