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
3425 - Feasibility and impact of prospective DPYD screening in the Irish population
Presenter: Mohammed Zameer
Session: Poster Display session 2
Resources:
Abstract
1972 - Diet-derived metabolites and the risk of colorectal cancer: a nested case-control study in a population-based cohort, the Singapore Chinese Health Study
Presenter: Dawn Chong
Session: Poster Display session 2
Resources:
Abstract
4103 - Loss of subcutaneous adipose tissue during chemotherapy predicts reduced survival in patients with incurable colorectal cancer undergoing palliative therapy
Presenter: Erin Stella Sullivan
Session: Poster Display session 2
Resources:
Abstract
4309 - Obese and overweight is associated with better prognosis in metastatic colorectal cancer patients treated with bevacizumab.
Presenter: Bozena Cybulska-Stopa
Session: Poster Display session 2
Resources:
Abstract
3554 - Patient characteristics associated with poor performance status, ECOG 2-3, and effect on survival in 1086 Finnish metastatic colorectal cancers (mCRC) nationwide (prospective RAXO study)
Presenter: Pia Österlund
Session: Poster Display session 2
Resources:
Abstract
4572 - Discovery and Diagnosis of Metastatic Colorectal Cancer (mCRC) in the Real World: Final Results from a European Survey
Presenter: Iga Rawicka
Session: Poster Display session 2
Resources:
Abstract
4783 - Adherence to recommended intake of calcium and colorectal cancer risk in the HEXA study
Presenter: Jeeyoo Lee
Session: Poster Display session 2
Resources:
Abstract
5106 - Body size, sex and sidedness of incident colorectal cancer in a prospective Swedish cohort study
Presenter: Christina Siesing
Session: Poster Display session 2
Resources:
Abstract
3364 - Middle East & North Africa Registry to characterize RAS mutation status and tumor specifications in recently diagnosed patients with metastatic colorectal cancer (MORE-RAS Study)
Presenter: Mohamed Oukkal
Session: Poster Display session 2
Resources:
Abstract
3668 - Patient Demographics and Management Landscape of Metastatic Colorectal Cancer in the Third Line Setting: real-world data in an Australian Population
Presenter: Sandy Tun Min
Session: Poster Display session 2
Resources:
Abstract