Genetic testing is transforming cancer treatment: Here’s how it’s saving lives today

A woman in her mid-50s in Bangalore ignored subtle symptoms for months. Feeling full too soon, abdominal swelling, and fatigue slowly took over daily life. By the time she reached the hospital, doctors found advanced ovarian cancer. Surgery removed visible tumours, but the disease had already spread.What changed her course was not just surgery or chemotherapy. It was a deeper look into her cancer’s genetic code.Dr Ashwin KR, Head of Department – Surgical Oncology, Aster Hospitals, Bangalore, recalls, “The tumor tissue was sent to MedGenome, where it was analyzed using the HRDTrack NGS Assay. It showed a high genome aberration score indicating homologous recombination deficiency, or HRD.”In simple terms, her cancer cells could not repair damaged DNA. That single insight opened a treatment path that would have otherwise stayed closed.Cancer begins when changes in DNA push cells to grow out of control. These changes are not all the same. Some develop over time, while others are inherited.Genetic testing looks for these changes with precision. It helps doctors answer a key question: what is driving this specific cancer?There are two main types of testing used in treatment:This difference matters. A treatment that works for one mutation may fail for another.The case in Bangalore showed this clearly. The patient did not carry the well-known BRCA mutation. Under older rules, that could have ruled out certain targeted therapies.But the test revealed HRD, a different pathway leading to the same weakness in cancer cells.Dr Ashwin explains, “This mattered enormously because it made her eligible for PARP inhibitor maintenance therapy, even though she didn't carry BRCA mutations.”For decades, cancer treatment often followed a standard route. Surgery, chemotherapy, radiation. Doctors adjusted along the way, but choices were limited.Genetic testing is changing that model. It replaces guesswork with evidence.Here is what shifts in practice:Targeted treatment becomes possibleDrugs can attack specific mutations instead of affecting all fast-growing cells.Ineffective therapies can be avoidedSome mutations make treatments useless. Knowing this early saves time and reduces side effects.Treatment can adapt over timeCancer evolves. Genetic monitoring helps doctors track changes and switch strategies when needed.In the Bangalore case, this meant a precise decision. The patient received a PARP inhibitor, a therapy designed for cancers that cannot repair DNA properly.The result was clear.“The treatment worked and the tumor regressed. Today she's living a normal life, under careful surveillance,” says Dr Ashwin. Cancer numbers in India are rising steadily. Data from the Indian Council of Medical Research–National Cancer Registry Programme (ICMR-NCRP) estimates cases will increase from 14.61 lakh in 2022 to 15.7 lakh by 2025.Genetic testing cannot replace early detection. But it improves what happens after diagnosis. It gives patients a better shot, even in difficult stages.Not everyone needs genetic testing immediately. But some situations make it especially relevant:Testing is not just about treatment. It can also help families understand their risk and take preventive steps.Genetic testing brings clarity, but it can also raise questions. What does this mean for the future? What about family members?This is where counselling becomes essential. Experts help patients understand results, options, and next steps.A result alone does not change outcomes. Understanding it does.That idea is becoming real in cancer care today.The story from Bangalore is not an exception anymore. It reflects a broader shift. Cancer care is moving from one-size-fits-all to deeply personalised treatment.Genetic testing is at the centre of this change. It helps doctors see what was once invisible. It helps patients access treatments that were once out of reach.And in many cases, it changes not just outcomes, but lives.Medical experts consultedThis article includes expert inputs shared with TOI Health by:Dr Ashwin KR, Head of Department – Surgical Oncology, Aster Hospitals, Bangalore.Inputs were used to explain how genetic testing is transforming cancer treatment by guiding targeted therapies and helping doctors make more precise, personalised care decisions.