Does wine increase or decrease breast cancer risk?

Increases. Alcohol consumption increases breast cancer risk , studies show consumption of 3 to 4 alcohol drinks a wk showed 15 % increase of breast cancer risk, if you don't drink don't start.
Probably not. The whole field of epidemiology, based on people's recollections of their "bad habits" when faced (or not faced) with a deadly illness, and with the likelihood of confounding variables, generates huge amounts of often-contradictory claims about risks and benefits that are mostly moonshine. I'd urge you to ignore all the links that aren't obviously true (i.e., cigs and lung cancer).
Male or female? Great question. If you are asking about it in males, i will refer to some surgeons who are experts in cancer and male breast disorders. I also referred it to additional experts in case you were referring to adults in general. We will also try to provide some data references. Thanks for asking!
Red wine protective. Cedars-sinai researchers - braunstein and his team provided 8 ounces of red wine daily to 36 women and 8 ounces of white to another 36. After one month, the scientists reversed the servings. Blood was collected twice during the women's menstrual cycle to measure hormone levels. When women were drinking red wine, the study reports, hormone levels were at much more favorable levels.