Analysis of false reasons based on the artificial intelligence RRCART model to identify frozen sections of lymph nodes in breast cancer

BACKGROUND

Breast cancer is the most common malignant tumor in the world. Intraoperative frozen section of sentinel lymph nodes is an important basis for determining whether axillary lymph node dissection is required for breast cancer surgery. We propose an RRCART model based on a deep-learning network to identify metastases in 2362 frozen sections and count the wrongly identified sections and the associated reasons. The purpose is to summarize the factors that affect the accuracy of the artificial intelligence model and propose corresponding solutions.

METHODS

We took the pathological diagnosis of senior pathologists as the gold standard and identified errors. The pathologists and artificial intelligence engineers jointly read the images and heatmaps to determine the locations of the identified errors on sections, and the pathologists found the reasons (false reasons) for the errors. Through NVivo 12 Plus, qualitative analysis of word frequency analysis and nodal analysis was performed on the error reasons, and the top-down error reason framework of "artificial intelligence RRCART model to identify frozen sections of breast cancer lymph nodes" was constructed based on the importance of false reasons.

RESULTS

There were 101 incorrectly identified sections in 2362 slides, including 42 false negatives and 59 false positives. Through NVivo 12 Plus software, the error causes were node-coded, and finally, 2 parent nodes (high-frequency error, low-frequency error) and 5 child nodes (section quality, normal lymph node structure, secondary reaction of lymph nodes, micrometastasis, and special growth pattern of tumor) were obtained; among them, the error of highest frequency was that caused by normal lymph node structure, with a total of 45 cases (44.55%), followed by micrometastasis, which occurred in 30 cases (29.70%).

CONCLUSIONS

The causes of identification errors in examination of sentinel lymph node frozen sections by artificial intelligence are, in descending order of influence, normal lymph node structure, micrometastases, section quality, special tumor growth patterns and secondary lymph node reactions. In this study, by constructing an artificial intelligence model to identify the error causes of frozen sections of lymph nodes in breast cancer and by analyzing the model in detail, we found that poor quality of slices was the preproblem of many identification errors, which can lead to other errors, such as unclear recognition of lymph node structure by computer. Therefore, we believe that the process of artificial intelligence pathological diagnosis should be optimized, and the quality control of the pathological sections included in the artificial intelligence reading should be carried out first to exclude the influence of poor section quality on the computer model. For cases of micrometastasis, we suggest that by differentiating slices into high- and low-confidence groups, low-confidence micrometastatic slices can be separated for manual identification. The normal lymph node structure can be improved by adding samples and training the model in a targeted manner.

[Sentinel node-positive melanoma]

Two recent randomised studies found no survival difference in patients, who had melanoma with metastasis to the sentinel node (SN) and underwent immediate complete lymph node dissection (CLND), compared with patients, who were followed closely with ultrasound scans and only underwent CLND if metastases developed. From 2018, the Danish guidelines concur: SN-positive patients will no longer undergo routine CLND, which has high morbidity, but will be followed with ultrasound scans of the SN-positive region(s) at their follow-up visits every third month for two years, then every six month for three years, except if PET-CT is performed.

[Sentinel Lymph Node Diagnosis for Lung Cancer]

Many researchers have reported that the sentinel node (SN) theory has been established for lung cancer. However, sentinel node navigation surgery (SNNS) has not yet become a routine medical procedure in lung cancer surgery. SN identification is important for efficient retrieval of micrometastases. Methods for identifying SNs include the dye method and the radioisotope (RI) method, but methods such as the indocyanine green (ICG) method, computed tomographic lymphography (CTLG), and the magnetic method are also being studied. More careful surgical adaptation is required for reduction surgery for early lung cancer, and rapid intraoperative diagnosis is frequently used. SN lymph nodes may be used as an indicator for selecting lymph nodes to be diagnosed intraoperatively. SN identification is considered an important method for ensuring that reduction surgery is curative. Furthermore, if overlooking lymph node metastases can be avoided by using intraoperative rapid diagnosis of micrometastases, we believe that the safety of reduction surgery will be enhanced. In addition, SN identification provides a theoretical basis to support the omission of lymph node dissection. Future developments of SN research and technology are expected.

Validation of a Novel Diagnostic Kit Using the Semidry Dot-Blot Method to Detect Metastatic Lymph Nodes in Breast Cancer: Distinguishing Macrometastases From Nonmacrometastases

BACKGROUND

The semidry dot-blot method is a diagnostic procedure for detecting lymph node (LN) metastases using the presence of cytokeratin (CK) in lavage fluid from sectioned LNs. We evaluated 2 novel kits that use newly developed anti-CK-19 antibodies to diagnose LN metastases in breast cancer.

PATIENTS AND METHODS

We examined 159 LNs dissected that we sliced at 2-mm intervals and washed with phosphate-buffered saline. The suspended cells in the lavage were centrifuged and lysed to extract protein. This extracted protein was used with a low-power and a high-power kit to diagnose LN metastasis. Diagnoses on the basis of the kits were compared with pathological diagnoses.

