RT-PCR and immunohistochemical evaluation of sentinel lymph nodes after in vivo mapping with Patent Blue V in colon cancer patients

A pancreatic adenocarcinoma mimicking hepatoid carcinoma of uncertain histogenesis: A case report and literature review

In rare cases, metastatic adenocarcinomas of different origin may exhibit the features of hepatoid carcinoma (HC), a rare malignant epithelial tumor, most commonly occurring in the ovaries and stomach, as well as in the pancreas and biliary ducts. A case of a 72-year-old female patient who developed a highly aggressive, poorly differentiated pancreatic ductal adenocarcinoma with peritoneal carcinomatosis, demonstrating hepatoid differentiation upon conventional hematoxylin and eosin staining is reported in the present study. The patient presented with severe abdominal pain, and the radiological investigations performed revealed ovarian and hepatic tumor masses and peritoneal lesions, which were surgically removed. The gross examination of the peritoneum and omentum revealed multiple solid, firm, grey-white nodules, diffusely infiltrating the adipose tissue. The microscopic examination revealed a malignant epithelial proliferation, composed of polygonal cells with abundant eosinophilic cytoplasm and irregular, pleomorphic nuclei. Certain cells presented with intracytoplasmic mucus inclusions, raising suspicion of a HC with an uncertain histogenesis. Immunohistochemical staining was performed, and the tumor cells were found to be positive for cytokeratin (CK)7, CK18 and mucin 5AC, whereas negative staining for CK20, caudal-type homeobox transcription factor 2, α-fetoprotein, paired box gene 8, GATA-binding protein 3 and Wilms tumor 1 were documented. Thus, the diagnosis of metastatic pancreatic adenocarcinoma was established. The main aim of the present study was to provide further knowledge concerning poorly differentiated metastatic adenocarcinoma resembling HC, emphasizing the histopathological and immunohistochemical features of these malignant lesions and raising awareness of the diagnostic difficulties that may arise, as well as the importance of the use immunohistochemistry in differentiating carcinomas of uncertain histogenesis.

Lymphatic Mapping in Colon Cancer Depending on Injection Time and Tracing Agent: A Systematic Review and Meta-Analysis of Prospective Designed Studies

An optimized lymph node yield leads to better survival in colon cancer, but extended lymphadenectomy is not associated with survival benefits. Lymphatic mapping shows several colon cancers feature aberrant drainage pathways inducing local recurrence when not resected. Currently, different protocols exist for lymphatic mapping procedures. This meta-analysis assessed which protocol has the best capacity to detect tumor-draining and possibly metastatic lymph nodes. A systematic review was conducted according to PRISMA guidelines, including prospective trials with in vivo tracer application. The risk of bias was evaluated using the QUADAS-2 tool. Traced lymph nodes, total resected lymph nodes, and aberrant drainage detection rate were analyzed. Fifty-eight studies met the inclusion criteria, of which 42 searched for aberrant drainage. While a preoperative tracer injection significantly increased the traced lymph node rates compared to intraoperative tracing (30.1% (15.4, 47.3) vs. 14.1% (11.9, 16.5), p = 0.03), no effect was shown for the tracer used (p = 0.740) or the application sites comparing submucosal and subserosal injection (22.9% (14.1, 33.1) vs. 14.3% (12.1, 16.8), p = 0.07). Preoperative tracer injection resulted in a significantly higher rate of detected aberrant lymph nodes compared to intraoperative injection (26.3% [95% CI 11.5, 44.0] vs. 2.5% [95% CI 0.8, 4.7], p < 0.001). Analyzing 112 individual patient datasets from eight studies revealed a significant impact on aberrant drainage detection for injection timing, favoring preoperative over intraoperative injection (OR 0.050 [95% CI 0.010-0.176], p < 0.001) while indocyanine green presented itself as the superior tracer (OR 0.127 [95% CI 0.018-0.528], p = 0.012). Optimized lymphatic mapping techniques result in significantly higher detection of aberrant lymphatic drainage patterns and thus enable a personalized approach to reducing local recurrence.

