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
2104 - Clinical implications of regorafenib-induced hypothyroidism in metastatic colorectal cancer refractory to standard therapies: A prospective evaluation
Presenter: Jwa Hoon Kim
Session: Poster Display session 2
Resources:
Abstract
2143 - Clinical impact of BRAF V600E mutations in patients (pts) with resectable solitary colorectal liver metastases (CRLM)
Presenter: Shin Kobayashi
Session: Poster Display session 2
Resources:
Abstract
3136 - Trifluridine/tipiracil in metastatic colorectal cancer: an updated multicentre real-world analysis on efficacy, safety and predictive factors.
Presenter: Chara Stavraka
Session: Poster Display session 2
Resources:
Abstract
4234 - Correlation between p53 expression and clinical outcome in RAS/BRAF wild type metastatic colorectal cancer patients receiving later-line irinotecan-cetuximab
Presenter: Eleonora Lai
Session: Poster Display session 2
Resources:
Abstract
4287 - Safety and effectiveness of aflibercept + FOLFIRI for the treatment of patients with metastatic colorectal cancer (mCRC): OZONE secondary analyses
Presenter: Ian Chau
Session: Poster Display session 2
Resources:
Abstract
1820 - A Phase Ib study of the safety and efficacy of atezolizumab (atezo) + bevacizumab (bev) + cobimetinib (cobi) in patients (pts) with metastatic colorectal cancer (mCRC)
Presenter: Johanna Bendell
Session: Poster Display session 2
Resources:
Abstract
5644 - Development and validation of a metastasis-associated immune prognostic model for concurrent metastatic colorectal cancer
Presenter: Zhiwen Luo
Session: Poster Display session 2
Resources:
Abstract
5697 - Prognostic role of blood cell count-based immuno-inflammatory parameters in the Valentino trial
Presenter: Giovanni Fuca
Session: Poster Display session 2
Resources:
Abstract
4704 - Evaluation of safety, immunogenicity and preliminary efficacy of PolyPEPI1018 vaccine in subjects with metastatic colorectal cancer (mCRC) with a predictive biomarker
Presenter: Joleen Hubbard
Session: Poster Display session 2
Resources:
Abstract
3266 - Morphology of tumor-associated macrophages dictates the prognosis of patients with colorectal liver metastases.
Presenter: Matteo Donadon
Session: Poster Display session 2
Resources:
Abstract