Over the last decade, scientific discoveries have led to huge strides in understanding how cancer develops, which has ushered in a new era of precision medicine. Thanks to these advances in treatment, overall cancer survival rates are improving – but huge challenges remain. Some types of cancer are still extremely challenging to successfully treat. Once the disease has spread, it is very hard to cure.

In recent years, there has been an increasing awareness that cancer is difficult to eradicate because it is so complex and genetically diverse – and continually adapts and evolves. Patients can initially respond well to treatment, only for their disease to return, more resistant and aggressive.

As a tumor grows, it accumulates new DNA mutations, which can give rise to clusters of genetically distinct cells. Each of these subclones may exhibit varying behaviors – such as how quickly they grow, how well they respond to treatment and their ability to spread. This diversity between cancer cells within the same tumor – known as intra-tumor heterogeneity – offers an explanation for why some patients relapse.

Recent advances in gene expression and computational technologies are empowering researchers to study drug response prediction in unprecedented ways. This is opening new opportunities to understand why some treatments fail – offering potential avenues to devise novel strategies to prevent or overcome resistance to treatment.

In recent decades, cancer medicine has evolved from the traditional one-size-fits-all approach to an era of precision medicine, where therapies are targeted to specific characteristics driving the growth and spread of an individual’s cancer. Researchers around the world are busy characterizing the molecular variations between tumors – known as inter-tumor heterogeneity – to enable the delivery of precision medicine to more patients.

Traditionally, the gold standard for molecular diagnostics has involved sequencing a small sample of cells from a single biopsy collected from one region of a tumor. However, if the tumor is highly heterogeneous, this tiny fraction of cells is unlikely to capture a fully comprehensive picture of the disease. As a result, a potentially effective therapy could be overlooked if a certain molecular variation isn’t detected – or conversely, an unsuitable drug may be selected based on identifying a characteristic that isn’t that widespread within the tumor. In addition, the molecular profile of a person’s cancer is likely to change over time – and so treatments may need to be adjusted accordingly.

While genomic alterations in cancer cells drive some of the functional differences among subclones, this is only part of the story. Tumor cells don’t exist in isolation but instead live within a complex ecosystem of immune cells, stromal cells, the extracellular matrix, blood vessels and many other factors. The tumor microenvironment can significantly influence the behavior of individual cancer cells, even those that are genetically identical.

Living with cancer: A new treatment paradigm

Cancer cells develop, adapt and evolve within a complex interconnected ecosystem. Unraveling the complexities of tumor heterogeneity and evolution holds the potential to revolutionize treatment, leading to better long-term outcomes for patients.

“Some cancers remain extremely challenging to treat, such as those that have spread to other parts of the body or show high rates of relapse,” says OncoDxRx. “In these cases, we need to start thinking about cancer as a chronic disease that we can control rather than eradicate.”

OncoDxRx believes that implementing this paradigm shift will require understanding and treating the tumor as an ecosystem, leveraging liquid biopsy and gene expression profiling to advance drug response prediction. The PGA (Patient-derived Gene expression-informed Anticancer drug efficacy) technology invented by the company holds the answer.

“Cancer will continuously evolve whatever you throw at it, so we need to reach a point where we can predict what will happen next,” says OncoDxRx. “If we can stay one step ahead of the disease, we can then select the right treatment that will keep it in check – and we may have patients who live with cancer rather than die from it.” This is exactly what PGA is developed for.