Abstract
We aimed to externally validate the association of 2- and 3-year disease-free survival (DFS) with 5-year overall survival (OS) in patients treated with radical cystectomy (RC) for urothelial carcinoma (UC) of the bladder. We reviewed the clinical data of 422 patients who underwent RC for UC of the bladder in our institution between 1991 and 2012. Survival curves were plotted with the Kaplan-Meier method. The Kappa statistic and Kendall tau-b test were used to assess the agreements between 2- and 3-year DFS and 5-year OS. In the entire study population, 2- and 3-year DFS and 5-year OS rates were 76.4, 71.5, and 67.4%, respectively. All Kappa and Kendall's tau-b test values for agreements between 2- and 3-year DFS and 5-year OS were more than 0.40, indicating moderate agreement for all patients and in each patient subgroup selected according to specific variables (all p-values <0.05). Kaplan-Meier analysis for DFS and Cox-proportional hazard models for landmark analysis at each time point indicated that most recurrences occurred within 3 years after surgery. The 5-year OS rates of patients who were recurrence-free at each time point gradually increased to more than 95% in an extended recurrence-free interval of 12-36 months. Our external validation results support the existing finding that 2- and 3-year DFS can be a valid early surrogate end point to predict 5-year OS after RC in patients with UC of the bladder.
Highlights
Urothelial carcinoma (UC) of the bladder is a heterogeneous malignant disease with a variable clinical course and presentation [1]
Radical cystectomy (RC) with pelvic lymph node dissection (PLND) is the primary treatment option for muscle-invasive disease, which accounts for approximately 30% at initial diagnosis, and several high-risk non-muscle-invasive diseases, such as those refractory to bacillus Calmette–Guérin (BCG) therapy, histological variants of UC, and pT1 high-grade tumor with carcinoma in situ (CIS) [2,3,4]
Previous reports suggest that disease-free survival (DFS) at 2 and 3 years (2- and 3-year DFS) represents an early surrogate end point that can replace or predict Overall survival (OS) after surgical intervention or systemic chemotherapy in various malignancies, including UC [13,14,15,16,17]
Summary
Urothelial carcinoma (UC) of the bladder is a heterogeneous malignant disease with a variable clinical course and presentation [1]. Radical cystectomy (RC) with pelvic lymph node dissection (PLND) is the primary treatment option for muscle-invasive disease, which accounts for approximately 30% at initial diagnosis, and several high-risk non-muscle-invasive diseases, such as those refractory to bacillus Calmette–Guérin (BCG) therapy, histological variants of UC (i.e., micropapillary), and pT1 high-grade tumor with carcinoma in situ (CIS) [2,3,4] Both the risk for undetectable occult micro-metastasis and tumor recurrence rates of 30–60% within 5 years after RC suggest that a unimodal treatment of RC may be insufficient for complete tumor control [1]. Because a majority of recurrences or metastases after RC generally occur within 3 years [18], it is probable that decrease in the disease-recurrence risk within 3 years following RC may improve the OS According to this hypothesis, the use of the 2- and 3-year DFS as an early surrogate marker will facilitate the development of effective adjuvant chemotherapeutic regimens for RC
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
