Interobserver Variability in Assessing Pathologic Response to Preoperative Treatment in Rectal Cancer: Standardization of an Evaluation Method and Comparisons Between Published Scales.

BACKGROUND: Evaluating tumor response of rectal cancer to preoperative chemoradiotherapy (NCRT) has a prognostic value on overall survival; however, grading tumor response is a controversial issue due to lack of reproducibility and the lack of information about the standardization of the evaluation. METHODS: We performed this study to examine the variability between observers' assessment of the pathological responses to NCRT using a systematic quantitative grading system based on a percentage of tumor response against the proportion of residual tumor burden. As a secondary aim, we classified the tumor response according to six published systems to determine the correlation between the observers into each grading system. RESULTS: From 70 cases, the mean age was 60.6 ± 11.78 years, 36 (51.47%) patients were female, the pathological T stage was pT3 in 48.6% of cases, pT2 in 32.9%, pT1 in 11.4% and 7.1% in pT4, whereas 40% had lymph node metastasis. The median lymph node count was ten lymph nodes (range 6-43). Our method of tumor regression evaluation has a good intraclass correlation (ICC) value. From the scales compared regarding interobserver agreement, the Ryan's and Royal College of Pathologists showed fair agreement (but good ICC); the scales from Dworak, Becker, and Rizk showed substantial agreement (and good to excellent ICC values); and the scale from Rödel showed almost-perfect agreement. RESULTS: All the evaluated systems showed good interobserver agreement, but the best interobserver agreement was reached with the Rödel's scale.

Stage I-III colon cancer patients with tumor deposits behave similarly to stage IV patients. Cross-section analysis of 392 patients.

BACKGROUND AND OBJECTIVES: Tumor deposits (TDs) are associated with adverse prognostic factors and decreased survival in colorectal cancer. However, controversy exists regarding their definition, evaluation, and staging categories. This study aimed to determine the survival and recurrence impact of the TD in colon adenocarcinomas; and to determine if TD patients behave similarly to stage IV patients. METHODS: Cross-section study from 392 patients with colon adenocarcinoma from 2005 to 2012. We performed survival analysis and further stratified patients considering TD patients as a "stage IV-TD" to demonstrate if they behave similarly than stage IV patients. RESULTS: From 392 patients, 204 (52%) were men, the mean age was 57.4 ± 13.9 years and 11.5% of cases had TD. In a multivariate analysis, TD failed to predict mortality and recurrence. Considering cases with TD as stage IV-TD, their mean survival was similar to stage IV patients (69.3 and 64.6 months, respectively) and different to those in stage III (110.5 months), II (135.7 months), and I (114.9 months) (P < 0.001). CONCLUSIONS: TD failed to predict mortality and recurrence. Patients with TD in stage I-III shows similar mortality than stage IV patients; then, we suggest putting them into a substage IV category instead of the N1c category.