Invasive Breast Cancers: What You Need to Know

Invasive breast cancer (IBC) refers to cancer that has spread to the surrounding breast tissue from its place of origin. Breast cancers often originate from the linings of milk ducts or lobules of the breast. When cancer cells break through the wall of the lining into the surrounding breast tissue, it is said to be an invasive cancer.

The purpose of this article is to provide readers with a comprehensive understanding of IBC, and how it differs from other types of breast cancer.

Metastatic breast cancer refers to cancer originating from the breast but has spread to other organs or parts of the body. This type of breast cancer is said to be both invasive and metastatic as it has spread to the surrounding breast tissue and other parts of the body outside the breast. However, not all invasive cancers are metastatic. If breast cancer has spread to the surrounding tissue but has not gone beyond the breast, it is called localized invasive breast cancer that has not metastasized.

There are several types of invasive breast cancer. The two most common types are:

• Invasive Ductal Carcinoma (IDC)

IDC refers to breast cancer that originates from the cells that line the milk duct in the breast but have grown past the lining wall and spread to the surrounding breast tissue. It is the most common type of invasive breast cancer. Approximately 80% of all invasive breast cancer are IDCs.

• Invasive Lobular Carcinoma (ILC)

ILC refers to breast cancer that starts in the lobules in the breast but has progressed and spread to the surrounding tissue. ILC is the second most common type of invasive breast cancer. Around 10% of all invasive breast cancer are ILCs.

If left untreated or uncontained, IDCs and ILCs may metastasize and spread to other parts of the body through the lymphatic system or the bloodstream as they multiply and grow. It’s crucial to address these issues promptly. Staying informed and maintaining communication with medical professionals is always a wise decision.

Another type of invasive breast cancer is Inflammatory Breast Cancer (IBC).

Although it is a rare form of breast cancer (only 1% to 5% of all breast cancers are IBC), it is a much more aggressive cancer as compared to IDC and ILC. In IBC, cancer cells block the lymph vessels in the skin of the breast and do not often result in a lump or a mass that can be detected from imaging tests. IBC is therefore much harder to diagnose and normally has a poorer prognosis as compared to IDC and ILC.

Other rarer forms of invasive breast cancer include:

• Tubular Carcinoma
• Mucinous Carcinoma
• Cribriform Carcinoma
• Papillary Carcinoma

It is good to know that these types of invasive breast cancer are not very common, accounting for only 1% to 5% of all breast cancers. The encouraging news is that typically, the prognosis for this type of cancer is favorable.

Women with invasive breast cancer may have the following symptoms:

• A lump or thickening in the breast or the armpit
• Changes in the size, shape, and feel of the breast
• Changes in the skin of the breast (e.g. dimpling or unexplained redness of the skin)
• Fluid discharge from the nipple that is not breastmilk

It can be difficult to detect breast cancer, including IBC, as it often does not exhibit noticeable symptoms. This can be frightening and overwhelming, but it is important to stay vigilant and prioritize regular check-ups with your doctors.

Invasive breast cancer may be discovered from regular breast screenings or reported symptoms.

Upon discovery, one or more of the following tests may be recommended to confirm the presence of cancer and further identify the type of cancer:

• Mammogram (x-ray of the breast)
• Ultrasound (Younger women are usually recommended to go for an ultrasound instead of a mammogram)
• Magnetic resonance imaging (MRI)
• Biopsy (a small sample of tissue is taken from the breast)
• Blood test (to check for certain tumor markers that may be present in the blood which may provide more information about the cancer, if any)

The treatment method recommended will be dependent on several factors:

• Breast cancer type
• Cancer stage (size of the cancer and how far it has spread if it has spread)
• Cancer grade (how abnormal the cancer cells look under the microscope)
• Presence of receptors for certain hormones (mainly estrogen and progesterone)
• Presence of receptors for targeted cancer drug therapy
• General health and medical history

After evaluating the factors above, your breast cancer specialist may recommend one or more of the following treatments:

• Surgery

There are several types of surgery that may be recommended for invasive breast cancer. The common types are lumpectomy (breast-preserving surgery) and mastectomy (removal of the entire breast). The kind of surgery depends on several factors such as the size of the tumor and the number of affected areas on the breast.

• Chemotherapy

For invasive breast cancer, chemotherapy may be recommended even before surgery to shrink the size of the tumor(s) to allow for as much preservation of the breast as possible. This may allow women who might have needed a mastectomy to get breast-preserving surgery instead. This is called neoadjuvant therapy. Chemotherapy done after surgery to get rid of any remaining cancer cells is called adjuvant therapy.

• Radiation therapy

Radiation therapy may also be used to get rid of any remaining cancer cells after surgery.

• Hormone therapy

For cancers that have hormone receptors, hormone therapy may be recommended to block these receptors to prevent or stop the growth of tumors.

• Targeted drug therapy

For HER2-positive breast cancers, certain drugs may be used to target the HER2 proteins to help stop the cells from growing.

• Drugs to prevent or reduce therapy-induced osteoporosis (bone thinning)

Some of the hormone therapy drugs such as aromatase inhibitors may speed up bone thinning which can lead to osteoporosis. Additional medication may be prescribed to slow down or reduce the chances of getting osteoporosis.

The five-year relative survival rates for women with invasive breast cancer are as follows*.

Please keep in mind that survival rates for breast cancer are calculated based on the average experience of all women and should not be used to predict an individual’s outcome as there are several factors that may affect it. Moreover, these rates are based on data collected several years ago, when diagnostic technology and treatments were not as advanced as they are now. The most important thing to do is to seek the guidance and expertise of medical professionals.