Indication for a Single Postoperative Instillation of Chemotherapy in Non-muscle-invasive Bladder Cancer: What Factors Should Be Considered?

High and selective cytotoxicity of ex vivo expanded allogeneic human natural killer cells from peripheral blood against bladder cancer: implications for natural killer cell instillation after transurethral resection of bladder tumor

BACKGROUND

Non-muscle-invasive bladder cancer (NMIBC) is treated with transurethral resection of bladder tumor (TURBT) followed by intravesical instillation of chemotherapy or Bacillus Calmette-Guérin therapy. However, these treatments have a high recurrence rate and side effects, emphasizing the need for alternative instillations. Previously, we revealed that expanded allogeneic human natural killer (NK) cells from peripheral blood are a promising cellular therapy for prostate cancer. However, whether NK cells exhibit a similar killing effect in bladder cancer (BCa) remains unknown.

METHODS

Expansion, activation, and cryopreservation of allogeneic human NK cells obtained from peripheral blood were performed as we previously described. In vitro cytotoxicity was evaluated using the cell counting kit-8. The levels of perforin, granzyme B, interferon-γ, tumor necrosis factor-α, and chemokines (C-C-motif ligand [CCL]1, CCL2, CCL20, CCL3L1, and CCL4; C-X-C-motif ligand [CXCL]1, CXCL16, CXCL2, CXCL3, and CXCL8; and X-motif ligand 1 and 2) were determined using enzyme-linked immunosorbent assay. The expression of CD107a, major histocompatibility complex class I (MHC-I), MHC-I polypeptide-related sequences A and B (MICA/B), cytomegalovirus UL16-binding protein-2/5/6 (ULBP-2/5/6), B7-H6, CD56, CD69, CD25, killer cell Ig-like receptors (KIR)2DL1, KIRD3DL1, NKG2D, NKp30, NKp46, and CD16 of NK cells or BCa and normal urothelial cells were detected using flow cytometry. Cytotoxicity was evaluated using lactate dehydrogenase assay in patient-derived organoid models. BCa growth was monitored in vivo using calipers in male NOD-scid IL2rg-/- mice subcutaneously injected with 5637 and NK cells. Differential gene expressions were investigated using RNA sequence analysis. The chemotaxis of T cells was evaluated using transwell migration assays.

RESULTS

We revealed that the NK cells possess higher cytotoxicity against BCa lines with more production of cytokines than normal urothelial cells counterparts in vitro, demonstrated by upregulation of degranulation marker CD107a and increased interferon-γ secretion, by MICA/B/NKG2D and B7H6/NKp30-mediated activation. Furthermore, NK cells demonstrated antitumor effects against BCa in patient-derived organoids and BCa xenograft mouse models. NK cells secreted chemokines, including CCL1/2/20, to induce T-cell chemotaxis when encountering BCa cells.

CONCLUSIONS

The expanded NK cells exhibit potent cytotoxicity against BCa cells, with few toxic side effects on normal urothelial cells. In addition, NK cells recruit T cells by secreting a panel of chemokines, which supports the translational application of NK cell intravesical instillation after TURBT from bench to bedside for NMIBC treatment.

Precise diagnosis and treatment of non-muscle invasive bladder cancer - A clinical perspective

According to the guidelines, transurethral resection of bladder tumor (TURBT) followed by intravesical therapy remains the standard strategy for the management of non-muscle invasive bladder cancer (NMIBC). However, even if patients receive standard strategy, the risk of postoperative recurrence and progression is high. From the clinical perspective, the standard strategy needs to be optimized and improved. Compared to conventional TURBT, the technique of en bloc resection of bladder tumor (ERBT) removes the tumor tissue in one piece, thus following the principles of cancer surgery. Meanwhile, the integrity and spatial orientation of tumor tissue is protected during the operation, which is helpful for pathologists to make accurate histopathological analysis. Then, urologists can make a postoperative individualized treatment plan based on the patient's clinical characteristics and histopathological results. To date, there is no strong evidence that NMIBC patients treated with ERBT achieve better oncological prognosis, which indicates that ERBT alone does not yet improve patient outcomes. With the development of enhanced imaging technology and proteogenomics technology, en bloc resection combined with these technologies will make it possible to achieve precise diagnosis and treatment of bladder cancer. In this review, the authors analyze the current existing shortcomings of en bloc resection and points out its future direction, in order to promote continuous optimization of the management strategy of bladder cancer.

Recurrence mechanisms of non-muscle-invasive bladder cancer - a clinical perspective

Non-muscle-invasive bladder cancer (NMIBC) is an early-stage cancer without invasion into the detrusor muscle layer. Transurethral resection of bladder tumour (TURBT) is a diagnostic and potentially curative procedure for NMIBC, but has some limitations, including difficulties in ascertaining complete tumour removal upon piecemeal resection and the possibility of tumour re-implantation after the procedure. The oncological control of NMIBC is far from satisfactory, with a 1-year recurrence rate of 15-61%, and a 5-year recurrence rate of 31-78%. Various recurrence mechanisms have been described for NMIBC, such as undetected tumours upon cystoscopy, incomplete resection during TURBT, tumour re-implantation after TURBT, drop metastasis from upper tract urothelial carcinoma and field change cancerization. Understanding the recurrence mechanisms from a clinical perspective has strong implications for the optimization of NMIBC oncological outcomes, as a cure for patients with NMIBC can only be achieved by tackling all possible recurrence mechanisms in a comprehensive manner.

