Impact of substratification on predicting oncological outcomes in patients with primary high-risk non-muscle-invasive bladder cancer who underwent transurethral resection of bladder tumor

Impact of an optimized surveillance protocol based on the European Association of Urology substratification on surveillance costs in patients with primary high-risk non-muscle-invasive bladder cancer

OBJECTIVES

The optimal frequency and duration of surveillance in patients with high-risk non-muscle-invasive bladder cancer (NMIBC) remain unclear. The aim of the present study is to develop an optimal surveillance protocol based on the European Association of Urology (EAU) substratification in order to improve surveillance costs after transurethral resection of bladder tumor (TURBT) in patients with primary high-risk NMIBC.

MATERIALS AND METHODS

We retrospectively evaluated 428 patients with primary high-risk NMIBC who underwent TURBT from November 1993 to April 2019. Patients were substratified into the highest-risk and high-risk without highest-risk groups based on the EAU guidelines. An optimized surveillance protocol that enhances cost-effectiveness was then developed using real incidences of recurrence after TURBT. A recurrence detection rate ([number of patients with recurrence / number of patients with surveillance] × 100) of ≥ 1% during a certain period indicated that routine surveillance was necessary in this period. The 10-year total surveillance cost was compared between the EAU guidelines-based protocol and the optimized surveillance protocol developed herein.

RESULTS

Among the 428 patients with primary high-risk NMIBC, 97 (23%) were substratified into the highest-risk group. Patients in the highest-risk group had a significantly shorter recurrence-free survival than those in the high-risk without highest-risk group. The optimized surveillance protocol promoted a 40% reduction ($394,990) in the 10-year total surveillance cost compared to the EAU guidelines-based surveillance protocol.

CONCLUSION

The optimized surveillance protocol based on the EAU substratification could potentially reduce over investigation during follow-up and improve surveillance costs after TURBT in patients with primary high-risk NMIBC.

Predicting Recurrence and Progression in Patients with Non-Muscle-Invasive Bladder Cancer: Systematic Review on the Performance of Risk Stratification Models

BACKGROUND

Several classifications have been reported to stratify non-muscle-invasive bladder cancer (NMIBC) in risk groups according to the probability of recurrence and progression.

OBJECTIVE

To systematically review the current evidence regarding risk stratification of NMIBC.

METHODS

The systematic review was performed in accordance with the PRISMA statement. Studies providing data on development and/or external validation cohorts of models and risk stratification tables for recurrence and/or progression for patients with NMIBC, reporting at least one discrimination measure (AUC or C-Index) were included.

RESULTS

Twenty-five studies involving 22,737 patients were included. Six classifications were identified, three of them were predictive models (EORTC, CUETO, EAU 2021) and three were based on expert opinion (EAU 2020, AUA, NCCN). A high risk of bias was present in the majority of the studies. Certain heterogenicity was found among the studies regarding adjuvant therapy, postoperative instillation or second resection. The definition of oncological outcomes was not standardized in the included studies. CUETO and EORTC scoring systems are the most validated. In general, validations showed a poor discrimination capability to predict recurrence, slightly better for progression. The EAU 2021 model overestimates the risk of progression in patients treated with BCG. Carcinoma in situ is underrepresented in all the studies analyzed.

CONCLUSIONS

The existing classifications show poor discrimination capability for recurrence and possibly helpful discrimination capability for progression in NMIBC patients. These results highlight the unmet need to develop novel accurate risk models for patients with NMIBC, which could be improved with the combination of clinicopathological and molecular information.

Single immediate instillation of chemotherapy is associated with decreased recurrence and progression in patients with high-risk non-muscle-invasive bladder cancer who receive adjuvant induction bacillus Calmette-Guérin therapy

OBJECTIVES

To investigate whether a single intravesical instillation of chemotherapy is associated with improved oncological outcomes in patients with high-risk non-muscle-invasive bladder cancer who receive adjuvant induction bacillus Calmette-Guérin therapy.

