LCIS is not cancer. There are changes to the cells within the lining of the lobules of the breast. Having LCIS increases the risk of breast cancer.
What LCIS is
Lobular carcinoma in situ (LCIS) means that cells inside some of the breast lobules have started to become abnormal. The lobules are glands that make milk when breast feeding. The abnormal cells are all contained within the inner lining of the breast lobules.
LCIS is also called lobular neoplasia. It might be found in both breasts.
Having LCIS means that you have an increased risk of getting invasive breast cancer in either breast in the future. Even so, most women with LCIS will not develop breast cancer. Men can develop LCIS but this is very rare.
LCIS is more common in women who have not had their menopause. About 560 women are diagnosed with LCIS each year in the United Kingdom.
LCIS doesn't usually show up on breast x-rays (mammograms), and it normally doesn't cause symptoms. It's often diagnosed by chance when you have tests, such as a biopsy, for other breast conditions.
Please note that there is a type of breast cancer called invasive lobular breast cancer - this is different to LCIS.
Following a diagnosis of LCIS
Most women with LCIS will not get breast cancer. So you usually don't need to have any treatment.
Your doctor might suggest monitoring because there is an increased risk of breast cancer. You might have:
- a breast examination every 6 to 12 months
- a breast X-ray (mammogram) every year for about 5 years
Your specialist might suggest yearly mammograms until you are invited for 3 yearly mammograms as part of the national breast screening programme. Or if you are already part of the screening programme, you might have yearly mammograms for 5 years.
If a cancer does start to develop, the monitoring should pick it up at a very early stage. Then you can have the treatment you need as early as possible.
You might have surgery rather than monitoring if you have a particular type of LCIS called pleomorphic LCIS. You might have surgery to remove your breast (mastectomy). Or you might have a lumpectomy (a wide local excision) to remove the area surrounding the LCIS.
Pleomorphic LCIS is treated more like ductal carcinoma in situ (DCIS), which is a very early form of breast cancer.
If you have been diagnosed with LCIS, your doctor might suggest that you take a type of hormone therapy to lower the chance of breast cancer in the future.
Trials and research
Research has focused on the genetic changes which might increase the risk of developing LCIS. Trials have shown that some of the known genetic changes that increase the risk of breast cancer in general, also increase the risk of developing LCIS.
Researchers are also looking at the use of hormone therapy to prevent invasive breast cancer following a diagnosis of LCIS.
The IBIS 2 prevention trial followed post menopausal women who took the hormone therapy, anastrozole (Arimidex), for 5 years. This included some women with LCIS. Results showed that hormone therapy did reduce the risk of breast cancer in these women.