That's no wonder as energies of cancer's growth and spreading in Su-jok acupuncture terms are:
--- Wind, Heat, Burn
presenting Hetero of Yang spectrum of energies.
Cancer has it's main or root energy of Cold=Yin so
governed by "internal 24 hours energies circle".
This circle has morning hours as:
--- 2.00-6.00 - energy of Wind
--- 6-00-10.00 - energy of Heat
--- 10.00 - 14.00 - energy of Burn
Any initial impulse to any process is energy of Wind,
growth of anything is energy of Heat so there is clear correspondence with morning hours.