RESULTS

Of the 159 LNs, 68 were assessed as positive and 91 as negative in permanent section examination. Sensitivity, specificity, and accuracy of the low-power kit for detecting LN metastases was 83.8%, 100%, and 93.1%, respectively. Those of the high-power kit were 92.6%, 92.3%, and 92.5%, respectively. Combining the low- and high-power kit results, those for distinguishing macrometastases were 94.5%, 95.2%, and 95.0%, respectively. Diagnosis was achieved in approximately 20 minutes, at a cost of less than $30 USD.

CONCLUSION

The kits were accurate, fast, and cost-effective in diagnosing LN metastases without the loss of LN tissue.

Blinded review of archival radical prostatectomy specimens supports that contemporary Gleason score 6 prostate cancer lacks metastatic potential

BACKGROUND

Retrospective identification of Gleason pattern 4 in metastatic Gleason score 3 + 3 = 6 (GS6) radical prostatectomy (RP) specimens has suggested true GS6 prostate cancer (CaP) lacks metastatic potential. However, pathologist awareness of study design and metastasis outcomes at the time of RP review might have introduced upgrading bias. We used pathologist-blinded methodology for unbiased characterization of metastasis rates for contemporarily defined pathologic GS6 (pGS6) CaP.

METHODS

An institutional RP database was queried to identify pGS6 patients with metastasis or concern for micrometastasis based on: 1) biochemical failure (BF) despite negative surgical margins or 2) incomplete biochemical response to salvage/adjuvant radiation. RP specimens were regraded independently by two genitourinary pathologists blinded to study aims or clinical outcomes. Additional blinding was performed by random inclusion of pGS6 control specimens from BF-free patients. Only upgrading identified independently by both pathologists was considered.

RESULTS

Among 451 pGS6 patients identified, none had synchronous lymph node metastases and 43/451 (10%) suffered BF. Two patients (0.4%) developed metachronous metastasis during a 110-month median follow-up for BF patients. Both metastatic cases had Gleason pattern 4 on blinded RP review, as did 88% of cases with concern for micrometastasis versus 38% of control cases (P = 0.02). All BF patients (29/29) undergoing postoperative radiation had a complete biochemical response or Gleason pattern 4 on blinded RP review.

CONCLUSIONS

Unbiased pathologist review of archival RP specimens supports absent metastatic potential for contemporarily defined GS6 CaP. Reduced postoperative monitoring is appropriate for pGS6, but may require pathology review to confirm absent Gleason pattern 4.

Predictors of Micrometastases in Patients with Barcelona Clinic Liver Cancer Classification B Hepatocellular Carcinoma

PURPOSE

Transarterial chemoembolization (TACE) is indicated for Barcelona Clinic Liver Cancer (BCLC) B hepatocellular carcinoma (HCC). Whether TACE provides any long-term survival benefits remains unclear. We aimed to investigate micrometastases predictors with which to identify patients who would benefit from surgical resection (SR).

MATERIALS AND METHODS

First, we analyzed risk factors of micrometastases, microvascular invasion, and poor histologic grade in 38 patients with newly diagnosed resectable BCLC stage B HCC limited to one or two segments with well-preserved liver function and who underwent SR between January 2006 and December 2013. Second, we validated identified risk factors in 54 newly diagnosed resectable BCLC B HCC patients with well-preserved liver function who underwent TACE during the same period to determine their influence on survival.

RESULTS

Risk factors of micrometastases in SR patients were α-fetoprotein (AFP) ≥110 [hazard ratio (HR)=5.166; 95% confidence interval (CI), 1.031-25.897; p=0.046] and prothrombin induced by vitamin K absence-II (PIVKA-II) ≥800 (HR=5.166; 95% CI, 1.031-25.897; p=0.046). The cumulative probability of tumor recurrence (p=0.009) after SR differed according to levels of AFP and PIVKA-II. After validation of these risk factors in the TACE group, patients with SR and AFP <110 and PIVKA-II <800 had superior survival outcomes than other patients (HR=0.116; 95% CI, 0.027-0.497; p=0.004).

CONCLUSION

AFP and PIVKA-II levels predict micrometastases and survival. Therefore, they should be considered when selecting SR for BCLC B HCC.

New evidence guiding extent of lymphadenectomy for esophagogastric junction tumor: Application of Ber-Ep4 Joint with CD44v6 staining on the detection of lower mediastinal lymph node micrometastasis and survival analysis

