Treating Invasive Ductal Carcinoma: Chemotherapy

Obie Editorial Team

After the total profile for invasive ductal carcinoma has been determined, including the stage, grade, and hormone receptor status, your treatment team will put together a comprehensive treatment plan to eliminate your cancer and, hopefully, prevent its return. Invasive ductal carcinoma treatments come in two categories: localized treatments and systemic treatments. Whereas localized treatments focus directly on the affected area, systemic treatment work on the whole body to body eradicate the tumor and also kill any rogue cancer cells that have infiltrated other areas of the body. Systemic treatments also reduce the risk of recurrence. The most common systemic treatments are targeted therapies, hormonal therapies, and chemotherapy.

Chemotherapy is probably the most familiar systemic treatment, and there are a vast number of chemotherapy treatments available that vary in strength to treat different types and levels of cancer. Chemotherapy is administered in one of two ways: intravenously or orally.  It is not uncommon for multiple medications to be administered together or consecutively to achieve the desired result. These medicines travel throughout the body via the bloodstream. Although chemotherapy is designed to kill cancer cells, they also sometimes destroy healthy, normal cells as well. This is why side effects such as hair loss are common with treatments. It is usually the fast-growing cells that are most affected.  The size of the invasive ductal carcinoma (IDC) tumor will usually dictate whether chemotherapy is administered as adjuvant or neoadjuvant therapy. More details about these administration methods can be found at Adjuvant Chemotherapy for Breast Cancer and Neoadjuvant Chemotherapy for Breast Cancer. More about managing some of the side effects can be found at The Cause of Chemotherapy-Induced Nausea and Vomiting, Tips for Coping with Chemotherapy-Induced Nausea and Vomiting and Chemotherapy and Anti-Nausea Medications (Antiemetics), Chemotherapy and Menopause, and Chemotherapy and Migraine Headaches

Chemotherapy is usually administered in cycles with a period of ‘off day(s)’ between treatment days. The type of medication used dictates the majority of the cycle, and the complete course of treatment can last from 3 to 6 months. Some of the many types of chemotherapy that may be used are Adriamycin (doxorubicin – also called the ‘Red Devil’), Cytoxan (cyclophosphamide), Ellence (epirubicin), fluorouracil (also called 5-fluorouracil or 5-FU), methotrexate, Taxol (paclitaxel), Taxotere (docetaxel), and Xeloda (capecitabine). You and your doctor will collaborate to figure out which chemotherapy combinations are best for your particular situation. Contributing factors are your total cancer profile and other health conditions you may also have. For example, having a history of heart disease or other risk factors for heart-related conditions will provide cause for avoiding medications that can affect the heart, like Adriamycin. Your hormone receptor status will also contribute to your treatment plan. Treatment combinations like Cytoxan and Taxol are commonly used in conjunction with Herceptin to treat breast cancers that are HER2 positive. (I received Adriamycin, Cytoxan, Taxol, and Herceptin. I did not need hormonal therapies like tamoxifen).

Certain tests may be administered to see if chemotherapy is the best treatment for your particular cancer, especially if your tumor is very, very small. These three tests MammaPrint, Mammostrat, and Oncotype DX. These are used to predict the risk of your cancer coming back, or recurring. Genomic assay tests analyze specific genes within the tumor to assess this recurrence risk. If a cancer is identified as “high risk,” it is usually considered best to proceed with chemotherapy treatments. 

MammaPrint is a test that was developed in and more frequently used in Europe. This test looks at the activity of 70 specific genes with cancer’s genetic material that was extracted from the tissue of the tumor, which is called RNA. The profile generated by this test identifies the risk of recurrence to be low, medium, or high at the 5 and 10-year points after treatment. The MammaPrint test requires the tissue to go through special processing at the time of your surgery.

Mammostrat is a test that reviews and measures the levels of five certain genes within the breast cancer cells. The results of this test establish a risk index score. The risk categories are low, moderate, or high, and the higher the risk level, the greater the likelihood of the cancer returning. The Mammostrat test is usually done on a sample of tissue that was preserved after removal from the breast during the original surgery or biopsy. 

Oncotype DX is the most common test in the United States. This test looks at a sample taken from the tumor and analyzes the activity patterns in 21 genes. This test indicates a recurrence risk through the 10-year mark. The test scores on a scale of 1-100. A score of 0-17 indicates low risk, 18-30 is considered moderate or intermediate risk, and 31 or above indicates high risk. Chemotherapy is recommended for anyone with a score of 18 or above, but especially those that are at 31 or above. The Oncotype DX test is usually done on a preserved tissue sample of cancer that was removed from the breast area during the original surgery or biopsy.

These three tests are not automatically ordered for every case of breast cancer. Instead, they are usually reserved for patients that either have breast cancer in the early stages and that has not yet spread to the lymph nodes or only a few lymph nodes or in cases where the patient had an Oncotype DX test which identified ductal carcinoma in situ (DCIS), which is a stage 0 cancer. If you qualify based on these criteria, your doctor may consult with you about whether genomic testing is appropriate in your case.