From March 12 to 15, 2025, the 19th St. Gallen Breast Cancer Conference (SGBCC 2025) was held in Vienna, the capital of music. Experts from around the world in the field of breast cancer gathered to discuss cutting-edge advancements and hotly debated topics in breast cancer diagnosis and treatment. Oncology Frontier invited Dr. Giuseppe Curigliano, the ESMO President-Elect and Associate Professor at the University of Milan and European Institute of Oncology, to share his views on the presentation topic and the outlook for curing advanced breast cancer.

Oncology Frontier: At this SGBCC conference, you presented a talk titled “Breakthroughs and Innovation in Advanced Disease—Arriving in the Curable Setting Soon?” First, could you elaborate on your interpretation of “cure”? How should we define the cure of advanced breast cancer?

Dr. Giuseppe Curigliano: So, thank you for your question, because I tried in my presentation first to explain which is the timeframe between the approval of a drug in the metastatic setting that will arrive in the early breast cancer setting. And there is a range that is between 10 years in the 90s to four years today. Just if you remember Pembrolizumab, it was approved in the metastatic setting at least four years before the data had been translated in the early breast cancer setting. But the most important point I raised is how to predict the benefit of a specific drug in the early breast cancer setting in terms of overall survival. Because in my opinion, a drug is really transformative if you increase the cure rate. And the cure rate, namely, is an overall survival benefit. All the clinical trials are designed and having as a primary endpoint or pCR or invasive disease-free survival or event-free survival.

As I said in my talk, we have statistical methods on the patient level and the trial level to better understand if a drug will be positive on overall survival or not. And one of the methodologies, the coefficient of determination, R-squared. If this is more than 0.7, usually there is a strong correlation between pCR and overall survival. If between 0.5 and 0.6, usually there is no correlation. And if you check the data in the clinical trials for Pembrolizumab, this was exactly the case because an increase in pCR was also related to an improvement in overall survival. So in future trial design, you need also to apply this specific methodology.

Oncology Frontier: What innovative approaches currently hold promise for achieving a cure in advanced breast cancer? How would you evaluate the potential of these methods?

Dr. Giuseppe Curigliano: You know, in advanced breast cancer, of course, is another issue because in that case, you don’t need, for sure, overall survival, sometimes you may have, some other times, no. Because personally, I believe also response rate and progression-free survival is a valid endpoint in the metastatic setting. So metastatic disease is not curable. The impact on overall survival cannot be guaranteed due to the biology of the disease. So in advanced breast cancer or metastatic breast cancer, I believe still PFS is a valid surrogate endpoint.

Oncology Frontier: In your view, how far are we from achieving a cure for advanced breast cancer? What specific efforts can organizations like ESMO, CSCO, SGBCC, and clinical practitioners make to advance breast cancer treatment toward a curative goal?

Dr. Giuseppe Curigliano: This is an excellent question. I believe in some disease, like HER2-positive, we need to design a clinical trial in which potentially cure rate can be really the primary endpoint. I mean, if you have a de novo metastatic disease with the no lethal metastatic presentation, don’t you believe that we can achieve to cure some of these patients? Now we have a very effective treatment. So it’s important that societies like CSCO, ASCO, ESMO may work together to promote clinical trial in very special populations that maybe are rare if you consider them in a single center or in a single country. But there are many if you collaborate on the global level to specifically meet medical need like cure in advanced disease. So these should be the effort of all scientific societies together.

Oncology Frontier: On the path to curing advanced breast cancer, what do you consider the most significant challenges today? What are your hopes for the future of breast cancer treatment and its potential for cure?

Dr. Giuseppe Curigliano: We cure a lot of patients now because with the early diagnosis, the cure rate is very high for triple negative, HR positive and HER2 positive disease. So I believe what we need to improve now is optimized treatment in order to reduce toxicity. So we need innovative trial that beyond cure, they should consider also toxicity of specific agents because in my opinion, if you have to cure a patient that is a low risk with five years of endocrine therapy that may impact on the quality of life of those patients. If you have a trial that is a non-inferiority trial in which you demonstrate that an alternative regimen can achieve the same results in terms of cure rate but with less toxicity. So this is what we need may be in the interest of our patients.