Including some dairy food options is a good way to boost your protein intakes. But many people give up dairy foods when they find out they have cancer, especially women with breast cancer. I do not recommend this and would advise anyone who has taken this step to revisit the evidence behind this hot issue. Recent studies actually suggest that dairy foods or foods high in calcium are protective for some cancer including breast. Dairy is also a much better source of quality proteins than alternate milks, it also provides a more usable source of calcium. If you are eating well then it is may be better to use lower fat, no added sugar options. Whilst full cream might be the better choice if you are struggling with your appetite or having problems with weight loss.
Zhang.J., The Association between Dairy Intake and Breast Cancer in Western and Asian Populations. A systematic review and meta-analysis. J Breast Cancer. 2015 Dec;18(4):313-22.