Predicting post-radiation genitourinary hospital admissions in patients with localised prostate cancer.

PURPOSE: The risk of treatment-related toxicity is important for patients with localised prostate cancer to consider when deciding between treatment options. We developed a model to predict hospitalisation for radiation-induced genitourinary toxicity based on patient characteristics. METHODS: The prospective South Australian Prostate Cancer Clinical Outcomes registry was used to identify men with localised prostate cancer who underwent curative intent external beam radiotherapy (EBRT) between 1998 and 2019. Multivariable Cox proportional regression was performed. Model discrimination, calibration, internal validation and utility were assessed using C-statistics and area under ROC, calibration plots, bootstrapping, and decision curve analysis, respectively. RESULTS: There were 3,243 patients treated with EBRT included, of which 644 (20%) patients had a treated-related admission. In multivariable analysis, diabetes (HR 1.35, 95% CI 1.13-1.60, p < 0.001), smoking (HR 1.78, 95% CI 1.40-2.12, p < 0.001), and bladder outlet obstruction (BOO) without transurethral resection of prostate (TURP) (HR 7.49, 95% CI 6.18-9.08 p < 0.001) followed by BOO with TURP (HR 4.96, 95% CI 4.10-5.99 p < 0.001) were strong independent predictors of hospitalisation (censor-adjusted c-statistic = 0.80). The model was well-calibrated (AUC = 0.76). The global proportional hazards were met. In internal validation through bootstrapping, the model was reasonably discriminate at five (AUC 0.75) years after radiotherapy. CONCLUSIONS: This is the first study to develop a predictive model for genitourinary toxicity requiring hospitalisation amongst men with prostate cancer treated with EBRT. Patients with localised prostate cancer and concurrent BOO may benefit from TURP before EBRT.

Association between perioperative intraperitoneal local anaesthetic infusion and long-term survival and cancer recurrence after colectomy: follow-up analysis of a previous randomized controlled trial.

BACKGROUND: High concentrations of local anaesthetic have an anti-proliferative effect on colonic cancer in vitro. Intraperitoneal local anaesthetic (IPLA) has shown analgesic benefit and improved recovery in the perioperative setting. The long-term effects of IPLA in colon cancer resection have not been examined. This study aims to review the survival and oncological outcomes of a previously conducted trial that compared perioperative IPLA with placebo. METHODS: Sixty patients underwent colonic resection for benign and malignant disease as part of a double-blinded, randomized, placebo-controlled study between September 2008 and November 2009. The IPLA group received instillation of intraperitoneal ropivacaine before dissection followed by a 3-day infusion. The placebo group was treated identically but with 0.9% saline solution. A follow-up analysis was conducted to evaluate overall survival, disease-free survival and recurrence specifically for patients undergoing resection for stages I-III colon cancer. Kaplan-Meier analysis was performed, and the log-rank test was used to evaluate difference in survival between groups. RESULTS: Thirty-seven of the 60 patients had stages I-III colon cancer and were included in this analysis. Nineteen patients were in the placebo group. There was no significant difference in overall survival or all-cause mortality. There was a higher incidence of cancer-specific mortality in the local anaesthetic group (P < 0.046). CONCLUSION: It does not appear that IPLA is associated with a significant survival benefit in patients with colonic malignancy undergoing colectomy. Other studies are needed to analyse the long-term outcomes.