For Siewert type II adenocarcinoma of the esophagogastric junction (AEJ), the optimal surgical approach and extent of lymph nodes dissection remain controversial. Immunohistochemistry (IHC) has been reported to be available for identifying lymph node micrometastasis (LNMM) in patients with AEJ. This was a prospective case series of patients who underwent R0 resection and lower mediastinal lymphadenectomy from January 2010 to June 2015 in Fujian Medical University Union Hospital for Siewert type II AEJ. The outcomes were analyzed retrospectively. A total of 1325 lymph nodes were collected from 49 patients, grouped into 3 groups: lower mediastinal, paracardial, and abdominal. The former 2 groups were examined by monoclonal antibodies against Ber-Ep4 and CD44v6. The incidence of LNMM in mediastinal group was 37% (18/49) for Ber-Ep4 and 33% (16/49) for CD44v6. While in routine histological diagnosis, the number of patients with the positive lymph nodes was 7 (14%). When combining IHC with histopathology (HE) staining, the incidence of positive mediastinal lymph nodes was increased to 24%, with a total number of 37 lymph nodes from 28 patients (57%). Micrometastases indicated by Ber-Ep4 and CD44v6 were associated with the depth of tumor invasion (P = 0.020 and 0.037, respectively), histopathological nodal status (P = 0.024 and 0.01, respectively), and Lauren classification (P = 0.038 and, respectively). Expression of CD44v6 and Ber-Ep4 was positively correlated (r = 0.643, P < 0.001). The 3- and 5-year survival rates for all patients were 66% and 50%, respectively. The patients with LNMM had a lower 3-year survival rate of 51%, compared to 80% from no LNMM group; 5-year survival rate was also lower in LNMM group, which is 29% versus 68% (P = 0.006) in the no LNMM group. Patients with positive Ber-Ep4 cells had a lower survival, but not statistically significant (P = 0.058). CD44v6-positive group had a significantly reduced survival (P < 0.001). In patients group with negative lower mediastinal lymph nodes, patients without LNMM obtained a significant survival benefit (P = 0.021). Our study demonstrated that routine test for LNMM is necessary for patients with negative lymph nodes. As a positive prognostic factor, thorough lower mediastinal lymphadenectomy in an invasive approach should be considered when necessary. Ber-Ep4 and CD44v6 were shown to be great markers for detecting LNMM.

Tissue factor-specific ultra-bright SERRS nanostars for Raman detection of pulmonary micrometastases

Here we demonstrate a novel application of 'surface enhanced resonance Raman scattering nanoparticles' (SERRS NPs) for imaging breast cancer lung metastases with much higher precision than currently feasible. A breast cancer lung metastasis mouse model was established by intravenous injection of LM2 cells. These mice were intravenously administered SERRS NPs conjugated with ALT-836, an anti-tissue factor (TF) monoclonal antibody, and subjected to Raman imaging to visualize the expression of TF both in vivo and ex vivo. Raman imaging indicated marked uptake of αTF-SERRS-NPs by the lung metastases compared to isotype and blocking controls. Conversely, little uptake of αTF-SERRS-NPs was observed in the lungs of healthy mice. Successful detection and delineation of pulmonary micrometastatic lesions as small as 200 μm, corroborated by histology, immunohistochemistry, and bioluminescence imaging confirmed the suitability of both TF as a target and αTF-SERRS-NPs as an effective contrast agent for imaging breast cancer lung metastases. Further advancements of this technique in the form of Raman endoscopes coupled with ultrabright SERRS NPs developed in this work could lead to minimally invasive detection and resection of lung metastases.

CXCR-4 Targeted, Short Wave Infrared (SWIR) Emitting Nanoprobes for Enhanced Deep Tissue Imaging and Micrometastatic Cancer Lesion Detection

Realizing the promise of precision medicine in cancer therapy depends on identifying and tracking cancerous growths to maximize treatment options and improve patient outcomes. This goal of early detection remains unfulfilled by current clinical imaging techniques that fail to detect lesions due to their small size and suborgan localization. With proper probes, optical imaging techniques can overcome this by identifying the molecular phenotype of tumors at both macroscopic and microscopic scales. In this study, the first use of nanophotonic short wave infrared technology is proposed to molecularly phenotype small lesions for more sensitive detection. Here, human serum albumin encapsulated rare-earth nanoparticles (ReANCs) with ligands for targeted lesion imaging are designed. AMD3100, an antagonist to CXCR4 (a classic marker of cancer metastasis) is adsorbed onto ReANCs to form functionalized ReANCs (fReANCs). fReANCs are able to preferentially accumulate in receptor positive lesions when injected intraperitoneally in a subcutaneous tumor model. fReANCs can also target subtissue microlesions at a maximum depth of 10.5 mm in a lung metastatic model of breast cancer. Internal lesions identified with fReANCs are 2.25 times smaller than those detected with ReANCs. Thus, an integrated nanoprobe detection platform is presented, which allows target-specific identification of subtissue cancerous lesions.

[Study on the correlation between BRAF(V600E) mutation and lymphatic metastases in papillary thyroid cancer staged preoperativelv as N0]

OBJECTIVE

To study the prevalence of BRAF(V600E) mutations in small (≤ 2 cm) papillary thyroid carcinoma (PTC), explore the correlation with occult central nodal metastasis (CNM) of clinically-nodal negative (cN0) neck for small (≤ 2 cm) papillary thyroid carcinoma (PTC).

METHOD

Primary tumor tissue (paraffin-embedded) from 72 patients with small (≤ 2 cm) cN0 PTC who underwent prophylactic central neck dissection (pCND) was tested for BRAF mutation. by nested PCR, the factors of lymph node metastasis such as clinicopathologic including tumor size, multifocality, extrathyroidal invasion, and BRAF mutations were analyzed. Prediction scores were generated using logistic regression models and BRAF was evaluated to see if it was a risk factor for CNM.

