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S172
ESTRO 36
_______________________________________________________________________________________________
Purpose or Objective
As result of the aging population, increasing life
expectancy and increasing rectal cancer incidence, more
elderly patients will undergo treatment for rectal cancer.
Neoadjuvant (chemo)radiotherapy and surgery are
associated with considerable morbidity and mortality. In
this study we compared treatment course, postoperative
complications and quality of life (QoL) in older versus
younger rectal cancer patients.
Material and Methods
All patients within the Dutch prospective colorectal
cancer cohort with primary rectal cancer referred for
Radiotherapy at the UMC Utrecht between February 2013
and January 2016 were selected. QoL was assessed with
the EORTC-C30 questionnaire before start of neoadjuvant
treatment and at 3, 6 and 12 months afterwards. Patients
were divided into elderly (≥70 years) and non-elderly (<70
years). Differences in QoL were analyzed with generalized
estimation equations, adjusted for baseline score, and
stratified according to presence of postoperative
complications.
Results
A total of 115 elderly (33.3%) and 230 non-elde rly (66.6%)
patients were included. Compared to non-eld erly, elderly
patients were less often male (62.6% vs. 75.2%), had more
often previous abdominal surgery (40.9% vs. 30.0%) and
presence of comorbidities (80.0% vs. 59.1%). Elderly were
more likely to undergo short-course radiation with delayed
surgery and less likely to undergo chemoradiation (resp.
19.1% and 39.1% vs. 6.1% and 62.6% in non-elderly,
p<.001). Surgery was performed equally in both groups
(83.5% in elderly vs. 87.8% in non-elderly, p=.318). The
reasons for no surgical treatment, included disease
progression and poor performance status in elderly, and
disease progression or a wait-and-see policy in non-
elderly. No differences were observed in postoperative
complications between elderly and non-elderly (surgical-
and non-surgical complication rate 36,5% vs. 34,7%,
p=.780), neither when stratified for type of neoadjuvant
therapy or surgical procedure. Trends of functional QoL
domains were similar between elderly and non-elderly
during the first year after diagnosis with lowest scores at
3 and/or 6 months. In elderly, postoperative
complications had a stronger impact on physical- and role
functioning (at 6 months resp. MD -19.2 and -18.4, relative
to non-elderly with postoperative complications) (Figure
1). In a sensitivity analysis, comparing patients >80 years
with younger patients, comparable results were observed.
Conclusion
Elderly are more often treated by less invasive
treatments, which deviates from the standard treatment.
Compared with younger patients, elderly have similar
postoperative complication rates. Nevertheless, the
impact of postoperative complications on physical- and
role functioning is stronger in elderly than in younger
patients. These results suggest a need to predict the
frailest elderly patients who are at risk for postoperative
morbidity and hereby an impaired quality of life.
PV-0328 Factors associated with complete response
after brachytherapy for rectal cancer; the HERBERT
study.
E.C. Rijkmans
1
, R.A. Nout
1
, E.M. Kerkhof
1
, A. Cats
2
, B.
Van Triest
3
, A. Inderson
4
, R.P.J. Van den Ende
1
, M.S.
Laman
1
, M. Ketelaars
1
, C.A.M. Marijnen
1
1
Leiden University Medical Center LUMC, Department of
Radiotherapy, Leiden, The Netherlands
2
The Netherlands Cancer Institute, Department of
Gastroenterology and Hepatology, Amsterdam, The
Netherlands
3
The Netherlands Cancer Institute, Department of
Radiotherapy, Amsterdam, The Netherlands
4
Leiden University Medical Center LUMC, Department of
Gastroenterology and Hepatology, Leiden, The
Netherlands
Purpose or Objective
The HERBERT study was performed to examine the
feasibility of a high hose rate endorectal brachytherapy
(HDREBT) boost after external beam radiotherapy (EBRT)
in elderly patients with rectal cancer who were unfit for
surgery. The primary results and long term clinical
outcomes have been presented at ESTRO 2014 and 2016.
With rising interest for organ preservation, the role of
definitive (chemo)radiotherapy becomes increasingly
important. This current analysis evaluates factors that are
associated with a complete response to treatment.
Material and Methods
A dose finding feasibility study was performed from 2007
to 2013 in inoperable rectal cancer patients. Patients
received 13x3 Gy EBRT followed by three weekly
applications HDREBT of 5 to 8 Gy per fraction. Clinical
target volume (CTV) for HDREBT was defined as residual
scarring or tumor after EBRT. Clinical tumor response was
evaluated based on digital rectal examination and
endoscopy (MRI or biopsy was not routinely performed).
Complete response was determined after serial
assessments.
Patient,
tumor
and
treatment
characteristics of complete responders (CR) were
compared to non-complete responders (nCR) using Chi-
square test and the independent samples t-test.
Results
Of the 38 patients included in the study 33 were evaluable
for response evaluation. Seven were treated with 5 Gy per
fraction, four with 6 Gy, 12 with 7 Gy and 10 with 8 Gy per
fraction. In total 20 patients achieved a complete
response. Baseline patient characteristics (age, ASA, WHO
and co-morbidity) and tumor-characteristics (T-stage, N-
stage, cranio-caudal length of the tumor and distance
from anal verge) were not associated with response to
treatment. A trend was observed in complete response
between dose levels; 2/ 7 treated with 5 Gy per fraction;
1/4 with 6 Gy; 9/12 with 7 Gy and 8/10 with 8 Gy per
fraction (p=0.05). The actual planned D98 (dose to 98% of
the CTV) was however not significantly different between
patient with a complete response and no complete
response: 6.25 Gy (range 3.8-8.3 Gy) vs. 5.98 Gy (range
1.2-8.8 Gy) respectively (p=0.63).
Endoscopic evaluation of response after EBRT was
significantly associated with the overall response rate.
Seven patients already had a CR after EBRT, whereas
13/21 patients (62%) with a partial response after EBRT
achieved a CR. None of the five patients with stable
disease achieved a complete response (p=0.002). Mean
residual volume and thickness of residual scarring or tumor
after EBRT were significantly lower in complete
responders (see Figure). In addition, tumors encompassing
less than 1/3 of the circumference were more likely to
achieve a complete response than larger tumors (70% vs
17% respectively, p=0.025).