Invasive (Infiltrating) Ductal Carcinoma

What are the symptoms of invasive ductal carcinoma?

Invasive ductal carcinoma (IDC) is the most common type of breast cancer, accounting for about 80% of all breast cancers. The symptoms of IDC can vary from person to person, but common signs and symptoms include:

1. A lump or thickening in the breast: This is usually the first symptom of IDC. The lump may be hard, firm, or soft, and may or may not be painful.
2. Changes in the size or shape of the breast: IDC can cause the breast to become swollen, inflamed, or misshapen.
3. Nipple retraction or discharge: In some cases, IDC can cause the nipple to retract (pull inward) or produce discharge (fluid).
4. Skin changes: Redness, scaliness, or dimpling of the skin over the breast can occur due to IDC.
5. Swollen lymph nodes: Enlarged lymph nodes under the arm (axillary nodes) or near the collarbone (supraclavicular nodes) can indicate spread of cancer to the lymph nodes.
6. Pain: Breast pain is a common symptom of IDC, but it’s not always present.
7. Numbness or tingling: IDC can cause numbness or tingling sensations in the breast or arm.
8. Changes in breast appearance: IDC can cause changes in breast appearance, such as a change in shape, size, or texture.

It’s essential to remember that not all lumps are cancerous, and many women with IDC do not experience any symptoms until the cancer has advanced.

Risk factors:

• Family history of breast cancer
• Genetic mutations (BRCA1 or BRCA2)
• Older age
• Previous radiation therapy to the chest
• Dense breast tissue
• Hormone replacement therapy (HRT)

Self-examination:

• Perform regular self-examinations to check for any changes in your breasts.
• Use a mirror to inspect your breasts from different angles.
• Use your fingers to feel for lumps or thickening in your breasts.
• Report any changes to your healthcare provider.

What are the causes of invasive ductal carcinoma?

Invasive ductal carcinoma (IDC) is a type of breast cancer that develops from the ducts of the breast. The exact causes of IDC are not fully understood, but several factors can increase a woman’s risk of developing the disease. Here are some of the known causes and risk factors:

1. Genetic mutations: Inheritance of certain genetic mutations, such as BRCA1 and BRCA2, increases the risk of developing IDC.
2. Family history: A family history of IDC or other types of breast or ovarian cancer can increase a woman’s risk.
3. Age: IDC is more common in older women, with the majority of cases occurring in women over 50.
4. Hormone replacement therapy (HRT): Long-term use of HRT, particularly estrogen and progesterone, has been linked to an increased risk of IDC.
5. Radiation therapy: Women who have received radiation therapy to the chest area, especially at a young age, have an increased risk of developing IDC.
6. Breast density: Women with dense breasts have a higher risk of developing IDC due to the difficulty in detecting tumors on mammograms.
7. Obesity: Being overweight or obese may increase the risk of developing IDC, particularly after menopause.
8. Reproductive factors: Women who have had their first child at a later age or who have never been pregnant may have a higher risk of developing IDC.
9. Environmental factors: Exposure to certain environmental toxins, such as pesticides and certain chemicals, may increase the risk of developing IDC.
10. Lifestyle factors: Smoking, physical inactivity, and poor diet may also contribute to an increased risk of developing IDC.

Other potential causes and risk factors:

• Age at menopause
• Menstrual history (e.g., early menarche, late menopause)
• Hormone levels (e.g., high estrogen levels)
• Lifestyle factors (e.g., sedentary lifestyle, high alcohol consumption)
• Breastfeeding history
• Previous breast biopsies or surgeries
• Certain medical conditions (e.g., benign breast disease)

It’s essential to note that many women with these risk factors do not develop IDC, and many women without these factors do develop the disease. If you’re concerned about your risk of developing IDC or have any symptoms, consult a healthcare provider for personalized advice and screening recommendations.

How is the diagnosis of invasive ductal carcinoma made?

The diagnosis of invasive ductal carcinoma (IDC) is made through a combination of physical examination, medical imaging, and biopsy. Here are the common steps involved in the diagnosis process:

