Conditional survival after radical nephroureterectomy for upper tract carcinoma

Conditional survival (CS) provides better estimates of the survival probability at each follow-up time, and its usefulness has been proven in several solid malignancies.

To assess the changes in 5-yr CS rates after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) and to determine how well-established prognostic factors evolve over time.

We analysed data from 3544 patients treated with RNU at 15 international academic centres between 1989 and 2012.

RNU.

Conditional intravesical recurrence-free (IVRFS), cancer-specific survival (CSS), and overall survival (OS) estimates were calculated using the Kaplan-Meier method. A multivariable Cox regression model was used to calculate proportional hazard ratios for the prediction of mortality.

The 5-yr bladder cancer recurrence-free survival, CSS, and OS rates were 54.9%, 72.2%, and 62.6%, respectively. Given a 1-, 2-, 3-, and 4-yr survivorship, the 5-yr conditional OS rates improved to 65.2%, 69.3%, 71.5%, and 73.0%, respectively. The 5-yr CS improvement was primarily noted among surviving patients with advanced-stage disease. The impact of pathologic parameters on CS estimates decreased over time for both CSS and OS, whereas the impact of age and gender increased with survivorship. No survival benefit was noted regarding the adjuvant chemotherapy status. Findings were confirmed upon multivariable analyses. Tumour location, the presence of carcinoma in situ, and the type of bladder cuff excision were continuously predictive for IVRFS whatever the survivorship. A limitation is the retrospective design.

CS analysis demonstrates that the patient risk profile evolves during the post-RNU follow-up. The probability of survival markedly increases over time in patients having high-stage disease. The impact of prognostic pathologic features decreases over time and can disappear for long-term CS.

In this study, we found that the risk of intravesical recurrence, cancer-specific survival, and overall mortality evolves over the follow-up after surgery. Taking into account the survivorship provides better estimates of the survival probability at each follow-up time.