Breast Cancer Basics
Breast Cancer Basics
Richard E. Gould (Hematologist/Oncologist, Cedars-Sinai Outpatient Cancer Center) gives expert video advice on: What are the most common types of breast cancer?; What causes breast cancer?; Is breast cancer fatal? and more...
What is "breast cancer"?
Breast cancer is cancer that starts in the breast, and it is where normal healthy tissues initially start to become hyperplastic, so they start to grow. There can also be genetic abnormalities and mutations that occur in the healthy cells, which cause them to start to become a little atypical. Once they become atypical, they start to grow faster, there are more genetic mutations, and they turn into a full-blown cancer. At that point, the breast cancer is usually an "in situ" cancer, meaning it is just there, within the breast. It has not invaded through the basement membrane, which is the lining of the normal, healthy cells. Once it becomes invasive cancer, it invades through that basement membrane, and spreads throughout the breast. It can then spread to lymph nodes and then spread to other organs and become metastatic.
What are the most common types of breast cancer?
With regards to breast cancer basics, before I talk about what the most common types of breast cancer are, let me talk about the anatomy of the breast. Basically, you have a lot of different lobules which are the glands where milk is produced in the breast which then as you move towards the nipple become ducts. These ducts go up to the nipple where the milk is expressed and released, any area along those paths can turn into cancer. The most common place for cancer to start is in the duct. About 85% of breast cancers start in the duct. After that, the lobule, the lining of the glandular tissue is the second most common place that cancer can start within the breast. Then there are other more rare forms of breast cancer. For example, medullary carcinoma, tubular carcinoma and other less aggressive carcinomas can occur in the breast and in the tissues between the lovules and between the ducts. In addition, there is something caused inflammatory breast cancer which is where cancer invades into the lymphatics in the skin. The tissue can become thickened, red and painful. Inflammatory breast cancer is one of the most aggressive types of breast cancer that there is.
What causes breast cancer?
That's a difficult question to answer because there are so many different factors which go into how and why cancer develops. To break it down, the two most basic components are genetics and environment. Somebody is born with a certain genetic predisposition to cancer. For instance, if they have BRCA1 or BRCA1 mutations, they have a greater risk of developing breast cancer, and these are genetic mutations that people can inherit from their parents. In addition, environment plays a role. If somebody is exposed to a lot of oestrogen over their lifetime, it can increase their risk of developing breast cancer. In addition, if they're exposed to radiation, it can increase the risk of developing breast cancer. So, in other words, it's a play between somebody's genes and their ability to withstand environmental hits to those genes. That determines whether somebody's going to develop breast cancer over their lifetime or not. It's very difficult for any one individual to say exactly what it was that lead to them to develop breast cancer.
How common is breast cancer?
With regards to breast cancer, breast cancer is the most common cause of cancer for women in the United States, and it's estimated that one in eight women will develop breast cancer over her lifetime. The majority of women who are diagnosed with breast cancer are post menopausal and over the age of fifty, although premenopausal women can and do develop breast cancer. Therefore it's important for women to get the appropriate screenings to pick up breast cancer early, because the earlier breast cancer is found, the greater the chance of a cure.
Is breast cancer on the rise?
Actually the incidence of breast cancer is decreasing, and it's one of the exciting things that we've just noticed is that over the last couple of years there's been a decrease in the number of new breast cancer diagnoses in the United States. It's not clear exactly why that is. Some people are hypothesizing that the downward trend in the number of women on hormone replacement therapy is decreasing the number of new breast cancers, or maybe it's because more women are using Tamoxifen or other medications to reduce the risk of developing breast cancer. But it has been noted that the number of new breast cancers are decreasing and that is an exciting thing.
Is breast cancer fatal?
Breast cancer, like any cancer, can be fatal. The chances of breast cancer being fatal or the chances of it being cured come down to when it is diagnosed. The earlier a cancer is diagnosed, or the earlier breast cancer is diagnosed, the greater the chances are that it's going to be cured. Therefore it's really important to do the appropriate mammographic screening and breast exams to catch breast cancer early when it's curable. Breast cancer presents at a more advanced stage if it's metastatic. Usually at that point it is not curable. If breast cancer relapses in just one organ, one site in the liver, or in the lung, potentially it can be resected similarly to colorectal cancer. It can potentially be cured, but for the majority of women once breast cancer relapses or if it presents in a metastatic setting, it's not curable. All the treatments we have at that point are to help women live longer and to live longer feeling better, and to try to turn breast cancer into a chronic disease, but we know that at some point the breast cancer will grow through the treatment and that women will die of the breast cancer or a complication of it. So, that's why it is so important to catch breast cancer early before it becomes more advanced, before it's metastatic.
Does breast cancer occur in men?
