Breast cancer develops when cells within the ducts, lobules or the nipple of the breast develop genetic mutations. The mutated cells can divide uncontrollably and evade cell death to give rise to unlimited numbers of cancer cells. Breast cancer is commonly treated with a number of strategies, including surgery, radiation therapy, hormone-based therapies or chemotherapy. Chemotherapy has a number of advantages in the treatment of advanced or severe breast cancer cases.
Breast Tumor Shrinkage
The obvious benefit of chemotherapy for breast cancer is cancer cell death, leading to a decrease in the size of the breast tumor. Chemotherapy drugs work by inhibiting essential cellular mechanisms required to sustain life. Some types of chemotherapy drugs damage cellular DNA, the blueprint for the cells' proteins, so the cell cannot synthesize the proteins required to survive and grow. Other chemotherapy drugs target the cytoskeleton--the network of structural proteins that allow for cell stability, division and migration. Finally, some chemotherapy drugs target proteins essential for metabolism in breast cancer cells--without the activation of metabolic pathways, the cancer cells do not have access to energy required for growth and survival. Several chemotherapy drugs have been approved for use alone or in combination in treating breast cancer.
Systemic Action
The systemic action of chemotherapy drugs is another benefit of chemotherapy as a treatment for breast cancer. Some breast cancer treatments, such as breast removal surgeries or radiation therapy, effectively remove or kill cancer cells within one part of the body. In advanced cancers, breast cancer cells metastasize--they break away from the initial tumor and travel throughout the body, forming secondary tumors in several distant organs. Since surgery or radiation therapy typically only target cancer cells in one location, they may not be effective in treating metastatic breast cancer. In contrast, chemotherapy drugs travel throughout the bloodstream to target rapidly proliferating cancer cells throughout the entire body. As a result, chemotherapy treatment can target cancer growth in multiple organs and tissues, and so chemotherapy may present an effective treatment for metastatic breast cancer, reports the National Cancer Institute.
Non-Selective Mechanism of Action
Breast cancer represents several genetically distinct diseases. Breast cancer is caused by mutations to any number of genes within the cell's DNA, so the genetic profile of breast cancers often differs from patient to patient. As a result, some cancer therapies may prove effective for some cases of breast cancer but not others. For example, a popular breast cancer treatment, Tamoxifen, effectively treats many estrogen-responsive breast cancers, but does not target breast cancers that are resistant to estrogen. Chemotherapy drugs are almost universally cytotoxic, so they can effectively target breast cancer cells regardless of their genetic profile. As a result, biologically aggressive cancers that do not respond to targeted or hormone-based therapies may still respond to chemotherapy, reports CancerHelp UK.
