Abstract 425P
Background
A complete tumor response to neoadjuvant chemo-radiation (CRT) for locally advanced rectal cancer (LARC) is associated with better outcomes, but it is achieved in only 20-30% of patients (pts). The potential role of concomitant medications in addition to CRT has been evaluated in many studies to enhance response rate, but data are not definitive. In this multicentric, retrospective study, we investigated the influence of various concomitant medications on outcomes in this setting of pts.
Methods
246 pts treated at Azienda Ospedaliero-Universitaria of Modena, University of Parma, and Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori from 2003 to 2018 were retrospectively identified. Demographical and clinicopathological data of potential interest were collected. Odds Ratio (OR) was used to assess the association between the use of concomitant drugs and outcomes (Dworak tumor regression grade [TRG] and disease-free survival [DFS]).
Results
All pts received neoadjuvant CRT. Of them, 15.8% were taking antihypertensive drugs, 3.7% statins, 1.2% antiplatelet drugs, and 1.6% antidiabetic drugs. Moreover, 30.5% of pts were taking ≥2 of these drugs simultaneously. Roughly 40% of pts have experienced CRT-related toxicity, leading to a dose reduction or treatment discontinuation in 27% of cases. Of the 221 surgical specimens available, a Dworak TRG score 3-4 was achieved in 30.7% of cases. At both univariate and multivariate analysis, we found an association between statins and a Dworak 3-4 (OR 8.78, p=0.01). Furthermore, statins were also significantly associated with more frequently CRT-related toxicity (OR 2.39, p=0.0098) and a more frequent chemotherapy dose reduction or discontinuation (OR 2.26, p=0.03). No correlations were found between the use of the evaluated drugs and the DFS.
Conclusions
Despite a higher frequency of chemotherapy interruption or dose reduction and radiotherapy interruption, in this series of pts with LARC treated with neoadjuvant CRT, the concomitant use of statins proved to be associated with better tumor regression, according to the Dworak system. Larger prospective trials are awaited to confirm this hypothesis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.