Men can develop breast cancer. Men have breast tissue, not as much as women, and they don't have the circulating oestrogens that women have. And so men's risk of breast cancer is less. The segment of the male population who are a greater risk for breast cancer are those who carry certain genes that predispose them to breast cancer. So men with BRCA1, BRCA2, they have a greater risk of developing breast cancer. In addition, if men have had radiation to the chest, that can increase their risk of developing breast cancer as well. So while men can get breast cancer, it is rare.
Is breast cancer slow or fast-growing?
Breast cancer can be both slow growing and fast growing. When you say breast cancer; breast cancer is not just breast cancer. There are so many different types of breast cancer, and one woman's breast cancer is not the same as another. Some are hormone receptor positive, some are hormone receptor negative. Some divide very fast and are very poorly differentiated, meaning they look less like normal, healthy breast tissue and more just like atypical cancer cells; others look more like healthy breast tissue. In general, the ones that are more well differentiated and look more like healthy breast tissue grow slower, and those that are less differentiated and look more atypical, grow faster. There's wide variation in how fast a breast cancer will grow between one individual and another.
What are the most common benign conditions in the breast?
The most common Benign conditions in the Breast include fibrocystic changes, benign tumors like fibroadenomas, or inflammation in the Breast. The majority of breast changes, particularly in younger women, are benign. Having said that, if you fill in any change in your breast or any abnormality that you're concerned with you should present with your doctor and explain to them what's going on so that they can assess you, get mammogram, ultrasound, whatever imaging modality is necessary as well as biopsy to confirm that this is in fact a Benign condition. Benign conditions are not cancerous. They don't turn into cancer, but it's important to separate them out because if they are cancer or precancer it's better to catch it earlier when it's more treatable and curable.
What are "breast lumps"?
When a woman feels lumps in her breast, it can be a number of different things. The breast lump can be a cyst or fibrocystic changes. The breast lump can be a benign adenoma. It can be cancer. Or the breast lump can be a collection of a fatty deposit there, or a normal lobule or a normal duct. And it's important to separate these out. And so, if you feel a lump in your breast which you're not sure about, again, it's really important to see your physician, so that you can get it evaluated to make sure that it is not cancer. While the majority of lumps are not cancer, you've got to get it checked out.
What is a "breast cyst" and a "breast cyst aspiration"?
A breast cyst is a fluid collection that occurs inside the breast tissue and it can oftentimes be felt as a lump or as a mass which initially can be concerning because of the possibility of breast cancer. On further evaluation with a mammogram and ultrasound, this lump or mass is found to be a fluid filled collection. Oftentimes what is used to treat this is breast cyst aspiration which is where a small needle is inserted into the cyst and the fluid is withdrawn. If the fluid is clear there is nothing further to do except to just observe the breast and make sure that the cyst does not return. If the fluid comes back bloody then it needs to be evaluated for any atypical cells or cancer cells underneath the microscope, and the breast has to be followed more closely to make sure that it's not breast cancer or that breast cancer does not develop there. However, as a rule, simple breast cysts are benign; they are not cancerous.
Where in the body does breast cancer tend to spread?
Breast cancer starts in the breast, and the first place it goes to is the axilla or the armpit. That's where lymph nodes drain the breast. The cancer goes to the armpit first, and once it hits the lymph nodes there's a greater risk of the cancer spreading to the rest of the body. The cancer can go to the lungs, to the liver, to the bones, to the brain, the cancer can go pretty much anywhere in the body. It's really important to catch the cancer early when it's just in the breast. Once it has spread to the armpit and involves the lymph nodes there, it can still be cured. There's a greater risk of relapse but if it's only in the lymph nodes and the breast, it can still be cured. Once cancer spreads beyond the armpit and it's found in the lungs, the liver, the bones, the brain or another organ, at that point as a rule the cancer cannot be cured. That's why it is so important to catch the breast cancer early, when it's curable. It's always treatable, even if it has spread to other organs, but at that point the cancer is just not curable.
What does "benign" and "malignant" mean?
A benign condition is a non-cancerous condition. It will not turn into cancer, it is not life-threatening. A benign condition can grow locally, but it is not going to spread anywhere else in your body. A malignant condition is a cancer and as a cancer a malignant condition can spread to other organs in the body and it can be life-threatening.
What are "fibrocystic changes" in a breast?
With regards to breast cancer basics, fibrocystic changes describe the changes in a breast that is denser, with areas of nodularity and areas of thickening. Fibrocystic changes are benign, they are not cancerous. They usually happen in younger women with denser breasts, but it's important to separate them out from cancerous changes. So, you have to work with your health care professional to make sure you're getting appropriate monitoring to make sure there are not changes occurring in the breast.
What are "carcinogens" and how are they related to breast cancer?
With regards to breast cancer basics, carcinogens are compounds or chemicals that increase our risk for developing cancer. Specifically for breast cancer, alcohol has been related with an increased risk of developing breast cancer, and with smoking there's some evidence to suggest that it may increase the risk of breast cancer too. It's not as strong as the link between smoking and lung cancer, but there does seem to be a link between smoking and breast cancer.