Investigation of the genotoxic effects of patent blue V (E131) in human peripheral lymphocytes and in silico molecular docking

Patent Blue V (PBV) is a water-soluble synthetic dyestuff that is used as a coloring agent in the food industry and for medical imaging in health monitoring. The aim of this study was to investigate the in vitro clastogenic, aneugenic and cytotoxic effects of PBV in human peripheral lymphocytes using micronucleus assay, comet assay, as well as plasmid DNA interaction and bacterial AMES tests. In addition to in vitro tests, the affinity of PBV against DNA was determined by molecular docking analysis in silico. PBV produced significant MN formation only at high doses and longer treatment time, however, it did not significantly affect the nuclear division index (NDI). Furthermore, PBV was unable to cause DNA single-strand breaks and significant oxidative damage on the pBR322 plasmid DNA and it didn't reverse the harmful effects caused by the clastogenic treatment of UV + H₂O₂ on plasmid DNA. In the Ames test, no significant increase was detected in the number of revertant colonies of mutant strains, TA98 and TA100, following PBV treatment. No significant molecular interaction between B-DNA and PBV occured in molecular docking simulations. In conclusion, PBV had no significant genotoxic and cytotoxic effects in this study. However, considering that the information intensity related to the genotoxic effects of PBV in the literature is still insufficient, reports of further studies with different genotoxicity endpoints will be needed to elucidate the exact genotoxic feature.

Comparing the efficacy of routine H&E staining and cytokeratin immunohistochemical staining in detection of micro-metastasis on serial sections of dye-mapped sentinel lymph nodes in colorectal carcinoma

BACKGROUND

The significance of techniques used for detecting micro-metastasis (MM) or isolated tumor cells (ITCs) is a controversial issue among investigators. We evaluated the different techniques used on sentinel lymph node (SLN) to detect MM/ITCs.

MATERIALS AND METHODS

Ninety-one SLNs of 15 patients underwent serial section with 100 μm interval. In each level, two sections were prepared. One section was stained with H&E and another with anti-cytokeratin antibody (immunohistochemistry). Then the sections were evaluated for detecting MM/ITCs. Results were analyzed by chi-square test.

RESULTS

1656 sections of 91 SLNs of 15 patients were evaluated by a pathologist; MM was found in 1 and ITCs in 1 case. Overall, 2 out of 15 cases (13.3% of the patients) showed MM/ITCs by IHC staining. So, serial section along with using IHC was superior than serial section and routine H&E staining. But it did not affect the 5-year survival of the patients (P = 0.47).

CONCLUSION

Using the combined techniques of serial section and IHC staining could up-stage 13.3% of colon cancer patients who were lymph node negative. In other studies with different combination of serial section, IHC staining, and PCR, investigators were able to find MM/ITCs in 3-39% of the cases. In our study, although serial section and IHC staining could up-stage 13.3% of patients, it could not affect the 5-year survival of the patients.

Evaluation of lymph node numbers for adequate staging of Stage II and III colon cancer

BACKGROUND

Although evaluation of at least 12 lymph nodes (LNs) is recommended as the minimum number of nodes required for accurate staging of colon cancer patients, there is disagreement on what constitutes an adequate identification of such LNs.

METHODS

To evaluate the minimum number of LNs for adequate staging of Stage II and III colon cancer, 490 patients were categorized into groups based on 1-6, 7-11, 12-19, and ≥ 20 LNs collected.

RESULTS

For patients with Stage II or III disease, examination of 12 LNs was not significantly associated with recurrence or mortality. For Stage II (HR = 0.33; 95% CI, 0.12-0.91), but not for Stage III patients (HR = 1.59; 95% CI, 0.54-4.64), examination of ≥20 LNs was associated with a reduced risk of recurrence within 2 years. However, examination of ≥20 LNs had a 55% (Stage II, HR = 0.45; 95% CI, 0.23-0.87) and a 31% (Stage III, HR = 0.69; 95% CI, 0.38-1.26) decreased risk of mortality, respectively. For each six additional LNs examined from Stage III patients, there was a 19% increased probability of finding a positive LN (parameter estimate = 0.18510, p < 0.0001). For Stage II and III colon cancers, there was improved survival and a decreased risk of recurrence with an increased number of LNs examined, regardless of the cutoff-points. Examination of ≥7 or ≥12 LNs had similar outcomes, but there were significant outcome benefits at the ≥20 cutoff-point only for Stage II patients. For Stage III patients, examination of 6 additional LNs detected one additional positive LN.

CONCLUSIONS

Thus, the 12 LN cut-off point cannot be supported as requisite in determining adequate staging of colon cancer based on current data. However, a minimum of 6 LNs should be examined for adequate staging of Stage II and III colon cancer patients.

