Detection Of Lymph Node Micrometastases Research Articles

Prognostic significance of histologically detected lymph node micrometastases of sizes between 0.2 and 2 mm in colorectal cancer

Minimal lymph node involvement is a potential prognostic factor in colorectal cancer. The International Union Against Cancer defined tumour deposits between 0.2 and 2 mm as micrometastases and clusters and single-cell infiltrations below this cutoff as isolated tumour cells. Nevertheless, only a minority of studies discriminated metastatic involvements according to this definition. In order to investigate the prognostic significance of micrometastases (0.2-2 mm), we performed a retrospective study enrolling 44 routinely diagnosed micrometastatic cases within 15 years which represent about 1% of our cases. These cases have been re-evaluated. Seven of the micrometastatic cases turned out to be macrometastases after step sectioning. Complete follow-up was available in 33 remaining cases. Collections of node-negative and macrometastatic cases served as control groups. The Kaplan-Meier curves of macro- and micrometastatic cases showed a similar adverse course (p = 0.830) especially during the first 40 months. The 5-year-survival rates were 51, 60 and 64 months for macro-, micrometastatic and node-negative cases, respectively. The difference in overall survival, however, reached only a statistical trend and was not significant (p = 0.137). After re-evaluation with step sections and cytokeratin immunohistochemistry out of an initial 91 node-negative cases, 11 (12%) cases were identified with isolated tumour cells and one (1%) case with a micrometastasis. Our data show that micro- and macrometastatic colorectal cancers show very similar survival rates. Therefore, efforts to improve the detection of lymph node micrometastases seem to be justified.

Lymph node micrometastases detected by carcinoembryonic antigen mRNA affect long-term survival and disease-free interval in early-stage lung cancer patients

The majority of stage I lung cancer patients undergo a complete resection of their tumor; however, they still harbor a considerable risk of mortality due to recurrences. A correlation between the presence of lymph node micrometastases and poor prognosis has been observed. The aim of this study was to correlate the lymph node molecular staging with the 5-year survival and disease-free interval following pulmonary lobectomy for non-small cell lung cancer (NSCLC). A quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for carcinoembryonic antigen (CEA) mRNA was performed on primary lung tumors and regional lymph nodes from 55 surgically resected NSCLC patients classified as clinical stage I. CEA mRNA was found to be present in all the primary tumors. RT-PCR revealed the presence of cancer cells in the lymph nodes of 20 patients (36.3%) and routine staining detected lymph node metastases in 11 patients. Significant differences in survival and disease-free intervals were observed in patients with lymph node micrometastases versus patients with negative lymph nodes (P=0.0026 and P=0.0044, respectively). Multivariate analyses confirmed that micrometastases were an independent predictor for worse prognosis (P=0.0098) and a short disease-free interval (P=0.0137). This study demonstrated strong correlations between the molecular detection of lymph node micrometastases and 5-year survival rates and disease-free interval in patients who underwent pulmonary lobectomy for early-stage lung cancer.

Clinical Significance of Lymph Node Micrometastasis in Gastric Cancer

Recently, the existence of lymph node micrometastasis (LNM), including isolated tumor cells, has been focused on during the development of molecular diagnostic tools for lymph node metastasis in various malignant neoplasms. In particular, immunohistochemistry and reverse transcription-polymerase chain reaction have been reported to be available for the detection of LNM in gastric cancer. However, at present, the clinical significance of LNM remains unclear in patients with gastric cancer. Therefore, we cannot strategically make light of this issue in clinical management. Currently, minimally invasive treatments, such as endoscopic submucosal dissection and laparoscopic surgery with personalized lymphadenectomy, are widely performed in consideration of postsurgical quality of life (QOL). However, it is important to maintain the balance between QOL and curability when selecting surgical treatments for patients with gastric cancer. If minimally invasive surgery based on LNM status was established for patients with early gastric cancer, it could be performed safely. We reviewed the clinical significance of LNM as an important strategic target in patients with gastric cancer.

Biomarkers vs conventional histological analysis to detect lymph node micrometastases in bladder cancer: a real improvement?

