Cancer and Precancerous Conditions of the Breast
The following is a primer on precancerous and cancerous conditions that affect the breast.
Lobular carcinoma in situ (LCIS): Even though this condition comes with “carcinoma” as part of its name, it is not a cancer but a marker for cancer. Changes seen in cells of the lobules suggest that cancer could occur in the future. Both breasts are at elevated cancer risk when LCIS is discovered even on only one side. These patients, Hudis and other specialists say, must be monitored closely. Patients usually are checked every six months or so and undergo regular mammograms. One course of action is to prescribe tamoxifen, which can prevent cancer in some patients.
Ductal carcinoma in situ (DCIS): While LCIS is a marker for future cancer anywhere in either breast, DCIS means cancer is developing in the spot where malignant cells are found. This form of cancer was rarely diagnosed until the advent of mammography. As detection has become more precise, doctors have begun to find DCIS in increasing numbers.
There is a misconception, however, that these cells are precancerous. The truth is, said Dr. Clifford Hudis, chief of the breast cancer service at Memorial Sloan-Kettering Cancer Center in Manhattan, that they are cancerous but pre-invasive. “The cells have become cancerous but they are in isolation. As a group they are not acting as a cancer. They are not invading.” When these cells do break beyond the confines of a duct, they become invasive ductal carcinoma.
One of the great mysteries of cancer is that many DCIS lesions never break beyond the duct. Autopsies of elderly women have revealed DCIS lesions that had remained in place for decades. The women never developed full-blown breast cancer. Currently 36,000 cases of DCIS are diagnosed annually in the United States. This form of breast cancer is not included in the estimated 182,000 cases that occur each year in the United States.
This form of breast cancer has raised a firestorm of controversy over how best to treat it. As recently as the early 1990s, doctors performed mastectomies for these tiny tumors. Then, studies showed that lumpectomies followed by radiation were the best treatment. Now, some researchers are asking if any treatment is necessary and whether watchful waiting could prove a better approach.
Invasive ductal carcinoma: This form of breast cancer constitutes 80% to 95% of all breast cancer cases that occur annually in the United States. By invasive, doctors are referring to the cancer’s spread beyond the duct in which it originated and into surrounding tissue. That also can mean the tumor has invaded one or more nearby lymph nodes. “When most people say they have breast cancer, this is what they are usually talking about,” Hudis said.
At the time of detection, tumors can be in any range of dimensions. Doctors determine what stage the disease is in after tissue is taken in a biopsy and subjected to an array of tests. Therefore, invasive ductal carcinoma can refer to a range, from a Stage 1 tumor with no evidence of lymph node involvement to a Stage IV tumor with multiple affected nodes and metastases to distant sites. Treatment normally includes surgery, radiation and chemotherapy.
Invasive lobular carcinoma: These tumors begin in the lobules and are less common than ductal cancers. These cancers differ from ductal carcinomas in that they are usually more diffuse throughout the breast. Moreover, when invasive lobular cancer is found in one breast, it is likely that lobular carcinoma will occur in the other. But given that so many cancers begin at the junction between the duct and lobule, how do pathologists know which form of cancer they are witnessing under a microscope? “There’s a subtle difference in how it looks under the microscope,” compared with ductal carcinoma,” Hudis said. “But the treatment is the same.”
Inflammatory breast cancer: This is among the rarer forms of breast cancer and without question among the most insidious. It usually becomes evident when a reddening develops on the chest, something breast cancer patients call “the burn.” The chest is also warm to the touch, and many patients experience breast swelling. The symptoms on occasion prompt some physicians to prescribe antibiotics, having assumed the condition is mastitis--an infection. “The skin is inflamed. There is a lump, but it may not be palpable. This is a very aggressive form of breast cancer and represents a higher risk for metastasis,” Hudis said. He added that inflammatory breast cancer is often discovered late in its development. “Typically chemotherapy is given first so the cancer shrinks.”
Paget’s disease: This form of breast cancer usually is evident in the area of the nipple. Itchiness and scaling are the key characteristics and can be mistaken as eczema in some cases. Paget’s disease of the breast is very rare, so a misdiagnosis as a dermatological condition would not be surprising, Hudis said. The cancer can be limited to the nipple region, or it may be more extensive inside the breast and as such may be related to ductal carcinoma that is progressing outward. Paget’s disease, when confined to the nipple, has a better prognosis than more invasive disease. When it is confined, the disease tends not to be particularly aggressive.
Cystosarcoma phylloides: This is another form of breast cancer that tends to be less aggressive, even though the lump that this type of disease produces can be quite large. Cystosarcoma phylloides is unlike virtually all other forms of breast cancer because it does not develop from epithelial tissue. “It gets its name because it comes from tissue with a different embryological source,” Hudis said. “So, technically speaking, it’s not breast cancer. It is a sarcoma. All breast cancers are technically carcinomas. There is a separate class of cancers called sarcomas.
“The treatment is different in that there is usually surgery but rarely chemotherapy or radiation. Drugs such as tamoxifen have no role,” Hudis said. These tumors, he added, rarely metastasize.
