radiation therapy and skin cancer

Hi-
Three months before I was diagnosed with breast cancer, a skin lesion from the inside of the opposite arm was biopsied and diagnosed as basal cell carcinoma. I do have numorous "skin tags" and kerotsis (sp?) on my torso which the dermotologist has been checking annually and says they are nothing to worry about. Now, 1.5 yrs after my lumpectomy, AC chemo and 6 weeks of radiation, there are 3 kerotses in the middle of my sternum which have changed shape and texture.  In 2 weeks, I have an appointment with a new dermotologist who is at the same hospital as my oncologist but in the meantime was wondering--is there any data/info which shows whether or not radiation treatment can cause an increase in the risk or rate of skin cancer??
Thanks in advance for your insight on this issue!

[CCF-RN,MSN-JS]

Dear vermontgirl, The side effects of radiation therapy depend on the treatment dose and the part of the body that is being treated. Rashes, redness, irritation, or sunburned-like effects on the skin can occur to the site of the body where the radiation is received. These effects are usually temporary and go away after treatment is completed; although in some cases, the skin will be slightly darker than it was originally.  I did not find any data that indicates a specific increase in skin cancers at the site of prior radiation therapy.  However, it is prudent to have these changes in the skin lesions checked out, as you are doing.

[ritavv]

Since I have had at least 20 basal cell skin cancers in the last 15 years, I was very concerned about the radiation causing more problems.  My radiation oncologist called my dermatologist and after discussing it they there should be no extra risk to me.  However, I do have a whole body dermatology check every 6 months because of my history.  Have your spots checked out.  However, spots can be a function of aging.  (My husband teases me he could draw any shape requested just by connecting the spots!)
ps- I live in So. California and spent my youth on the beach... now I'm paying for it.