Breast Cancer Types and Treatments
What is Breast cancer?
Cancer is a class of diseases where abnormal cells start to grow uncontrollably and invade healthy cells in the body, these cells can spread to the surrounding tissues or spread to other areas of the body.
Breast cancer starts in the cells of the breast and has a tendency to invade the surrounding tissues or spread to other organs (metastasize). [1]
Breast cancer cells are often first felt as a lump or can be seen on an x-ray. Breast cancer occurs almost entirely in women but can also be found in men. [2]
Any breast lump should be checked by a health care professional to determine if it is benign or malignant, in order to decide the treatment course.
Although most breast lumps are non-cancerous (benign), which are abnormal growths that do not spread outside of the breast, some benign lumps can increase a woman’s risk of getting breast cancer. [3]
WHERE DOES BREAST CANCER STARTS?
- DUCTAL cancer: the most common site where breast cancer begins in the ducts that carry milk to the nipple.
- LOBULAR cancer: other cancers start in the glands that make breast milk.
- Metastatic cancer: from these two sites, cancer can spread to other parts of the body through lymph vessels and blood vessels. [4]
TYPES OF BREAST CANCER:
The types of breast cancer vary depending on its site and tissue. Your doctor will need to determine certain characteristics of breast cancer before starting treatment, these are:
- Whether the cancer cells have spread beyond the breast
- the type of tissue where cancer began [5]
INVASIVE VS NON-INVASIVE BREAST CANCER
Invasive breast cancer
Invasive breast cancers mean that cancerous cells have spread from the original site to other areas, like nearby lymph nodes, breast tissue, or elsewhere in the body. Invasive type is also called infiltrating breast cancer, where cells break through normal breast tissue barriers and spread to other parts of the body through lymph nodes and the bloodstream.
The two most common invasive breast cancers are invasive ductal carcinoma and invasive lobular carcinoma. [6]
INVASIVE DUCTAL CARCINOMA:
Invasive ductal carcinoma is the most common type of breast cancer accounting for nearly 70 to 80 percent of all breast cancer cases. IDC also called infiltrative ductal carcinoma, is a type of breast cancer that begins in the milk ducts (the tubes in the breast that carry milk to the nipple) and invades surrounding parts of the breast. Later it may also spread to other parts of the body (metastasize). [7]
INVASIVE LOBULAR CARCINOMA:
Invasive lobular carcinoma is the second most common type of breast cancer and accounts for roughly 5 to 10 percent of all cases. ILC begins in lobules (the tissue where milk is made) and then invades the nearby breast tissue. It may also metastasize like IDC. This cancer is however more difficult to detect on mammograms and other exams as compared to IDC.
Research shows one in five women with ILC have both breasts involved. [8]
INFLAMMATORY BREAST CANCER:
Inflammatory breast cancer tends to spread faster than other types of breast cancer. It may be detected in the ducts or lobules. According to the NCI, this rapidly growing, the aggressive disease accounts for about 1 to 5 percent of breast cancers in the United States.
It is called inflammatory breast cancer owing to the signs it causes, which are swelling and redness on the surface of the breast. Due to these signs, it is often misdiagnosed as a breast infection. According to the ACS (American Cancer Society), every one out of three patients with this type of cancer is not diagnosed correctly until the more advanced stage of the disease has reached, where it has already metastasized to other areas of the body. Hence this type of cancer has a much lower survival rate. [9]
PAGET’S DISEASE OF THE BREAST:
This disease is also known as Paget’s disease of the nipple and is a much less common type of breast cancer. According to NCI, it primarily affects around 1 to 4 percent of patients diagnosed with another breast cancer. It creates unique tumor cells called Paget cells and usually develops in the skin of the nipple and the areola. [10]
ANGIOSARCOMA OF THE BREAST:
When breast cancer develops in the lining of lymph or blood vessels it is called Angiosarcoma. According to NCI, this cancer of the breast is rare ad accounts for only 1 to 2 percent of all sarcomas (including sarcomas found in other parts of the body). It is most common in people older than 70 years of age. It is a type of cancer that grows rapidly and is often undiagnosed until it has already spread to other areas of the body.
PHYLLODES TUMORS:
These are the rarest type of breast cancer and are found in the connective tissues of the breast. Although it may develop in patients of all ages, it mostly affects women in their 40s. People who have a genetic condition called Li-Fraumeni syndrome running in their family are at a higher risk for this tumour. According to ACS, about 25 percent of phyllodes tumours are cancerous. [11]
Non-Invasive Breast Cancer
Non-invasive or in situ breast cancer cells remain in the particular site of origin in the breast, without spreading to surrounding tissues, ducts, or lobules.
Carcinoma In-Situ is a term commonly used for breast cancers where carcinoma means cancer, and in situ means ‘in the original place’. [12]
DUCTAL CARCINOMA IN SITU (DCIS):
Ductal carcinoma in situ is non-invasive cancer in which abnormal cancerous cells are found in the lining of the breast milk duct, which carries milk from the glands, or lobules to the nipple. These atypical cells usually do not spread outside the ducts into the surrounding breast tissue. However, if left untreated chances of this mass of atypical cells breaking through the ductal walls into the surrounding breast tissue and fat, increase. Most patients treated at stage 0 breast cancer of DCIS, have positive outcomes. [13]
LOBULAR CARCINOMA IN SITU (LCIS):
Lobular carcinoma in situ is another non-invasive cancer of the breast where abnormal cells are found in the lobules.