1. Medical history and physical examination: The healthcare provider will take a detailed medical history and perform a physical examination to assess the patient’s overall health, breasts, and lymph nodes.
2. Breast imaging: Imaging tests such as mammography, ultrasound, magnetic resonance imaging (MRI), or positron emission tomography (PET) scans may be ordered to visualize the breast tissue and detect any abnormalities.
3. Mammography: A mammogram is an X-ray of the breast tissue that helps detect abnormalities such as tumors, calcifications, or architectural distortions.
4. Ultrasound: Ultrasound uses high-frequency sound waves to produce images of the breast tissue, which can help detect abnormalities such as tumors or fluid accumulation.
5. MRI: MRI uses a strong magnetic field and radio waves to produce detailed images of the breast tissue, which can help detect abnormalities such as tumors or lymph node involvement.
6. Biopsy: A biopsy is the removal of a sample of tissue from the suspicious area for further examination under a microscope. There are several types of biopsies, including:
   • Fine-needle aspiration biopsy: A thin needle is inserted into the breast to collect a sample of cells or fluid.
   • Core needle biopsy: A thicker needle is used to remove a larger sample of tissue from the breast.
   • Surgical biopsy: A surgical incision is made in the breast to remove a sample of tissue.
7. Histopathological examination: The removed tissue sample is then examined under a microscope by a pathologist to determine if it is cancerous and what type of cancer it is.
8. Immunohistochemistry (IHC): IHC is a laboratory test that uses antibodies to identify specific proteins on cancer cells. It can help diagnose IDC and determine its subtype.
9. Molecular testing: Additional tests may be performed to analyze the genetic characteristics of the cancer cells, such as HER2 status, hormone receptor status, and genetic mutations.

The diagnostic process may involve multiple steps and may take several days or weeks to complete. If IDC is diagnosed, further testing may be necessary to determine the extent of the cancer and plan treatment.

Staging:

• Clinical staging: Based on physical examination, imaging tests, and medical history.
• Pathological staging: Based on the examination of the removed tissue sample.

The American Joint Committee on Cancer (AJCC) TNM staging system is commonly used to stage IDC:

• T: Tumor size (T0: no tumor, T1-4: increasing tumor size)
• N: Lymph node involvement (N0: no lymph nodes involved, N1-3: increasing lymph node involvement)
• M: Metastasis (M0: no distant metastasis, M1: distant metastasis)

The stage of IDC helps determine treatment options and prognosis.

What is the treatment for invasive ductal carcinoma?

The treatment for invasive ductal carcinoma (IDC) typically involves a combination of surgery, radiation therapy, chemotherapy, and/or hormone therapy, depending on the stage and characteristics of the tumor. Here are some common treatments used to manage IDC:

1. Surgery: The primary goal of surgery is to remove the tumor and any affected tissue. The type of surgery depends on the stage and location of the tumor:
   • Lumpectomy: Removal of the tumor and a small amount of surrounding tissue.
   • Mastectomy: Removal of the entire breast.
   • Axillary lymph node dissection (ALND): Removal of the lymph nodes under the arm to determine if they contain cancer cells.
2. Radiation therapy: Radiation therapy uses high-energy rays to kill cancer cells. It may be used after surgery to reduce the risk of recurrence or as a standalone treatment for early-stage tumors:
   • External beam radiation therapy (EBRT): Radiation is delivered from outside the body using a machine.
   • Internal radiation therapy (brachytherapy): A small device containing radioactive material is placed inside the breast.
3. Chemotherapy: Chemotherapy uses drugs to kill cancer cells. It may be used before surgery (neoadjuvant therapy) or after surgery (adjuvant therapy) to reduce the risk of recurrence:
   • Hormone-sensitive cancers: Aromatase inhibitors or tamoxifen may be used to block estrogen production and slow tumor growth.
4. Targeted therapies: These treatments target specific molecules or pathways that contribute to cancer growth and progression:
   • HER2-targeted therapies: Trastuzumab (Herceptin) or pertuzumab (Perjeta) may be used in combination with chemotherapy to treat HER2-positive IDC.
5. Hormone therapy: Hormone therapy is used to block estrogen production and slow tumor growth:
   • Aromatase inhibitors: Anastrozole (Arimidex), letrozole (Femara), or exemestane (Aromasin) may be used to block estrogen production.
   • Tamoxifen: A selective estrogen receptor modulator that blocks estrogen from binding to cancer cells.
6. Immunotherapy: Immunotherapy uses the body’s immune system to fight cancer:
   • PD-1/PD-L1 inhibitors: Pembrolizumab (Keytruda) or atezolizumab (Tecentriq) may be used in combination with chemotherapy to treat IDC.

The choice of treatment depends on the stage and characteristics of the tumor, as well as the patient’s overall health and preferences. A multidisciplinary team of healthcare professionals will work together to develop a personalized treatment plan for each patient.

Adjuvant therapy: Adjuvant therapy is given after primary treatment (surgery, radiation, or chemotherapy) to reduce the risk of recurrence. It may include hormone therapy, chemotherapy, or targeted therapies.

Palliative care: Palliative care focuses on managing symptoms, improving quality of life, and providing emotional support during treatment and beyond.

Survivorship care: Survivorship care involves long-term follow-up and monitoring after primary treatment has been completed. It may include regular check-ups, imaging tests, and hormone replacement therapy.