From what I understand, they found a correlation between disturbed circadian cycles and hormone-caused cancers, the mean of lighting doesn't seem to play a role.

That seems right - they only mention LEDs as a possible factor for the increase in disturbance of circadian cycles, as people keep them on at night more than they used to with filament bulbs. The study isn't about LEDs themselves.

It was reported elsewhere that it was the increased level of blue light. So perhaps something that can be addressed. Still, unintended consequences.