RESULT

The prevalence of BRAF was 47.22% (34/72) while the rate of CNM was 36.11% (26/72). Univariate analysis showed that the risk factors of lymph node metastasis for cN0 PTC were significantly correlated with tumor size (P = 0.016), bilateral tumor (P = 0.010), multifocality (P = 0.026), extrathyroidal invasion (P = 0.024), and BRAF mutations (P = 0.041). Univariate analysis showed that tumor size (OR = 2.674, 95% CI = 1.702-3.997), multifocality (OR = 1.371, 95% CI = 1.065-2.087), extrathyroidal invasion (OR = 0.540, 95% CI = 0.396-0.794) and BRAF (OR = 1.647, 95% CI = 1.101-2.463) were risk predictors of CNM.

CONCLUSION

The incidence of central neck micrometastatic disease is 36.11% in patients with PTC deemed N0 preoperatively by clinical examination and ultrasound of the neck lymph nodes and intraoperatively by inspection of the central compartment. The factors of high risk of CNM included tumor size, multifocality, extrathyroidal invasion, BRAF mutations. When a patient has the risk factors of lymph node metastasis should be electived prophylactic CCND.

The prognostic value of sentinel lymph node micrometastases in patients with invasive breast carcinoma

AIM

The prognostic value of sentinel lymph node micrometastases in invasive breast cancer patients is still widely debated. Even if, in the absence of unequivocal guidelines, the axillary lynphadenectomy is not still performed in the routine clinical care of these patients.

METHOD

We have retrospectively analyzed 746 patients with operable invasive breast cancer and clinically negative axillary lymph nodes. These patients underwent conservative surgery or total mastectomy with sentinel lymph node biopsy. Patients with micrometastases in the sentinel lymph node treated with axillary dissection has been checked and the involvement of the remaining lymph nodes analyzed. Patients with micrometastases in the SLN not followed by axillary dissection have been checked as well and the incidence of recurrences has been evaluated in both groups.

RESULTS

Micrometastases were found in 51 (6.83%) patients and isolated tumor cells in 8 (1.07%) patients at frozen section and confirmed at the final hystopathologic examination. Fifteen of these patients underwent complete axillary dissection: two of them (13.33%) had metastatic involvement of other axillary lymph nodes. The other 44 patients didn't receive further surgical axillary procedure. No axillary recurrences in these patients were found during a median follow up of 65.3±9.65 months (range 42-78 months).

CONCLUSION

Based on the results and according to some recent randomized trials we can say that axillary lynphadenectomy can be avoided when micrometastases are found in sentinel lynph nodes. It should be performed anyway, depending on the analysis of the biomedical profile of the tumor.

KEY WORDS

Breast carcinoma, Micrometases, Sentinel lymph node.

Sentinel lymph node biopsy in breast cancer New indications and our experience

INTRODUCTION

Owing to complexity and difficulty regarding evaluation of all the regional lymph nodes, the Sentinel Lymph Node Biopsy (SLNB) has represented in recent years a suitable technique for setting lymph node status; it allows pathologists to focus on a small number of lymph nodes and stage patients with clinically negative lymph nodes; this sort of assessment leads surgeons to a correct approach; on the contrary, the presence of metastases makes advisable to perform Axillary Lymph Node Dissection (ALND).

MATERIALS AND METHODS

From September 2008 to December 2013, 142 patients suffering from breast cancer were enrolled. Mean age was 54 years (range 37-80), in 88 (62%) patients the lesion was localized to the right breast, while in the remaining 54 (38%) the disease was localized in the left breast. Also in 85 (60%) patients, the tumor involved the upper-outer quadrant, in 24 (17%) the lower external quadrant, in 19 (13%) the upper-inner quadrant and in the remaining 14 (10%) the inferior-internal quadrant.

RESULTS

There were neither intra nor post-operative complications. The all removed breast lesions were histologically malignant: 99 (70%) patients had a histological diagnosis of invasive ductal, 30 (21%) of invasive lobular, 9 (6%) ductal in situ and 4 (3%) of mixed invasive cancer. Sentinel Lymph Node (SLN) was always identified and it was extemporaneously positive in 62 cases (44%): 40 cases had macro-metastatic involvement whereas the remaining 22 cases had micro-metastases only. The definitive histological examination confirmed the presence of micro-metastases in 18 cases, while in 2 cases there was a supra-staging to macro-metastases and in other 2 a sub-staging of Isolated Tumor Cells (ITC). None of the patients with micro-metastatic SLN involvement developed recurrence within 24 months, whereas only one patient died after one year owing to at distance dissemination.

CONCLUSION

Lymph node status has increasingly been getting one of the most important prognostic factor. Consequently the bigger the tumor nodal involvement appears the worse the prognosis becomes. Our data confirm the main role of SLNB on managing surgical treatment of breast cancer.

KEY WORDS

Biopsy, Breast cancer, Sentinel lymph node.

