By Rachael Curry
What is IDC?
Invasive ductal carcinoma (IDC) is the most common type of breast cancer, accounting for 80% of all breast cancers in women and 90% in men. Yes, you read that correctly – 1% of men are diagnosed with breast cancer. Also called infiltrating ductal carcinoma, it refers to a type of cancer that has spread beyond the ducts, which carry milk from the breast lobules to the nipple. “Invasive” refers to this spread of the cancerous cells, while “ductal” refers to the origination of the cancer in the milk ducts, and “carcinoma” refers to a type of cancer that begins in the skin or protective tissues such as breast tissue. While IDC is most common in older women, especially those over the age of 55, it can also affect younger women and men.
Like many forms of breast cancer, IDC often has no symptoms at first. However, signs might include:
A lump in the breast or underarm,
Skin irritation, pain,
Redness or scaly texture on the breast and nipple,
Unusual discharge from the nipple, or
The nipple turning inwards.
IDC is usually initially detected as a lump in a screening mammogram, which takes an x-ray picture of the breast. This then leads to a biopsy and other testing procedures to assess the size and spread of the tumor. Potential tests include CT scans (using multiple angles of x-rays to create cross-sectional imaging), PET scans (using imaging to visualize metabolic processing within the organs and tissues), MRI (using a magnetic field to create images of organs and tissues), bone scans (using nuclear imagine to detect the presence of metastatic cancer in bones), and chest x-rays.
Invasive Ductal Carcinoma Prognosis
So – is invasive ductal carcinoma “curable”? The linguistics of the word “curable” are not black and white. In this case, we will assume that “curable” means that there is no remaining evidence of disease. The short answer, then, is that IDC can be curable with the correct treatment methods. Treatment will be determined based on the stage of IDC, which classifies the size and location of the cancerous cells. The provider will analyze the growth and spread of the lump throughout the body to determine this. IDC consists of four stages. Stage 1 means that the tumor is smaller than 2 centimeters in diameter and the breast cancer is contained to just the breast. Stage 2 is a smaller lump that has only spread to a few lymph nodes in the underarm area while Stages 3-4 refer to a larger lump that has spread to multiple lymph nodes or other organs. The 5-year survival rate of Localized IDC is 99% while Regional IDC is 86% and Distant IDC is 27%. With IDC, there are usually strong positive prognoses, although as with any medical procedure, it is impossible to guarantee a 100% success rate.
How is IDC Treated?
Treatments are classified as either local, meaning they only target one area of the body, or systemic, meaning they target the entire body – likely for a cancer that has spread and progressed to a further along stage.
Local treatments include surgery and radiation therapy. Surgery is used to remove the breast tumor, which is sufficient if the cancer has not spread to the lymph nodes. Either a lumpectomy will remove the lump and a bit of surrounding tissue, or a mastectomy will remove part or all of the breast tissue. Radiation therapy directs rays of high energy on the breast to destroy any remaining cancerous cells after surgery.
Systemic treatments include chemotherapy, hormonal therapy, and targeted therapy. Chemotherapy utilizes powerful medicine to destroy cancerous cells in the body by traveling throughout the bloodstream. Side effects are frequent since this also weakens healthy cells within the body. Hormonal therapy, also called anti-estrogen or endocrine therapy, is used to lower the amount of estrogen in the body. Because the hormone estrogen signals the growth of cancerous cells, this form of therapy can either destroy or block the hormonal receptors that create this signal. Targeted therapy similarly targets certain parts of cancerous cells to inhibit their growth.
The treatment method for IDC will be determined between yourself and your provider. Regardless of the treatment selected for your personal circumstances, there is a largely positive outlook. Routine mammogram screenings are important to detect potential invasive ductal carcinoma early on when there may be no symptoms, and lead to prompt treatment initiation.
Read more about breast cancer risk factors.
About the Author
I am a 2019 graduate of the University of Michigan with a BA in Gender and Health, and a current MPH candidate at Boston University focusing in Healthcare Management.
I am interested in the intersection of social identity and women’s reproductive health. In the future, I hope to help create a more accessible and equitable healthcare system for all women.
During my free time, I enjoy painting, drawing, running, and hiking.