Study Type - Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Muscle invasive bladder cancer has a mortality rate at 5 years of 50%, despite radical therapy, as a result of tumour progression and dissemination. This suggests that half of patients have disseminated disease at the time of diagnosis, which is not detected by the staging techniques currently used. The prognostic factors (histological grade and tumour stage) and current staging techniques do not discriminate between those patients who will be cured with surgical treatment and those who will die from metastatic spread. New diagnostic and prognostic tools that complement the existing methods and provide a proper assessment of carcinoma invading bladder muscle are therefore essential. Molecular staging techniques using specific biomarkers have been applied in various solid tumours to determine the presence of missed tumour cells in lymph nodes (LNs) during routine pathological examination. These techniques could identify patients with LN micrometastases who may potentially benefit from early treatment with chemotherapy. This study compares the performance of conventional histological analysis and molecular biomarkers in detecting bladder cancer LN micrometastases and predicting patient's clinical outcome. The study found that, even though a clear trend to a worse outcome was shown in those patients who became node-positive after molecular analysis, no statistical differences were found in cancer-specific and recurrence-free survival analysis between those patients who were negative by histology but positive by molecular analysis and those who were negative by both techniques. We concluded that molecular analysis of LN spreading in bladder cancer has a better detection rate than conventional histological examination. • To improve the sensitivity of histological examination in detecting occult lymph node (LN) dissemination of bladder cancer using gene expression analysis. • We carried out a retrospective study that included 504 formalin-fixed paraffin-embedded LNs from 90 patients with muscle invasive bladder cancer and 35 controls. • Gene expression values of two molecular biomarkers (FXYD3 and KRT20) were analysed using reverse transcription real-time quantitative PCR (RT-qPCR). • Molecular results were compared with histological status and patients' clinical outcomes. • Of the 90 patients analysed, 16 were positive and 74 were negative by histological analysis. Of these 74, 19 were classified as positive using RT-qPCR. • Significant differences in cancer-specific (P= 0.011) and recurrence-free (P= 0.009) survival were found between the three patient groups (patients positive by both techniques, patients negative by both techniques, and patients negative by histological but positive by molecular analysis). • A significant difference was not found between histologically negative but molecularly positive patients and patients who were negative by both techniques, but a clear trend to a worse outcome was found in those patients who became node-positive after molecular analysis. • The analysis of FXYD3 and KRT20 could improve current pathological examination for the detection of micrometastases in LNs. • Further and more extensive studies will determine the real prognostic value of such LN micrometastases.

Expression of high-risk HPV DNA and CK19 in pelvic lymph nodes in stage Ⅰa-Ⅱa cervical cancer and their clinical value

The aim of this study was to investigate the detection rate and methods of micrometastases in early-stage cervical cancer by detecting the expression of high-risk HPV DNA and CK19 in pelvic lymph nodes. A total of 104 lymph nodes with/without pathologically confirmed metastases, from 28 patients with early-stage cervical cancer, were included for detection of high-risk HPV DNA and CK19 expression using in situ hybridization and immunohistochemistry, respectively. The detection rate of high-risk HPV DNA and CK19 in lymph nodes in patients with pathologically-confirmed lymph node metastases was higher compared to that in lymph nodes in patients without pathologically-confirmed lymph node metastases (P<0.001). In all 80 pathologically-negative lymph nodes, the positivity rates of high-risk HPV DNA and CK19 detection were 45 and 25%, respectively. In 57 lymph nodes in patients without pathologically-confirmed lymph node metastases the positivity rates of high-risk HPV DNA and CK19 detection were 43.5 and 24.6%. The detection rate of high-risk HPV DNA and CDK19 in 15 patients without pathologically-confirmed lymph node metastases were 60 and 46.6%, respectively. The detection rates of high-risk HPV DNA and CK19 in 104 lymph nodes were 56.7 and 41.3% (KI=0.46). The results of the two detection methods showed good consistency. Both detection of high-risk HPV DNA by in situ hybridization, and CK19 by immunohistochemical method detected lymph node micrometastases in early-stage cervical cancer. As a method of detection on the molecular level, in situ hybridization was more sensitive for the detection of lymph node micrometastases in early-stage cervical cancer.