Prognostic value of bone marrow micrometastasis in patients with operable esophageal squamous cell carcinoma: a long-term follow-up study

INTRODUCTION

Detection of bone marrow micrometastasis (BMM) has been focused on as a prognostic parameter in various malignant neoplasms recently. This study was designed to evaluate the prognostic significance of BMM detection in patients with operable esophageal squamous cell carcinoma (ESCC) after long-term follow-up.

METHODS

In 61 consecutive patients with ESCC who had undergone radical surgical resection, BMM was detected through reverse transcriptase-polymerase chain reaction (RT-PCR). Correlation between BMM detection and prognosis of the 61 patients was analyzed.

RESULTS

BMM was found in 13 patients (21.3%). No significant correlation between BMM detection and tumor, node, metastasis (TNM) stage was found. The median survival time, 5-year overall survival rate, 5-year disease-free survival rate, and 5-year distant disease-free survival rate for cases with positive BMM were 13.0 months, 15.4%, 7.7%, and 34.2%, respectively, compared with that of 66.0 months, 59.7%, 49.1%, and 60.6% for cases with negative BMM (p < 0.05). In multivariate analysis, BMM were found to be an independent factor in the prediction of overall survival (odds ratio [OR] 3.928, p = 0.001), disease-free survival (OR 4.285, p < 0.001), and distant disease-free survival (OR 3.270, p = 0.013).

CONCLUSIONS

BMM is an independent prognostic factor in the prediction of the subsequent development of metastatic disease and disease outcome for operable ESCC patients, and may be a useful adjunct to conventional tumor staging. Further studies are required to evaluate the value of neoadjuvant or adjuvant systemic therapy in ESCC patients with BMM.

Comparative analysis between multilevel sectioning with conventional haematoxylin and eosin staining and immunohistochemistry for detecting nodal micrometastases with stage I and II colorectal cancers

Management of patients with stage II colorectal carcinomas remains challenging as 20 - 30% of them will develop recurrence. It is postulated that these patients may harbour nodal micrometastases which are imperceptible by routine histopathological evaluation. The aims of our study were to evaluate (1) the feasibility of multilevel sectioning method utilizing haematoxylin and eosin stain and immunohistochemistry technique with cytokeratin AE1/AE3, in detecting micrometastases in histologically-negative lymph nodes, and (2) correlation between nodal micrometastases with clinicopathological parameters. Sixty two stage I and II cases with a total of 635 lymph nodes were reviewed. Five-level haematoxylin and eosin staining and one-level cytokeratin AE1/AE3 immunostaining were performed on all lymph nodes retrieved. The findings were correlated with clinicopathological parameters. Two (3.2%) lymph nodes in two patients (one in each) were found to harbour micrometastases detected by both methods. With cytokeratin AE1/AE3, we successfully identified four (6.5%) patients with isolated tumour cells, but none through the multilevel sectioning method. Nodal micrometastases detected by both multilevel sectioning and immunohistochemistry methods were not associated with larger tumour size, higher depth of invasion, poorer tumour grade, disease recurrence or distant metastasis. We conclude that there is no difference between the two methods in detecting nodal micrometastases. Therefore it is opined that multilevel sectioning is a feasible and yet inexpensive method that may be incorporated into routine practice to detect nodal micrometastases in centres with limited resources.

Detection of micrometastases of squamous cell carcinoma tumor cells in muscle tissue

The aim of this study was to evaluate microarray technology in the detection of micrometastases of head and neck squamous cell carcinoma (HNSCC) in muscle tissue. Three hundred SCCVII tumor cells were injected intramuscularly into the right flank of ten C3H/Km mice. One week later, the animals were euthanized and the muscle tissue was taken out. Histology (H&E staining), microarray and reverse transcriptase polymerase chain reaction analysis (RT-PCR) of the tissue was performed. Histology showed a few tumor cells between the muscle fibers. Microarray technology showed the different gene expression pattern of the muscle tissue with micrometastases in comparison to normal muscle tissue. Only genes with a fold change difference of 10 or greater were considered. Gene expression analysis revealed changes in the expression levels of 91 genes of micrometastases in muscle tissue. RT-PCR confirmed gene up-regulation. Significant differences in gene expression between micrometastases in muscle tissue and pure muscle tissue were found. The genes found to be up-regulated could be used to detect micrometastases in muscle tissue.

The clinical importance of a transcription reverse-transcription concerted (TRC) diagnosis using peritoneal lavage fluids in gastric cancer with clinical serosal invasion: a prospective, multicenter study

PURPOSE

We have developed a novel molecular method of diagnosis using the technique of transcriptase-reverse transcriptase concerted reaction (TRC) for the detection of cancer micrometastasis. This study prospectively examined the clinical importance of the TRC diagnosis with peritoneal lavage fluids collected from gastric cancer operations at multiple institutes.

METHODS

TRC amplification targeting carcinoembryonic antigen mRNA was applied to detect gastric cancer cells in peritoneal lavage fluids obtained during gastric cancer resections from nine different hospitals. A total of 137 patients with a clinical diagnosis of serosa-invading neoplasms were enrolled to investigate the correlation between the TRC diagnosis and patient prognosis.

