title: The impact of colorectal screening program on the detection of right-sided colorectal cancer. A 5-year cohort study in the Mantua District.
abstract: BACKGROUND
  High rates of advanced colorectal cancer (CRC) are still diagnosed in the right side of the colon. This study aimed to investigate whether screening programs increase CRC detection and whether tumor location is associated with survival outcome.
  
  
  METHODS
  Patients affected by CRC, aged from 50 to 69 years and operated on from 2005 to 2009 were reviewed. Other than patient-, disease-, and treatment-related factors, detection mode and tumor location were recorded. Overall (OS) and disease-free survival (DFS) were investigated, using univariate and multivariate analyses.
  
  
  RESULTS
  Mean age of 386 patients included was 62.0 years, 59 % were males. CRC was detected by screening in 17 % of cases, and diagnosis was made from symptoms in 67 % and emergency surgery for 16 %. Screen-detected CRCs were located in the left colon (59 %), then in rectum (25 %) and in proximal colon (16 %) (p = 0.02). Most of CRC patients urgently operated on had cancer located in proximal colon (45 %), then in the left colon (36 %) and in rectum (18 %) (p = 0.001). Right-sided CRC demonstrated higher pTNM stage (p = 0.001), adequate harvest count nodes (p = 0.0001), metastatic nodes (p = 0.02), and poor differentiation grading (p = 0.0001). With multivariate analysis, poor differentiation grade was independently associated with both worse OS (HR 3.6, p = 0.05) and worse DFS (HR 8.1, p = 0.0001), while distant recurrence was associated with worse OS (HR 20.1, p = 0.0001).
  
  
  CONCLUSIONS
  Low rates of right-sided CRC are diagnosed following screening program. Proximal CRC demonstrates aggressive behavior without impact on outcome. These findings prompt concern about population awareness for CRC screening.
authors.affiliation: Department of Surgery and Orthopaedics, General Surgery Units of Asola, Mantua and Pieve C., Carlo Poma Hospital, 80° Fanteria Place, 1-46041, Asola, Mantua, Italy. corrado.asteria@libero.it.
authors.forename: Corrado R
authors.initials: CR
authors.lastname: Asteria
authors.affiliation: Department of Surgery Oncology and Gastroenterology, Surgical Clinic I, School of Medicine, University of Padua, Padua, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Pucciarelli
authors.affiliation: Department of Surgery and Orthopaedics, General Surgery Units of Asola, Mantua and Pieve C., Carlo Poma Hospital, 80° Fanteria Place, 1-46041, Asola, Mantua, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Gerard
authors.affiliation: Department of Surgery and Orthopaedics, Digestive Endoscopy Unit, Carlo Poma Hospital, Mantua, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Mantovani
authors.affiliation: Department of Medicine, Medicine Unit, Pieve Coriano, Carlo Poma Hospital Mantua, Mantua, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Pagani
authors.affiliation: Department of Surgery and Orthopaedics, General Surgery Units of Asola, Mantua and Pieve C., Carlo Poma Hospital, 80° Fanteria Place, 1-46041, Asola, Mantua, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Boccia
authors.affiliation: Epidemiological Observatory Local Health-care Authority (LHCA), Mantua, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Ricci
authors.affiliation: Department of Surgery and Orthopaedics, Digestive Endoscopy Unit, Carlo Poma Hospital, Mantua, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Troiano
authors.affiliation: Department of Healthcare Medical Management, Biostatistic Service, Carlo Poma Hospital, Mantua, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lucchini
authors.affiliation: Department of Surgery and Orthopaedics, General Surgery Units of Asola, Mantua and Pieve C., Carlo Poma Hospital, 80° Fanteria Place, 1-46041, Asola, Mantua, Italy.
authors.forename: Coriolano
authors.initials: C
authors.lastname: Pulica
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D055088:Early Detection of Cancer / Q000379:methods*; D005243:Feces / Q000737:chemistry; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007558:Italy / Q000453:epidemiology; D008207:Lymphatic Metastasis; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate
keywords: Colorectal cancer; Detection mode of cancer; Disease-free survival; Immunochemical fecal screening; Overall survival; Right-side tumor location