METHODS

This multi-institutional retrospective study included 205 patients with high-risk non-muscle-invasive bladder cancer who received adjuvant induction bacillus Calmette-Guérin therapy. Patients were divided into two groups: those who received the combined therapy of a single instillation of chemotherapy plus subsequent adjuvant induction bacillus Calmette-Guérin therapy (combined therapy group), and those who received adjuvant induction bacillus Calmette-Guérin therapy alone (bacillus Calmette-Guérin monotherapy group). Multivariable analyses using the inverse probability of treatment weighting method and Fine-Gray competing risk regression models were performed to evaluate the impact of a single instillation of chemotherapy on intravesical recurrence-free survival and muscle-invasive bladder cancer-free survival.

RESULTS

Among the 205 patients, 130 (63%) and 75 (37%) were classified as the combined therapy and bacillus Calmette-Guérin monotherapy groups, respectively. Multivariable analyses using the inverse probability of treatment weighting method showed that a single instillation of chemotherapy was significantly associated with longer intravesical recurrence-free survival (hazard ratio 0.279; P < 0.001) and muscle-invasive bladder cancer-free survival (hazard ratio 0.078; P < 0.001). Fine-Gray competing risk regression model revealed that a single instillation of chemotherapy was associated with a significantly lower probability of intravesical recurrence and muscle-invasive bladder cancer progression, with an adjusted subdistribution hazard ratio of 0.477 (P = 0.008) and 0.261 (P = 0.043), respectively.

CONCLUSION

A single intravesical instillation of chemotherapy may be a potential treatment option in patients with high-risk non-muscle-invasive bladder cancer who receive adjuvant induction bacillus Calmette-Guérin therapy.

Management of bladder cancer in older patients

Evidence has shown that patients with bladder cancer are diagnosed at a much older age compared with those with other cancers. Given that co-morbidities and frailty are prevalent in older patients with advanced bladder cancer, they are easily excluded from randomized controlled trials. As little evidence has been available regarding assessment tools for frailty, the management of those patients remains challenging. This weakness is strongly manifested in muscle-invasive bladder cancer. Despite radical cystectomy is the standard of care for bladder cancer, there is an extensive undertreatment of older adult patients with potentially curative muscle-invasive bladder cancer. However, it is also true that radical cystectomy is often unsuitable for vulnerable or frail patients. Bladder preservation using trimodality therapy has been utilized as an alternative option, but the appropriate selection criteria for trimodality therapy remain unclear. Cisplatin-based regimens have been the first choice for advanced disease among eligible patients. Moreover, immunotherapy appears to have similar benefits and tolerability in both older and younger patients. Furthermore, palliative or supportive interventions need to be initiated earlier in patients with metastatic disease. Accumulating evidence suggests that frailty may play a key role in the selection of treatment modalities. Older patients should be considered for standard treatment based on frailty and not chronological age. Moreover, older patients with bladder cancer need to undergo geriatric assessment for proper decision-making.

Non-Muscle Invasive Bladder Cancer with Variant Histology: Biological Features and Clinical Implications

BACKGROUND

The most common bladder cancer (BC) histotype is pure urothelial carcinoma (UC), which may undergo divergent differentiation in some cases. Variant histology (VH) presents along variable morphologies, either single or combined between them or with pure UC. From a clinical standpoint, the vast majority of BC is diagnosed at non-invasive or minimally invasive stages, namely as non-muscle invasive BC (NMIBC). There is a wide range of therapeutic options for patients with NMIBC, according to their clinical and pathological features. However, current risk stratification models do not show optimal effectiveness. Evidence from the literature suggests that VH has peculiar biological features, and may be associated with poorer survival outcomes compared to pure UC.

SUMMARY

In order to describe the biological features and prognostic/predictive role of VH in NMIBC, and to discuss current treatment options, we performed a systematic literature search through multiple databases (PubMed/Medline, Google Scholar) for relevant articles according to the following terms, single and/or in combination: "non-muscle invasive bladder cancer," "variant histology," "micropapillary variant," "glandular differentiation," "squamous differentiation," "nested variant," "plasmacytoid variant," and "sarcomatoid variant." We extracted 99 studies including original articles, reviews, and systematic reviews, and subsequently analyzed data from 16 studies reporting on the outcome of NMIBC with VH. We found that the relative rarity of these forms as well as the heterogeneity in study populations and therapeutic protocols results in conflicting findings overall. Key Messages: The presence of VH should be taken into account when counseling a patient with NMIBC, since it may upgrade the disease to high-risk tumor and thus warrant a more aggressive treatment.