After being told they have stage 0 breast cancer, patients may have many questions: What does stage 0 breast cancer mean and is it also cancer?
In fact, there are some questions that doctors are not so sure about. Some experts consider stage 0 breast cancer to be the earliest stage of breast cancer, while others consider it to be a precancerous stage.
Cancer is defined as a group of diseases in which abnormal cells divide and proliferate uncontrollably. Stage 0 breast cancer is not invasive, but may become invasive later in life. Stage 0 breast cancer is less “advanced” than stage I breast cancer.
Stage 0 breast cancer includes the following 3 types:
- Lobular carcinoma in situ (LCIS), an abnormal proliferation of the lobules (glands) of the breast, is not cancer, but it increases the risk of developing cancer later in life.
- Eczema-like breast cancer (Paget’s disease), a rare type of breast cancer that occurs in the nipple.
- Ductal carcinoma in situ (DCIS), most often referred to as stage 0 breast cancer, is this type. In this group of patients, the cells are still located in the ducts of the breast and do not involve the fatty tissue that makes up the majority of the breast. There is no known cause and most patients do not have symptoms, although some may have a lump in the breast or a bloody nipple discharge. It is possible for the diseased cells to become aggressive and begin to metastasize, but there is no way to predict whether this will occur.
Should it be treated?
When a diagnosis of ductal carcinoma in situ is made, the pathology report will include a grade: grade 3 is the most likely to spread and grade 1 is the least likely to spread. Patients will also receive a test to see if the cancer cells have estrogen receptors (the presence of estrogen receptors is called ER-positive or ER+). If the cancer cells are confirmed to have estrogen receptors, it suggests that the cancer may progress more slowly.
Also, the doctor may recommend that the patient undergo genetic testing, which can identify genes that may increase the risk of breast cancer.
What happens next will depend on the above factors, as well as the patient’s personal wishes. Most experts believe that this group of patients should be treated. Although stage 0 breast cancer is not aggressive, it can change. Most doctors would agree that it is better to be prepared.
Treatment consists of three main types:
- Mastectomy only, which involves removing the lesion and a small amount of nearby normal tissue.
- Mastectomy plus radiotherapy.
- Mastectomy, in which the entire breast is removed.
Should I watch and wait?
Some experts believe that “watch and wait” is a good idea.
Some experts believe that “watch and wait” is another desirable option. About half of women with DCIS develop aggressive cancer, which means the other half don’t. Doctors may advise patients not to treat immediately, but to monitor their disease closely.
This is paradoxical. If surgery is performed directly (possibly with radiation therapy), the patient may not progress to invasive cancer again, but may also endure painful surgery without good reason.
But if a patient forgoes surgery and radiation therapy and chooses to be screened more frequently, there is a risk that the cancer will be advanced (and difficult to treat) by the time it is detected. This is a choice that only patients and doctors can make.