What is "Paget's disease of the breast"?
With breast cancer basics, Paget's disease of the breast is where the skin of the nipple becomes dry; it becomes scaly, or basically becomes eczematous. It is indicative of a cancer deeper down in the breast. For that reason, it's important that if you notice that you're getting changes to your nipple, the skin is becoming dry; the skin is becoming scaly, that you go to see your physician so that they can do a breast exam and get a mammogram and further evaluation to see if you have Paget's disease of the breast. This will make sure that you do not have an underlying breast cancer. If an underlying breast cancer is found, the treatment for Paget's disease is the same as the treatment for the breast cancer. Hence, this means surgery, with or without radiation, with or without chemotherapy, and with or without hormonal therapy. Whatever would be indicated for that breast cancer is the treatment that you would need.
Can breast cancer be a chronic disease?
Absolutely, in some women breast cancer can definitely be a chronic disease. Once breast cancer spreads beyond the breast and the axilla and its metastatic we're not able to cure it. Our goals of therapy at that point are to help women live longer; to live longer feeling well, living their lives and involved in their lives. That becomes our goal of therapy. So, we attempt to turn breast cancer into a chronic condition, so that women can be out there living their lives. It is something that has to be monitored and treated like just diabetes and just like high blood pressure. For women with bone only metastatic breast cancer, they can live many, many years, and some women live upwards of ten years with metastatic breast cancer. That is not the typical course of breast cancer, but that can happen and we are able to provide that life expectancy for some women. So, breast cancer can be a chronic disease for some individuals.
What is the "TNM system"?
The TNM system is a way of staging cancer. The TNM system is not just for breast cancer, but for any type of cancer. And the T stands for the size of the initial tumor. The N stands for the nodal involvement, in other words the lymph nodes that are involved with cancer. And M stands for metastases. Is there any cancer outside of where the cancer initially started? So is there cancer that has spread through another organ like the liver or the lung? Based upon the TNM, for breast cancer women are diagnosed with either a Stage I, a Stage II, a Stage III, or a Stage IV cancer. And all of them have different prognoses and different treatment goals.
What is the "Bloom-Richardson score"?
The Bloom-Richardson score is a way that the pathologist grades the tumor and what that means is after a woman has surgery and her cancer is removed or if it is just biopsied, the cancer is stained and looked at underneath the microscope. The pathologist then describes the cells based on how normal they look or how abnormal they look and they give the cancer a score. This is the Bloom-Richardson score. The higher the number, the less the cells look like normal breast tissue. The lower the number, the more the cells look like normal breast tissue. And, in general, the higher the number, the more aggressive the cancer, the lower the number, the less aggressive the cancer. There are a number of different other factors which go into the overall prognosis but this is an important one for determining prognosis for breast cancer.
How is a "radiologist" different than a "radiation oncologist"?
A radiologist is a physician who specializes in reading imaging tests. So mammography, ultrasound, x-ray, CT scan, MRI: a radiologist reads those. A radiation oncologist is a specialist who focuses on providing radiation to – in general – cancer, and helping to treat cancer. Radiologists and radiation oncologists are both MD's, and they've gone through medical school, as well as a residency specializing in either radiology or radiation oncology.
What are "genes"?
In regards to breast cancer basics, genes are basically our DNA. Genes are what we're born with, we get half of our genes from our mothers, half of our genes from our fathers, and based upon that, it makes up who we are to a degree. Environment also plays a factor too, but we are all born with a certain genetic predisposition to medical conditions like diabetes, like high blood pressure, as well as cancer. It's important to realize that genes alone do not determine whether you're going to get cancer or not. Just because a relative of yours, your mom, brother or sister develop cancer, does not mean that you will develop cancer because you share some genes. Genes are important, but environment also plays a role.
What does "carcinoma" and "sarcoma" mean?
They are both different types of cancer. Carcinoma is cancer of epithelial tissue, which is basically tissue that lines the surface of a structure. In other words, in the case of carcinoma breast cancer, it is in the lining of the ducts in the breasts, and the lining of the lobules in the breast. The majority of carcinoma is adenocarcinoma in the breast. Sarcoma is cancer of connective tissue, so in breasts it's the tissue between the ducts; between the glands. While sarcomas can develop in the breast, they are much rarer than the adenocarcinomas that develop in breast cancer cases.
What are "lymph nodes" and why are they important?
Lymph nodes are part of our immune system. Lymph nodes also drain our different organs and drain the different tissues, and clean the body. It's an opportunity for the immune system to attack any bacteria or anything that should not be in the body. In terms of cancer, lymph nodes also can be the first spot that cancer can go to after it starts in its initial organ. So for instance, the cancer starts in the breast, but depending upon which lymph nodes are draining the breast, the cancer will usually spread to those lymph nodes first before it spreads anywhere else in the body. And so it can be one of the first places to look to give you a clue if the cancer may have spread beyond the local area.