Lobular Breast Cancer
by Beth G. Hodges, MD

Lobular breast cancer is the second most common type of breast cancer as a whole and can itself be broken down into two subgroups: carcinoma in situ(LCIS) and invasive.

The hallmark of the difference between the two types is that the cells of LCIS are clumped together, separate from the neighboring healthy breast tissue, while invasive lobular carcinoma cells have spread into that neighboring tissue like the annoying stranger at the crowded oceanfront who encroaches on the edge of your beach towel.

LCIS often presents in multiple sites and even can present in both breasts at the same time. Even after treatment, the risk of it recurring as an invasive breast cancer is 1% per year. It sometimes does not recurr for up to 20 years and can do so in the other breast.

Invasive lobular breast cancer comprises only 5-10% of all breast cancers. It can occur as single or multiple tumors in one breast and about 20% of the time it presents bilaterally. If contained to a small area, it can be treated initially with lumpectomy, but if a large area is involved, the surgeon may recommend mastectomy. Surgery should be followed by chemotherapy or radiation or both, and eventually hormonal therapy, such as tamoxifen or Arimidex or Femara long term. Careful surveillance needs to continue to monitor for any recurrence.

How it is Diagnosed and Treated

Invasive lobular breast cancer does not always present as a mass on mammogram. It often shows up better on ultrasound or MRI of the breast. MRI is a fairly new way of monitoring for breast cancer. Ultrasound is not routinely done for screening for breast cancer.

Usually, what occurs is the radiologist on mammography sees a subtle area of different density than the rest of the breast. To further evaluate this area, he or she suggests an ultrasound. The ultrasound can help determine if the area is a cyst, an area of dense breast tissue, a fibroadenoma, which is a benign breast tumor, or a more concerning area of possible breast cancer.

Invasive breast cancer often shows up best on an ultrasound. The radiologist will then either recommend return to routine annual mammogram (if nothing is of concern,) close follow up with repeat mammogram and possibly ultrasound in 3 or 6 months if low suspicion, breast MRI if suspicion is still there or the radiologist just does not feel comfortable after evaluating the mammogram and the ultrasound, or biopsy if there is something of a suspicious nature. A definitive diagnosis of breast cancer, let alone the type of breast cancer, cannot be made until tissue is obtained via a biopsy.

The biopsy can be done by needle localization, where the radiologist places a thin needle in the area of concern, checks the position under mammography, leaves it in place, and the surgeon follows the tract of the needle in the operating room to the area of the involved tissue, removing it for evaluation under the microscope by the pathologist.

More commonly these days, stereotactic biopsy is done by a radiologist. In this method, the involved tissue is sampled with a needle under x-ray visualization by the radiologist.

If there is an obvious lump that can be palpated, the surgeon can remove that in its entirety for pathologic review with a brief surgery, leaving a small incision. The surgeon will usually take a fair amount of the surrounding tissue, just in case it is a breast cancer, so that the edges of the cancer are hopefully contained in the sample. The end of the cancer cells to the outer edge of the biopsied area is referred to as the "margin" and is very important in the evaluation of almost any kind of cancer.

Lobular breast cancer can take several tests to diagnose and more evaluation to define a treatment plan. If there is a question of an abnormality of the breast, whether on mammogram or exam or due to symptoms, it is important to comply with any recommended testing and to stay in close contact with the physician so an accurate diagnosis can be made as quickly as possible.

Published - October, 2009