A Pragmatic Approach to the Diagnosis of Nodal Micrometastases in Early Stage Non-small Cell Lung Cancer

This study was designed to develop a both sensitive and efficient algorithm for detection of lymph node micrometastases and to determine its prognostic impact in patients with early stage non-small cell lung cancer (NSCLC). One hundred seventy patients with NSCLC p stage I and II were included in this study, of which n = 5299 lymph nodes were obtained and submitted to histopathologic analysis. From each patient, a median number of 31 lymph nodes was received (N-1 position: median n = 16; N-2 position: median n = 15). Immunohistochemistry was performed to detect micrometastases unobvious by conventional microscopy using antibodies against cytokeratins (CK) (pan-CK: KL-1, CK 5/6, CK 7) and the epithelial marker Ber-EP4. In 82 patients (48.2%), micrometastases were revealed in immunohistochemistry staining. KL-1 detected micrometastases in 201 (99.5%) of 202 positive lymph nodes. Subsequently, this resulted in an upstaging in 39 patients (20.5%). Detection of micrometastases in otherwise tumor-free N2-lymph nodes had a significant prognostic impact (mean disease-free survival 21.4 versus 45.3 months, p = 0.022), affecting 4.7% of patients. Survival differences between patients who were upstaged into stage II (N0>N1) and those remaining in stage I were not statistically significant (p = 0.537). Extended workup of N2-lymph nodes using one broad-spectrum keratin marker in otherwise N2-negative lymph nodes may represent a both efficient and sensitive approach to the identification of micrometastases in dissected lymph nodes of patients with early stage NSCLC.

Detection of lymph node micrometastasis for patients with extrahepatic cholangiocarcinoma and its prognostic significance

To observe the expression of antibodies of cytokeratin 19 and 20 in lymph node micrometastasis in patients with extrahepatic cholangiocarcinoma (EHCC), evaluate the prognostic significance of lymph node (LN) micrometastasis and study the correlation between lymph node micrometastasis and clinicopathological features, CA19-9 and CEA. A total of 279 lymph nodes was intra-operatively collected from 59 EHCC patients and routine histological examination performed. Immunohistochemical staining was performed on all samples by the murine antibodies of anti-CK19 and anti-CK20 respectively. Then the micrometastasis was identified microscopically according to the color of cells. The results were analyzed according to clinical, pathological and follow-up data. And the relation of micrometastasis with clinical pathological factors and its impact upon survival rate were analyzed. Among 59 EHCC patients, 14 (23.72%) LN metastasis were found with HE staining and 21 micrometastases with CK staining. The incidence of nodal involvement in 59 EHCC patients increased from 5.37% (15/279) by HE staining to 13.98% (39/279) by CK staining. Among 45 patients not positive for LN metastases with HE staining, CK staining was positive in 7 patients and the incidence of micrometastasis was 15.56%. The preoperative serum CA19-9 levels in patients with LN micrometastasis was higher than that those without LN metastasis (P < 0.05). And there was a positive correlation between occult nodal micrometastasis and serum concentrations of CA19-9 (r(s) = 0.371, P < 0.05). The histological type and lymphatic vessel infiltration of tumor were the most importance factors for LN micrometastasis through Logistic regression analysis (P < 0.05). The CK immunohistochemical staining can detect the micrometastases in HE negative LN. And LN micrometastasis can more accurately predict the prognosis of EHCC patients.

Liver transplantation for colorectal liver metastases: revisiting the concept

Liver transplantation (Lt) for colorectal cancer (CRC) liver metastases is no more considered due to the poor outcome observed up to the 1990s. According to the European Liver Transplant Registry (ELTR), 1- and 5-year patient survival following Lt for CRC liver metastases performed prior to 1995 was 62% and 18%, respectively. However, 44% of graft loss or patient deaths were not related to tumor recurrence. Over the last 20 years there has been dramatic progress in patient survival after Lt, thus it could be anticipated that survival after Lt for CRC secondaries today would exceed from far, the outcome of the past experience. By utilizing new imaging techniques for proper patient selection, modern chemotherapy and aggressive multimodal treatment against metastases, long term survivors and even cure could be expected. Preliminary data from a pilot study show an overall survival rate of 94% after a median follow up of 25 months. While long term survival after the first Lt is 80% all indications confounded, 5-year survival after repeat Lt is no more than 50% to 55%. If patients transplanted for CRC secondaries can reach the latter survival rate, it could be difficult to discriminate them in the liver allocation system and live donation could be an option.

