Semi-competing risk model to predict perioperative and oncologic outcomes after radical cystectomy

Abstract

Background: To utilize a semi-competing risk model to predict perioperative and oncologic outcomes after radical cystectomy and to compare the findings with the univariate Cox regression model. Methods: We reviewed the Institutional Review Board approved database of radical cystectomy of 316 patients who had undergone robot-assisted radical cystectomy (RARC) or open radical cystectomy between 2006 and 2016. Demographic data, perioperative outcomes, complications, metastasis, and survival were analyzed. The Bayesian variable selection method was utilized to obtain models for each hazard function in the semi-competing risks. Results: Of 316 patients treated, 48% and 18% experienced any or major complication respectively within 30 days. Intracorporeal RARC was associated with decreased metastasis risk. Extracorporeal RARC was associated with marginally decreased risks of overall complications or major complications. Patients with advanced cancer had an increased risk of metastasis, death after metastasis and death after complication. Positive nodes were associated with an increased risk of death without overall or major complications and increased risk of death after metastasis occurs. When a serious complication was taken into account there was no significant difference in mortality, irrespective of disease stage. Conclusions: A semi-competing risk model provides relatively more accurate information in comparison to Cox regression analysis in predicting risk factors for complications and metastasis in patients undergoing radical cystectomy.

A novel Bayesian continuous piecewise linear log‐hazard model, with estimation and inference via reversible jump Markov chain Monte Carlo

“…We demonstrate an application of our method using the dataset described by Peak et al This dataset consists of 316 patients with bladder cancer between 2006 and 2016 at Wake Forest Baptist Medical Center who underwent a radical cystecomy, a procedure that includes removal the bladder, prostate (men), uterus and ovaries (women), and pelvic lymph nodes, and then creation of a urinary diversion. The urinary diversion requires incorporation of bowel segments into the urinary tract.…”

“…Next we performed a Cox regression using the two different Bayesian reversible jump baseline hazard models for the radical cystectomy data. Similar to the paper by Peak et al, we looked at the covariates: age, gender, white race vs other, body mass index (BMI), an ASA score ≥ 2, operating room time, estimated blood loss, whether or not a patient received a blood transfusion, advanced cancer (stage 3 or 4), lymphovascular invasion (LVI), positive nodes, positive margins, carcinoma in situ (CIS), upper tract invasion, whether or not a patient had neoadjuvant chemotherapy, total lymph nodes. We also looked at two treatment variables: extracoporeal and intracorporeal RARC which are compared to open radical cystectomy.…”