New Research Suggests Many Breast Cancer Patients Could Safely Skip It: DNA Test Before Chemo?

For decades, chemotherapy has been considered an almost inevitable part of breast cancer treatment. While it has saved countless lives, it often comes with significant physical side effects, emotional stress and financial burden. Now, a growing body of research suggests that many women with early-stage breast cancer may not need chemotherapy at all.

The latest evidence comes from the international OPTIMA trial, which found that genomic testing can help identify patients who are unlikely to benefit from chemotherapy, allowing them to avoid treatment without compromising outcomes. The findings add momentum to the global shift towards personalised cancer care, where treatment decisions are guided by a tumour’s biology rather than a one-size-fits-all approach.

For India, where breast cancer is the most common cancer among women, the development could help reduce overtreatment and improve quality of life, provided such testing becomes more accessible and affordable.

EVERY BREAST CANCER IS DIFFERENT

Experts say breast cancer is not a single disease. “Breast cancer is not a single entity— each person has specific molecular markers on their tumour cells,” says Dr Q Annie Hasan, Senior Consultant and HOD, Department of Genetics and Molecular Medicine, Kamineni Hospitals. These markers can be identified through genetic testing, helping doctors select treatments that are most likely to work for a particular patient.

For instance, triple-negative breast cancer lacks estrogen, progesterone and HER2 receptors, making hormonal therapy and HER2-targeted drugs ineffective. In such cases, identifying specific molecular targets can help doctors personalise treatment and potentially improve outcomes.

HOW THESE TESTS WORK

Advanced next-generation sequencing (NGS) tests analyse inherited genetic traits as well as mutations that develop within tumour cells. According to Anu Acharya, founder of Mapmygenome, these tests can identify harmful mutations in genes such as BRCA1 and BRCA2, along with other DNA-repair genes that influence how cancers behave. When defects in DNA-repair pathways are detected, patients may benefit from targeted therapies such as PARP inhibitors, either alongside or instead of conventional treatments. NGS is also increasingly being used when cancers progress despite standard therapy, helping doctors identify new mutations that may be matched with targeted drugs

WHO BENEFITS MOST?

According to Dr Madhavi Dokku, Senior Consultant Gynec Oncologist at Medicover Hospitals, genomic testing is most useful for women with early-stage, ER-positive and HER2-negative breast cancer. While initially used for patients without lymph node involvement, it is now increasingly being recommended for selecte postmenopausal women with one to three positive lymph nodes.

By identifying women at low risk of recurrence, doctors can determine who is unlikely to gain significant benefit from chemotherapy and who may safely avoid it.

HOW ACCURATE ARE THESE TESTS?

Genomic assays such as Oncotype DX, MammaPrint, Prosigna and EndoPredict are backed by strong scientific evidence and are widely used to guide treatment decisions. Studies show that women classified as low risk have excellent outcomes, with 95–98 per cent remaining recurrence-free at five years. However, experts stress that genomic tests are not definitive and must be interpreted alongside factors such as tumour size, lymph node involvement and pathology findings. The OPTIMA trial has further reinforced the value of genomic profiling, showing that many women with hormone receptor-positive, HER2-negative breast cancer can safely avoid unnecessary chemotherapy.

MAJOR SHIFT IN CANCER CARE

Dr Pragnya Chigurupati, breast oncologist and oncoplastic surgeon at AIG Hospitals, says breast cancer treatment is undergoing a major shift towards personalised care. “These tests analyse the biological behaviour of a tumour after surgery and generate recurrence scores that help doctors estimate both the risk of cancer recurrence and the likely benefit of chemotherapy,” she says. According to her, advances in genomic and mRNA-based tumour testing, backed by landmark studies such as TAILORx, RxPONDER, MINDACT and OPTIMA, have shown that many women with early-stage breast cancer can safely avoid chemotherapy without compromising outcomes.She says this marks a move away from a one-size-fits-all approach and towards treatment plans tailored to the biology of each tumour.

WHAT ABOUT INDIA?

Genomic testing is already available at many major cancer centres in India. International assays such as Oncotype DX, MammaPrint, Prosigna and EndoPredict can be accessed, although samples are often sent overseas, increasing costs and turnaround times. At the same time, Indian-developed tools such as CanAssist Breast are helping make genomic risk assessment more affordable and accessible. “Many patients still associate cancer treatment with chemotherapy, despite the fact that some breast cancers may respond very well to hormonal therapy alone in carefully selected cases,” says Dr Chigurupati, adding that Indian genomic tools are helping personalise treatment decisions for Indian patients.

CHEMOTHERAPY STILL HAS AN IMPORTANT ROLE

Doctors emphasise that genomic testing does not replace chemotherapy. Treatment decisions continue to depend on factors such as age, disease stage and tumour subtype, says Dr Krishna Mani, Medical Oncologist, Apollo Hospitals. Hormone receptor-positive cancers often respond well to endocrine therapy, HER2-positive cancers are treated with targeted drugs, while immunotherapy has emerged as an important option for selected cases of triple-negative breast cancer. Genomic testing serves as an additional tool to help doctors choose the most appropriate treatment strategy.

FUTURE: TREATING SMARTER, NOT HARDER

The message emerging from global research is clear: As genomic testing becomes more widely available, doctors are increasingly able to identify who genuinely needs chemotherapy and who can safely avoid its side effects.

Who Needs Chemotherapy?

· Many women with early-stage breast cancer may safely avoid chemotherapy.

· Genomic tests estimate recurrence risk and likely chemotherapy benefit.

· The strongest evidence exists in ER-positive, HER2-negative breast cancer.

· International and Indian genomic tests are already available.

· Wider adoption in India will depend on affordability, awareness and access.

WHAT IS GENOMIC TESTING?

· Genomic testing studies the genetic profile of a tumour to determine:

· Risk of recurrence

· Likely benefit from chemotherapy

· Potential response to targeted therapies

· Overall tumour behaviour

· The goal is to avoid both under-treatment and over-treatment.