RESULTS

Of the 137 patients, 27 (20%) were positive by cytologic examination. In contrast, TRC targeting carcinoembryonic antigen mRNA was positive in 59 of 137 (54%) patients. TRC positivity was associated with a poorer overall survival in all patients and in the 104 patients who underwent a curative operation. TRC positivity also was associated with the peritoneal recurrence-free survival rate in the 104 curative cases. Multivariate analysis showed that TRC positivity and the pathologic N factor were prognostic factors for the overall survival time.

CONCLUSION

Our prospective multicenter study showed that the TRC test using peritoneal lavage fluids could be a potential prognostic factor to predict patient survival and peritoneal recurrence with clinically diagnosed, serosa-invading gastric cancer.

[Micrometastases: strategies for detection]

Micrometastasis or minimal residual disease has become critically important in oncology since it represents a true clinical problem that must be solved, as the response of these tumor foci to the different treatments that are used for the control of cancer, is still unknown. Even though this is a fundamental specific problem to be solved, there are already immunohistochemical and molecular biology diagnostic methods that have allowed microfoci location of tumor cells in various organs and tissues, and different techniques are available to determine and quantify these lesions. Within these techniques, flow cytometry and different molecular methods are included, and they range from the traditional to the newest and most sophisticated. The goal of this review was aimed to evaluate new diagnostic methods that permit the identification of this residual disease, which would serve to establish individualized treatments and prevent the recurrence of the disease in cancer patients under treatment.

[Detection of micrometastases and its clinical significance in sentinel and non-sentinel lymph nodes from early cervical carcinoma]

OBJECTIVE

To investigate the clinical significance of micrometastasis detection in sentinel lymph nodes (SLN) from patients with early cervical carcinoma.

METHODS

Thirty patients with early cervical carcinoma were studied to identify SLN intraoperatively using methylene blue. One lymph node was removed randomly from palpable SLN and other pelvic lymph nodes (nSLN) in each patient, so 268 lymph nodes were collected and cut into two halves, one half of the lymph node was used to analyze the expression of cytokeratin 19 (CK19) mRNA by real-time fluorescence quantitative polymerase chain reaction to determine the presence of micrometastasis, the other half was examined by routine histology with HE staining.

RESULTS

67 SLNs were detected in 28 cases (93.3%). Pelvic lymph nodes of 6 cases were confirmed pathological metastasis. The sensitivity of SLN detection was 66.7%, the accuracy rate was 96.4%, and the false negative rate was 16.7%. Among 268 lymph nodes (including 9 lymph nodes with pathological metastasis) detected by real-time fluorescence quantitative polymerase chain reaction, 68 lymph nodes were pathological negative but had micrometastasis, accounting for 26.3% (68/259) in pathologically negative lymph nodes. Among 24 patients with pathological negative lymph nodes, 16 cases had micrometastasis, accounting for 66.7% in those patients. Among 16 patients with micrometastasis, SLN of 3 cases were negative, but nSLN were micrometastasis, so the SLN false-negative rate rose to 18.2%. There were no significant relationships between pelvic lymph nodes micrometastasis and perivascular space involvement, deep stromal invasion and tumor grade (all P > 0.05). The micrometastasis rate of nSLN in patients with SLN micrometastasis was 100%, significantly higher than that in the patients with SLN non-micrometastasis (27.3%, P < 0.01).

CONCLUSIONS

Real-time fluorescence quantitative polymerase chain reaction is a sensitive method to detect SLN micrometastasis. SLN micrometastasis may be an effective complement to SLN pathology to predict nSLN metastasis. Pelvic lymph nodes micrometastases have no significant relationship with pathological risk factors in cervical cancer and prognosis of patients.

[Analysis of intraoperative molecular assessment of sentinel lymph nodes in breast carcinoma]

OBJECTIVE

To evaluate the reliability and application of GeneSearch(TM) breast lymph node assay (Genesearch), a real-time fluorescence quatitative PCR method, in intraoperative assay of metastasis in sentinel lymph nodes (SLNs) from breast cancer patients.

METHODS

Totally 140 SLNs from 80 patients with breast carcinoma were prospectively studied from May 2010 to August 2010. The 80 patients included 78 women and 2 men who ranged in age from 29 to 85 years, and the median age is 49 years. The expression of CK19 and mammaglobulin in all 140 SLNs were detected by Genesearch, and the results were compared with that of histological evaluation of both frozen and paraffin-embedded sections.

RESULTS

Among SLNs, by histological analyses, there were 121 without metastasis, 17 with macrometastasis, 2 with micrometastasis, and none of isolated tumor cell. By Genesearch, there were 119 without metastasis and 21 with metastasis. Genesearch showed sensitivity of 89.4%, positive predictive value of 81.0%, negative predictive value of 98.3% and specificity of 96.7% by comparing to histological analyses. The concordance between Genesearch and histological analysis was 95.7%. The sensitivity of Genesearch was 15/17 for macrometastasis and 2/2 for micrometastasis.

