Breast Cancer Awareness Month: Here’s all you need to know about invasive, non-invasive types and symptoms
Invasive ductal carcinoma makes up about 70-80% of all breast cancers
Breast cancer is a disease in which cells in the breast grow out of control. It can begin in different parts of the breast — ducts, lobules, and the tissue in between. The lobules are the glands that produce milk. The ducts are tubes that carry milk to the nipple. The connective tissue surrounds and holds everything together. Most breast cancers begin in the ducts or lobules. Breast cancer can spread outside the breast through blood vessels and lymph vessels. When breast cancer spreads to other parts of the body, it is said to have metastasized. Also classified as stage 4 breast cancer, in this case, cancer may have spread to the liver, lungs, brain, or bones. So what are the different types of breast cancer that you should be aware of?
Invasive breast cancers
The type of breast cancer is determined by the specific cells in the breast that are affected. “Most breast cancers are carcinomas, which are tumors that start in the epithelial cells that line organs and tissues throughout the body,” according to the American Cancer Society (ACS). The type of breast cancer can also refer to whether cancer has spread or not. Invasive breast cancers are those where the cancer cells have spread into surrounding breast tissue. Most breast cancers are invasive, but the most common types are invasive ductal carcinoma and invasive lobular carcinoma.
Invasive ductal carcinoma (IDC)
Also called infiltrative ductal carcinoma, the cancer cells grow outside the milk ducts into other parts of the breast tissue. Invasive cancer cells can also spread, or metastasize, to other parts of the body. Sometimes called infiltrative ductal carcinoma, it is the most common type of breast cancer: about 8 in 10 invasive breast cancers are IDC. The ACS says that it makes up about 70-80% of all breast cancers.
Invasive lobular carcinoma (ILC)
About 1 in 10 invasive breast cancers is an invasive lobular carcinoma (ILC). Here, cancer cells spread from the lobules to the breast tissues that are close by. These invasive cancer cells can also spread to other parts of the body. Compared to other kinds of invasive carcinoma, about 1 in 5 women with ILC might have cancer in both breasts.
There are less common types of invasive breast cancer and each typically makes up fewer than 5% of all breast cancers. Some of them may have a better prognosis than the more common IDC, and they include adenoid cystic (or adenocystic) carcinoma, mucinous (or colloid) carcinoma, papillary carcinoma, and tubular carcinoma, among others. Some sub-types have the same or maybe worse prognoses than IDC, which includes metaplastic carcinoma, micropapillary carcinoma, and mixed carcinoma. In general, all of these sub-types are still treated like IDC, says the ACS.
Triple-negative breast cancer (TNBC)
An aggressive type of invasive breast cancer that is difficult to treat, it accounts for about 15% of all breast cancers. These cancers are more likely to affect women younger than 40, African-Americans, and/or those with a BRCA1 mutation.
“The term triple-negative breast cancer refers to the fact that the cancer cells don’t have estrogen or progesterone receptors and also don’t make too much of the protein called HER2. The cells test ‘negative’ on all 3 tests. Triple-negative breast cancer differs from other types of invasive breast cancer in that they grow and spread faster, have limited treatment options, and a worse prognosis (outcome),” describes ACS.
Inflammatory breast cancer (IBC)
This is a rare type of breast cancer and accounts for an estimated 1% to 5% of all breast cancers. However, it is an aggressive and fast-growing breast cancer where the cancer cells block lymph vessels in the skin causing the breast to look ‘inflamed’. The lymph channels are part of the lymphatic system and they normally drain excess tissue fluid away from the body tissues and organs. The lymph channels are unable to do this properly if they are blocked. Since the lymph channels are blocked, the breast might become red, swollen, and firm or hard.
IBC does not look like a typical breast cancer: it often does not produce a lump, and it might not show up on a mammogram, which makes it harder to diagnose. IBC is more common among women younger than 40, African-American women, as well as among women who are overweight or obese, as per ACS.
Angiosarcoma of the breast
Such cancers start in the cells that make up the walls of blood vessels or lymphatic vessels. They are very rare and make up less than 1 in 100 breast cancers or less than 1%. Many times it is a complication of previous radiation treatment to the breast and can happen 8 to 10 years after getting radiation treatment to the breast.
Phyllodes tumors of the breast
They are rare and they start in the connective tissue of the breast. Most phyllodes tumors are benign (not cancerous), but about 1 out of 4 of these tumors are malignant (cancer). While Phyllodes tumors can occur at any age, they tend to develop when a woman is in her 40s.
Paget’s disease of the breast
This is again a rare form of breast cancer and the condition develops in the nipple or the darker area of skin around it, that is, the areola. Most people with Paget disease of the breast also have one or more tumors inside the same breast, which are either ductal carcinoma in situ or invasive breast cancer.
Ductal carcinoma in situ (DCIS)
It is a non-invasive cancer where abnormal cells are present inside a milk duct in the breast but have not spread to other tissues in the breast (in situ implies “in the original place”). It has a low risk of becoming invasive. About 1 in 5 new breast cancers will be ductal carcinoma in situ (DCIS), and nearly all women with this early stage of breast cancer can be cured, according to ACS. However, DCIS can sometimes become invasive cancer. At that time, cancer has spread out of the duct into nearby tissue, and from there, it could metastasize to other parts of the body.
Lobular Carcinoma In Situ (LCIS)
It is not cancer, but it increases a person’s risk of developing invasive breast cancer in the future. LCIS implies that abnormal cells are found in the lobules, and it is more common in women who have not had their menopause.
Breast cancer symptoms
Different people have different symptoms of breast cancer. According to the US Centers for Disease Control and Prevention (CDC), some people do not have any signs or symptoms at all.
Some warning signs or symptoms may include a new lump in the breast or underarm/armpit; a change in the size or the shape of the breast; changes to the skin over the breast, such as dimpling, thickening, or swelling of part of the breast, or a rash or redness of the skin; peeling, scaling, or flaking in the nipple area; a newly inverted nipple; pain in the nipple area or any area of the breast. These symptoms can happen with other conditions that are not cancer, say experts.