Parabens are a chemical family of preservatives that are used in a large number of cosmetics and skin care products as well as in food products. According to some pro-paraben sources the substances are benign and extend product life considerably. They are estrogen-like molecules in their structure, which means they would potentially fit into estrogen-receptor sites in the body. Some recent studies have shown this is, in fact, the case. Parabens have been found in a wide variety of different breast cancer tumors. So what does this mean?
It means that parabens leave circulation in the body, or get absorbed through the skin and find their way to estrogen-sensitive tissues. In fairness, just because they have been found in breast cancer tumors does not necessarily mean they cause cancer or sustain cancer growth. The high metabolic nature of estrogen-sensitive cancers may just be accidently pulling in parabens since they look like estrogen. Parabens MAY be inert and do nothing. Then again, they may do everything they could be feared of doing: initiate and/or sustain cancer. The trouble is: we don't know.
So if we have a chemical substance that is proven to appear in cancer tumors, but we don't know what that chemical's actions are does it make sense to continue using this chemical until we do know? I would argue no; especially where the necessity of the chemical's preservative nature is not as important as a woman's breast health.
Hence, get serious, get reading glasses, and start obsessively reading the ingredient lists of ALL those products you use a lot and dump the ones with any kind of paraben would be my advice.