1st of all how your PAP smear is possible ??? :) if you had a TOTAL Hysterectomy what you mean to say is that complete removal of your uterus was done... But if you are getting done it on regular basis that means the cervix is their and the rest of the part was removed... :O Secondly as you have mentioned that you were having precancer cells earlier the same are they now what is called as dysplasia. HPV i.e. Human Papilloma Virus infection is their which is responsible for this condition. I alters your genes and stimulate cancer producing genes to start for a malignancy formation.. In short yes, viruses can cause cancer especially when it comes to HPV but you can still protect yourself with good and proper food habbits which can increase your immunity to fight with this virus.. You are also having a 1st degree generation history cancer from both of your parents.. so beware for the future .. but for now these are only pre-cancer cells which may lead to the formation of cancer.. Your answer could not be elaborated as each type of cancer have its own mechanism which you have not stated properly in any of the case amongst your family.. Hope this much is sufficient for now ...:)