Clinical significance of EMA in detection of lymph node micrometastasis of colorectal cancer

Objective To evaluate the prognostic impact of a wide spectrum of pathologic parameters in a consecutive series of homogenously treated and well-characterized patients with stage Ⅰ and Ⅱ coloreetal cancer,and the prognostic value of lymph node occult disease(micrometastasis)in disease-free survival rate detected by immunohistechemistry with epithelial membrane antigen.Methods The study included 126 patients operated on by a single surgeon for stage Ⅰ and Ⅱ colorectal tumors.The average postoperative follow-up period was 64.11(range,64-106)months.At least 10 more lymph nodes were harvested and examined in all the specimens.The prognostic value of 10 pathologic parameters,including lymph node occult disease(micrometastasis)detected by immunohistochemistry,was investigated.Results Multivariate analysis identified lymphatic vessel invasion(absent or present;P ＜ 0.05)and depth of tumor invasion(T1,T2,T3 or T4;P ＜ 0.05)in positive and negative lymph nodes by immunohistochemistry with epithelial membrane antigen.The five-year disease-free survival rate was 74.6,68.0 and 46.2 percent for the negative lymph node negative,isolated tumor cells and micrometsstasis groups,respectively.There was significant difference between the lymph node negative and micrometastasis groups(P ＜ 0.05),however;the lymph node negative and isolated tumor cells groups were no significant dfferrence(P ＞ 0.05).Conclusion We propose that patients found micrometastasis in lmphy node with high-risk Stage Ⅰ and Ⅱ colorectal cancer for whom adjuvant therapies may be justified and effective. Key words: Carcinoma of rectum; Prognosis; Lymph node metastasis

Lymphadenectomy in colorectal cancer liver metastases resection: Incidence of hilar limph nodes micrometastasis

Liver resection is considered the best treatment for metastatic colorectal cancer. Several prognostic factors have been investigated, and many studies have shown that hepatic hilum lymph nodes involvement has a negative impact on prognosis. The present study evaluated the frequency of microscopic involvement of hilar lymph nodes, through systematic lymphadenectomy and analysis of micrometastases in patients undergoing hepatectomy due to colorectal metastasis. A total of 28 patients underwent hepatic resection with hilar lymphadenectomy. Lymph nodes considered negative by conventional hematoxylin and eosin (H&E) staining were analyzed by serial sectioning with 100-microm intervals and immunohistochemistry (IHC) with anti-human pancytokeratin antibody AE1/AE3. In average, 6.18 lymph nodes were dissected per patient. No morbidity or mortality was associated to lymphadenectomy. In two patients, conventional H&E analysis showed presence of microscopic lymph node metastasis. IHC analysis allowed the identification of three other patients with lymph node micrometastases. The overall frequency of microscopic metastases, including micrometastasis, was 18%. Systematic lymphadenectomy allowed the detection of microscopic lymph node metastases, resulting in more accurate staging of extrahepatic disease. The inclusion of IHC increased the detection of lymph node micrometastasis.

Sentinel Node Biopsy as a Prognostic Factor in Cutaneous Melanoma

Background The aim of sentinel node biopsy (SNB) is to identify subclinical lymph node metastases using a procedure with minimal morbidity, establish more accurate staging in patients with melanoma, determine prognosis, and choose the most suitable treatment in each patient. Objectives To analyze the outcomes of SNB in patients with cutaneous melanoma, and the impact of this procedure on survival. Material and methods Information was gathered retrospectively on all patients in whom this procedure was performed at Hospital General Universitario Gregorio Marañón, Madrid, Spain, over an 11-year period (1997-2007). Descriptive epidemiological analysis of the variables and survival analysis were performed. Results Sentinel node invasion by melanoma was present in 42 of 238 patients (17.6%). Tumor thickness and nodular melanomas were associated with the presence of lymph node micrometastases. There were no differences in overall survival, but disease-free survival was significantly lower in patients with a positive SNB, who also had a higher melanoma-related mortality. Conclusions Detection of lymph node micrometastases by sentinel node biopsy is a marker of tumor aggressiveness and an important prognostic factor in melanoma patients. Information from SNB permits better staging and determines the diagnostic and therapeutic approach in these patients.

