ESTRO 2022

Session Item

Sunday

May 08

16:55 - 17:55

Room D3

Oligometastatic disease

Co-Chair: , Austria;

Chair: Jonas Willmann, Switzerland

Session Code: 2510

Session Type: Proffered Papers

Track: Clinical

17:25 - 17:35

A pREDictive model of polymetastatic disease on oligometastatic colorectal cancer: the RED LaIT-SABR

Luca Nicosia, Italy

Presentation Number: OC-0602

Abstract

Abstract Title:

A pREDictive model of polymetastatic disease on oligometastatic colorectal cancer: the RED LaIT-SABR

Authors:

Luca Nicosia¹, Davide Franceschini², Francesca Perrone Congedi³, Franco Casamassima⁴, Marianna Alessandra Gerardi⁵, Michele Rigo¹, Rosario Mazzola¹, Marco Perna⁶, Vieri Scotti⁷, Andrei Fodor⁸, Aurelia Iurato⁹, Francesco Pasqualetti¹⁰, Giovanni Gadducci¹⁰, Silvia Chiesa¹¹, Rita Marina Niespolo¹², Alessio Bruni¹³, Giulia Alicino¹³, Luca Frassinelli¹³, Paolo Borghetti¹⁴, Alessandro Di Marzo¹⁵, Andrea Ravasio¹⁶, Berardino De Bari¹⁷, Matteo Sepulcri¹⁸, Dario Aiello¹⁹, Gianluca Mortellaro²⁰, Claudia Sangalli²¹, Marzia Franceschini²¹, Giampaolo Montesi²², Francesco Maria Aquilanti²³, Gianluigi Lunardi²⁴, Riccardo Valdagni²¹, Ivan Fazio¹⁹, Luigi Corti²⁵, Vittorio Vavassori²⁶, Ernesto Maranzano²⁷, Stefano Maria Magrini¹⁴, Stefano Arcangeli¹³, Vincenzo Valentini¹¹, Fabiola Paiar¹⁰, Sara Ramella⁹, Nadia Gisella Di Muzio⁸, Lorenzo Livi⁶, Barbara Alicja Jereczek-Fossa⁵, Mattia Falchetto Osti³, Marta Scorsetti²⁸, Filippo Alongi²⁹

¹IRCCS Sacro Cuore Don Calabria Hospital, Cancer Care Center, Advanced Radiation Oncology Department, Negrar, Italy; ²IRCCS Humanitas Research Hospital, Radiation Oncology Department, Milan, Italy; ³"Sapienza" University, Sant'Andrea Hospital, Department of Radiation Oncology, Rome, Italy; ⁴Ecomedica Radioterapia, Radioterapia, Empoli, Italy; ⁵IEO European Institute of Oncology IRCCS, Division of Radiation Oncology, Milan, Italy; ⁶Azienda Ospedaliera Universitaria Careggi, University of Florence, Radiation Oncology Unit, Florence, Italy; ⁷Azienda Ospedaliera Universitaria Careggi, University of Florenc, Radiation Oncology Unit, Florence, Italy; ⁸IRCCS San Raffaele Scientific Institute, Department of Radiation Oncology, Milan, Italy; ⁹Campus Bio-Medico University, Radiation Oncology, Rome, Italy; ¹⁰Pisa University Hospital, Radiation Oncology Unit, Pisa, Italy; ¹¹Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, UOC di Radioterapia Oncologica, Rome, Italy; ¹²Azienda Ospedaliera S. Gerardo, Department of Radiation Oncology, Monza, Italy; ¹³University Hospital of Modena, Radiotherapy Unit, Modena, Italy; ¹⁴ASST Spedali Civili di Brescia - Brescia University, Radiation Oncology Department, Brescia, Italy; ¹⁵S. Maria Hospital, Terni, Radiation Oncology Centre, Terni, Italy; ¹⁶Humanitas Gavazzeni, Bergamo, Radiotherapy Unit, Bergamo, Italy; ¹⁷University Hospital of Besançon, Besançon, Radiation Oncology Department, Besançon, France; ¹⁸Veneto Institute of Oncology IOV-IRCCS, Padua, Radiation Oncology Unit, Padua, Italy; ¹⁹Casa di Cura Macchiarella, Radiotherapy Unit, Palermo, Italy; ²⁰ARNAS Ospedale Civico, Department of Radiation Oncology, Palermo, Italy; ²¹Fondazione IRCCS Istituto Nazionale dei Tumori, Department of Radiation Oncology 1, Milan, Italy; ²²ULSS5, Radiotherapy Unit , Rovigo, Italy; ²³Marrelli Hospital, Radiotherapy Marrelli Hospital, Crotone, Italy; ²⁴IRCCS Sacro Cuore Don Calabria Hospital, Medical Analysis Laboratory, Negrar, Italy; ²⁵Veneto Institute of Oncology IOV-IRCCS, Radiation Oncology Unit, Padua, Italy; ²⁶Humanitas Gavazzeni, Radiotherapy Unit, Bergamo, Italy; ²⁷S. Maria Hospital, Radiation Oncology Centre, Terni, Italy; ²⁸IRCCS Humanitas Research Hospital, Radiotherapy, Milan, Italy; ²⁹IRCCS Sacro Cuore Don Calabria Hospital, Advanced Radiation Oncology Department, Negrar, Italy

