Swelling
Breast cancer can cause swelling of the entire breast area. After this swelling, there may not be a distinct lump but the breast may differ in size from the other breast.
Although people can have breasts that are always slightly different in size, this swelling would cause a change from their usual size of the breast. Because of the swelling, the skin may also feel tight. Women should not be in fear or scared when they notice changes to the breast. Aging, hormone imbalances, and other non-cancerous factors can also result in changes in the breast.