Yes, age and life expectancy is a huge part of it. In the book "Rebel Cell: Cancer, Evolution, and the New Science of Life's Oldest Betrayal", Kat Arney touches

Yes, age and life expectancy is a huge part of it. In the book "Rebel Cell: Cancer, Evolution, and the New Science of Life's Oldest Betrayal", Kat Arney touches upon this exact question and reaches the conclusion that cancer was as prevalent in ancient times as it is now (perhaps accounting for surges like smoking-related cancers), and also mentions age as a big factor in the archaeological discrepancy.