Verfasser: R. Bücker, G. Jaenke, F. Hartmann, T. Hansen, U. Schäfer A retrospective analysis. In this small patient, the kind of chemotherapy regimen appaers to have a signifcant influence on pathologic tumor regression after preoperative combined chemo radiotherapy of rectal cancer.

1. Effect of different chemotherapy regimens on
pathological response in the preoperative combined
chemo radiotherapy of rectal adenocarcinomas:
A retrospective analysis
R. Bücker1
| G. Jaenke1
| F. Hartmann2
| T. Hansen3
| U. Schäfer1
Klinikum Lippe GmbH | Radiation Oncology Department
Rintelner Straße 85 | 32657 Lemgo | Germany | Phone +49 (0) 52 61 . 26 - 46 21 | www.klinikum-lippe.de
Background
Standard treatment of advanced stage rectal cancer consists of neoadjuvant chemo
radiotherapy followed by surgery. Some studies show the prognostic relevance of
Tumor Regression Grading (TRG). The purpose of the study was to investigate the
influence of the different chemotherapy modalities on TRG.
Material and methods
We analyzed a total of 80 patients (pts) with locally advanced stage rectal adenocar-
cinoma, treated at the Radiation Oncology Department of Klinikum Lippe Deutsch-
land between January 2013 and January 2017. In all cases, treatment consisted of
preoperative radio chemotherapy. Radiotherapy was delivered in daily single frac-
tions of 1.8 Gy to a total dose of 50.4 Gy in 28 fractions (5 fractions per week) to the
lower pelvis. Chemotherapy was administered by various oncologists. Three diffe-
rent regimens were used: 5-Fluorouracil 1000 mg/m2
week 1 and 5 (5-FU W1+W5),
5-Fluorouracil 225mg/m2
as a continuous infusion (5-FU cont.) or Capecitabine 825
mg/m2
twice daily. After surgery Tumor Regression Grading (TRG) according to the
Dworak system (grade 0 – 1 versus grade 2 versus grade 3 – 4; Figure 1 – 4 show hi-
stological samples) was assessed in all cases and compared with the different che-
motherapy regimens. To exclude bias of other variables, preoperative histological
grading, preoperative UICC-stage, age and treatment interruption (more than 10 %
of treatment time) were also included in this analysis. To determine whether there
is a significant difference between the expected frequencies and the observed fre-
quencies, a chi-squared test was used.
Figure 1: RG Dworak grade 1
Figure 3: TRG Dworak grade 3
Figure 2: TRG Dworak grade 2
Figure 4: TRG Dworak grade 4
1
Department of Radiotherapy, Lippe Clinical Center
2
Department of Hematology and Oncology, Lippe Clinical Center
3
Department of Pathology, Lippe Clinical Center
Results
In 35/80 (44 %) pts, chemotherapy consisted of 5-FU W1+W5, in 20/80 (25 %) pts
of Capecitabine, and in 25/80 (31 %) pts of 5-FU cont.
Of all patients, 13/80 (16 %) pts achieved TRG grade 0 – 1, 40/80 (50 %) pts TRG
grade 2 and 27/80 (34 %) pts TRG grade 3 – 4 (table 1). Compared with all tested
variables, only the variable „chemotherapy regime“ has a significant influence on
tumor regression (table 2).
Conclusion
In this small patient cohort, the kind of chemotherapy regimen appears to have a significant influence on pathologic tumor regression after preoperative combined
chemo radiotherapy of rectal cancer, with the best results of 5-Fluorouracil 225 mg/m2
as a continuous infusion. Further investigations seem to be useful.
Table 1: Tumor Regression Grading (TRG) according to the Dworak system after neoadjuvante therapy
Table 2: Tumor Regression Grading (TRG) according to the Dworak system after neoadjuvante
therapy: All tested variables