9 All cancers evolve along the same trajectory

Cancer is a triad manifested by:

1. Tumor (T)
2. Paraneoplasia (Neuro-hormonal changes) (P)
3. Cachexia (progressive weight loss and wasting) (C)

Cancer progression involves all three. Paraneoplasia  and weight loss may even precede tumor appearance.

Mathematically cancer is a triplet, consisting of three components {T,P,C}. It is a  three dimensional vector. Al cancers evolve along the same trajectory.  The polyp-cancer sequence is a prototype of a typical neoplastic trajectory. The polyp-cancer sequence serves here as a prototype  of neoplastic progression of all tumors. They all  proceed  through states analogous to the polyp  cancer  sequence.
Since cells stream to their graveyards, they do not de-differentiate. Neither does the tumor. What appears as tumor de-differentiation results from an ongoing accumulation of younger and younger cells due to their arrested maturation. With time tumor  becomes younger  and proliferates faster.

Trajectories of the following cancers are depicted: Colon, breast, CML

Maturation arrest is the main reason why cancer is  generally incurable. The other two are para-neoplasia and cachexia, which defy any  treatment.