Blue vs Green: Why one of breast cancer surgery's biggest advances is simply changing the colour of the dye

When people think about breakthroughs in breast cancer treatment, they often picture cutting-edge robots, artificial intelligence or revolutionary new medicines.
 

However, according to Associate Professor Sanjay Warrier, one of the most significant improvements in modern breast cancer surgery has come from something far simpler, a change in the colour of the dye used during an operation.
 

Associate Professor Warrier is one of the world's leading breast health and breast cancer surgeons who has built a highly respected practice in Sydney. The practice spans four locations with its main surgical centre located at the Chris O'Brien Lifehouse in Camperdown, and the other sites at BMA House, Macquarie Street, Sydney, a newly opened site in Campbelltown and Bondi Junction Medical, Oxford Street, Bondi Junction.

In addition to Associate Professor Warrier's breast health and surgical work, he also dedicates considerable time to research exploring and developing advancements in breast cancer detection and treatments to improve outcomes for patients.  He also codeveloped Australasia's first Master of Advanced Surgery (Breast Surgery) which is delivered through the University of Sydney.  
 

"Replacing the traditional blue dye used to identify cancer-draining lymph nodes with a newer green fluorescent dye is quietly improving patient safety while delivering the same high level of surgical precision," Associate Professor Warrier said. 
 

"It's a perfect example of how some of the biggest improvements in medicine don't always involve expensive new technology.
 

"Sometimes changing one simple step in a procedure can make surgery safer for thousands of patients."
 

A small change making a significant difference
 

During breast cancer surgery, surgeons must identify the sentinel lymph node, the first lymph node that drains fluid from the breast and the most likely place breast cancer will spread if it has moved beyond the breast tissue.
 

For decades this has commonly been achieved using blue dye.
 

"The blue dye travels naturally through the lymphatic system and stains the first lymph node blue so we can identify and remove it for testing," Associate Professor Warrier explained.
 

"It has been an excellent technique for many years and has helped transform breast cancer surgery."
 

However, while highly effective, blue dye is not without risk.
 

"A small number of patients experience allergic reactions to blue dye and, although uncommon, these reactions can occasionally be severe," Associate Professor Warrier said. 
 

Why green is becoming the new standard
 

Associate Professor Warrier has adopted the use of indocyanine green (ICG), a fluorescent dye that is detected using a specialised near-infrared camera rather than by direct visual inspection.
 

"The green dye isn't actually seen by the naked eye during surgery.  It fluoresces under infrared imaging, allowing us to clearly map the lymphatic channels and identify the sentinel lymph node with remarkable precision," Associate Professor Warrier said. 
 

Importantly, the risk profile is significantly improved.
 

"Serious allergic reactions to indocyanine green are exceptionally rare compared with traditional blue dye," Associate Professor Warrier said. 
 

"It allows us to achieve the same surgical objective while reducing one of the avoidable risks associated with the procedure.
 

"In my role and work, research and innovative exploration is essential to continue to find ways to reduce risk and improve outcomes for patients. Often some of the greatest gains in medicine are made in small increments that have a large cumulative effect over time.   
 

"My use of green dye is a good example of this that helps to reduce risk and improve outcomes."
 

Innovation doesn't always have to be complicated
 

Associate Professor Warrier said modern medicine often celebrates large technological breakthroughs, but many of the greatest improvements occur through refining existing procedures.
 

"We're constantly asking how we can make surgery safer, more accurate and less invasive. Sometimes the answer isn't inventing an entirely new operation, it is improving the operation we already perform every day," Associate Professor Warrier said. 
 

He said these incremental improvements often benefit thousands of patients over many years.
 

"When you make a procedure safer for every patient who undergoes it, that becomes a very significant advance,"  he added. 
 

Better surgery through better vision
 

The infrared technology used alongside the green dye also provides surgeons with enhanced visualisation of the lymphatic system.
 

"Rather than relying solely on colour visible to the human eye, we're able to watch the fluorescent dye travel through the lymphatic channels in real time," Associate Professor Warrier said. 
 

"That provides an additional level of confidence when identifying the correct sentinel lymph node.  The result is precise surgery while avoiding unnecessary removal of healthy lymph nodes.

"For many women, preserving healthy lymph nodes reduces the risk of long-term complications such as lymphoedema, discomfort and reduced shoulder mobility."
 

The future of surgery is continual refinement
 

Associate Professor Warrier believes the future of breast cancer surgery will increasingly be driven by continual refinement rather than dramatic overnight breakthroughs.
 

"We're seeing improvements in imaging, wound care, surgical planning, reconstruction and technologies like fluorescent imaging," Associate Professor Warrier said. 
 

"Each advancement may appear small on its own, but together they significantly improve patient outcomes."
 

He said the transition from blue dye to green fluorescent imaging demonstrates how medicine continues evolving through evidence, research and a willingness to challenge established practice.
 

"The best innovation isn't always the most expensive. Sometimes it's simply finding a better way to do something we've been doing for years.  For patients, those small improvements can make a very real difference," Associate Professsor Warrier said. 
 

About Associate Professor Sanjay Warrier

Associate Professor Sanjay Warrier is a past President and current committee member of Breast Surgeons of Australia and New Zealand (BreastSurgANZ). His views are those of his own, not BreastSurgANZ. Associate Professor Warrier's surgery is located at the Chris O'Brien Lifehouse and he also has clinics at Oxford Street, Bondi Junction, Macquarie Street and newly opened rooms in Campbelltown, Sydney. He is published in numerous peer-reviewed journals and won the Royal Prince Alfred Hospital's Patron's Prize for best scientific research.  In addition, he was also recently recognised on the international stage, receiving the India Australia Business and Community Alliance (IABCA) Australia India Science, Research and Development Award at the organisation's Gala in Mumbai. The award, one of the most significant honours across the Australia-India corridor, acknowledges outstanding contributions to science and research that strengthen bilateral ties between the two nations.

www.drsanjaywarrier.com.au