Rashes between and under the breasts are very common skin complaints and fortunately are rarely serious. The doctors who will be well qualified to discuss this issue with you include your primary care doctor
or your dermatologist
. It is very unlikely that the rash you describe is a sign of breast cancer. A rare form of breast cancer does present as a rash, but this is a scaly, itchy rash on the nipple itself, called Paget's disease. A rash between the breast does not signal skin cancer. The most likely cause of a rash between the breasts is simply skin irritation from moisture or chafing from a bra. Wearing a well-fitting bra and keeping the skin dry, clean, and well moisturized is the key to treatment here. Another likely possibility is a fungal infection. Two different fungal infections can present here. Yeast infections are red, inflamed areas usually under the breast while tinea versicolor shows up as dry, light-colored areas. Both infections can be treated with antifungal creams. As always the diagnosis and the management of your particular skin condition will require a physical examination by your personal physician. Setting up an office visit with your primary care doctor is recommended.