I have been using - maybe abusing - OTC Contact C Cold and Flu medications for the past 3 years. I have been utilizing it for sleep purposes. I might go as far to say I have a slight addiction to these pills. On average, I consume approx... per vening equivalent 1500-2000mg of acetaminophen, and 50-100mg pseudophedrine and 100-150 diphenhrdramine hydrochloride each evening.
I have had liver panels done recently and all tests are within normal reference. Besides the minor addiction factor, can OTC meds like this abused over this length of time cause any types of cancer?
Please, no criticims, just medical related comments.
The chances of you getting cancer from continued usage of an OTC drug is VERY low. If you were to abuse it, you would run in to something like liver damage and kidney damage before a process like cancer would be started. Cancer usually happens from continued injury to a certain site of the body which eventually causes the cells to undergo metaplasia (a change in type) dysplasia (disorganization) and then malignancy. This is a very specific process which takes years and "bad luck" to develop, and the chances of it happening from OTC drugs is very low.
A couple comments....the acetaminophen and the pseudophedrine are not helping you sleep. The only sleeping drug in the mix you're taking is the diphenhydramine. In fact, the pseudophedrine is like legal speed so it would have the OPPOSITE effect. Pseudophedrine is primarily used as a decongestant.
It is completely unnecessary to be taking either the pseudophedrine or acetaminophen for sleep as neither contain any drug action that aids in sleep.
On the other hand, the diphenhydramine is a sleep aid and you can get sleeping pills over the counter with just this ingredient. It's also an antihistamine; better known as Benadryl. It's basic action is to block histamine in allergies. As a secondary effect, it can cause drowsiness.
I know you didn't ask for nor want advise but take it or leave it, I'd look for a sleep aid with just the diphenhydramine in it. They make them.
As far as a cancer link. I'd doubt it. None of those drugs are know cancer causing agents.
Cancer and OTC meds?!?! 
