• Increasing late stage colorectal cancer and rectal cancer mortality demonstrates the need for screening: a population based study in Ireland, 1994-2010

      Clarke, Nicholas; McDevitt, Joseph; Kearney, Patricia M; Sharp, Linda (2014-05-13)
      Abstract Background This paper describes trends in colorectal cancer incidence, survival and mortality from 1994 to 2010 in Ireland prior to the introduction of population-based screening. Methods We examined incidence (National Cancer Registry Ireland (NCRI) and mortality (Central Statistics Office) from 1994 to 2010. Age standardised rates (ASR) for incidence and mortality have been calculated, weighted by the European standard population. Annual percentage change was calculated in addition to testing for linear trends in treatment and case fraction of early and late stage disease. Relative survival was calculated considering deaths from all causes. Results The colorectal cancer ASR was 63.7 per 100,000 in males and 38.7 per 100,000 in females in 2010. There was little change in the ASR over time in either sex, or when colon and rectal cancers were considered separately; however the number of incident cancers increased significantly during 1994-2010 (1752 to 2298). The case fractions of late stage (III/IV) colon and rectal cancers rose significantly over time. One and 5 year relative survival improved for both sexes between the periods 1994-2008. Colorectal cancer mortality ASRs decreased annually from 1994-2009 by 1.8% (95% CI -2.2, -1.4). Rectal cancer mortality ASRs rose annually by 2.4% (95% CI 1.1, 3.6) and 2.8% (95% CI 1.2, 4.4) in males and females respectively. Conclusions Increases in late-stage disease and rectal cancer mortality demonstrate an urgent need for colorectal cancer screening. However, the narrow age range at which screening is initially being rolled-out in Ireland means that the full potential for reductions in late-stage cancers and incidence and mortality are unlikely to be achieved. While it is possible that the observed increase in rectal cancer mortality may be partly an artefact of cause of death misclassification, it could also be explained by variations in treatment and adherence to best practice guidelines; further investigation is warranted.
    • Predicting response to vascular endothelial growth factor inhibitor and chemotherapy in metastatic colorectal cancer

      Martin, Petra; Noonan, Sinead; Mullen, Michael P; Scaife, Caitriona; Tosetto, Miriam; Nolan, Blathnaid; Wynne, Kieran; Hyland, John; Sheahan, Kieran; Elia, Giuliano; et al. (2014-11-27)
      Abstract Background Bevacizumab improves progression free survival (PFS) and overall survival (OS) in metastatic colorectal cancer patients however currently there are no biomarkers that predict response to this treatment. The aim of this study was to assess if differential protein expression can differentiate patients who respond to chemotherapy and bevacizumab, and to assess if select proteins correlate with patient survival. Methods Pre-treatment serum from patients with metastatic colorectal cancer (mCRC) treated with chemotherapy and bevacizumab were divided into responders and nonresponders based on their progression free survival (PFS). Serum samples underwent immunoaffinity depletion and protein expression was analysed using two-dimensional difference gel electrophoresis (2D-DIGE), followed by LC-MS/MS for protein identification. Validation on selected proteins was performed on serum and tissue samples from a larger cohort of patients using ELISA and immunohistochemistry, respectively (n = 68 and n = 95, respectively). Results 68 proteins were identified following LC-MS/MS analysis to be differentially expressed between the groups. Three proteins (apolipoprotein E (APOE), angiotensinogen (AGT) and vitamin D binding protein (DBP)) were selected for validation studies. Increasing APOE expression in the stroma was associated with shorter progression free survival (PFS) (p = 0.0001) and overall survival (OS) (p = 0.01), DBP expression (stroma) was associated with shorter OS (p = 0.037). Increasing APOE expression in the epithelium was associated with a longer PFS and OS, and AGT epithelial expression was associated with a longer PFS (all p < .05). Increasing serum AGT concentration was associated with shorter OS (p = 0.009). Conclusions APOE, DBP and AGT identified were associated with survival outcomes in mCRC patients treated with chemotherapy and bevacizumab.
    • Randomized controlled trial comparing telephone and mail follow-up for recruitment of participants into a clinical trial of colorectal cancer screening