Could lymphatic mapping and sentinel node biopsy provide oncological providence for local resectional techniques for colon cancer? A review of the literature

BACKGROUND

Endoscopic resectional techniques for colon cancer are undermined by their inability to determine lymph node status. This limits their application to only those lesions at the most minimal risk of lymphatic dissemination whereas their technical capacity could allow intraluminal or even transluminal address of larger lesions. Sentinel node biopsy may theoretically address this breach although the variability of its reported results for this disease is worrisome.

METHODS

Medline, EMBASE and Cochrane databases were interrogated back to 1999 to identify all publications concerning lymphatic mapping for colon cancer with reference cross-checking for completeness. All reports were examined from the perspective of in vivo technique accuracy selectively in early stage disease (i.e. lesions potentially within the technical capacity of endoscopic resection).

RESULTS

Fifty-two studies detailing the experiences of 3390 patients were identified. Considerable variation in patient characteristics as well as in surgical and histological quality assurances were however evident among the studies identified. In addition, considerable contamination of the studies by inclusion of rectal cancer without subgroup separation was frequent. Indeed such is the heterogeneity of the publications to date, formal meta-analysis to pool patient cohorts in order to definitively ascertain technique accuracy in those with T1 and/or T2 cancer is not possible. Although lymphatic mapping in early stage neoplasia alone has rarely been specifically studied, those studies that included examination of false negative rates identified high T3/4 patient proportions and larger tumor size as being important confounders. Under selected circumstances however the technique seems to perform sufficiently reliably to allow it prompt consideration of its use to tailor operative extent.

CONCLUSION

The specific question of whether sentinel node biopsy can augment the oncological propriety for endoscopic resective techniques (including Natural Orifice Transluminal Endoscopic Surgery [NOTES]) cannot be definitively answered at present. Study heterogeneity may account for the variability evident in the results from different centers. Enhanced capacity (perhaps to the level necessary to consider selective avoidance of en bloc mesenteric resection) by its confinement to only early stage disease is plausible although not proven. Specific study of the technique in early stage tumors is clearly essential before proffering this approach.

Sentinel node mapping does not improve staging of lymph node metastasis in colonic cancer

PURPOSE

This study was designed to evaluate the reliability of the sentinel node concept in colonic cancer.

METHODS

Patent blue was used as tracer. The four blue nodes closest to the tumor were defined as the sentinel node(s) by the pathologist. All nodes were examined by routine microscopy (hematoxylin-eosin staining). If no metastases were detected, all lymph nodes were examined immunohistochemically with antibody to cytokeratin.

RESULTS

Two hundred colon specimens were examined. Sentinel node(s) were identified in 93 percent. Sixty contained metastases in hematoxylin-eosin sections. In 32 these were found in sentinel nodes (sensitivity 53 percent). Twenty-eight patients had metastases in nonsentinel nodes only, giving a false-negative rate of 47 percent. Immunostaining revealed 39 (30 percent) micrometastases or submicrometastases in 131 TNM Stages I and II patients, and in 17 of these patients metastases were found in nonsentinel nodes only (false-negative rate 44 percent).

CONCLUSIONS

Sentinel lymph node mapping shows low sensitivity for detection of ordinary metastases, micrometastases, and submicrometastases. If only the sentinel nodes had been examined, approximately half of the metastases would have been lost after routine staining, as well as half of the micrometastases and submicrometastases when immunohistochemical examination was added.

Is occult lymph node disease in colorectal cancer patients clinically significant? A review of the relevant literature

The clinical significance of micrometastasis of colorectal cancer (CRC) to regional lymph nodes remains controversial. In this review, we analyze publications that have evaluated the clinical significance of occult lymph node metastasis in CRC. An extensive literature search identified 19 publications that evaluated the clinical significance of micrometastatic CRC by various methods, including immunohistochemistry (IHC; n = 13) and reverse transcription-polymerase chain reaction (RT-PCR, n = 6). These studies were reviewed for methodology and findings. Significant limitations in methodology were identified, including inconsistent histological definitions of micrometastatic disease, poor sampling because of an inadequate number of lymph nodes or number of sections per lymph node analyzed, lack of conformity with respect to IHC antibody or RT-PCR marker, and inadequate power because of small sample size. Micrometastatic lymph node metastasis identified by RT-PCR was consistently found to be prognostically significant, but this was not true of micrometastatic disease identified by IHC. RT-PCR analysis of lymph nodes with specific markers can help identify pN0 (pathological-negative lymph node) CRC patients at increased risk for recurrence. The identification of occult disease by IHC techniques may also ultimately prove to be associated with worse outcome, but a number of inadequately powered studies have concluded conversely.