The mesenteric and antimesenteric site of the tumor as possible prognostic factor in colorectal cancer: 5-year survival analysis

INTRODUCTION

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.

AIM OF THE STUDY

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.

PATIENTS AND 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.

Genetic polymorphisms influence Plasmodium ovale PCR detection accuracy

Detection of Plasmodium ovale by use of a nested PCR assay with a novel Plasmodium ovale primer set was superior to detection of Plasmodium ovale by real-time PCR assays. Nested PCR was also better at detecting P. malariae. The detection of P. ovale in many patients first admitted >2 months following their return to Italy indicated that P. ovale relapses are common.

Comparative evaluation of molecular assays for the identification of intestinal spirochaetes from diseased pigs

Rapid identification of porcine Brachyspira species is required in order to differentiate pathogenic from non-pathogenic species. The aim of our study was to compare a recently described genetic method based on polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), nox RFLP-PCR assay, and three species-specific PCRs described previously in the literature with a 16S rRNA gene RFLP-PCR discriminatory reference assay (16S RFLP-PCR) for the identification of Brachyspira spp. of swine origin. In this study, 20 porcine spirochaetal strains were identified and compared to 33 reference strains by 16S RFLP-PCR and nox RFLP-PCR and three species-specific PCRs. RFLP-PCR methods showed concordant results for 47 strains and discordances for 6 strains (2 differently identified and 4 not revealed by nox RFLP-PCR). In our hands species-specific PCRs showed concordant results with 16S and nox RFLP-PCR for 43 strains and discordances for 10 strains (2 differently identified and 8 not amplified). The same results observed testing the 20 field-isolated spirochaetes were obtained for the corresponding porcine faecal samples. The detection limit was 10(2) -10(3) cells/g of faeces for 16S rRNA gene PCR and 10(4) cells/g of faeces for nox PCR. In our experience nox RFLP-PCR appeared successful for the speciation of B. hyodysenteriae reserving 16S RFLP-PCR for all other pathogenic and non-pathogenic Brachyspira species. Among the species-specific PCR assays tested only that for B. pilosicoli was useful in our hands.