The study also sheds light on cancer’s strategy for hiding from defenses. Tumor cells increase the production of prostaglandin E2, a lipid substance that blocks the action of monocytes. At the same time, they decrease the production of interferons, proteins that stimulate the immune system. The Vienna group argues that anti-inflammatory drugs that inhibit cyclooxygenase, such as aspirin, are “a promising strategy” to increase the effectiveness of immunotherapy, since they block the production of inflammatory molecules, such as prostaglandin E2.

Interesting as aspirin, acetaminophen, and ibuprofen all inflame the gut to some degree, so although they reduce inflammation in the rest of the body your GI doesn't react well.

Interesting trade off. Amazing development in understanding!