If i eat food that has passed threw airport security machines, does it contribute to the development of cancer?

No: High doses of radiation can affect living tissue and cause mutations when those living cells divide. Low levels of radiation (like at the airport) are very weak, to say the least, and are being aimed at processed foods which are of course, not living. Once your bag passes through the machine, there is no residual radiation in the food for you to ingest. Have a great trip !