Vienna, Austria

ESTRO 2023

Session Item

Poster (Digital)
Predictors of Patient-Reported decline in Social activity 2-years after WPRT for prostate cancer
Cesare Cozzarini, Italy


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

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.


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.


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.