Invasive Breast Cancer: Symptoms, Diagnosis
Invasive breast cancer is the most common form of breast cancer. Learn about its types, symptoms, diagnosis methods, staging, and treatment options.
Breast Cancer
When cells in the breast grow out of control and develop into a lump or tumor, breast cancer begins. These cancer cells have the ability to penetrate neighboring tissues and perhaps spread to other organ regions.
Read more about breast cancer, symptoms, diagnosis and treatment
Breast Cancer: How to Recognize Early Signs & Get Treatment
Types of Breast Cancer
- Non-Invasive Breast Cancer
- Invasive Breast Cancer
Non-Invasive Breast Cancer
Non-invasive breast cancer is an early-stage cancer that does not spread outside the breast tissue. The good news is that it is highly treatable when detected early; however, if left undetected or untreated, it may progress and spread to the surrounding breast tissue.
Read more about Non-Invasive breast cancer: Non-Invasive Breast Cancer
Invasive Breast Cancer
When breast cancer spreads to the surrounding breast tissue through the duct lining, it is commonly referred to as invasive breast cancer.
The majority of breast cancers are invasive, which means they spread to other parts of the body, such as nearby breast tissue or lymph nodes. Normal breast tissue barriers are penetrated by invasive (infiltrating) breast cancer cells, which then spread through the bloodstream and lymph nodes to other parts of the body.
When a doctor examines cancer cells under a microscope, the term “special type” refers to distinct histological features of the cells. Certain uncommon forms of breast cancer are classified as special types.
The majority of invasive breast cancers are classified as No Special Type (NST), previously referred to as Not Otherwise Specified (NOS), because they lack distinctive histological features. This category accounts for approximately 70–80% of all invasive breast cancer cases.
The two most common types of invasive breast cancer are
- Invasive ductal carcinoma
- Invasive lobular carcinoma
Invasive ductal carcinoma
Invasive ductal carcinoma (IDC) is the most prevalent type of breast cancer, accounting for approximately 70–80% of all cases.
IDC begins in a milk duct and spreads into the surrounding breast tissue. It may eventually metastasize, spreading to other parts of the body.
Note: A milk duct is a tube-like structure in the breast that carries milk from the milk-producing glands (lobules) to the nipple.
Invasive lobular carcinoma
About 5 to 10 percent of all breast cancer cases are invasive lobular carcinoma (ILC), which is the second most frequent form.
ILC begins in the lobules, which produce breast milk, and subsequently spreads to adjacent breast tissue. It might spread like IDC. Most women with ILC experience a thickening rather than a breast lump.
Compared to IDC, this cancer is more difficult to find on mammograms and other tests. ILC affects both breasts in one in five women.
Note: Lobule is a cell where breast milk is made.
Invasive breast cancer symptoms
- A new lump or thickening in your armpit or breast
- A change in the size, shape, or feel of your breast
- Skin changes in the breast, such as puckering, dimpling, a rash, or redness of the skin
- A change in the color of your breast, which could appear red, darker, or inflamed
- Fluid leaking from nipple
- Nipple positional changes
- Discharge from the nipple
- Nipple-related rashes
Regular breast screenings sometimes detect cancer before any symptoms appear. After undergoing breast screening without exhibiting any of the symptoms listed above, some individuals may receive a diagnosis of invasive breast cancer (NST).
The risk of invasive breast cancer
There’s no way to know if you’ll develop an invasive form of breast cancer, but there are things that increase your chances, many of which you can’t change.
Age Factor
Older women are at higher risk of invasive breast cancer. Approximately 10% of women diagnosed with invasive breast cancer are under the age of 45. In contrast, about two out of every three women diagnosed with invasive breast cancer are 55 years of age or older.
Genetic factor
Your family’s history of breast cancer and your genetics both play a part. Compared to black, Asian, or Hispanic women, white women are more likely to experience it.
Obesity
Additionally, you are more vulnerable if you are overweight, have dense breasts, have never had children, or became pregnant after the age of 35.
Invasive Breast Cancer Examination
Physical Examination
A doctor checks for lumps, thickening, skin changes, or nipple discharge.
Mammogram
The most effective method for identifying breast cancer in its early stages is frequently a mammography, or low-dose breast x-ray. Even before symptoms appear, mammograms can detect breast cancer or other problems.
Breast ultrasound
Doctors may also suggest a breast ultrasound, which uses sound waves to see into the breasts, following an initial mammography. A sonogram, an image produced by the ultrasound, can be used to assess the size and position of a lump and identify if it is breast cancer or a cyst, which is usually not cancerous.
Magnetic resonance imaging (MRI)
MRI in invasive breast cancer provides detailed images of breast tissue. It helps determine the extent and stage of the tumor and detects multifocal or multicentric disease. In some cases, mammography may not detect cancerous tissue, whereas MRI can more effectively identify abnormal lesions. MRI is particularly helpful in women with dense breast tissue or those at higher risk of breast cancer.
Biopsy
To confirm the diagnosis of invasive breast cancer, a biopsy is necessary. The most popular technique is core needle biopsy since it yields enough tissue for biomarker analysis and histological examination. Tumor type, grade, hormone receptor status (estrogen and progesterone receptors), and HER2 status are all identified through biopsy results, and these factors are crucial for influencing therapy alternatives.
Biomarker Tests: After biopsy, tests (like hormone receptor tests, HER2 status) check receptors on cancer cells, guiding therapy.
Tumor grading
If abnormal cells are detected on a mammogram, your doctor may recommend a follow-up needle biopsy. This procedure removes a small sample of cells from the area of concern for further testing to determine whether the abnormal cells are malignant.
DCIS, or stage 0 breast cancer, is classified into three grades—sometimes referred to as nuclear grades—which help guide treatment decisions. In general, the lower the grade, the less aggressive the cancer.
Grade 1 (low grade): Cancer cells look similar to normal breast cells and tend to grow slowly.
Grade 2 (intermediate grade): Cancer cells still resemble normal breast cells but grow faster than grade 1 cells.
Grade 3 (high grade): Cancer cells look very different from normal breast cells and grow faster than grade 2 cells. This grade is associated with a higher risk of spreading into surrounding breast tissue if left untreated.
