How does tumour profiling inform cancer treatment?

What is tumour profile information used for?

A molecular profile reveals unique characteristics of a person’s disease at the molecular level, providing doctors with knowledge about which treatments are most likely to produce the best results, including treatments that may not have been previously considered. Molecular profiling may also help patients avoid treatments that are ineffective, unnecessary, and potentially harmful.1

How is tumour profiling associated with cancer treatment?

Precision medicine in oncology relies on the unique molecular profile of a patient’s tumour for optimal treatment selection. The terms “personalised medicine” and “precision medicine” are often used interchangeably to describe the ability to tailor treatments to an individual patient based on the unique characteristics of his or her disease. In contrast, standard treatment is based largely on the location where the tumour originated, such as the breast or lungs, and may not always produce optimal results.1

In recent years, increasing numbers of oncologists have adopted precision medicine as a treatment approach for various cancers that have historically been characterised and treated based on body location. This approach has been aided by the development of molecular profiling that can help doctors personalise treatment plans for individual patients.1

Examples of therapies informed by molecular profiling

Biomarkers that trigger cells to grow and multiply abnormally

An example of this type of biomarker is the HER2 protein, which helps to control cell growth. If HER2 is “overexpressed” in cancer cells, the cells are considered “HER2-positive,” meaning they produce more of the protein than is normal. This condition can possibly cause the cells to grow more quickly and increase their chances of metastasising (spreading) to other parts of the body. It also means that treatments known to disrupt the HER2 signalling pathway are likely to help stop the cancer’s growth.2

Biomarkers that support a treatment’s cellular or molecular action

This type of biomarker is exemplified by a gene called SPARC, which stands for Secreted Protein, Acidic, Cysteine-Rich. SPARC helps bring albumin — a type of protein found in blood, egg whites, milk, and other substances — into cells. Some chemotherapeutic drugs are bound (“packaged”) with albumin to prevent them from being dissolved in the bloodstream before they reach their target cells. Therefore, an overexpression of SPARC helps treatments bound with albumin work more effectively by bringing the treatment right into the cell.2

Biomarkers that disrupt a treatment’s cellular or molecular action

Some chemotherapeutic drugs are made with platinum to disrupt tumour DNA. However, there is a protein called ERCC1 that repairs tumour DNA. If biomarker testing detects high levels of ERCC1 in a patient’s tumour, platinum-based agents aren’t likely to be very effective for that patient.

Even within the above biomarker categories, there is variety. For example, molecules that trigger abnormal cell growth can come from a gene mutation or from extra copies of an otherwise healthy gene within the tumour’s DNA.2

 

References

  1. Caris Life Sciences. Exploring New Options: What is precision medicine? 2017 [cited 16 July 2017]. Available from: [URL link]
  2. Caris Life Sciences. What are Biomarkers? The Growing Importance of Biomarkers in Cancer. 2017 [cited 16 July 2017]. Available from: [URL link]