The effect of number of treatment cycles of platinum-based first-line chemotherapy on maximum radiological response in patients with advanced urothelial carcinoma

Reevaluating the role of platinum-based chemotherapy in the evolving treatment landscape for patients with advanced urothelial carcinoma

Platinum-based chemotherapy has been the standard first-line (1L) treatment for advanced urothelial carcinoma (UC) for decades, based on the proven efficacy and established safety profiles of cisplatin- and carboplatin-based regimens. With the emergence of novel regimens, it is important to reevaluate and contextualize the role of 1L platinum-based chemotherapy. Platinum-based chemotherapy followed by avelumab 1L maintenance in patients without disease progression following platinum-based chemotherapy was established as a standard 1L regimen based on the JAVELIN Bladder 100 phase III trial. More recently, the EV-302 phase III trial showed the superiority of 1L enfortumab vedotin (EV) + pembrolizumab versus platinum-based chemotherapy, and the Checkmate 901 phase III trial showed the superiority of 1L nivolumab + cisplatin/gemcitabine versus cisplatin/gemcitabine alone. These 2 regimens have now been included as standard 1L options in treatment guidelines for advanced UC. EV + pembrolizumab is now the preferred 1L treatment, and in locations where EV + pembrolizumab is not available or individual patients are not considered suitable, recommended options are platinum-based chemotherapy followed by avelumab maintenance or nivolumab + cisplatin-based chemotherapy. In this review, we discuss current treatment options for advanced UC recommended in guidelines, practical considerations with platinum-based chemotherapy, the role of avelumab 1L maintenance, recent phase III trials of EV + pembrolizumab and nivolumab + cisplatin/gemcitabine, safety profiles of recommended 1L treatments, and second-line treatment options.

Pre-first-line chemotherapy risk stratification for overall survival in advanced urothelial carcinoma in sequential therapy era

PURPOSE

To explore pre-treatment risk factors for overall survival (OS) in advanced urothelial carcinoma (UC) patients treated with first-line (1L) chemotherapy in sequential therapy (ST) era. Additionally, to evaluate the proportion of patients who were not able to undergo subsequent immune checkpoint inhibitor (ICI) therapy according to the subgroups stratified by the risk factors.

METHODS

A multicenter retrospective study was conducted. Metastatic or locally advanced UC patients treated between 2017 and 2022 were included. The Kaplan-Meier method with the log-rank test and multivariate Cox regression models were used to address OS.

RESULTS

Three hundred and fourteen patients treated with 1L chemotherapy were included in the study and 57 (18.2%) patients were not able to proceed to subsequent ICI therapy. Pre-chemotherapy risk factors for OS in 314 patients were ECOG-PS 1 or more, having no primary site resection, C-reactive protein (CRP) level of 3 mg/dL or more, and non-cisplatin-based regimen. Patients having 3 or 4 risk factors had higher risk for not being able to receive ST (Mann-Whitney U test, P < 0.001). As risk factors for OS in 230 patients who were able to receive ST, having no primary site resection, a neutrophil to lymphocyte ratio of 3 or more, and the presence of liver metastasis were identified.

CONCLUSION

We reported the risk factors for OS in advanced UC patients treated with 1L chemotherapy in ST era. Patients with high risk for OS may not be able to proceed to subsequent ICI therapy even in the ST era.

Limited predictive impact of tumor size dynamics on further tumor shrinkage after 4 cycles of first-line chemotherapy in patients with advanced urothelial carcinoma

PURPOSE

To investigate the correlation between tumor size changes during the initial 4 cycles of first-line chemotherapy and tumor shrinkage following 2 additional cycles of chemotherapy in patients with advanced urothelial carcinoma (aUC) who experienced disease control after initial chemotherapy.

METHODS

We retrospectively reviewed 128 patients with aUC who received first-line chemotherapy. We analyzed 51 patients with disease control (stable disease or better) at the end of the fourth cycle. Of these, 47 patients received 1 to 2 additional cycles of chemotherapy, whereas the remaining patients underwent observation. For patients who received additional chemotherapy, the change in tumor size after additional chemotherapy (cycles 5-6) was defined as "no shrinkage" (tumor growth), "minor shrinkage" (no tumor growth or ≤10% reduction in tumor size), or "shrinkage" (>10% reduction in tumor size). Then, we investigated the relationship between the rate of tumor size change during the initial 4 cycles and that after additional chemotherapy.

RESULTS

Of the patients who received additional chemotherapy, the change in tumor size was categorized as no shrinkage in 21 patients (44.7%), minor shrinkage in 18 patients (38.3%), and shrinkage in 8 patients (17%). Regarding predictors of tumor shrinkage after additional chemotherapy, the rate of tumor size change between the cycles 3 and 4 (area under the receiver operating characteristics curve = 0.642) was correlated with the trend of the tumor shrinkage (P = 0.009) and the likelihood of beneficial tumor shrinkage after additional chemotherapy (minor shrinkage + shrinkage; P = 0.02). However, the change in tumor size between cycles 1 and 2, cycles 1 and 4, or cycles 3 and 4 was not satisfactorily predictive of further tumor shrinkage because of substantial overlaps of the tumor size changes.

CONCLUSIONS

Only a small subset of patients would have substantial tumor shrinkage by additional cycles after successful induction of 4 cycle chemotherapy. Tumor size dynamics during the initial 4 cycles of chemotherapy displayed limited ability to predict the subset of patients with further tumor shrinkage after additional chemotherapy. Therefore, it might be better to consider switch maintenance immunotherapy for patients who experience disease control after the fourth cycle of first-line chemotherapy.

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.

A retrospective study on optimal number of cycles of the first-line platinum-based chemotherapy for metastatic urothelial carcinoma

BACKGROUND

Recently, switch maintenance with avelumab has been approved for the treatment of advanced or metastatic urothelial carcinoma (UC), with no progression after four to six cycles of first-line platinum-based chemotherapy. However, the optimal number of cycles of platinum-based chemotherapy has not been determined.

OBJECTIVE

To analyze the clinical characteristics of patients with advanced UC who were treated with platinum-based chemotherapy and investigate the association between the number of cycles of the treatment and the patients' overall survival.

METHODS

A total of 124 patients with advanced UC who were treated with first-line platinum-based chemotherapy at Osaka City University Hospital between April 2009 and January 2020 were retrospectively reviewed.

RESULTS

Of the 124 patients, clinical information regarding overall survival was available for 115 patients. The median age was 72 years (range, 43-95 years). Only 59 patients (51.3 %) were treated with gemcitabine and cisplatin, and 52 patients (45.2 %) were treated with gemcitabine and carboplatin. The median number of cycles was three (1-8), and the percentage of patients who discontinued chemotherapy due to progressive disease was 80.3%, 64.0%, and 86.4% in those receiving one to three, four, and five or more cycles, respectively. Moreover, no difference in overall survival was observed between patients who received four cycles and those who received five or more cycles at both univariate and multivariate levels.

CONCLUSIONS

The present study shows that five or more cycles of first-line platinum-based chemotherapy did not prolong overall survival compared with four cycles, suggesting that four cycles of chemotherapy might be sufficient, considering the new treatment strategy involving switch maintenance with avelumab.