      Wong, Arthur D; Kirby, John; Guyatt, Gordon H; Moayyedi, Paul; Vora, Parag; You, John J (2013-02-11)
      Abstract Background Investigators often face challenges when recruiting participants into randomized controlled trials (RCTs). Some data suggest that telephone reminders may lead to greater participant enrollment. Methods Patients aged 50 to 70 years from family practice rosters were initially mailed invitations to participate in an RCT of colorectal cancer screening. Patients who did not respond were randomly allocated to follow-up invitations by either telephone or mail four weeks after the initial invitation. The primary outcome was attendance for eligibility screening with the study nurse. Results After mailing invitations to 1,348 patients, 104 patients were initially enrolled in the RCT of colon cancer screening. Of 952 patients who did not respond to the initial mailed invitation, we randomly allocated 480 to follow-up invitation by telephone and 472 to follow-up invitation by mail. Attendance for eligibility screening with the study nurse was more frequent when non-responders were followed-up by telephone (84/480, 17.5%) than by mail (43/472, 9.1%) (relative risk (RR) 1.92, 95% confidence interval (CI) 1.36 to 2.71, P < 0.001). Enrollment into the RCT was also greater among patients followed-up by telephone (59/480, 12.3%) compared to those followed-up by mail (35/472, 7.4%) (RR 1.66, 95% CI 1.11 to 2.47, P=0.01). Conclusions Telephone-based follow-up results in greater enrollment compared to a mail-based method. Our findings should be of interest to investigators conducting RCTs, particularly trials of screening interventions involving asymptomatic participants for which volunteer participation may be challenging. Trial registration Clinicaltrials.gov NCT00865527
    • Virtual colonoscopy, optical colonoscopy, or fecal occult blood testing for colorectal cancer screening: results of a pilot randomized controlled trial

      You, John J; Liu, Yudong; Kirby, John; Vora, Parag; Moayyedi, Paul (2015-07-09)
      Abstract Background No head-to-head randomized controlled trials have demonstrated the superiority of one colorectal screening modality over another in reducing colorectal cancer mortality. We conducted a pilot randomized controlled trial of fecal occult blood testing (FOBT), optical colonoscopy (OC), and virtual colonoscopy (VC), to inform the planning of a larger evaluative trial. Methods Eligible patients (aged 50 to 70) were recruited from five primary care practices in Hamilton, ON, Canada, between March 23, 2010 and August 11, 2010, and randomized 1:1:1 in a parallel design using an automated, centralized telephone service to either FOBT, OC, or VC. To reflect conventional practice, patients received no additional reminders to complete their allocated screening test beyond those received in usual practice. The primary outcome was completion of the assigned screening procedure. Results of the index test and any follow-up investigations were ascertained at 6 months. Participants, caregivers, and outcome assessors were not blinded to group assignment. The trial was stopped early due to lack of ongoing funding. Results A total of 198 participants were enrolled, of whom 67 were allocated to FOBT, 66 to OC, and 65 to VC. The allocated screening procedure was completed by 43 (64 %) subjects allocated to FOBT (95 % confidence interval [CI], 52–75 %), 53 (80 %) subjects allocated to OC (95 % CI, 69–88 %), and 50 (77 %) subjects allocated to VC (95 % CI, 65–85 %); because the trial stopped early, we had insufficient statistical power to detect clinically relevant differences in completion rates. During 6 months follow-up, colorectal adenomas were detected in 0 (0 %) subjects allocated to FOBT, 12 (18 %) subjects allocated to OC, and 2 (3 %) subjects allocated to VC. One subject in the OC arm had histological evidence of high-grade dysplasia. No subjects were diagnosed with colorectal cancer. Conclusions In this pilot randomized controlled trial of colorectal cancer screening in a primary care setting, 64–80 % of subjects completed their allocated screening test. These findings may be of value to investigators planning clinical trials to evaluate the effectiveness of colorectal cancer screening. Trial registration ClinicalTrials.gov NCT00865527. https://clinicaltrials.gov/ct2/show/NCT00865527