Prognostic value of the detection of lymph node micrometastases in colon cancer

A study is made of the clinical repercussions of occult metastases-micrometastases (MMs+)-or isolated tumour cells (ITCs+) in the lymph nodes of patients with stage IIA and IIB colon adenocarcinoma initially considered as corresponding to N0. A retrospective study of 39 patients with stage IIA and IIB (T3-T4 N0 M0) colon adenocarcinoma, subjected to similar surgical and adjuvant chemotherapy treatment, with long and careful follow-up (minimum: 5 years, mean: 81.7 months) was performed on their previously resected lymph nodes, with the aid of new histological and immunohistochemical (cytokeratin) sections, in order to detect MMs or ITCs. Disease-free survival (DFS) and global survival (GS) in the two groups (patients with MMs+ or ITCs+ vs. patients without MMs or ITCs) were compared at 5 years based on the corresponding Kaplan-Meier survival curves, with the Breslow test. A total of 382 lymph nodes from the 39 patients (mean: 9.8; standard deviation: 6.09) were revised. MMs+ were detected in 2 cases and ITCs+ in 2 more cases on the Cytokeratin study. GS of the whole series at 5 years was 89.74% (35 patients alive) with a DFS at 5 years of 79.49% (31 patients free of disease), but the 2 cases with MMs+ were dead at 5 years, with high statistical differences between both groups (MMs+/MMs-) (p<0.0001). When comparing the group of MMs+/ITCs+ patients and the group of MM-/ITCs- patients, the DFS and GS times at 5 years were higher in the MMs-/ITCs- group (p=0.0692 and p=0.006 respectively). Although the incidence of MMs+ or ITCs+ in the examined lymph nodes was low, the presence of MMs is related to a dramatic reduction in GS and DFS at 5 years. We encourage a detailed histological study of lymph nodes resected in patients with deep penetrating colon tumours in order to assure a pN0 status.

Usefulness of sentinel lymph node biopsy for the detection of lymph node micrometastasis in early lung cancer

The purposes of this study were to examine the usefulness of the biopsy of the sentinel lymph nodes (SNs) for the accurate and effective detection of lymph node micrometastasis in early lung cancer and to clarify the spread of lymph node micrometastasis. One hundred and thirty-three c-stage IA non-small cell lung cancer patients in whom SNs could be identified by radioisotope (RI) method were enrolled. All dissected lymph nodes were stained with cytokeratin AE1/AE3 for the examination of micrometastasis. A total of 1375 lymph nodes including 220 SNs were dissected from the 133 patients. From the 220 SNs, 35 (15.9%) were found to be positive for metastasis. Of the other 185 SNs negative for metastasis, 19 (8.6%) were positive for micrometastasis. When patients were limited to those with pN0, there were no lymph nodes positive for micrometastasis other than SNs. In pN1-2 patients, micrometastasis to non-SNs were observed in 2.3-13.2%. In patients with pN0, micrometastasis was limited to SNs, and the results of the examination of SNs for micrometastasis accurately represented those of the examination of all lymph nodes. With advancement of the stage, micrometastasis was not limited to SNs and showed an irregular distribution.

Detection of lymph node micrometastases in patients with squamous carcinoma of the head and neck

While the significance of large cervical node metastases in patients with head and neck squamous carcinomas is well established, the import of a finding of regional nodal micrometastases (where a micrometastasis is defined as a metastatic deposit greater than 0.2 mm and not greater than 2.0 mm in greatest dimension) or isolated tumor cells in those patients is less clearly understood. Some earlier investigators have suggested that finding micrometastases does not have an impact on prognosis; some later investigators, however, have taken issue with this position, arguing that finding either micrometastases or isolated tumor cells might portend a poorer prognosis for head and neck cancer patients. At this juncture, it is difficult to advance a single recommendation for handling a finding of micrometastases or isolated tumor cells. It would be helpful if two courses of action were followed: first, while the detection of micrometastases and isolated tumor cells remains an investigatory practice, data should be collected and analyzed with an eye to discerning whether such findings are indeed of significance to the individual head and neck cancer patient. Second, rigorous definitions of micrometastases and isolated tumor cells (such as the definitions suggested here) should be developed and widely employed so as to permit ready comparison between the results as they are reported by different investigators.

