Today, two patients with the same diagnosis of breast cancer do not necessarily have the same disease, nor will they necessarily receive the same treatment. Differences in the molecular characteristics of tumors can significantly affect the course of the disease, the response to treatment and the final outcome. This is the key message of the public lecture of prof. Ph.D. sc. Semir VranićPh.D. med., corresponding member of the Academy of Sciences and Arts of Bosnia and Herzegovina (ANUBiH), held at the Academy of Sciences and Arts of Bosnia and Herzegovina under the name “Modern diagnosis of breast cancer: biomarkers and the latest WHO classification (6th edition, IARC, Lyon, 2026)“.
The audience was introduced to the public lecture by an academician Lidija Lincender-Cvijetićemphasizing the importance of modern research in the field of pathology and oncology and the contribution of professor Vranić to international projects that shape modern diagnostic standards.
Breast cancer is today the most common malignant tumor in women in the world. Around 2.5 million women fall ill every year in the world, and estimates indicate that this number could double by 2050 and reach as many as five million new cases per year. In Bosnia and Herzegovina, we record about 1,539 new cases every year, and the mortality rate is about 564 patients per year, which means that the disease ends fatally in almost a third of cases. These data further emphasize how vital progress in diagnostics and access to new therapies are.
Speaking about the most significant changes in the diagnosis of breast cancer in the last five years, Professor Vranić singled out the expansion of the application *HER2 biomarker, which opened up new treatment options for a significantly larger number of patients.
“Previously, anti-HER2 therapy was intended mainly for patients with HER2-positive breast cancer. Today, tumors with low and ultra-low expression of the HER2 receptor are also a therapeutic target, which has increased the number of potential candidates for this type of treatment from approximately 15-20% to almost 50% of patients,” Vranić pointed out.
This progress is particularly significant because patients with so-called HER2-low and HER2-ultra-low expression, who were previously excluded from targeted therapy, can now have access to drugs that act directly on the HER2 receptor, thus greatly improving their chances of successful treatment.
The new WHO/IARC classification: precision as the foundation of treatment
Professor Vranić paid special attention to the new, sixth edition of the WHO/IARC classification of breast tumors – a publication to which he himself made a significant contribution, and which is currently in the final stages of printing.
“Through this classification, the World Health Organization strives to make diagnostics as precise and exact as possible so that therapy is as appropriate as possible for each patient. Since diagnostics is one of the key steps in the treatment of breast cancer, improving the classification directly contributes to better treatment outcomes,” he emphasized.
The new edition brings clearer guidelines for diagnostics on small tissue samples, introduces a special chapter dedicated to the application of artificial intelligence in pathology, and elaborates reporting in clinical practice, with special emphasis on coordination between radiologists and pathologists.
Artificial intelligence takes on a role in breast diagnostics
One of the most significant features of modern oncology is the accelerated digitization of pathology laboratories and the increasingly widespread use of artificial intelligence (AI). Today, pathologists are increasingly working with digital preparations on large screens instead of traditional microscopes, and the entire diagnostic process is becoming more automated and efficient. This process has been going on intensively since 2015 and has brought significant advantages: diagnosticians are not tied to one place, they can log in and work from any location, and the quality is just as valuable as a traditional microscopic examination.
The first AI tools for breast cancer diagnosis have already been approved in the US. Artificial intelligence is applied in tumor grading, quantitative analysis of biomarkers, detection of micrometastases in lymph nodes, as well as in prediction of disease behavior, which provides clinicians with valuable information when making therapeutic decisions. However, Professor Vranić emphasized that AI in diagnostic pathology must always have a final confirmation by a pathologist: “The final word still rests with the human brain, which must approve what the AI has suggested.”
Personalized medicine: no longer the future
Professor Vranić pointed out that personalized oncology has already become a reality in the modern treatment of malignant diseases.
“We are no longer talking about the future of precision medicine, we are already living in it. Today, breast cancer therapy is significantly adapted to the molecular characteristics of the tumor, and biomarkers play a key role in making therapeutic decisions,” he said.
Answering the question whether two women with the same diagnosis of breast cancer can have completely different diseases, Vranić was clear: “Two patients can have diametrically opposite molecular characteristics, different clinical behavior of the disease, different response to therapy and ultimately different outcome of treatment. This is precisely why accurate diagnostics plays a crucial role in oncology today.”
He especially pointed out the specifics of breast cancer with low estrogen receptor expression, a more aggressive form of the disease that occurs more often in younger women and carries a higher risk of recurrence in the first five years, and requires special attention from pathologists when reporting.
Clarification of term:
*HER2 (Human Epidermal Growth Factor Receptor 2) is a protein that is found on the surface of cells and participates in their growth and division. In some breast cancer patients, the tumor produces too much HER2 protein. Such tumors usually grow faster, but can be treated with special targeted drugs that act on the HER2 receptor. Therefore, determining the HER2 status is one of the most important tests in the diagnosis of breast cancer, as it helps doctors choose the most effective therapy. The latest research has shown that anti-HER2 therapy can benefit not only patients with a high level of HER2, but also those with low (HER2-low) or very low (HER2-ultra-low) expression of this protein, which significantly expanded the number of women who can receive targeted therapy.
The entire lecture is available at to the YouTube channel of the Academy of Sciences and Arts of Bosnia and Herzegovina.
