title: The mesenteric and antimesenteric site of the tumor as possible prognostic factor in colorectal cancer: 5-year survival analysis.
abstract: BACKGROUND
  Colorectal cancer is still one of the many factors of death both in males and in females. To date, the most important prognostic factors are mainly related to the pathological stage of the disease.
  
  
  OBJECTIVE
  The purpose of this study was to analyze the possible role of tumor circumferential localization on the colonic wall (mesenteric (M) or antimesenteric (AM)) as a possible prognostic factor. In this study, we compare the localization of the tumor with patient's survival. The hypothesis of this study is that M tumors, closer to blood and lymphatic vessels, should be more aggressive in terms of hematogenous and lymphatic spread compared to the AM tumors.
  
  
  METHODS
  All patients undergoing curative resection for colorectal cancer were enrolled in this study; there was no statistical difference for age, sex and co-morbidity. The histopathological examination was carried out in the standard manner. Next, we have taken care to survival of neoplastic patients by examining of our 5-year follow-up archive: we divided patients in different groups concerning the different tumor stage and we compare these results with the different localizations of tumor at the operation.
  
  
  RESULTS
  In 45% of cases, we were able to distinguish the different localizations M (160 patients) or AM (47 patients) and this difference is statistically significant (P<0.0001, Pearson Chi-Square-test (PCS-t)). The number of metastatic nodes is statistically higher in the M group compared to the AM group one (P=0.003949). Medium time of follow-up was 36.54 months; AM and M patients have a rather similar survival, only at the end the two curves seem to change but not in a significant manner. Only if we consider the difference between the two groups comparing T3 tumor can we observe a statistically significant difference (P<0.005).
  
  
  CONCLUSIONS
  In conclusion, the localization of M or AM colorectal cancer is feasible in 45% of cases. M tumors have significantly more lymph nodes metastases but a better 5-year survival than AM tumors. A possible explanation for such results might be the different pattern of diffusion of cancer cells.
authors.affiliation: Department of Surgical Sciences, University of Insubria, Varese, Azienda-Ospedaliera Polo Universitario, Ospedale di Circolo-Fondazione, Viale Borri 57, 21100-Varese, Italy. luigi.boni@uninsubria.it
authors.forename: L
authors.initials: L
authors.lastname: Boni
authors.forename: F
authors.initials: F
authors.lastname: Cantore
authors.forename: E
authors.initials: E
authors.lastname: Colombo
authors.forename: A
authors.initials: A
authors.lastname: Benevento
authors.forename: G
authors.initials: G
authors.lastname: Dionigi
authors.forename: F
authors.initials: F
authors.lastname: Rovera
authors.forename: G
authors.initials: G
authors.lastname: Capriata
authors.forename: G
authors.initials: G
authors.lastname: Dettori
authors.forename: R
authors.initials: R
authors.lastname: Dionigi
mesh_terms: D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery*; D008207:Lymphatic Metastasis; D008643:Mesentery / Q000473:pathology / Q000601:surgery*; D020360:Neoadjuvant Therapy; D011379:Prognosis