AKT1 and PIK3CA activating mutations in Moroccan bladder cancer patients´ biopsies and matched urine

Monitoring circulating tumor DNA by recurrent hotspot mutations in bladder cancer

BACKGROUND

Liquid biopsy can evaluate minimally residual disease. Hotspot mutations are also common in non-coding regions among the MIBC patients. We evaluated the status of MIBC with hotspot mutations with cfDNA.

METHODS

Tumor and blood from MIBC patients were collected prospectively. We evaluate the VAF of mutations (TERT, PLEKHS1, ADGRG6 and WDR74) with digital PCR in tumor and cfDNA as somatic mutation. We originally designed and validated primers and probes. VAF of cfDNA and clinical imaging were matched. This study was approved by the Institutional Review Board (#2022-157).

RESULT

37 MIBC patients were enrolled and 28 (76%) patients had any hotspot. Among the 21 patients of follow-up cohort, cfDNA predicted recurrence 58 days earlier than the diagnosis by CT scan. Furthermore, the detection of ctDNA at the first visit after radical cystectomy was associated with recurrence free survival (P = 0.0043) and overall survival (P = 0.017). The patient who received neoadjuvant chemotherapy (NAC) and diagnosed as ypT0 belonged to the nonrecurrence group with negative ctDNA.

CONCLUSION

Hotspot mutation is promising biomarker to predict earlier recurrence than CT-scan. Multiple detection of mutations in cfDNA contributes to reliable recurrence prediction.

Predictive Molecular Biomarkers of Bladder Cancer Identified by Next-Generation Sequencing-Preliminary Data

Background: The majority of patients with bladder cancer suffer from tumour recurrence. Identifying prognostic factors for tumour recurrence is crucial for treatment and follow-up in affected patients. The study aimed to assess the impact of somatic mutations in bladder cancer on patient outcomes and tumour recurrence. Methods: The study group comprised 46 patients with urothelial bladder cancers referred for transurethral resection of the tumour. A molecular study on tumour-derived DNA was performed using next-generation sequencing. Somatic mutations were screened in 50 genes involved in carcinogenesis. Results: We identified 81 variants in 23 genes, including 54 pathogenic mutations, 18 likely pathogenic variants, and 9 variants of unknown significance. The most frequently mutated genes were FGFR3, PIK3CA, and TP53 in 52%, 35%, and 24% of tumours, respectively. The average tumour-free survival was significantly longer in cases with mutations in the PIK3CA gene (p = 0.02), and mutations in the PIK3CA gene were associated with a decreased risk of tumour recurrence (Hazard Ratio = 0.26; 95% CI: 0.11-0.62; p = 0.018). Conclusions: The PIK3CA gene was shown to be a predictive marker of a low risk of bladder tumour recurrence. Molecular screening of bladder cancers supported predictive biomarkers of tumour recurrence and showed that tumour-free survival is molecularly determined.

A Liquid Biopsy in Bladder Cancer—The Current Landscape in Urinary Biomarkers

The non-muscle invasive bladder cancer tends to recur and progress. Therefore, it requires frequent follow-ups, generating costs and making it one of the most expensive neoplasms. Considering the expensive and invasive character of the current gold-standard diagnostic procedure, white-light cystoscopy, efforts to find an alternative method are ongoing. Although the last decade has seen significant advancements in urinary biomarker tests (UBTs) for bladder cancer, international guidelines have not recommended them. Currently, the paramount urgency is to find and validate the test with the best specificity and sensitivity, which would allow for the optimizing of diagnosis, prognosis, and a treatment plan. This review aims to summarise the up-to-date state of knowledge relating to UBTs and new developments in the detection, prognosis, and surveillance of bladder cancer and their potential applications in clinical practice.