3511 Background: Radiotherapy reduces local recurrence (LR) when combined with surgery in resectable rectal cancer. The Medical Research Council CR07 trial was designed to compare two different radiotherapy policies when combined with mesorectal excision. Methods: Patients with operable non-metastatic adenocarcinoma of the rectum were randomised to either routine pre-op short course radiotherapy [25Gy/5F] (PRE) or selective post-op chemoradiotherapy (POST) for patients with involvement of the circumferential resection margin (CRM) - [45Gy/25F + 5fluorouracil]. Results: A total of 1350 patients were randomised from 52 centres in the UK, Canada, New Zealand and South Africa between March 1998 and August 2005. Median follow-up is 3 years. Patients (73% male, median age 65 years, 79% PS0) were well balanced between the 2 arms. 595 of 674 (88%) of the pre-op group received their allocated treatment. Of the 676 patients allocated to the selective post-op chemoradiotherapy arm, 73 (11%) were CRM +ve and 51 of these (70%) received chemoradiotherapy. Post operative chemotherapy was received by 85% of patients with stage III disease. At the time of analysis 23 PRE and 61 POST patients had confirmed LR, 96 and 106 patients respectively distant metastases, and 115 and 146 respectively had died. The 3 year rates for LR (primary end point) were 4.7% and 11.1% for PRE and POST groups respectively (HR 2.47, 95% CI 1.61–3.79), for disease free survival 79.5% and 74.9% (HR 1.31, 95% CI 1.02–1.67) and for overall survival 80.8% and 78.7% (HR 1.25, 95% CI 0.98–1.59. The LR benefit in favour of PRE was consistent for tumours 0–5,5–10 and >10cm from the anal verge (HR 2.00, 2.14 and 4.97 respectively). Further subset analysis based on TNM stage and operation performed will be presented. Conclusions: These preliminary results indicate that routine short course pre-operative radiotherapy results in a signifcant reduction in local recurrence and improved disease free survival at 3 years when compared with a highly selective post operative approach. No significant financial relationships to disclose.

3512 Background: The MRC CR07 trial compared routine short course pre-operative radiotherapy (PRE) with selective post-operative chemo-radiation if there was involvement of the circumferential resection margin (CRM) (POST) and included a prospective pathological assessment of the quality of resection of the surgical specimen. Methods: A total of 1350 patients were randomised from 52 centres between March 1998 and August 2005. Median follow-up is 3 years. Trial pathologists were trained in histopathological assessment and reporting of the involvement of the CRM and plane of surgery (PoS) according to pre-set criteria describing the plane of dissection (Grade 1-muscularis plane: 2-intramesorectal plane: 3-mesorectal plane). 1232 patients were prospectively assessed for CRM and 1119 for PoS. Results: The CRM was involved (tumour ≤1mm) in 139 (11%) of resected specimens, and for these patients the 3-year local recurrence (LR), disease-free survival (DFS) and overall survival rates were 18%, 50% and 57%. For the 1093 patients with CRM-ve the respective rates were 7%, 81% and 84%. LR and DFS rates were associated with PoS (log-rank test p=0.0019 and p=0.0506 respectively), and in addition there was clear evidence of a reduction in LR and improvement in DFS rates in favour of PRE for all grades of quality of surgical assessment as shown in the table . Conclusions: The results indicate a strong association between the quality of surgery and the rates of local recurrence and disease-free survival, as well as a clear benefit from the addition of PRE to all grades of surgical dissection. Thus for patients with rectal cancer short-course pre-operative radiotherapy and good quality surgery can almost completely eliminate local recurrence. [Table: see text] No significant financial relationships to disclose.

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IntroductionSymptoms alone are poor predictors of underlying colonic pathology.1 Yield of significant bowel disease (SBD), [colorectal cancer (CRC), high risk adenoma (HRA, defined as ≥3 or any ≥1 cm) and inflammatory bowel disease (IBD)] is low in patients referred for colonoscopy from primary care at 14%.2 We have shown that undetectable Faecal Haemoglobin (fHb) as measured by a faecal immunochemical test (FIT) is a good rule-out test for SBD.2,3 We introduced FIT tests to primary care in NHS Tayside from 7th December 2015 and report the impact on referral rates and the yield of SBD at colonoscopy from data collected up to 30th September 2016.MethodPatients in primary care with new bowel symptoms were encouraged to complete a FIT in addition to blood count and renal function check. FIT tests were analysed in Blood Sciences (HMJACKarc, Kyowa Medex Co. Ltd., Japan) to give fHb within a range of <10 to>400 µg Hb/g faeces. Referral rates with FIT were examined along with clinical findings at colonoscopy.Results4261 FIT kits were analysed (median age 64 years (range: 2–98, IQR: 51–75), 56% female). 3246 (76%) had undetectable fHb, 911 (21%) had detectable fHb and 2.4% were untestable. 1988 patients completed a FIT but were not referred, with 1855 (93.3%) having undetectable fHb. Referrals to the Colorectal Service were 14% lower than in the corresponding time period of the preceding year. 3512 patients were referred; 1925 (55%) had completed a FIT. Of the 924 patients with a FIT result plus colonoscopy, 43% had undetectable FIT, 41% detectable up to 400 µg Hb/g faeces and 16%>400 µg Hb/g faeces. There were 203 cases of SBD (22%); 58 CRC, 87 HRA, 58 new cases of IBD. 33% of those with any fHb had SBD compared with 7% of those with undetectable fHb. Furthermore, of 150 patients who had fHb >400 µg Hb/g faeces, 88 (55%) had SBD.ConclusionUndetectable fHb is offering reassurance that SBD is unlikely and referrals to the Colorectal Service have reduced. At colonoscopy, yield of SBD has increased and is highest in those with detectable fHb. FIT testing is an essential adjunct to the history, examination and blood tests in the assessment of bowel symptoms.References. Jellema P, van der Windt DAWM, Bruinvels DA, et al. Value of symptoms and additional diagnostic tests for colorectal cancer in primary care; systematic review and meta-analysis. BMJ2010;340:c1269.. Mowat C, Digby J, Strachan JA et al. Faecal haemoglobin and faecal calprotectin as indicators of bowel disease in patients presenting to primary care with bowel symptoms. Gut 2016;65(9):1463–9.. McDonald PJ, Digby J, Innes C et al. Low faecal haemoglobin concentration potentially rules out significant colorectal disease. Colorectal Dis 2013;15:e151-9.Disclosure of InterestNone Declared

Professor RJC Steele discusses the implications of a national colorectal cancer screening programme for practice nurses