Invasive ductal carcinomas
Invasive ductal carcinoma (IDC) is a common type of breast cancer that begins in the milk ducts and has the potential to invade surrounding breast tissue and lymph nodes. It represents 70 to 80 percent of all breast cancer cases and is most frequently diagnosed in women over the age of fifty-five. Risk factors include age, hormonal influences, reproductive history, and genetic predisposition linked to mutations in breast cancer susceptibility genes such as BRCA1 and BRCA2. Symptoms may present as changes in breast size or shape, lumps, nipple discharge, or skin changes resembling orange peel.
Early detection is crucial, with recommendations for monthly self-exams and regular mammograms for women over forty. Diagnosis typically involves biopsies of suspicious areas, and staging is determined using the TNM system. Treatment options vary but may include surgery, radiation therapy, chemotherapy, and hormonal treatments. The prognosis is generally favorable when detected early, with localized IDC having a five-year survival rate approaching 100 percent. Lifestyle factors such as physical activity, multiple pregnancies, and breastfeeding may contribute to lowering the risk of developing this disease.
On this Page
Subject Terms
Invasive ductal carcinomas
ALSO KNOWN AS: Breast cancer, infiltrating ductal carcinomas, IDC
RELATED CONDITIONS: Inflammatory breast cancer, invasive lobular carcinoma (ILC)
DEFINITION: Invasive ductal carcinoma originates in the ducts of the milk-secreting glands and has invaded other breast tissues. When contained in the milk ducts, the cancer is called ductal carcinoma in situ (DCIS).
Risk factors: Risk factors include never having a full-term pregnancy, first becoming pregnant after age thirty, starting menarche early, and entering menopause late. Risk increases with age and the use of synthetic hormones. Family history carrying the breast cancer susceptibility genes BRCA1, BRCA2, PALB2, CHEK2, and ATM appears in 5 to 10 percent of cases.
Etiology and the disease process: Invasive ductal carcinoma invades the surrounding breast tissue and lymph nodes and can spread throughout the body.
Incidence: About 13 percent of women will be diagnosed with breast cancer, making it the most common type of cancer in women, behind skin cancer. Some 70 to 80 percent of breast cancers are invasive ductal carcinomas. Invasive ductal carcinoma is more common in individuals over fifty-five.
Symptoms: Any change in the size or shape of the breast or in the look or feel of the breast or nipple, or any lumps or thickening in or near the breast or underarm area, can be a symptom of breast cancer. Other more obvious changes include nipple discharge, tenderness, an inverted nipple, and ridges or pitting of the breast (when the skin looks like that of an orange).
Screening and diagnosis: Monthly breast self-exams after the age of twenty, yearly checkups, and regular mammograms after the age of forty are crucial to early detection. Biopsies of a suspicious lesion are taken to obtain a diagnosis.
Staging of breast cancer is based on the TNM (tumor/lymph node/metastasis) system:
- Stage I: Has not spread beyond the breast
- Stage II: May or may not have spread to lymph nodes under the arm
- Stage III: Has spread to nearby lymph nodes but not spread beyond the breast
- Stage IV: Has spread to other parts of the body
Treatment and therapy: Treatments, which vary from case to case, include surgery, radiation treatment, and chemotherapy. The standard treatment is a lumpectomy or mastectomy followed by radiation, followed by whole-body treatments, including hormonal therapies, chemotherapies, and biological therapies.
Prognosis, prevention, and outcomes: Early detection and treatment increase overall survival rates. Localized invasive ductal carcinoma caught early has a five-year survival rate of nearly 100 percent. Patients with cancer that spread to nearby tissue have a survival rate of about 85 percent, and the five-year survival rate of individuals with distant malignancies is around 28 percent. Physical activity, multiple pregnancies, breastfeeding, and early removal of both ovaries may lower the risk of getting this disease.
Bibliography
DePolo, Jamie. "Invasive Ductal Carcinoma (IDC)." 19 June 2024, Breast Cancer, www.breastcancer.org/types/invasive-ductal-carcinoma. Accessed 20 June 2024.
"Invasive Breast Cancer (IDC/ILC)." American Cancer Society, 19 Nov. 2021, www.cancer.org/cancer/types/breast-cancer/about/types-of-breast-cancer/invasive-breast-cancer.html. Accessed 20 June 2024.
"Invasive (Infiltrating) Ductal Carcinoma." Cleveland Clinic, 29 Nov. 2021, my.clevelandclinic.org/health/diseases/22117-invasive-ductal-carcinoma-idc. Accessed 20 June 2024.
Kumaraswamy, Eelandula, et al. "An Invasive Ductal Carcinomas Breast Cancer Grade Classification Using an Ensemble of Convolutional Neural Networks." Diagnostics, vol. 13, no 11, 2023. doi.org/10.3390/diagnostics13111977.
Pareja, Fresia, et al. "Whole-exome Sequencing Analysis of the Progression from Non–low-grade Ductal Carcinoma in Situ to Invasive Ductal Carcinoma." Clinical Cancer Research, vol. 26, no. 14, 2020, pp. 3682-3693. doi:10.1158/1078-0432.CCR-19-2563.
Rebbeck, Clare A., et al. "Gene Expression Signatures of Individual Ductal Carcinoma in Situ Lesions Identify Processes and Biomarkers Associated with Progression Towards Invasive Ductal Carcinoma." Nature Communications, vol. 13, no. 1, 2022. doi.org/10.1038/s41467-022-30573-4.
Shockney, Lillie D. "Invasive Ductal Carcinoma (IDC)." National Breast Cancer Foundation, 18 Jan. 2024, www.nationalbreastcancer.org/invasive-ductal-carcinoma. Accessed 20 June 2024.