What is the Difference Between DCIS and Invasive Ductal Carcinoma

The key difference between DCIS and invasive ductal carcinoma is that in DCIS breast cancer, cancer cells are still contained in the milk ducts, while in invasive ductal carcinoma, cancer cells have begun to spread to other nearby surrounding breast tissue.

Breast cancer is a type of cancer predominantly seen in women. It is the second most common cancer type diagnosed in women in the United States. Breast cancer occurs due to errors in the breast cells. Breast cells grow uncontrollably, forming abnormal cell masses. There are many different types of breast cancers, including DCIS, invasive ductal carcinoma, angiosarcoma, and phyllodes tumor.

CONTENTS

1. Overview and Key Difference
2. What is DCIS  
3. What is Invasive Ductal Carcinoma
4. Similarities – DCIS and Invasive Ductal Carcinoma
5. DCIS vs Invasive Ductal Carcinoma in Tabular Form
6. Summary – DCIS vs Invasive Ductal Carcinoma

What is DCIS?

DCIS (ductal carcinoma in situ) is a type of cancer where cancer cells are still contained in the milk ducts. In this type of breast cancer, the abnormal cells are only present inside a milk duct in the breast. It is the earliest form of breast cancer. It is a non-invasive breast cancer. Normally, DCIS does not have any signs or symptoms. However, sometimes DCIS may cause a breast lump, bloody nipple discharge, and irregularly shaped and sized small clusters of calcified cells. DCIS forms when genetic mutations like BRCA1 and BRCA2 mutations occur in the DNA of breast duct cells. There are several risk factors for DCIS, including age (adults are affected more), family history, not becoming pregnant, giving birth to the first baby after 30, having the first period before the age of 12, menopause after age 55, and genetic mutations.

DCIS can be diagnosed through physical examination, mammogram, breast biopsy, ultrasound, X-ray, and MRI. Furthermore, DCIS can be treated through breast-conserving surgery (lumpectomy), breast removal surgery (mastectomy), radiation therapy, and hormone therapy.

What is Invasive Ductal Carcinoma?

Invasive ductal carcinoma (IDC) is the most common form of breast cancer. It accounts for 80% of all diagnosed breast cancers. In this cancer type, the cells growing in the lining of the milk ducts become abnormal and invade the breast tissue nearby. Its signs and symptoms may include a breast lump, thickening of the skin, redness of the skin, shape changes in the breast, localized or persistent pain in the breast, dimpling of the skin of the breast, nipple discharge, an ulceration on the skin of the breast, lumps in the area of underarm, changes in the appearance of the nipple, which are different from the normal monthly changes. Moreover, IDC forms when genetic mutations such as CTCF mutation take place in the breast tissue. The risk factors for IDC include age and gender (women older than 55 are at more risk), family or personal history of breast cancer, dense breast tissue, long-term use of hormone replacement therapy, exposure to diethylstilbestrol (DES), obesity, a sedentary lifestyle, night shift work, and alcohol and tobacco use.

Invasive ductal carcinoma is diagnosed through physical examination, digital mammogram, breast ultrasound, breast magnetic resonance imaging, biopsy, and staging workup. Furthermore, treatment for invasive ductal carcinoma includes surgeries like lumpectomy, mastectomy, and non-surgical procedures such as radiation therapy, chemotherapy, hormone therapy, and biological or targeted therapy.

What are the Similarities BetweenDCIS and Invasive Ductal Carcinoma?

• DCIS and invasive ductal carcinoma are two different types of breast cancers.
• Both types are predominantly occurring in women.
• Both types may have similar signs and symptoms, like lumps in the breast, nipple discharge, etc.
• They can be diagnosed through imaging techniques and biopsy.
• They can be treated through surgeries like lumpectomy, mastectomy, and radiation therapy.

What is the Difference Between DCIS and Invasive Ductal Carcinoma?

DCIS is a form of breast cancer in which the cancer cells are still contained in the milk ducts, while invasive ductal carcinoma is a form of breast cancer in which the cancer cells have begun to spread to other surrounding breast tissue. Thus, this is the key difference between DCIS and invasive ductal carcinoma. Furthermore, DCIS accounts for 20-25% of all diagnosed breast cancers, while invasive ductal carcinoma accounts for 80% of all diagnosed breast cancers.

The below infographic presents the differences between DCIS and invasive ductal carcinoma in tabular form for side-by-side comparison.

Summary – DCIS vs Invasive Ductal Carcinoma

Breast cancer is a disease in which cells of the breast grow out of control. There are different kinds of breast cancers. DCIS and invasive ductal carcinoma are two different types of breast cancers that predominantly occur in women. DCIS is a form of breast cancer in which the cancer cells are still contained in the milk ducts, while invasive ductal carcinoma is a form of breast cancer in which the cancer cells have begun to spread to other nearby surrounding breast tissue. So, this summarizes the difference between DCIS and invasive ductal carcinoma.

Reference:

1. “Ductal Carcinoma in Situ (DCIS).” Mayo Clinic, Mayo Foundation for Medical Education and Research, 18 May 2022.
2. “Invasive Ductal Carcinoma (IDC).” Johns Hopkins Medicine, 21 Jan. 2022.

Image Courtesy:

1. “Diagram showing ductal carcinoma in situ (DCIS) CRUK 115” By Cancer Research UK – Original email from CRUK (CC BY-SA 4.0) via Commons Wikimedia
2. “Micrograph of invasive ductal carcinoma with marked nuclear pleomorphism” By Sami Shousha – (2014). “Pleomorphic Invasive Ductal Carcinoma of the Breast in a Patient with Huntington’s Disease”. Case Reports in Pathology 2014: 1–3. DOI:10.1155/2014/979137. ISSN 2090-6781 – an open access article distributed under (CC BY 3.0) via Commons Wikimedia