Ultrastaging Using Ex Vivo Sentinel Lymph Node Mapping and One-Step Nucleic Acid Amplification (OSNA) in Gastric Cancer: Experiences of a European Center.

BACKGROUND: In this study, the effectiveness of One-step nucleic acid amplification (OSNA) in combination with ex vivo SLN mapping is compared with conventional histology including immunohistochemistry. METHODS: LNs were retrieved from gastrectomy specimens in an unfixed state. After ex vivo SLN mapping using methylene-blue, LNs were sliced to provide samples for histology and OSNA. RESULTS: In total, 334 LNs were retrieved in the fresh state from 41 patients. SLN detection was intended in 40 cases but was successful in only 29, with a correct LN status prediction in 23 cases (79%). Excluding one case out of 41 with a failure likely caused by a processing error, OSNA showed a high effectiveness with sensitivity, specificity, and accuracy rates of 85.4%, 93.5%, and 92.4%, respectively. The LN status could be predicted in all but one case, in which the single positive LN was not eligible for OSNA testing. Moreover, OSNA evaluation led to upstaging from N0 to N+ in three cases (14%). CONCLUSION: The ex vivo SLN protocol used resulted in a relatively poor detection rate. However, the OSNA method was not hampered by this detection rate and proved its potential to increase the sensitivity of metastases detection.

Malignancies associated with GIST: a retrospective study with molecular analysis of KIT and PDGFRA.

PURPOSE: Gastrointestinal stromal tumors (GISTs) are the most common soft tissue tumors of the GI tract. Studies have been published reporting additional neoplasms in GIST patients. This study aimed to evaluate possible associations of mutation type, morphology, and clinical aspects of GISTs. METHODS: All cases of GIST were identified from our pathology files. Coding exons of KIT and PDGFRA in GISTs with additional malignancies were sequenced. RESULTS: A total of 70 of 188 (37%) retrieved patients with confirmed diagnosis of GIST showed at least one additional malignant neoplasm. Fifty of these GISTs were located in the stomach (71%), 8 in the small intestine (11%), 5 in the colon/rectum (7%), and 7 cases (6.2%) were of undetermined sites of origin. The distribution of identified mutations was similar to that described in GISTs without secondary malignancies. A total of 37 of 57 cases (65%) showed mutations in the KIT gene exon 11, 3 (5%) cases in exon 9, and 1 (2%) case in exon 13. Nine tumors (16%) had mutations of the PDGFRA gene. KIT and PDGFRA wild-type status were found in seven cases (12%). Most of the secondary neoplasms were located within the GI tract (34%), in the urogenital system (24%), or the breast/female genital tract (20%). CONCLUSION: This study confirms the high rate of additional malignant tumors in GIST patients. GIST features in these cases are very similar to those with sole GIST.

Tumor Budding, uPA, and PAI-1 in Colorectal Cancer: Update of a Prospective Study.

Aims. The prognostic role of the proteases uPA and PAI-1, as well as tumor budding, in colon cancer, has been investigated previously. Methods. We provide 6-year follow-up data and results of the validation set. The initial test set and validation set consisted of 55 colon cancers and 68 colorectal cancers, respectively. Tissue samples were analyzed for uPA and PAI-1 using a commercially available Enzyme-Linked Immunosorbent Assay (ELISA). Tumor budding was analyzed on cytokeratin-stained slides. Survival analyses were performed using cut-offs that were determined previously. Results. uPA was not prognostic for outcome. PAI-1 showed a trend towards reduced cancer specific survival in PAI-1 high-grade cases (68 versus 83 months; P = 0.091). The combination of high-grade PAI-1 and tumor budding was associated with significantly reduced cancer specific survival (60 versus 83 months; P = 0.021). After pooling the data from both sets, multivariate analyses revealed that the factors pN-stage, V-stage, and a combination of tumor budding and PAI-1 were independently prognostic for the association with distant metastases. Conclusions. A synergistic adverse effect of PAI-1 and tumor budding in uni- and multivariable analyses was found. PAI-1 could serve as a target for anticancer therapy.

