Bromelain is widely available in supplement form, though it is a good idea to go with a quality product as it has been found that effectiveness and actual bromelain content varies widely from one manufacturer to another. A good place to look in my opinion would be iherb.com, where you can also find some good combination enzyme products such as Garden of Life's OmegaZymes as well as Serrapeptase supplements (I use the Doctor's Best brand). If you have never ordered from iherb before, you can use my referral code of X0T949 to get $5 off your first order (I am not an affiliate of iherb's, but I do get a few cents credit on my own future purchases when someone uses the code).
A modestly priced quality enzyme combo is JarrowZymes Plus, which you can get at a number of places including CureZone sponsor Utopia Silver Supplement Company (and you can get 15% off if it is not currently on sale at Utopia if you use the CureZone discount code of LR001).
Besides the fact that digestive/pancreatic enzymes may directly help fight cancer cells, they also help digest some of the foreign proteins in our diet, which can cut down on mucous production. Mucous is a defense mechanism the body uses in response to foreign objects. Thus, digesting and helping eliminate such objects can result in less mucous.
A further note: healthy mucousal linings are needed for optimum health and immune function. When they are stripped away, the body struggles mightily to rebuild them. For that reason, it is important to balance the need for cleansing with the need to maintain healthy mucousal linings. Perhaps the best plan would be initial cleansing and then limited cleansing thereafter. One exception when it comes to cancer in my opinion would be coffee enemas, especially at the outset of adopting an anti-cancer protocol.
The late great cancer pioneer Max Gerson observed that he never found a single cancer patient who did not have an impaired liver. In fact, initially half of his patients who were using his intensive juicing therapy ended up dying of liver failure due to the large release of toxins having to be processed by already impaired liver. Thus measures such as coffee enemas, coconut milk, curcumin, and beet root juice to help open the bile duct and keep it open and flowing to release toxins can be critical. I also consider milk thistle to be a critical element for liver health since it helps protect and regenerate the liver.