Cancer treatment has evolved from a generalised approach to a more precise one. Advances in precision medicine have transformed the way oncologists diagnose, stage, and treat cancer. At the core of this shift is molecular testing, which analyses the genetic and molecular characteristics of a tumour. Within this, mutation testing plays a key role by identifying specific changes or “mutations” in the DNA of cancer cells that may drive tumour growth. These insights can guide the selection of targeted therapies or immunotherapies that are more likely to be effective for a particular patient.
Unfortunately, even in cases where such testing could significantly alter the treatment plan, molecular and mutation tests are often performed later in the treatment process—typically after conventional therapies have failed. The later these tests are used, the more restricted treatment options become, the lower the chances of success, and the heavier the emotional and physical toll on patients.
What is mutation testing?
According to Dr Susovan Banerjee, Associate Director, Radiation Oncology, Cancer Care, Medanta Gurugram, mutation testing, also known as genomic profiling, includes genetic analysis of a tumour’s DNA to identify defects that control the growth of the cancer. These mutations, or variants, can act as biomarkers that point clinicians to targeted therapies or immunotherapies that may be the most effective treatment for a patient. Rather than relying on broad therapy such as chemotherapy or radiation, mutation testing can help identify therapies that are more specific to the biology of the patient's cancer.
Why and how early testing is important
Decision making: When mutation testing is done early, oncologists can select the therapies that are most likely to work right away. This avoids several months of trial-and-error treatment and side effects.
Access to targeted therapies: There are now several novel drugs available that specifically inhibit genetic mutations, including EGFR (Epidermal Growth Factor Receptor), ALK (Anaplastic Lymphoma Kinase), HER2 (Human Epidermal Growth Factor Receptor 2), BRAF (v-Raf Murine Sarcoma Viral Oncogene Homolog B1), and KRAS (Kirsten Rat Sarcoma Viral Oncogene Homolog). These breakthrough therapies are only of benefit to patients if the mutations are identified at the appropriate time—ideally before first-line treatment initiation.
Clinical trial access: Early testing can also lead to participation in clinical trials and access to next-generation therapies, which may still be in the investigational phase or not widely trusted. This is an important distinction for patients. This can mean the difference between limited options and cutting-edge therapies.
Cost & quality of life: Mutation testing may seem like an extra step, but it can save costs by eliminating treatment likely to be ineffective. Perhaps more importantly, it may save costs from associated ineffective treatment toxicity and preserve the quality of life.
The peril of operating too late
When mutation testing happens too late in the process, patients, in some cases, have already completed an even multiple of chemotherapy, radiation, or even both, and are starting to physically deplete or have fewer valid options left. If they have already experienced multiple rounds (5 or more), it is unfortunately likely that tumour clones resistant to treatment have formed. The 'targeted' therapies may not have the same effectiveness. What started as a bullseye towards the malignancy when first detected can suddenly become a complex, multifaceted disease that is resistant to any kind of treatment.
Cancer care discourse needs to flip upside down: mutation testing must not be considered a stopgap, but the viable first starting point. Healthcare systems, their insurers and their policymakers must realise the long-term benefits of early genetic profiling and make it a point to implement and require testing early in the process.
Cancer is not one disease—it comprises multiple conditions that arise from unique genetic drivers. Attempting to treat cancer without knowing our tumour’s genetic makeup is like wandering without a map. By mandating that mutation testing occurs first, we may be able to offer patients the best possible chance to leverage personalised and targeted treatment right from the start in the future, when treatment is going to be too late! With the advent of pristine medicine, identifying and making sense of cancer as early as we can is not only a plausible option—it is the single most important piece to provide a future around survival.
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