Adjuvant therapies for non-muscle-invasive bladder cancer: advances during BCG shortage

Non-muscle-invasive bladder cancer (NMIBC) represents a significant global therapeutic challenge, particularly in the era of Bacillus Calmette-Guérin (BCG) shortage. High-risk NMIBC can progress to muscle invasive or metastatic disease in 25% of patients. Optimal treatment selection, according to risk stratification, is imperative. International guidelines slightly differ in their categorisation of low, intermediate and high-risk NMIBC. Nonetheless, a single post-operative instillation of chemotherapy with Mitomycin C (MMC) or Gemcitabine improves relapse-free survival (RFS) in low-risk NMIBC. Induction and maintenance intravesical BCG remains the historical gold standard for patients with intermediate or high-risk NMIBC. However, clinicians may be forced to consider alternatives given the current BCG shortage. Both intravesical MMC and Gemcitabine have been associated with similar efficacy to BCG, albeit in smaller studies. MMC may also be manipulated using a variety of methods to potentiate its effects. BCG treatment delivery may also be modified without affecting efficacy through dose reduction and abbreviation or omission of maintenance therapy. Preliminary data also highlight that directly proceeding to radical cystectomy may not adversely affect long-term quality of life measures. Access to new systemic and intravesical therapies must be prioritised for patients with BCG recurrent or unresponsive disease. When used in conjunction with molecularly defined biomarkers, these agents herald the potential for improved survival outcomes and alleviation of the current BCG shortage.

En Bloc Tumor Resection, Optical Molecular Imaging, and the Potential Synergy of the Combination of the Two Techniques in Bladder Cancer

Although transurethral resection of bladder tumor is the golden standard for the treatment of non-muscle invasive bladder cancer, this surgical procedure still has some serious drawbacks. For example, piecemeal resection of tumor tissue results in exfoliated tumor cells dissemination and implantation, and fragmented tumor specimens make it difficult for pathologists to accurately assess the pathological stage and histologic grade. En bloc tumor resection follows the basic principle of oncological surgery and provides an intact tumor specimen containing detrusor muscle for pathologists to make accurate histopathological assessment. However, there is no robust clinical evidence that en bloc tumor resection is superior to conventional resection in terms of oncological outcomes. Considering the high recurrence rate, small or occult tumor lesions may be overlooked and incomplete tumor resection may occur during white light cystoscopy-assisted transurethral resection. Molecular fluorescent tracers have the ability to bind tumor cells with high sensitivity and specificity. Optical molecular imaging mediated by it can detect small or occult malignant lesions while minimizing the occurrence of false-positive results. Meanwhile, optical molecular imaging can provide dynamic and real-time image guidance in the surgical procedure, which helps urologists to accurately determine the boundary and depth of tumor invasion, so as to perform complete and high-quality transurethral tumor resection. Integrating the advantages of these two technologies, optical molecular imaging-assisted en bloc tumor resection shows the potential to improve the positive detection rate of small or occult tumor lesions and the quality of transurethral resection, resulting in high recurrence-free and progression-free survival rates.

Overnight Continuous Saline Bladder Irrigation After En Bloc Resection of Bladder Tumor Does Not Improve Oncological Outcomes in Patients Who Have Received Intravesical Chemotherapy

Objective

To evaluate the safety and efficacy of overnight continuous saline bladder irrigation (CSBI) for patients who have received thulium laser en bloc resection of bladder tumor (TmLRBT) combined with immediate intravesical chemotherapy previously.

Methods

From October 2014 to June 2018, 235 patients with newly diagnosed non-muscle invasive bladder cancer (NMIBC) were included in this retrospective study. All patients received intravesical instillation of pirarubicin immediately after TmLRBT. The patients were divided into two groups according to the duration of postoperative bladder irrigation with normal saline. After immediate intravesical chemotherapy, patients in group 1 received overnight CSBI, while patients in group 2 did not receive overnight CSBI. Data on the time of initial tumor recurrence, recurrence-free survival (RFS) and progression-free survival (PFS) rates, and perioperative complications were collected and analyzed.

Results

Of 235 included patients (129 in group 1 and 106 in group 2), the median follow-up periods were 42 and 38 months, respectively. There were no significant differences in patients' baseline characteristics between the two groups. The RFS rates of patients in group 1 were 90.7, 82.7, and 76.8% at the end of the first, third, and fifth years, while the corresponding RFS rates of patients in group 2 were 87.7, 78.9, and 73.3%, respectively. Four patients in group 1 and five patients in group 2 experienced tumor progression. No significant differences between the two groups were observed in the time of initial tumor recurrence, RFS, and PFS rates. Only Grade I complications occurred in the two groups, and no significant difference was reached between the two groups.

Conclusions

For patients with NMIBC who have previously received TmLRBT combined with immediate intravesical chemotherapy, overnight CSBI may not improve oncological outcomes and reduce perioperative complications.

Metastatic non-muscle invasive bladder can-cer with cervical lymph node metastasis

Bladder cancer is a common cancer that may present as superficial, invasive, or metastatic disease. Non-muscle-invasive bladder cancer (NMIBC) represents the majority of bladder cancer diagnoses, but represents a spectrum of disease with a variable clinical course, notably for significant risk of recurrence and potential for progression. NMIBC metastasis to distant organs without local invasion or regional metastasis is a very rare occurrence, so there are limi-ted case reports about early metastasis in the literature.