Breast cancer is the most frequently diagnosed cancer in women, excluding cancers of the skin. While it usually affects women, in rare cases men can also get breast cancer. According to the American Cancer Society, each year in the United States, an estimated 234,000 new cases of invasive breast cancer are expected to occur and an estimated 40,000 women will die from breast cancer. The death rate for women with breast cancer has declined recently, which is probably the result of earlier detection and improved treatment.
Atlanta: American Cancer Society; 2015
There are several types of breast tumors. In fact, some of the most common lumps in the breasts aren’t really “tumors” at all – many lumps are fibrocystic changes, which are not malignant. Other types of tumors are malignant.
Some common breast cancers include:
Ductal carcinoma in situ (DCIS): the cancer is confined to the ducts and has not spread through the walls of the ducts into the fatty tissue of the breast. Nearly all women with cancer at this stage can be cured.
Infiltrating (invasive) ductal carcinoma (IDC): the cancer starts in a milk passage or duct, breaks through the wall of the duct, and invades the fatty tissue of the breast. From there it can spread to other parts of the body. IDC is the most common type of breast cancer. It accounts for nearly 80% of breast cancers.
Infiltrating (invasive) lobular carcinoma (ILC): This cancer starts in the milk glands (lobules). It can spread to other parts of the body. Between 10% and 15% of invasive breast cancers are of this type.
Screening is the most important way to find breast cancer early.
The American Cancer Society recommends:
These screening criteria are set up because the most common sign of breast cancer is a new lump or mass. A lump that is painless, hard, and has irregular edges is more likely to be cancer. It’s important to have anything unusual checked by a physician.
Other signs of breast cancer include the following:
If breast cancer is found early, prompt treatment could save a life. Mammograms are used most commonly to X-ray the breast and use very low levels of radiation. During a mammogram, the breast is pressed between two plates for a few seconds while pictures are taken. Although this may cause some discomfort, it is necessary to get a good picture.
The current standard of care for diagnosis of breast cancer relies on physical examination, mammography and/or ultrasound, and fine needle aspiration to diagnose breast cancer. A PET/CT scan can show whether or not a lump in the breast is benign or malignant, and may prove to be a very useful addition to mammography. Patients with breast implants, dense breasts, and others may benefit from having a PET/CT scan to locate abnormalities.
The earlier that breast cancer is found, the better the chances for successful treatment.
Atlanta: American Cancer Society; 2015
Doctors diagnose cancer and determine its origin by looking at a sample of the tumor under a microscope. Then, before deciding on a treatment strategy, physicians must determine if or how much the breast cancer has spread. This is called staging.
Prognosis, or the patient’s outlook for recovery, depends on the stage of the cancer and the best choice of treatment. Whether or not lymph nodes are involved and if the cancer has spread are pivotal factors in deciding what treatment to utilize. If breast cancer is found and treated before it has spread to lymph nodes or other organs, the five-year survival rate is extremely high – about 98%.
Breast cancer can spread nearly anywhere in the body, but most commonly it spreads to the brain, bone, and liver. The information from a whole-body PET/CT scan is used to accurately stage the entire body for the presence and location of active tumor and to aid the physician in treatment decisions.
The type of treatment chosen is based on both the type of cancer cells found as well as the stage of the cancer. Surgery may be recommended to remove the breast tumor and the doctor may also recommend radiation therapy, hormonal therapy or chemotherapy as well. A PET/CT scan provides the physician with additional information to determine the amount and type of chemotherapy to use as well as the area to be treated by the radiation beams in radiation therapy. Treatment can be tailored specifically to the patient, depending upon the location and extent of cancer.
During the course of treatment, it is important to know if the treatment is working. Metabolic changes occur before anatomical changes and in general, the greater the decline in radiopharmaceutical uptake, the better the response to treatment and the better the patient’s outcome. The information from the PET/CT scan allows physicians to monitor the effectiveness of cancer therapies and provides physicians with the opportunity to change the treatment strategy if it is not working, avoiding the cost and discomfort of ineffective therapeutic procedures. Generally, responses to breast cancer treatments are assessed by comparing a baseline PET/CT scan with another one done after one or two cycles of treatment.
PET/CT is a noninvasive test that physicians utilize to stage the entire body for the presence or absence of active tumor.
After treatment is complete, it is important to know if any active cancer cells remain in the body. This is called restaging. A follow-up whole-body PET/CT scan is used to restage the entire body for the presence or absence of active tumor.
If the cancer cells have been destroyed they will not absorb the radioactive glucose. Conversely, if the cancer cells have come back, the PET/CT scan can detect the accumulation of radioactive glucose. This helps the physician determine if the treatment was successful or if the tumor has returned.
Often, scar tissue at the site of surgical resection or radiation treatment may appear as an abnormality on the CT scan. The PET portion of the scan can detect any accumulation or absence of radioactive glucose, which helps the physician differentiate scar tissue, from recurrent tumor or residual disease. If anything suggests that the cancer might have come back in either the breast or elsewhere, the doctor will want to do more tests. If retreatment by surgery, radiation therapy, hormonal therapy, or chemotherapy can be started sooner, it can improve the chance of beating the disease.
PET/CT can be used to image breast tumor response to therapy and to detect recurrence in treated lesions.
PET/CT is a noninvasive test that physicians utilize to stage the body for the presence or absence of active tumor, localize the tumor, assess the tumor response to treatment and detect recurrence in treated lesions.
PET/CT Utilization for Breast Cancer
Source: Atlas of Clinical Positron Emission Tomography by Sallie F. Barrington, Michael N. Maisey and Richard R. Wahl. Oxford University Press, Inc. New York, NY.