The role of lymph node size and FOXP3+ regulatory T cells in node-negative colon cancer.

Recently, we demonstrated that the intratumoural density of CD3+ and CD8+ T cells is independently prognostic and associated with lymph node (LN) harvest and LN size in node-negative colon cancer. We assumed that FOXP3+ T cells (Tregs) could be inversely associated with these LN features. Therefore, we performed a retrospective immunohistochemical analysis using an already well-characterised collection of stage I/II colon cancer cases. Receiver operating characteristic analysis revealed the optimal cut-off for predicting cancer-related death to be 70 FOXP3+ Tregs/mm2 at the invasion front. Other than T-stage, none of the relevant histopathological parameters were associated with the density of FOXP3+ cells. In particular, no relation to LN size and count were found. Cancer-specific survival was significantly improved in cases with high densities (115 vs 86 months; p=0.026) in univariable but not in multivariable analysis. In contrast to other cancers, FOXP3+ T cells are associated with a favourable outcome.

A new simple morphology-based risk score is prognostic in stage I/II colon cancers.

A portion of stage I/II colon cancers (10-20%) exhibit an adverse clinical course. The administration of adjuvant chemotherapy is recommended only in certain high-risk situations. However, these risk factors recently failed to predict benefit from adjuvant therapy. We composed a new morphology-based risk score that includes pT1/2 versus 3/4 stage, vascular or lymphovascular invasion, invasion type according to Jass, tumor budding and paucity (less than two) of lymph nodes larger than 5 mm. The occurrence of each of these factors accounts for one point in the score (Range 0-5). This score was evaluated in a retrospective study that included 301 cases. The overall survival differed significantly between the three groups with median survival times of 103, 90, and 48 months, respectively. Multivariable analysis revealed morphology-based risk-high risk and low risk-as the sole independent factors for the prediction of death. Morphology-based risk scoring was superior to microsatellite status and NCCN risk stratification. This method identifies a group of patients that comprises 18% of the stage II cases with an adverse clinical course. Further studies are necessary to confirm its prognostic value and the possible therapeutic consequences.

Clinical Significance of International Union Against Cancer pN Staging and Lymph Node Ratio in Node-Positive Colorectal Cancer after Advanced Lymph Node Dissection.

BACKGROUND: Lymph node retrieval in colorectal cancer can be improved by using advanced histopathological techniques like methylene blue-assisted lymph node dissection, which results in a doubling or even tripling of the lymph node count in comparison with conventional lymph node dissection techniques. However, it is not clear whether the established lymph node staging systems are suitable for predicting patients' prognoses under these circumstances. OBJECTIVE: The aim of this study was to determine whether the current lymph node staging systems are suitable when advanced dissection methods are used. DESIGN: This is a retrospective cohort study. SETTING AND PATIENTS: We formed a study group (methylene blue-assisted lymph node dissection) of 293 patients and a control group (conventional lymph node dissection) of 232 patients, each with node-positive cases. Conventional pN staging according to the International Union Against Cancer, seventh edition, and lymph node ratio were applied. MAIN OUTCOME MEASURES: Overall survival was compared by using the different staging systems in a uni- and multivariable fashion. RESULTS: The lymph node ratio values were reduced in the advanced methylene blue-assisted lymph node dissection group in comparison with the conventional lymph node dissection group (0.1 vs 0.3, p < 0.001). Although pN staging proved to be reliable, the cutoff values for lymph node ratio staging had to be adapted. The new cutoffs (0.07, 0.15, and 0.34) were prognostic. However, multivariable analysis revealed pN staging and vascular invasion, but not lymph node ratio, as independently prognostic in the methylene blue-assisted lymph node dissection group. LIMITATIONS: The study group and historical control group are not perfectly balanced because the case number in the stage III subgroup of the control group is small. CONCLUSIONS: pN staging proved to be a robust prognostic marker in colorectal cancer under the circumstances of improved lymph node harvest. After adaptation of the cutoff values, lymph node ratio is also prognostic but not superior to pN staging.