Can oncogenesis happen without apoptosis pathway being affected?
Usually the cell death mechanisms are overridden and therefore oncogenesis. The pathway components themselves are not mutated. One classical case I can cite is that of Ras-oncogene. See this article for details. Usually the survival/growth signals (MAP-kinase) are activated with simultaneous inactivation of apoptotic regulators (Akt-pathway). A mutation of MAP-kinase component ERK can also cause cancer but apoptosis is nonetheless supressed because of the interconnections of these tow pathways in the gene regulatory network. 

Whereas in the case of tumor suppressors, the cause of cancer is genomic instability and failure to initiate apoptosis.