CT based scoring system accurately predicts outcome for clinical LN in bladder cancer patients: Study

A contrast-enhanced (CT) scan is the standard staging modality for patients with bladder cancer undergoing radical cystectomy (RC). Involvement of lymph nodes (LN) determines the prognosis of patients with bladder cancer. The detection of lymph nodes (LN) metastasis by CT scan is still insufficient.

A group of researchers from Germany conducted a study to investigate various CT scan characteristics to predict lymph node ratio (LNR) and its impact on survival. Also, pre-operative CT scan characteristics might hold the potential to risk stratify cN+ patients.

They analyzed preoperative CT scans of patients undergoing RC in a tertiary high volume centre. Retrospectively, local tumour stage and LN characteristics such as size, morphology (MLN) and a number of loco-regional LN (NLN) were investigated and correlation to LNR and survival was analyzed. CT scan characteristics were used to develop a risk stratification using Kaplan-Maier and multivariate analysis.

The results of the study are as follows:

· 764 cN0 and 166 cN+ patients with complete follow-up and imaging data were included in the study.

· Accuracy to detect LN metastasis and locally advanced tumour stage in CT scan was 72% and 62%. LN larger than 15mm in diameter were significantly associated with higher LNR.

· Increased NLN correlated with decreased CSS and OS.

· Furthermore, CT scan-based scoring system precisely differentiates low-risk and high-risk profiles to predict the oncological outcomes.

Thus, the researchers concluded that solely LN size >15mm significantly correlated with higher lymph node ratio (LNR). Identification of increased loco-regional lymph node was associated with worse survival. For the first time, precise risk stratification based on computed-tomography findings was developed to predict the oncological outcomes for clinical lymph node-positive patients undergoing radical cystectomy (RC).

Reference:

Computed-tomography based scoring system predicts outcome for clinical lymph node-positive patients undergoing radical cystectomy by Eismann L et. al published in the International Brazilian Journal of Urology.

DOI: 10.1590/S1677-5538.IBJU.2021.0329