ESTRO 36 Abstract Book

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S171 ESTRO 36
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biological agents and tailor treatment-adaptive strategies
based on initial response in early phase trials in the era of
personalized medicine. Further examination and
validation of TRG as surrogate for DFS based on large
independent phase III trials is needed and should be
enhanced for its implementation in the regular pathologic
work-up.
PV-0326 Time to surgery and pCR after neoadjuvant
CRT in rectal cancer: a population study on 2113
patients
G. Macchia1, M. Gambacorta2, G. Chiloiro2, G. Mantello3,
A. De Paoli4, G. Montesi 5, A. Sainato6, M. Lupattelli7, L.
Caravatta8, F. Perrotti9, M. Rosetto10, F. Filippone11, R.
Niespolo12, M. Osti13, L. Belgioia 14, C. Boso 15, A.
Fontana 16, S. Parisi17, A. Galardi18, L. Turri 19, P.
Sciacero20, L. Giaccherini21, C. Masciocchi2, A. Morganti21,
V. Valentini2
1 Fondazione di Ricerca e Cura “Giovanni Paolo II,
Radiotherapy Unit, Campobasso, Italy
2 Fondazione “Policlinico Gemelli”- Università Cattolica
S. Cuore, Department of Radiotherapy, Roma, Italy
3 Azienda Ospedaliero Universitaria- Ospedali Riuniti,
Radiotherapy Unit, Ancona, Italy
4 Oncological Referral Center, Radiation Oncology
Department, Aviano, Italy
5 ULSS18, Radiotherapy Unit, Rovigo, Italy
6 University Hospital, Radiotherapy Unit, Pisa, Italy
7 'S. Maria della Misericordia' Hospital, Radiotherapy
Unit, Perugia, Italy
8 'A. Businco' Regional Oncological Hospital, Radiation
Oncology Department, Cagliari, Italy
9 'SS Annunziata' Hospital- 'G. D'Annunzio' University,
Radiotherapy Unit, Chieti, Italy
10 Ospedale Belcolle, Radiotherapy Unit, Viterbo, Italy
11 Azienda ospedaliera Papa Giovanni XXIII, Radiotherapy
Unit, Bergamo, Italy
12 Azienda Ospedaliera S. Gerardo-, Radiotherapy Unit,
Monza, Italy
13 Facoltà di Medicina e Psicologia- Università Sapienza,
Department of Radiation Oncology, Roma, Iceland
14 AOU IRCCS San Martino- IST National Cancer Research
Institute, Radiotherapy Unit, Genova, Italy
15 Veneto Institute of Oncology-IRCCS, Radiotherapy and
Nuclear Medicine Unit, Padova, Italy
16 Ospedale S.M. Goretti, Radiotherapy Unit, Latina, Italy
17 Casa Sollievo della Sofferenza- IRCCS-CSS,
Radiotherapy Unit, San Giovanni Rotondo, Italy
18 Florence University, Department of Radiotherapy,
Firenze, Italy
19 'Maggiore della Carità' Hospital, Radiotherapy Unit,
Novara, Italy
20 ASL TO4- General Hospital, Radiotherapy Unit, Ivrea,
Italy
21 Policlinico Universitario S. Orsola Malpighi,
Radiotherapy, Bologna, Italy
Purpose or Objective
Population based electronic health records, provide a
means of obtaining information on patient characteristics
and outcomes that can then be compared with the more
selected populations recruited within randomized
controlled trials. Aim of this analysis was to
retrospectively evaluate the difference in terms of
pathologic complete response (pCR) according to time
elapsed between chemoradiation (CRT) and surgery on a
large unselected real-life dataset of locally advanced
rectal cancer (LARC) patients.
Material and Methods
A multicentre retrospective cohort study of LARC patients
among 21 Italian Radiotherapy Institutions was performed.
3D conformal or intensity-modulated radiation treatment
was required as inclusion criteria. Surgery was performed
according to the principles of total mesorectal excision
(TME). Patients were stratified according to 3 different
time intervals. The 1st group included 305 patients
undergone TME within 6 weeks, the 2nd group included
1610 patients undergone TME within 7-12 weeks, and the
3rd group included 198 patients undergone TME within 13
or more weeks after CRT, respectively.
Results
Data on 2113 patients treated between 1997 and 2016
were retrieved from the historical database of
gastrointestinal radiation oncologists joined into the
study. Recruitment in the period investigated by the study
took place as follows: 183 patients from 1997 to 2002, 550
from 2003 to 2008, and the majority, 1380, from 2009 to
2016. Five hundred and eighty two patients had stage II
(T3–4, N0) and 1531 had stage III (any T, N1–2) histological
proven invasive rectal adenocarcinoma. A CRT schedule
with one (1600 pts) or 2-drugs was administered (513 pts).
Overall, pCR were 468 (22%). Among the 2113 assessable
patients the proportion of patients achieving a pCR
increased according with time interval, as follows: 12.4%
(1st group), 22.9% (2 nd group), and 30.8% (3rd group)
(p<0.001, ANOVA test), respectively. The 1st group had a
pCR odds ratio of 0.47 compared to 2nd group, while the
latter had a pCR odds ratio of 0.66 compared to 3rd group.
Moreover, 1st group had a pCR odds ratio of 0.31 compared
to 3rd group. The rate of complete response increments for
each week of waiting was 1.5% (about 0.2%/die) . At
univariate analysis, time interval (p<0.001), radiotherapy
dose (>5040 cGy; p=0.013), and clinical tumor stage
(p=0.029) were significantly correlated to pCR. The
positive impact of time interval (p<0.001) and clinical
tumor stage (p=0.038) were confirmed by multivariate
analysis, in agreement with the literature data (Table 1).
Conclusion
We confirmed on a population-level that lengthening the
interval (>13 weeks) from CRT to surgery improves the pCR
in comparison to historic data, possibly due to technical
improvement of radiotherapy such as the ability of high-
precision dose delivery and real-time knowledge of the
target volume location.
PV-0327 The effect of postoperative complications on
Quality of Life in elderly rectal cancer patients
A.M. Couwenberg 1, F.S.A. De Beer1, M.P.W. Intven1, M.E.
Hamaker 2, W.M.U. Van Grevenstein3, H.M. Verkooijen4
1UMC Utrecht, Radiotherapy, Utrecht, The Netherlands
2Diakonessenhuis, Geriatrics, Utrecht, The Netherlands
3UMC Utrecht, Surgery, Utrecht, The Netherlands
4UMC Utrecht, Imaging Division, Utrecht, The
Netherlands