Molecular approaches to the staging of head and neck carcinomas (Review)

Despite the efforts during the last decades to improve clinical management and therapy, carcinomas of the head and neck still represent a disease with an unfavourable course. Over 50% of the patients die from their disease within 5 years after diagnosis, with tumour recurrence, metastasis, and development of second primary neoplasms as major causes of treatment failure. In addition, surgical treatment of locally advanced disease often results in invalidating and disfiguring conditions that heavily affect patients' quality of life. Current criteria of tumour staging, essentially based on clinical and pathological assessment, fail to prove effective in providing reliable information on tumour prognosis or supporting an optimized planning of the therapies, prompting the identification of new and more accurate staging criteria. This review focuses on the impact of molecular biology in HNSCC staging, namely differentiation of second primary lesions from recurrence/metastasis and detection of lymph node micrometastasis, and highlights how the integration of the histopathological diagnosis with molecular analyses may result in a better management of HNSCC patients.

Significance of the immunohistochemical detection of lymph node micrometastases in Stage II Colorectal Carcinoma

Survival results of stage II colorectal cancer patients have led to major efforts to identify the subset of patients at risk for disease relapse and adjuvant therapies benefit. Immunohistochemistry is being explored to detect undetectable microscopic lymph node micrometastases. A retrospective analysis of a 105 consecutive stage II colorectal cancer patients was performed. Two four-micres sections were obtained from each lymph node. These slides were stained with AE1-AE3 monoclonal antibodies against cytoskeleton using DAKO EnVision visualization system. Micrometastases were identified either as isolated cells or as well-defined glandular cell clusters with cytoplasm but not the nucleus stained with cytoskeleton antibodies. 665 lymph nodes isolated from 105 patients were analyzed. Lymph nodes micrometastases were assessed in 26 out of the 105 patients. 42 (6.3%) out of 665 lymph nodes were infiltrated. Most of these metastases consisted of isolated cell cluster localized in marginal and interfollicular sinus of lymph nodes. The relapse rate was 23.1% among the patients with immunohistochemical detected lymph node micrometastes and 20.3% for the patients without lymph node involvement. This result lacked statistical significance (p = 0.759). AE1/AE3 lymph node immunohistochemical staining in stage II colorectal cancer is an interesting biological phenomenon but it fails to identify patients at higher risk of relapse who deserve a more aggressive adjuvant attitude.

Detection of lymph node micrometastasis in pN0 early gastric cancer: Efficacy of duplex RT-PCR with MUC2 and TFF1 in mucosal cancer

We previously reported that MUC2 is a useful marker in the detection of lymph node micrometastasis (LMM) in gastric cancer. To improve the detection rate, we focused on a TFF1 gene. We used the duplex reverse transcriptase-polymerase chain reaction (RT-PCR) method with MUC2 and TFF1 genes to detect LMM in histologically node negative (pN0) early gastric cancer (EGC) and evaluated their effectiveness. A total of 310 lymph nodes from 33 patients with pN0 EGC were analyzed. All carcinoma specimens were positive for MUC2 and/or TFF1. The positive rate of TFF1 was significantly higher than MUC2 in the undifferentiated carcinoma specimens (p=0.002). The detection rate of duplex RT-PCR with MUC2 and TFF1 was higher than that of MUC2 or TFF1 alone. In mucosal cancer, 7 cases were positive for duplex RT-PCR. Of these 7 cases, 3 were MUC2-positive/TFF1-negative while 4 were MUC2-negative/TFF1-positive. LMMs were not detected in elevated-type primary mucosal cancers with a 20-30-mm diameter. The duplex RT-PCR assay with both MUC2 and TFF1 provides a higher LMM detection rate than either MUC2 or TFF1 alone, especially in mucosal gastric cancer. LMM detected in this manner may prove useful in broadening the indications for endoscopic mucosal resection in elevated-type cancer.

