If a gene truly caused cancer, than the cancer would manifest 100% of the time and would be precisely predictable in regard to its onset. Meaning, a cancer gene related to normal body plan development in general would manifest 100% of the time and be present at birth. But as you suggested, perhaps a gene would be related to something like secondary sexual characteristics. In this case it would be possible that the cell in which the gene was expressed was only “active” at puberty. In this case then the cancer would be present in 100% of the carriers at exactly the same time (puberty). A true “cancer-causing” gene would generate cancer 100% of the time and at a very specific time in a person’s life, regardless of who they are, where they are or what they do.
The strength of our abilities to control our biology and diseases such as cancer are profoundly influenced by the “programs” that have been installed into our Subconscious Minds. Unfortunately, the primary programs stored in our Subconscious Minds are not “known” by the Conscious Mind, since they were learned before the Conscious Mind becomes functional which is around 6 years of age. So we may not know whether the “learned” beliefs in our Subconscious Mind are supporting us or sabotaging us, and as mentioned above, we rarely even observe our Subconscious behaviors when they are playing. Therefore we are unaware if our own behaviors are sabotaging us and conflicting with our Positive Thoughts.
Wishing you a happier, healthier future!