Any diagnosis, even cancer, is not automatically any specific level. It depends on the status of the problem as documented at the time of the encounter.
There are patients with a cancer diagnosis, who are currently being treated, with good response, and no side effects.
Example1: breast cancer patient who had partial mastectomy 2 years ago, no evidence of disease, and now on tamoxifen for 5 years without side effects. That problem is low level.
Example2: breast cancer patient who had partial mastectomy 2 years ago, no evidence of disease, on tamoxifen with minor side effects of hot flashes. That problem is moderate.
Example3: breast cancer patient who had partial mastectomy 2 years ago, no evidence of disease, on tamoxifen that is causing severe hot flashes, night sweats, and edema. That problem is high.
While many patients with an active cancer diagnosis *might* be high level problem, if it is not an aggressive or high stage cancer, it could easily be a lower level problem.