ABSTRACT
Background: In staging early rectal cancers (ERC), submucosal tumor depth is one of the most important features determining the possibility of local excision (LE). The micro-enema (Bisacodyl) induces submucosal edema and may hypothetically improve the visualization of tumor depth. Purpose: To test the diagnostic performance of MRI to identify ERC suitable for LE when adding a pre-procedural micro-enema and concurrent use of a modified classification system. Material and Methods: In this prospective study, we consecutively included 73 patients with newly diagnosed rectal tumors. Two experienced radiologists independently interpreted the MRI examinations, and diagnostic performance was calculated for local tumors eligible for LE (Tis-T1sm2, n = 43) and non-local tumors too advanced for LE (T1sm3-T3b, n = 30). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were registered for each reader. Inter- and intra-reader agreements were assessed by kappa statistics. Lymph node status was derived from the clinical MRI reports. Results: Reader1/reader2 achieved sensitivities of 93%/86%, specificities of 90%/83%, PPV of 93%/88%, and NPV of 90%/81%, respectively, for identifying tumors eligible for LE. Rates of overstaging of local tumors were 7% and 14% for the two readers, and kappa values for the inter- and intra-reader agreement were 0.69 and 0.80, respectively. For tumors ≤T2, all metastatic lymph nodes were smaller than 3 mm on histopathology. Conclusion: MRI after a rectal micro-enema and concurrent use of a modified staging system achieved good diagnostic performance to identify tumors suitable for LE. The rate of overstaging of local tumors was comparable to results reported in previous endorectal ultrasound (ERUS) studies.
ABSTRACT
BACKGROUND AND OBJECTIVES: The aim of the study was to evaluate the incidence of peritoneal carcinomatosis (PC) in a prospectively recorded series of colon cancer patients from a defined cohort and to compare clinicopathological characteristics, survival, and TP53 mutation status in primary tumors from patients with and without PC. METHODS: Clinical data from all colon cancer patients admitted in 1993-2006 were registered prospectively (n = 1,124). In a subset of PC patients, DNA was retrieved from tumor tissue and TP53 mutations analyzed and compared to the mutation status in a historical series. RESULTS: In the prospective series 10% of female and 7% of male patients had PC (P = 0.05). The PC patients were younger than those without PC (median 4 years, P = 0.002). The incidence of PC was 10.3% and 6.2% (P = 0.03) in patients with primary tumors in the right and left colon, respectively. TP53 was mutated in 57% of the PC patients as compared to 41% in the series of patients without PC (P = 0.05). CONCLUSIONS: The incidence of PC was higher in right-sided colon cancer and among women. PC patients were younger than non-PC patients, and PC was independently associated with TP53 mutation in the primary tumor.
