LCIS stands for lobular carcinoma in-situ. It is not actually a cancer but its presence means there is an increased risk of developing breast cancer in the future. The risk of breast cancer is five to ten times greater in women who have LCIS than in those who don't. Between 1 in 3 and 1 in 4 women with LCIS will develop breast cancer sometime during their lifetime. Although many women find these statistics worrying, they do mean that most women with LCIS will never develop breast cancer.

LCIS does not show up on mammograms and is usually discovered when small tissue samples (biopsies) are taken from benign (non-cancerous) breast lumps and examined under the microscope. It occurs in about one in every hundred benign breast lumps.

If cancer develops in a woman with LCIS, it can be either invasive ductal or invasive lobular and is as likely to be found in the opposite breast as on the side where the diagnosis was originally made.

In the past LCIS was often treated by a mastectomy. This is no longer considered necessary, as doctors are reluctant to perform a mastectomy when most women with this condition will never develop breast cancer. Instead careful check-ups are recommended with breast examinations every 6-12 months and mammograms every one or two years.

There is at present a clinical trial in progress, to test whether taking the drug tamoxifen reduces the risk of developing a breast cancer in women who have LCIS, but it will be many years before the results of this study are known.

So the recommendation that all you need is regular check-ups is quite correct.