Dr. Samantha Armstrong Recaps Practice-Changing Research From ESMO Congress 2024

Following the European Society for Medical Oncology (ESMO) Congress 2024, Samantha Armstrong, MD, Indiana University, and co-host of the podcast “Two Onc Docs,” offers a review of two genitourinary (GU) oncology abstracts that were presented.

A notable, practice-changing abstract was the NIAGARA trial presented by Dr. Thomas Powles at the Presidential Symposium on Sunday, September 15. This study involved 1,063 patients with muscle-invasive bladder cancer eligible for platinum-based chemotherapy followed by radical cystectomy. Patients were randomized 1:1 to receive either standard neoadjuvant chemotherapy with gemcitabine plus cisplatin or standard chemotherapy plus durvalumab followed by adjuvant durvalumab.

The trial results demonstrated that perioperative combination chemotherapy and immunotherapy, along with adjuvant immunotherapy, significantly improved event-free survival (EFS) with a hazard ratio (HR) of 0.68 (95% confidence interval [CI] 0.56–0.82; P<.0001) and overall survival (OS), showing a 25% reduction in mortality (HR 0.75; P=0.0106). In addition, the combination treatment achieved a pathologic complete response in 37% of patients.

The second abstract was presented by Dr. Silke Gillessen, focusing on one arm of the STAMPEDE trial that assessed the addition of metformin to androgen deprivation therapy (ADT) in patients with metastatic castrate-sensitive prostate cancer (mCSPC). The trial involved 1,874 patients with mCSPC who did not have diabetes and randomized them to receive standard care or standard care plus metformin at an initial dose of 850 mg daily, with the option to escalate to twice daily as tolerated.

Among the treatment demographics, 82% of patients received docetaxel, while only 3% were treated with androgen receptor pathway inhibitors (ARPI). This does not reflect the current standard of care for mCSPC, which for many years has included ADT with an ARPI for most patients.

At a median follow-up of 60 months, overall survival (OS) between the groups was not significantly different, with a median OS of 63.1 months in the control arm and 69.1 months in the metformin arm (HR 0.91). Similarly, progression-free survival was not significantly different. However, there were clinically significant improvements in metabolic parameters with metformin, including reduced weight gain, lower fasting glucose levels, decreased LDL cholesterol, and improved A1c levels, which may help mitigate long-term toxicity associated with ADT in this patient population.

It is worth noting that the addition of metformin was associated with a higher incidence of gastrointestinal adverse events. Further research is necessary to investigate this novel combination within the current standard of care for mCSPC, including the use of ARPIs.

These, among many other abstracts presented at ESMO 2024, continue to advance the field of GU oncology by introducing innovative treatment approaches, enhancing diagnostic techniques, and deepening our understanding of disease mechanisms. They provide valuable insights that can lead to improved patient outcomes.