The 2021 San Antonio Breast Cancer Symposium (SABCS) was the first hybrid breast cancer symposium at the beginning of another wave of the COVID-19 pandemic. The week before the conference, there as an eruption of a new variant of SARS-CoV-2, Omicron. Among breast cancer researchers, the question changed from “When are you going to San Antonio?” to “Are you still going to San Antonio?” As a breast medical oncologist and integrative medicine physician, I debated attending the conference, and ultimately decided to go in person despite Omicron. Why? Recently, I was on the other side of the table as the conference organizer for the September Society for Integrative Oncology (SIO) 2021 International Conference. I vividly remember that in the few weeks before our conference, during the weekly check-in sessions, we would find out how many people registered to attend in person and how many people withdrew or switched to virtual attendance. I understand the significant stress associated with decreased in-person conference attendance at the last minute as food-related contracts often require a certain number of attendees. In addition, I had a great time in-person at the SIO conference, which turned out to be a much better experience than that of the virtual attendees. In addition, it was the first time I was invited to speak at an education session at SABCS. This invitation to speak at the largest international breast cancer conference was a rare opportunity that I could not give up easily.
The conference started on Tuesday, December 7, 2021. Compared to the last in-person SABCS in 2019, there were significantly fewer people. Reportedly, 9,600 people registered for the conference, and only 1,000 to 2,000 people attended in person. The hybrid session was interesting as there may be very few people attending in person, and many more online. That was the case for the education session I was part of. There were about 16 people in a room that could hold 300 people. One international attendee jokingly said that the session he attended only had one person onsite. It took me a while to realize that all of the speakers were virtual, which was a strange experience. As a hybrid conference, there were occasional technical glitches such as not receiving or being unable to play a speaker’s pre-recorded video, which meant that the speaker had to present on site on the spot. Despite these difficulties, our education session on evidence based integrative therapies went very well with good presentations, many questions coming in, and lively discussions.
The main sessions were better attended, especially on the second and third conference days. There were about 500 people in person in a hall that could hold 2,000 people. Every attendee had two chairs to use: one to sit on and the other to put their drink or bag on. Presentations included a number of important large randomized controlled trials with some updated analysis, such as the DESTINY-Breast03 trial and MONALEESA-2 trials. Presenters were well-known researchers in the breast cancer field with results similar to what they had presented in an earlier major oncology conference. Fam-trastuzumab-deruxtecan-nxki continued to show progression free survival (PFS) and objective response rate benefits when compared to TDM-1, and is now well positioned to be the second line treatment for HER2+ metastatic breast cancer. It showed a remarkable response in patients with brain metastasis as it improved median PFS from three months to 15 months when compared with TDM-1. The MONALEESA-2 trial showed that first line ribociclib plus letrozole continued to show overall survival benefits compared to placebo plus letrozole in patients with ER+ metastatic breast cancer, regardless of metastatic site in postmenopausal patients with ER+/HER2- advanced breast cancer.
The trial I was most excited about at this year’s SABCS conference was EMERALD, a phase 3, randomized controlled trial comparing elacestrant, an oral selective estrogen receptor degrader (SERD), with the physician’s choice of second line endocrine therapy, such as fulvestrant or aromatase inhibitors, after 477 patients with ER+, HER2-metastatic breast cancer progressed on first line endocrine plus CDK4,6 inhibitor therapy. Elacestrant showed a significant longer progression-free survival compared to standard of care (2.8 versus 1.9 months, hazard ratio, (HR) 0.70 favoring elascestrant). The treatment benefits were also noted in 228 patients with the ESR1 mutation. Interim analysis of overall survival also favored elacestrant with HR: 075. Importantly, it was well tolerated with a similar toxicity profile as other endocrine therapies; the most common treatment-related adverse events were nausea and backpain. This is exciting as it gives patients additional treatment options as an oral effective agent with limited toxicities.
Overall, 2021 SABCS was a great experience for all of us in the breast cancer community. As a hybrid conference, it gave people options to join in person or online. An important benefit of in-person attendance is the option of connecting with others in real time. Nothing is better than bumping into old friends and catching up despite COVID-19. Scientifically, we all need such a gathering to bring scientists, physicians interested in breast cancer treatment, and research together to exchange ideas, communicate, and move the field forward.
Dr. Bao reports no conflicts of interest.
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