In cancers, It is remove the break and release!

Many cancers are allowed to occur when Breaks in genetic pathways are removed
and abnormal proteins are being released (or formed) as a result of failures.
Of course one of the way the gene acting as a break failure is through Mutations  (of course heterozygosity, missing or omission, or blockage will be the other ways of failing)...The failure is not alone...subsequent consequences result in the pathways leading to aberrations that ultimately engage the cancerous process.
These consequences end up amplifying a normal or abnormal gene (c-Myc) resulting in amplification of other genes in the pathways...and cancerous disease develop.   It is important to note that while this is happening, mechanisms to protect this dangerous development also are engaged...Mucus is formed to protect the cancer from detection (ie Colon cancer cells) and most importantly genes such as the PD-1/PDL-1 are also formed to hide the process even more deeply ...
say you want to check for Lynch Syndrome, you will find that the APC gene which is Mutated is not stopping the Wnt-signaling pathway which leads to "mutated proteins" or dysfunctional proteins which could block the Beta-Catenin from transcribing more resulting Oncogenes...This is an early event in the cancer development...making the cell loose the sens of containment and shape, a polyp will result...