Cancer of the breast is a universal thing, or related to western diet and lifestyle?

Yes somewhat. The short answer is we don't really know. We do know that obesity is related to an increased risk of some breast cancers we also know that exerise helps decrease the risk and potential recurrence. But, unfortunately, not much is being done to investigate environmental pollutants; like industrial wastes, radiation, emf, food additives, etc. Only 15% of breast cancer donations is spent in find causes.
Possibly related. Breast cancer is definitely greater in western countries but so is obesity and high fat diets. No one is immune to cancer even with a healthy lifestyle but you decrease the probability of it. The us has 70% of the population with a weight problem. Being overweight increases your risk of every cancer as well as heart disease. Eat more plants, keep a healthy weight, don't smoke or use alcohol.
Likely yes and other. While breast cancer is unfortunately a very common problems- worldwide as well as in us, the incidence is increased by some risk factors incluiding- obesity, sedentary lifestyle, alcohol, tobacco, red meat/dietary habit, previous radiation to the chest area, hormone use, genetic mutation/ factors, delayed pregnancy, etc. Yes, I think is related to dietary habit at some degree.
Related - YES. Breast cancer is collection of different cancers arising in the breast. It is clearly associated with lifestyle factors in many cases but not all. A sedentary lifestyle, delayed child bearing, not breast-feeding, obesity, alcohol, and even smoking (a smaller risk here) are all traits of developed countries. Rates of bc track very closely to urbanization and development.
Ancient disease. It is fairly common in mummies from the ancient world, and the classic greek, roman, and arabic writers wrote extensively about it. It is far more common where many women defer or forego childbearing and/or lactation. A possible relationship to diet and sedentary lifestyles is still an open question; I believe the claim that a high-fat diet causes it has been amply refuted.
Nondiscriminatory. Breast cancer occur in all ethnic group. Dietary play very little if any.