The coming year will bring worrisome news for both women and men on the breast cancer front. Consider that in 2017, the American Cancer Society projects 252,710 new cases of invasive breast cancer in women, another 63,410 new cases in women of carcinoma in situ — the noninvasive, earliest form of breast cancer — and 2,470 new cases of invasive breast cancer diagnosed in men. Each one of these diagnoses will include specific information about the cancer’s stage — a measure of how far along the cancer is — and this staging information will be used to help determine the best course of treatment.
Stage is determined by examining the characteristics of the tumor or cancerous cells after they have been removed during a biopsy or lumpectomy. This work will be conducted in the lab and involves measuring the tumor or sample of cells, looking at them under a microscope and possibly conducting other tests.
[See: A Tour of Mammographic Screenings During Your Life.]
In staging the cancer, your doctor or pathologist will take into consideration the size of the cancer, whether it’s invasive or noninvasive (meaning whether it’s moved beyond its point of origin), whether cancer is found in the lymph nodes and whether cancer is detected in other parts of the body outside the breast. Some pathologists use a system called TNM to determine the stage of cancer. This system categorizes the size of the tumor (T), lymph node involvement (N) and whether the cancer has metastasized (M) to other parts of the body. Once the lab work is complete, your cancer will be assigned a stage number. Breastcancer.org reports there are five stages of breast cancer, stages 0 through 4.
Stage 0
Stage 0 describes noninvasive breast cancers and indicates “there is no evidence of cancer cells or noncancerous abnormal cells breaking out of the part of the breast in which they started, or getting through to or invading neighboring normal tissue.” This means that the cancer is well confined to its point of origin and is very early on its path of development.
Most breast cancers start either in a milk duct or milk lobule, structures in the breast that create milk to nurse a baby. The National Breast Cancer Foundation reports that stage 0 lobular carcinoma in situ “describes a growth of abnormal but noninvasive cells forming in the lobules.” Although this type and stage of breast cancer is “generally not considered cancer,” it may “indicate a woman has an increased risk of developing breast cancer,” the NBCF reports. Many doctors will prescribe regular screening to check on the development of this form of cancer.
Stage 1
Stage 1 refers to invasive breast cancers. These are cancers that have broken through to, or have invaded, normal surrounding breast tissue. This means the cancer has begun to grow beyond its point of origin and is a little further along than a stage 0 cancer. Stage 1 is further divided into subcategories A and B. Stage 1A refers to tumors up to 2 centimeters but which have not spread outside the breast. No lymph nodes are involved in stage 1A breast cancers. Stage 1B indicates that cancerous cells have been found in the lymph nodes. Cancers designated as stage 1B may feature a small tumor up to 2 centimeters in the breast, but not always. The key to this classification is whether the lymph nodes contain cancer cells, Breastcancer.org reports.
[See: Breast Pain? Stop Worrying About Cancer.]
Stage 2
The NBCF reports that “stage 2 means the breast cancer is growing, but it is still contained in the breast or growth has only extended to the nearby lymph nodes. Stage 2 can be further categorized into stages 2A and 2B, with the size of the tumor and whether cancer has spread to lymph nodes being the distinguishing factor between these two sublevels.”
Stage 2A breast cancer cases may present with no tumor, but the presence of cancerous cells in one to three axillary lymph nodes makes it a stage 2A case. Stage 2A may also refer to a tumor of less than 2 centimeters in size with cancerous cells in the lymph nodes or a tumor of 2 to 5 centimeters if cancer is not found in the lymph nodes.
Stage 2B means that that the tumor is 2 to 5 centimeters and cancerous cells have been detected in the lymph nodes. If there’s no cancer in the lymph nodes but the tumor is larger than 5 centimeters, that may be classified as stage 2B.
Stage 3
Stage 3 is considered an advanced but treatable stage of breast cancer. In these cases, “the breast cancer has extended beyond the immediate region of the tumor and may have invaded nearby lymph nodes and muscles, but has not spread to distant organs,” the NBCF reports. Stage 3 can be further subdivided into stages 3A, 3B and 3C.
A stage 3A diagnosis would be applied to cases where the tumor is less than 2 centimeters and the cancer has spread to between four and nine lymph nodes. If the tumor is larger than 5 centimeters and cancer clusters are found in the lymph nodes, that would also qualify as stage 3A breast cancer, as would cases where the tumor is larger than 5 centimeters and cancer has spread to lymph nodes near the breastbone or underarm.
Stage 3B applies to any size tumor if the cancer has spread to the chest wall or breast skin and to the lymph nodes. Stage 3C is diagnosed in cases where a tumor of any size is detected if cancer is also found in 10 or more lymph nodes.
[See: 7 Innovations in Cancer Therapy.]
Stage 4
Stage 4 is the final and fatal stage of breast cancer. If you’ve been diagnosed with stage 4 cancer, this means that the cancer has spread to another organ in the body, typically the brain, bones, lungs or liver. “Although stage 4 breast cancer is considered incurable,” the NBCF reports, “current advances in research and medical technology mean that more and more women are living longer by treating the disease as a chronic condition,” or something that can be managed over a period of time.
The Susan G. Komen organization reports that “breast cancer stage is the most important factor for prognosis. In general, the earlier the stage, the better the prognosis will be.” The earlier your breast cancer is identified, the earlier your treatment can begin, and this is associated with better survival rates. The ACS reports that “the five-year relative survival rate for women with stage 0 or stage 1 breast cancer is close to 100 percent.” That rate drops to 93 percent for women with stage 2 breast cancer and 72 percent for stage 3. Finally, for stage 4 breast cancers that have metastasized or spread to other parts of the body, the five-year survival rate is about 22 percent. “Still, there are often many treatment options available for women with this stage of breast cancer,” the ACS reports. And increasingly, advances in management of late-stage cancer is leading to longer and better quality of life for many patients living with metastatic breast cancer.
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What Are the Stages of Breast Cancer? originally appeared on usnews.com