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Purpose or Objective

Aim: stereotactic ablative radiotherapy (SABR) has been shown to increase survival in oligometastatic patients. Few studies actually depicted the oligometastatic disease (OMD) evolution after SABR. There is few evidence on which patient will remain disease-free after SABR and which will develop rapidly a polymetastatic disease (PMD) therefore apart from the number of active metastases, there are no clues on which proven factor should be taken into account for prescribing local treatment in OMD. The aim of the present preliminary study based on a large retrospective database is to identify predictive factors of polymetastatic evolution in lung oligometastatic colorectal cancer patients to tailor SABR prescription.

Material and Methods

Methods: the study involved 23 centers, and was approved by the Ethical Committee (Prot. Negrar 2019-ZT). The data of 367 lung oligometastatic patients were reported. Primary end-point was the time to the polymetastatic conversion (tPMC), defined as the first occurrence of >5 simultaneous new metastases after SABR. Additionally, oligometastases number and cumulative gross tumor volume (GTV) were used as combined predictive factors of tPMC. Oligometastases number was stratified as 1, 2-3, and 4-5; cumulative GTV was dichotomized to the median value of 15.6 cc. The 6 groups are reported in table 1.

Table 1. group stratification for the analyzed patients

		Median tPMC (months)
1 metastasis	cumGTV <15.6 cc	35.8
1 metastasis	cumGTV >15.6 cc	19.3
2-3 metastases	cumGTV <15.6 cc	34.1
2-3 metastases	cumGTV >15.6 cc	12
4-5 metastases	cumGTV <15.6 cc	5.6
4-5 metastases	cumGTV >15.6 cc	3.7

Results

Results: the median tPMC in the overall population was 26.1 months. The median tPMC stratified for the 6 groups is reported in table 1 (p=0.00). After data checking we were able to classify patients according to their median tPMC in 4 risk classes: low risk (group 1+3), favorable intermediate (group 2), unfavorable intermediate (group 4), high risk (group 5+6). The median tPMC for the 4 risk classes was: 34.6, 19.3, 12, and 6.7 months, respectively (figure 1; p=0.00).

Figure 1. tPMC stratified for risk classes

Conclusion

Conclusion: the present study identified predictive factors of polymetastatic evolution after SABR in lung oligometastatic colorectal cancer. The results demonstrated that the sole numerical number is not enough to define the OMD since patients identified as oligometastatic from a numerical point of view might rapidly progress to the PMD when the cumulative tumor volume is high. A tailored approach in SABR prescription should be pursued considering the expected disease evolution after SABR, with the aim to avoid unnecessary treatment and side effect in those at high risk of polymetastatic spread, and maximize local treatment in those with a favorable disease evolution.