ESTRO 2023

Session Item

Urology

Session Code: 6018

Session Type: Poster (Digital)

Track: Clinical

Predictors of Patient-Reported decline in Social activity 2-years after WPRT for prostate cancer

Cesare Cozzarini, Italy

Presentation Number: PO-1509

Abstract

Abstract Title:

Predictors of Patient-Reported decline in Social activity 2-years after WPRT for prostate cancer

Authors:

Maddalena Pavarini¹, Giuseppe Girelli², Elisa Villa³, Barbara Avuzzi⁴, Andrea Bresolin¹, Elisabetta Garibaldi⁵, Adriana Faiella⁶, Alessandro Magli⁷, Domenico Cante⁸, Justyna Magdalena Waskiewicz⁹, Teodora Statuto¹⁰, Letizia Ferella¹¹, Barbara Noris Chiorda⁴, Luciana Rago¹², Paolo Ferrari¹³, Marco Gatti¹⁴, Cristina Piva², Tiziana Rancati¹⁵, Riccardo Valdagni¹⁵, Vittorio Luigi Vavassori³, Fernando Munoz¹¹, Giuseppe Sanguineti⁶, Nadia Gisella Di Muzio¹⁶, Claudio Fiorino¹, Cesare Cozzarini¹⁶

¹IRCCS San Raffaele Scientific Institute, Medical Physics, Milano, Italy; ²Ospedale degli Infermi, Radiotherapy, Biella, Italy; ³Cliniche Gavazzeni-Humanitas, Radiotherapy, Bergamo, Italy; ⁴Fondazione IRCCS Istituto Nazionale dei Tumori, Radiotherapy, Milano, Italy; ⁵A.O. SS. Antonio e Biagio, Radiotherapy, Alessandria, Italy; ⁶Istituto Nazionale dei Tumori "Regina Elena", Radiotherapy, Roma, Italy; ⁷Azienda Ospedaliero Universitaria S. Maria della Misericordia, Radiotherapy, Udine, Italy; ⁸Ospedale di Ivrea, Radiotherapy, Ivrea, Italy; ⁹Comprensorio Sanitario di Bolzano, Radiotherapy, Bolzano, Italy; ¹⁰Ospedale San Carlo, Biology, Potenza, Italy; ¹¹Ospedale Regionale Parini-AUSL Valle d’Aosta, Radiotherapy, Aosta, Italy; ¹²Ospedale San Carlo, Radiotherapy, Potenza, Italy; ¹³Comprensorio Sanitario di Bolzano, Medical Physics, Bolzano, Italy; ¹⁴Istituto di Candiolo - Fondazione del Piemonte per l'Oncologia IRCCS, Radiotherapy, Candiolo, Italy; ¹⁵Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program, Milano, Italy; ¹⁶IRCCS San Raffaele Scientific Institute, Radiotherapy, Milano, Italy

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Purpose or Objective

Intestinal toxicity (IT) after radiotherapy (RT) with pelvic nodal irradiation (PNI) for prostate cancer (PCa) may have a non-negligible impact on patients’ (pts) health-related quality of life (HRQoL). This work aims at identifying predictors of self-perceived decline of Social Domain 2 years after RT.

Material and Methods

A multi-Institute study recruited 886 pts between 2011 and 2021 and prospectively collected the Inflammatory Bowel Disease Questionnaire (IBDQ) at baseline, at RT mid-point and end, at 3 and 6 months and every 6 months up to 5 years. The 24-item Eysenck Personality Questionnaire Revised-Abbreviated (EPQR-A) and the 14-item Hospital Anxiety and Depression Scale (HADS) were also filled in by pts at baseline. The 32 IBDQ items (on a 1 to 7 scale, 1 corresponding to worse symptoms) pertain to four Domains: PNI-induced Bowel symptoms (BOWEL) and their impact on Emotional (EMOT), Social (SOCIAL) and Systemic (SYST) domains of HRQoL.

This analysis refers to 554 pts with complete baseline, 2-years (or 30 or 18 months, if missing) and at least one between RT mid-point and end questionnaires.

Thirty-one clinical, dosimetric and patient-reported covariates were considered for the prediction of the worst decline of Social Domain 2 years after RT as compared to baseline. The first decile of scores distribution was the event for Logistic Regression (LR).

Pts were first split into training (n=415) and validation (n=139) cohorts. Feature selection was performed by checking for any zero-variance covariate, standardizing the training set using Robust Scaling and balancing it via data augmentation and limiting variable redundancy.

Bootstrap resampling (1000 iterations) was carried out to identify the best combination of three most significant features in terms of p-values and AUC.

Goodness of fit was assessed by means of the Hosmer and Lemeshow (HL) test.

Results

The decile threshold value identifying pts (43/415 pts, 10.4%) with larger 2-year Social impairment was -1.4. The best three-variable model (p=0.0004) included Bowel Domain acute worsening compared to baseline, (p=0.049), Social Domain’s Score at baseline (p=0.0073) and adjuvant RT intent (p= 0.0059).

Odds Ratios (and 95% C.I.) of the variables were 0.66 (0.44-1.00), 2.07 (1.22-3.53) and 2.59 and (1.32-5.09), respectively.

The goodness of fit of the trained model was satisfactory (HL p-value=0.976).

In Fig. 1. the area under curve (AUC) of the ROC curves of the training (0.809) and the validation (0.721) sets showed the ability of the model's predicted values to distinguish between positive and negative cases.

Conclusion

The current model may help clinicians to identify those pts whose social activity could be more severely affected by treatment 2 years after RT with PNI. Results suggest that the risk of late relevant decline of SOCIAL Domain may be expected in pts with higher baseline SOCIAL score, more severe acute worsening of bowel symptoms and submitted to adjuvant RT.