CONCLUSIONS

Genesearch detection presents high sensitivity and specificity in evaluating metastasis of sentinel lymph nodes in breast cancer, but strict performance technically is necessary to avoid false positive and false negative results. Inability of further subtyping for the positive cases might be the key limitations for wide application of this method.

[Surgical oncologist or prophet?]

The prognostication of the future behavior of a head and neck malignancy is still achieved by mainly morphological criteria. A common problem is the incertainty regarding the existence of occult metastatic disease in early tumors of the head and neck. In the focus of current research projects is the identification of molecular markers predicting the presence or absence of such occult metastases. By the detection of molecular markers with statistically significant correlations to metastatic disease it woulde be possible the select patients more accurately for necessary additional surgical treatment (e.g. neck dissection).

[Lymph node micrometastases in gastric cancer]

Lymph node micrometastases in gastric cancer are based on the definition in the 6th version of the TNM classification of malignant tumours edited by the International Union Against Cancer, which is also quoted in the 14th version of the Japanese Classification of Gastric Carcinoma. Histopathologic examination such as immunohistochemistry and molecular biological techniques including RT-PCR and one-step nucleic acid amplification are used for the detection of micrometastases. Because the time required for such detection is shortened to 30 to 40 min, intraoperative detection is feasible. Many papers have reported the correlation between micrometastases and prognosis in gastric cancer, although whether micrometastases are correlated with poor prognosis even when completely resected remains unknown. Intraoperative detection of micrometastases is important to decide the operative procedure in sentinel node navigation surgery.

[Translational research and diagnostics for breast cancer]

In breast cancer, tumor biological markers are gaining impact and have become equal to traditional markers of pathology. Molecular expression profiling has led to new categories, which by receiving translation into immunohistochemical terms have entered routine pathology use. Besides the triple negative (basal) type, there are hormone receptor positive luminal A and B types and the HER2 type. The distinction between luminal A and B type is not yet clear cut and the proliferation marker Ki-67 as well as diverse RNA expression profiles are used for distinction in order to decide which patients might benefit from pure endocrine and which from combined chemo-endocrine therapy. Prospective studies are necessary to answer these questions. Study data are further awaited to clarify the heterogeneity of triple negative cases which include most of the BRCA1 associated cancers and to elucidate whether within the HER2 category, polysome or pseudopolysome cancer will respond to therapy.

Combination of pet imaging with viral vectors for identification of cancer metastases

There are three main ways for dissemination of solid tumors: direct invasion, lymphatic spread and hematogenic spread. The presence of metastases is the most significant factor in predicting prognosis and therefore evidence of metastases will influence decision-making regarding treatment. Conventional imaging techniques are limited in the evaluation and localization of metastases due to their restricted ability to identify subcentimeter neoplastic disease. Hence, there is a need for an effective noninvasive modality that can accurately identify occult metastases in cancer patients. One such method is the combination of positron emission tomography (PET) with vectors designed for delivery of reporter genes into target cells. Vectors expressing the herpes simplex virus-1 thymidine kinase (HSV1-tk) reporter system have recently been shown to allow localization of micrometastases in animal models of cancer using non invasive imaging. Combination of HSV1-tk and PET imaging is based on the virtues of vectors which can carry and selectively express the HSV1-tk reporter gene in a variety of cancer cells but not in normal tissue. A radioactive tracer which is applied systemically is phosphorylated by the HSV1-tk enzyme, and as a consequence, the tracer accumulates in proportion to the level of HSV1-tk expression which can be imaged by PET. In this paper we review the recent developments in molecular imaging of micrometastases using replication-competent viral or nonviral vectors carrying the HSV1-tk gene using PET imaging. These diagnostic paradigms introduce an advantageous new concept in noninvasive molecular imaging with the potential benefits for improving patient care by providing guidance for therapy to patients with risk for metastases.

Cancer imaging: Gene transcription-based imaging and therapeutic systems

Molecular-genetic imaging of cancer is in its infancy. Over the past decade gene reporter systems have been optimized in preclinical models and some have found their way into the clinic. The search is on to find the best combination of gene delivery vehicle and reporter imaging system that can be translated safely and quickly. The goal is to have a combination that can detect a wide variety of cancers with high sensitivity and specificity in a way that rivals the current clinical standard, positron emission tomography with [(18)F]fluorodeoxyglucose. To do so will require systemic delivery of reporter genes for the detection of micrometastases, and a nontoxic vector, whether viral or based on nanotechnology, to gain widespread acceptance by the oncology community. Merger of molecular-genetic imaging with gene therapy, a strategy that has been employed in the past, will likely be necessary for such imaging to reach widespread clinical use.

[Relationship between cervical micrometastasis and early recurrence and prognosis in laryngeal carcinoma]

OBJECTIVE

To analyse the correlation between the micrometastasis and early recurrence and prognosis in laryngeal cancer.

