Symmetry is defined in the dictionary as the "exact correspondence of form and constituent configuration on opposite sides of a dividing line, or plane. or about a center or an axis." Simply put, it means balance and proportion.
Humans have most of their body parts in twos --- two eyes, two ears, two arms, and yes, two breasts. It is easy to notice assymetry when we are comparing two opposing body parts. Some observers even comment that beauty is all about symmetry.
But this post will not talk about beauty but of a possible new risk factor for developing breast cancer. A new study has found out that "breast asymmetry was greater in healthy women who later developed breast cancer than in women who did not." The research authors suggested that assymetric breasts in healthy women can become reliable risk indicators of future breast disease, and thus, can be included in the evaluation of a woman's breast cancer risk profile.
Reasons for assymetry? Well, there are many factors, but the most notable is estrogen secretion.
The study also introduces a term called FA or fluctuating assymetry, which refers to "small, random deviations from perfect symmetry." It is a measure of developmental stability, or the ability of a person's body to resist both intrinsic and extrinsic factors affecting it. More change means more trouble, it seems.
You can read the full text of the study from the latest online copy of the Breast Cancer Research journal.