Adjuvant Chemotherapy Boosts OS In Neoadjuvant Chemotherapy-Treated Bladder Cancer Patients

Early results point to the survival benefit associated with adjuvant chemotherapy following neoadjuvant chemotherapy and surgery in patients with pathological T3/T4 or node-positive bladder carcinoma

medwireNews: Adjuvant chemotherapy could prolong overall survival (OS) over observation alone in patients with bladder cancer with adverse pathological features who have received neoadjuvant chemotherapy prior to undergoing radical cystectomy, an analysis suggests. 

“The present findings should be considered as preliminary evidence to conduct a randomized clinical trial to address this association”, say the study authors. 

They explain that prior research has shown a survival benefit with cisplatin-based adjuvant chemotherapy in patients with pathological T3/T4 or node-positive disease, but the studies were restricted to those who had not received neoadjuvant chemotherapy, prompting the team to conduct the present study. 

Using the National Cancer Database (NCDB), the researchers identified 788 patients with a diagnosis of bladder cancer treated with neoadjuvant chemotherapy and radical cystectomy between 2006 and 2012. Of these, 23.4% also received adjuvant chemotherapy, while the remaining 76.6% underwent observation after surgery. 

After adjusting for the inverse probability of treatment weighting (IPTW) to account for possible selection bias, regression analysis showed that receipt of adjuvant chemotherapy after neoadjuvant chemotherapy plus surgery was associated with a significant 22% reduced risk of death compared with observation. 

And in Kaplan–Meier analysis, also adjusted for IPTW, median OS was significantly longer for the group that received adjuvant chemotherapy than observation, at 29.9 and 24.2 months, respectively. 

The corresponding 5-year IPTW-adjusted survival rates were 36.8% and 24.7%, Quoc-Dien Trinh, from Brigham and Women’s Hospital in Boston, Massachusetts, USA, and fellow investigators report in JAMA Oncology

They caution that although they attempted to correct for selection bias by using IPTW-adjusted analyses, unmeasured confounders such as performance status or renal function could have affected the findings. 

Furthermore, as the NCDB does not record details of the administered chemotherapy regimen or the completeness and number of cycles, the study authors are unable to “comment on the specific treatment sequence that would provide the greatest overall survival benefit.” 

Quoc-Dien Trinh et al add, however, that “from a biological perspective, it may be appropriate to sequentially deliver different combination regimens with complementary cytotoxic effects to target different cell populations in the primary tumor.”  

Reference 

Seisen T, Jamzadeh A, Leow JJ, et al. Adjuvant chemotherapy vs observation for patients with adverse pathologic features at radical cystectomy previously treated with neoadjuvant chemotherapy. JAMA Oncol; Advance online publication 24 August 2017. doi: 10.1001/jamaoncol.2017.2374 

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