Managing Other Adverse Events in PIK3CA-Mutated HR+/HER2-Negative Advanced Breast Cancer

Dr. Jason Mouabbi discusses additional adverse events that require attention when managing patients with PIK3CA-mutated HR-positive/HER2-negative advanced breast cancer receiving combination therapy. Beyond hyperglycemia and diarrhea, he highlights stomatitis and rash as treatment-related toxicities associated with inavolisib and reviews practical approaches to their management. For rash, Dr. Mouabbi discusses the use of antihistamines, while for stomatitis, he emphasizes steroid mouthwash and good oral hygiene. He also highlights the importance of considering adverse events associated with the other components of the treatment regimen. With palbociclib, he discusses monitoring blood counts for neutropenia and adjusting treatment timing or dose when neutropenia does not adequately recover during the scheduled treatment break or recurs. For fulvestrant, he notes the importance of monitoring for injection-site reactions and discusses practical measures such as icing the injection area. The discussion emphasizes incorporating toxicity monitoring across the full treatment combination into routine follow-up for patients with advanced breast cancer.