There is no scientific basis for the distinction between Cancer and Noncancer pain. The difference is entirely philosophical and based on personal and professional biases.

As there is no foundation in science to base any policy, rule or regulation solely on the basis of whether pain is categorized as being Cancer related or non-cancer related, any such policy is inherently discriminatory..

Patients with cancer or those without cancer have essentially identical pain-generating physiologies, and thus the same mechanisms for the development of their pain (eg, inflammatory pain in a cancer patient will be the same physiological process as in a noncancer patient). Further, cancer patients are living longer and their original pain generators become chronic pain in and of themselves, little different from patients without cancer. 

It's time to consider not focusing on a dichotomy between cancer- and non-cancer-related pain, but realize that there are ways to approach each category of pain and that in fact, the categories of pain are often not distinct categories.