METHODS

Total of 126 patients with laryngeal squamous cell carcinoma were included in the study. The micrometastasis was detected with hematoxylin and eosin staining (HE) and immunohistochemical staining for cytokeratin (CK) of the lymph node specimens after selective neck dissection (II-IV). Chi-square test was used to analyse the relationship between the micrometastasis and early recurrence and prognosis, and Kaplan-Meier method was used for survival analysis.

RESULTS

HE staining showed positive micrometastasis in 41 cases and negative micrometastasis in 85 cases in which 33 cases were positive staining for CK. With a following-up of mean 6.3 years, recurrence or metastasis occurred in 15 cases with positive micrometastasis detected by HE staining, 14 cases with CK positive staining and 4 cases with CK negative staining. The correlation between micrometastasis and early recurrence was significant (P < 0.01). The total 5-year survival rate was 79.8%, 10-year survival rate was 60.5%. The 10-year survival rate (52.1%) of the patients with CK positive staining indicating micrometastasis was significantly higher than that of CK negative patients (81.2%, P < 0.01).

CONCLUSION

Cervical micrometastasis predicts poor prognosis and early recurrence in patients with laryngeal squamous cell carcinoma.

Ultrastaging of colon cancer by sentinel node biopsy using fluorescence navigation with indocyanine green

PURPOSE

Lymph node status is the most important prognostic factor in colon cancer, but the role of sentinel lymph node biopsy (SLNB) as a tool for identification of micrometastatic disease and extraanatomical lymph nodes for adjuvant strategies and a tailored approach still remains unclear. Indocyanine green (ICG) fluorescence detection is a new method for SLNB allowing real-time lymphography and lymph node detection. This study was designed to evaluate the feasibility of fluorescence-guided sentinel lymph node detection in colon carcinoma.

METHODS

Twenty six patients with colon adenocarcinoma were prospectively included in this study. Intraoperatively, a peritumorous injection with a mean of 2.0 ml ICG was performed, followed by lymphatic mapping and SLNB. Clinical feasibility, detection rate, and sensitivity of the method were analyzed.

RESULTS

No adverse reactions occurred due to the injection of ICG. Overall, ICG fluorescence imaging identified 1.7 sentinel lymph node (SLN) in average in 25 out of 26 patients (detection rate, 96%). Metastatic involvement of the SLN was found in nine out of 11 nodal positive patients by conventional histopathology. The sensitivity of the method was 82% for colon carcinoma, respectively.

CONCLUSION

ICG fluorescence imaging is a new, feasible method for SLNB of colon carcinoma and enables ultrastaging with improved accuracy but with limited validity due to the small number of cases. One advantage of this technique is real-time visualization of lymphatic vessels and SLNB without radiation exposure. Further, larger series are necessary to analyze the role of fluorescence-guided SLNB for colon cancer.

Local lymph node micrometastasis in a patient with negative sentinel lymph node biopsies after lymphatic mapping with wide local excision of primary melanoma on the head/neck area

Sentinel lymph node biopsy is widely accepted as a staging procedure for patients with cutaneous melanoma who are at risk for metastases. The complex lymphatic drainage pattern on the head and neck makes sentinel lymph node mapping more challenging compared with other sites. Here, we report a patient who underwent reexcision of the primary tumor site with lymphatic mapping on the right posterior auricular area. Four sentinel nodes were negative for melanoma metastasis; however, step sectioning of the wide local excision of the primary tumor site revealed a small lymph node with histopathologic detection of micrometastasis. Our findings highlight the importance of a careful histopathologic approach that may have prognostic impact on outcome and survival.

[Prevalence of micrometastases and isolated tumor cells in the sentinel node at early stage breast cancer]

AIM

To analyze the prevalence of isolated tumor cells (ITC) and micrometastases in the sentinel node of early stage breast cancer.

MATERIAL AND METHODS

A total of 234 patients diagnosed of breast cancer, stages T1 or T2, with no axillary involvement detected by palpation or ultrasound-FNA, were studied. The sentinel node (SN) was identified by lymphoscintigraphy and removed in the operating room. Serial sections and immunohistochemical staining were then performed, classifying them as negative (SN-), negative with ITC (SN-ITC), positive with micrometastases (SN+mic) and positive with macrometastases (SN+mac). A complete axillary lymphadenectomy (CAL) was carried out in those cases with micro- or macrometastases, the former being classified as negative (CAL-), positive with micrometatases (CAL+mic), and positive with macrometastases (CAL+mac). The follow-up ranged from 6-71 months.

RESULTS

ITC were found in 12 patients (5.1%) and micrometastases in 24 (10.3%). Thus, a total of 36 patients were affected by some of these conditions (15.4%). In the group with micrometastases, the result of CAL was CAL- in 19/24 (79.1%), CAL+mic in 2 (8.3%) and CAL+mac in 3 (12.5%). No axillary recurrences have occurred up to date.

CONCLUSIONS

ITC and micrometastases were found in the sentinel node in a significant percentage of patients in the early stages of breast cancer. The low percentage of further axillary invasion in the group of micrometastases may open up the possibility of avoiding CAL in favor of other adjuvant treatments (chemotherapy, radiotherapy).