Tumor heterogeneity is an important concept in breast cancer. In a single cancerous tumor, not all cancer cells may be the same—in fact, a single cancerous tumor can be made up of different types of cancer cells. This type of tumor is known as heterogeneous.
Within a single tumor, different cancer cells may exhibit varying growth rates and abilities to metastasize. A single tumor may even be composed of cancer cells that have spread from a different cancer at a different location.
Different types of cancer cells may respond differently to treatment. Tumor heterogeneity, hence, represents a significant challenge in cancer care.
How tumor heterogeneity affects treatment
In breast cancer, tumor heterogeneity may result in a mixture of cells, such as those expressing HER2, hormone-receptor-positive and triple-negative characteristics. This explains why a treatment targeting a single subtype of breast cancer may prove to be ineffective. Some cells respond to a specific treatment, while others do not.
In addition, tumor heterogeneity can also complicate diagnosis in cases of which a biopsy is taken. A biopsy is a procedure in which doctors extract a small sample of the tumor for analysis. Tumor heterogeneity means that the sample extracted and analyzed may not necessarily be representative of the whole.
Learn more about breast cancer therapies
A personalized treatment approach
Researchers are always looking for new ways to manage tumor heterogeneity in cancer care. One of the most commonly adopted strategies is to use combination therapies to ensure that differentiating cell subtypes are targeted. To avoid the problem of a biopsy sample being unrepresentative of the whole tumor, doctors sometimes perform repeat biopsies.
The term “personalized” or “precision” medicine in oncology has gained traction of late. This is because doctors recognize there is rarely a “one size fits all” approach to cancer care. Instead, doctors seek to understand the nature of the breast cancer in each patient and tailor treatment plans accordingly.
Personalized medicine is a strategy that can help doctors avoid the trappings of providing inadequate care due to under-recognized tumor heterogeneity. As a patient, it is important for you to work with your doctors as they determine what treatments suit you best. In addition, it helps to cooperate with your doctor if they request repeat testing to confirm the precise nature of your breast cancer. All of these are necessary to ensure that the care you receive is personalized to you.
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