Detection of lymph node micrometastases in malignant mammary tumours in dogs by cytokeratin immunostaining

A series of 131 local and regional lymph nodes from 40 dogs with malignant mammary tumours were evaluated by staining with haematoxylin and eosin and immunohistochemically for antibodies to pancytokeratin...

Lymph node micrometastases and expression of metastasis-related gene proteins in patients with colorectal cancer

To study lymph node micrometastases (LNMM), expression of nm23-H(1), MMP(9), TIMP(2) proteins, and their relationship and clinical significance in patients with stage Dukes B colorectal cancer. Thirty patients with stage Dukes B colorectal cancer were studied. LNMM in these patients was detected by immunohistochemical anti-cytokeratin 20 (CK20) staining. The expression of nm23-H(1), MMP(9) and TIMP(2) proteins in primary tumors was examined by Strept-avidin-biotin complex method. Clinical-pathological data and survival of each patient were recorded and analyzed. (1) The positive dyeing of CK20 was observed in 26.7% for cases and in 7.8% for lymph nodes of 30 patients with stage Dukes B colorectal cancer. (2) Different expression of nm23-H(1) and MMP(9) proteins in the patients between stage Dukes B and stage Dukes CD was observed (P < 0.05). The decreased nm23-H(1) expression, and/or the increased MMP(9) expression in primary stage Dukes B tumors were significantly associated with LNMM (P < 0.05). Sensitivity and specificity for detection of LNMM by using nm23-H(1) or MMP(9) were respectively 62.5% and 81.8% or 75.0% and 69.8%. If by combining nm23-H(1) with MMP(9), specificity for detection of LNMM became 90.9%. The expression of TIMP(2) protein was not related with stage Dukes and LNMM. (3) The percent of tumor recurrence and/or metastasis for the stage Dukes B patients with LNMM was significantly higher than that for the patients without LNMM (P < 0.05), but the survival percent for the patients with LNMM was significantly lower than that for the patients without LNMM. The outcome for the patients with nm23-H(1) (-) LNMM (+) or MMP(9) (+) LNMM (+) was significantly worse than that for patients with nm23-H(1) (+) LNMM (-) or MMP(9) (+) LNMM (-) (P < 0.05). LNMM is detected by immunohistochemical anti-CK20 staining. The expression of nm23-H(1) and MMP(9) in primary stage Dukes B tumors was significantly associated with LNMM. The outcome in the LNMM patients with nm23-H(1) (-) and/or MMP(9) (+) were worse. Combining examination of CK20 for lymph nodes with expression of nm23-H(1) and MMP(9) for primary tumors is of important clinical significance for staging of Dukes, selection of adjuvant treatment and evaluation of prognosis in patients with colorectal cancer.

Genetic Detection of Lymph Node Micrometastases: A Selection Criterion for Liver Transplantation in Patients with Liver Metastases after Colorectal Cancer

Liver transplantation for nonresectable liver metastases from colorectal cancer was abandoned in 1994 on account of high recurrence rates. The aim of this study was to investigate whether the genetic detection of micrometastases in histologically negative lymph nodes of the primary colon cancer could be applied to select patients for liver transplantation. We analyzed 21 patients with colorectal cancer who had undergone liver transplantation between 1983 and 1994 for liver metastases. Eleven patients were histologically lymph node negative at the time of surgery; ten patients with lymph node metastases served as control group. DNA sequencing was used to screen tumor material for p53 and K-ras mutations. Mutant allele-specific amplification (MASA) was then used to search for micrometastases in DNA from regional lymph nodes of the primary colorectal cancer. p53 and K-ras mutations were detected in 12 (57%) and 3 (14%) of 21 patients in the colorectal cancer, respectively. The mutations were confirmed in the corresponding liver metastases. Of 11 patients with histologically negative lymph nodes, nine were eligible for MASA due to presence of p53 or K-ras mutation. MASA revealed six of nine patients to be genetically positive for micrometastases. Three patients were both genetically and histologically negative. These three patients showed a significantly longer overall survival (P = 0.011) of 4, 5, and 20 years, respectively. We conclude that the genetic detection of micrometastases by MASA could be a powerful prognostic indicator for selecting patients with colorectal liver metastases who could benefit from liver transplantation.