The 9 hallmarks of cancer:

1. Inflammation
2. Stress
3. Immune suppression
4. Oxidative stress
5. Elevated growth hormones
6. Altered epigenetics (high promoter methylation, low histone acetylation)
7. Acidity
8. Hypoxia
9. Impaired metabolism

Most cancer treatments are simply poisons that kill healthy cells as well.

A more holistic / root cause approach would be optimal.