Abstract 5773
Background
Anal Squamous Cell Carcinoma (ASCC) is radically treated by chemoradiotherapy (CRT). The use of DW-MRI as a predictive marker of outcome would enable early individualisation of treatment. We aimed to quantify the changes in mean apparent-diffusion-coefficient (ADCMean) between a DW-MRI at diagnosis and on fraction 8-10 of CRT as a biomarker for cellularity, and correlate these with outcome.
Methods
This prospective study recruited patients with ASCC between October 2014 and November 2017. DW-MRI was performed at diagnosis and after fraction 8-10 of radical CRT. A region of interest (ROI) was delineated for all primary tumours and any lymph nodes >2 cm on high-resolution T2 –weighted images and propagated to the ADC map. A pre-defined cut-off for percentage change in ADCMean (ΔADC) was set at < 20%. Complete response (CR) was assessed 3 months following completion of CRT. Routine clinical follow up data from patients were collected from NHS electronic systems.
Results
Twenty-three of 29 recruited patients underwent paired DW-MRI scans. The median (range) tumour volume was 13.6 cm3 (2.8 cm3 to 84.9 cm3). The median ΔADCMean between scans was 20.7% (95% CI: 12.7%, 34.1%). Nine of 23 (43%) patients had a change of ADCMean <20%. Two patients failed to achieve a CR, with ΔADCMean of 14.6% and 20.3%, respectively. On routine follow up, 2 further patients had relapsed, with ΔADCMean of -1.2% and 6.8%.
Conclusions
In a subset of patients, <20% ΔADCMean on DW-MRI between diagnosis and day 8-10 of CRT was observed. Four patients in the study demonstrated persistent or recurrent disease, all of whom demonstrated an ADC on or below the pre-specified cut-off. Further investigation of the predictive merit of DW-MRI change, and the optimum cut-off is needed in larger cohorts.
Clinical trial identification
NCT02145416.
Editorial acknowledgement
Legal entity responsible for the study
University of Oxford.
Funding
CRUK EPSRC Cancer Imaging Centre in Oxford, the CRUK Oxford Centre and the NIHR.M Hawkins is supported by Medical Research Council grant MC_UU_00001/2.
Disclosure
R. Muirhead: Honoraria (self), Fee for lecture: Boehringer Ingelheim. V. Goh: Research grant / Funding (self): Siemens. All other authors have declared no conflicts of interest.
Resources from the same session
5887 - Factors of importance in procuring tumoroids from colorectal liver metastasis biopsies for precision medicine.
Presenter: Lars Henrik Jensen
Session: Poster Display session 2
Resources:
Abstract
2196 - FUSAFE individual patient data meta-analysis (MA) to assess the performance of dihydropyrimidine dehydrogenase (DPD) gene polymorphisms for predicting grade 4-5 fluoropyrimidine (FP) toxicity
Presenter: Marie-Christine Etienne-Grimaldi
Session: Poster Display session 2
Resources:
Abstract
2859 - Treatments (tx) after progression to first-line FOLFOXIRI + bevacizumab (bev) in metastatic colorectal cancer (mCRC) patients (pts): A pooled analysis of TRIBE and TRIBE-2 studies by GONO.
Presenter: Daniele Rossini
Session: Poster Display session 2
Resources:
Abstract
3888 - Randomized phase III study of sequential treatment with capecitabine or 5-fluorouracil (FP) plus bevacizumab (BEV) followed by the addition with oxaliplatin (OX) versus initial combination with OX+FP+ BEV in the first-line chemotherapy for metastatic colorectal cancer: The C-cubed study
Presenter: Takeshi Nagasaka
Session: Poster Display session 2
Resources:
Abstract
1065 - Early tumour shrinkage (ETS), depth of response (DpR) and associated survival outcomes in patients (pts) with RAS wild type (WT) metastatic colorectal cancer (mCRC) classified according to Köhne prognostic category: retrospective analysis of the panitumumab (Pmab) PRIME study
Presenter: Andrea Sartore-Bianchi
Session: Poster Display session 2
Resources:
Abstract
1702 - Randomized phase II trial of CAPOX with planned oxaliplatin stop-and-go strategy as adjuvant chemotherapy after curative resection of colon cancer (CCOG-1302 study)
Presenter: Hiroyuki Yokoyama
Session: Poster Display session 2
Resources:
Abstract
5104 - A metabolomic recurrence score for risk-stratification of elderly patients (pts) with early colorectal cancer (eCRC)
Presenter: Samantha Di Donato
Session: Poster Display session 2
Resources:
Abstract
5285 - RAS mutant allele fraction in plasma predicts benefit to anti-angiogenic based first line treatment in metastatic colorectal cancer
Presenter: Giulia Martini
Session: Poster Display session 2
Resources:
Abstract
1790 - Impact of prophylactic systemic antibiotics (SA) on outcome of patients (pts) with RAS-wildtype (RAS-wt) metastatic colorectal carcinoma (mCRC) treated with cetuximab-based first-line therapy. Subgroup analysis of the german non-interventional study ERBITAG
Presenter: Stephan Sahm
Session: Poster Display session 2
Resources:
Abstract
3059 - Intraoperative chemotherapy with 5-FU for colorectal cancer patients receiving curative resection (IOCCRC): A randomized, multicenter, prospective, phase III trial
Presenter: Rongxin Zhang
Session: Poster Display session 2
Resources:
Abstract