Emerging Trends and Innovations in the Diagnosis and Treatment of Muscle-Invasive Bladder Cancer

Bladder cancer is the tenth most common cancer worldwide and poses a significant burden on healthcare services. The poor progression rates of treatment options and the quality of life these interventions offer necessitate the exploration of new alternatives. This article reviews the diagnosis and treatment of muscle-invasive bladder cancer (MIBC) and cN+ disease, highlighting advancements in imaging modalities, radiomics, artificial intelligence (AI), and molecular biomarkers.

Imaging Modalities in MIBC Diagnosis

The gold-standard imaging modality for MIBC pelvic staging is multiphase contrast-enhanced CT with urinary excretory phase. However, this method has limited accuracy, and conventional radiological assessment of lymph nodes using CT also has limitations in accuracy and prognostic value. MRI, with its advantages in soft-tissue contrast resolution, unfortunately also presents poor accuracy in detecting pelvic lymph node (PLN) metastases.

Novel Imaging Approaches and Technologies

Emerging imaging modalities such as PET/CT, specifically FDG-PET/CT, have shown promise in improving cN+ disease detection. However, their performance varied across studies, leading to inconsistent utility for preoperative MIBC staging. To overcome these challenges, the field is exploring advancements in radiomics and artificial intelligence (AI) for improved diagnostic accuracy and patient management in MIBC.

Improvements in NMIBC Treatment

The American Urological Association (AUA)/Society of Urologic Oncology (SUO) guideline for the diagnosis and treatment of non-muscle invasive bladder cancer (NMIBC) was updated in 2023. The update seeks to improve clinicians' ability to evaluate and treat patients with NMIBC based on currently available evidence. It includes new statements on variant histologies, urine markers, intravesical therapy, BCG maintenance, and enhanced cystoscopy.

Targeted Drugs and Biomarkers

With the need for new alternatives in bladder cancer treatment, urinary biomarkers and targeted drugs are being explored. Notably, Asieris Pharmaceuticals released Phase III clinical trial data for APL-1706, a bladder cancer diagnosis and management drug. The study showed superior detection of bladder cancer, especially in the carcinoma in situ (CIS) population, when combined with Blue Light Cystoscopy (BLC).

Surgery Options for MIBC

Laparoscopic radical cystectomy (LRC) is a potential treatment for male octogenarian patients with MIBC. A study found LRC and intracorporeal pelvic lymph node dissection with bilateral cutaneous ureterostomy to be safe and feasible for this population. There was a decrease in estimated blood loss, transfusion need, and hospital stay after surgery compared to controls, although the operation time was longer.

Adjuvant Treatments for MIBC

The AMBASSADOR Alliance A031501 trial explored the use of adjuvant pembrolizumab in locally advanced/muscle-invasive urothelial carcinoma. The trial met its primary endpoint of disease-free survival (DFS), with patients receiving pembrolizumab showing significantly longer median DFS and overall survival (OS) compared to those who underwent observation. Adjuvant nivolumab is currently FDA approved for patients with high-risk urothelial carcinoma.

In summary, the field of bladder cancer diagnosis and treatment is rapidly evolving. With advancements in imaging modalities, AI, and molecular biomarkers, there is hope for improved outcomes for patients. Ongoing research and clinical trials will continue to inform and refine these emerging strategies.