LCIS is technically not considered cancer, but a change in the cells of the breast. There are tens of thousands of tiny clusters of lobules in the breast, which produce milk. Within these lobules, cells that resemble cancer cells may develop. These atypical cancer cells do not spread beyond the lobules into the surrounding breast tissue. Patients having LCIS in one breast are at an increased risk of developing breast cancer in either breast. [14]
METASTATIC BREAST CANCER:
When breast cancer cells are found in other parts of the body, for example in the liver, the disease will be classified as metastatic breast cancer that has metastasized to the liver. The stage 4 breast cancer is metastatic, this means it tends to spread to other parts or part of the body. They may spread directly to the surrounding organs, through blood vessels, or through lymph vessels. [15]
Common sites of metastatic breast cancer include;
- Liver,
- Lungs,
- Brain, or
- Bones.
Breast Cancer in Men
While most breast cancers occur in women, men also have breast tissue and since every cell in the body has the potential to become cancerous, men can develop breast cancer too. The two most common types of breast cancer in men are the same as for women; invasive ductal carcinoma and invasive lobular carcinoma. When a man has a family history of breast cancer or a genetic mutation such as BRCA2, his risk of developing breast cancer increases. [16]
TREATMENT OF BREAST CANCER
When a patient is diagnosed with Breast cancer, a multi-disciplinary team (MTD) is assigned to the patient, this team works together to determine the treatment and care. [17]
Following are the treatment options for breast cancer patients, these treatments may be offered alone or in combination and varies from patient to patient:
- Surgery
- Radiotherapy
- Chemotherapy
- Hormone therapy
- Targeted therapy
The type of treatment combination depends on cancer location and its stage.
Usually, breast cancers diagnosed during routine screening are at an early stage. Whereas breast cancers diagnosed after symptoms occur, are at a later stage of cancer and both these diagnoses require different treatments.
SURGERY
Breast surgery for removing breast cancer is approached in two ways:
- Breast-conserving surgery, where only the cancerous lump (tumor) is removed.
- Mastectomy, where the entire breast is removed.
Breast-conserving surgery:
This surgery ranges from removing a breast cancer lump (lumpectomy) or a wide local excision, where the entire tumour and some surrounding breast tissue is removed, to a partial mastectomy or a quadrantectomy, where a quarter of the breast is removed. [18]
The surgeon will always remove an area of non-diseased/healthy breast tissue and send it for testing for any traces of cancer. If there are no cancer traces in the healthy tissue, the chances of cancer recurring are low.
However, if traces are found in the healthy tissue, more tissue may be required to be removed from your breast.
Breast-conserving surgery is often combined with radiotherapy to remove any remaining cancer cells.
Mastectomy:
Mastectomy is a breast cancer surgery where the entire breast is removed including the nipple. If there are obvious signs that cancer has invaded the lymph nodes, more extensive removal of nodes from the underarm area (axilla), is performed. If no obvious signs of lymph node involvement is seen then the sentinel lymph node is removed along with the breast.
Radiotherapy
Radiotherapy is usually given after surgery and chemotherapy, targeting any remaining cancer cells. It is a technique, where controlled radiation doses are used to kill cancer cells. If radiotherapy is part of the treatment, it is commenced after a month of the patient’s surgery or chemotherapy, in order to give the body a chance to recover.
Radiotherapy types;
- – breast radiotherapy, where radiation is applied to the remaining breast tissues, after breast-conserving surgery
- – chest-wall radiotherapy, where radiation is applied to the chest wall, after a mastectomy
- – radiotherapy to lymph nodes, where radiation is applied to the axillary area (armpit) and the surrounding area, targeting the lymph nodes to kill any remaining cancer cells.
Chemotherapy
This is a very common treatment for cancer. In chemotherapy, cytotoxic (anti-cancer) drugs are used to kill the cancer cells.
Adjuvant chemotherapy is a commonly used term in cancer treatment, which means using chemotherapy after surgery to destroy any cancer cells that may have not been removed completely by surgery.
In other cases chemotherapy is used before surgery, aiming to reduce the size of a large tumor, this is called neoadjuvant chemotherapy. [19]
In chemotherapy, several combinations of cytotoxic drugs are given at once, through a drip into the vein. The choice and combination of medicine depend on the spread and type of tumor.
Hormone treatment
Stimulation and growth of some breast cancers occur by the hormones progesterone and estrogen, which are naturally found hormones in the body. These cancers are called receptor-positive cancers. This therapy aims to lower the levels of progesterone and estrogen in the body and stop their effect. The type of hormone therapy will depend on which hormone the cancer is sensitive to, the patient’s age, stage and grade of cancer, and what other type of treatment the patient is having.
Hormone therapy is mostly reserved for patients with breast cancer, who are not fit for surgery, radiotherapy, or chemotherapy.
Psychological support
Being diagnosed with cancer is a huge challenge for patients and their families and friends. It causes both practical and emotional difficulties. Where the treatment involves surgery, many women need support because it includes removing part or all of the breast. It is best to take help and counselling from an expert therapist.
