Molecular quantification and mapping of lymph-node micrometastases in cervical cancer

Laparoscopic paraaortic left-sided transperitoneal infrarenal lymphadenectomy in patients with gynecologic malignancies: technique and results

OBJECTIVE

Left-sided paraaortic infrarenal lymphadenectomy is indicated in patients with gynecologic tumors of high metastasing potential. We evaluated whether left-sided paraaortic inframesenteric lymphadenectomy can be extended up to the left renal vein by laparoscopy.

METHODS

Between January 2002 and August 2002, 46 consecutive patients with cervical (n = 26), or endometrial (n = 16), or early ovarian cancer (n = 4) underwent right-sided paraaortic lymphadenectomy up to the level of the right ovarian vein and left-sided inframesenteric paraaortic lymphadenectomy. Lymphadenectomy was extended up to the level of the left renal vein in 20 patients with high risk for lymph node metastasis: following elevation of the duodenum and the pancreas infrarenal lymph nodes in the area limited by the vena cava, left renal vein, left ovarian vein, inframesenteric artery, and aorta were laparoscopically removed under preservation of the inferior mesenteric artery.

RESULTS

Patients with infrarenal lymphadenectomy (group 1) and without infrarenal lymphadenectomy (group 2) were comparable in body mass index: the age of patients in group 2 was higher (P = 0.023). Duration of lymphadenectomy was 31.3 min (11-57 min) longer in group 1. There was no intraoperative complication. Number of paraaortic lymph nodes was on average 19.6 (range 5-35) in group 1 compared to a mean of 9 lymph nodes (range 2-19) in group 2 (P = 0,0001). Postoperatively 2 patients (10%) in group 1 developed chylascos.

CONCLUSIONS

Left-sided paraaortic infrarenal lymphadenectomy can be performed safely in adequate duration transperitoneally by laparoscopy. Compared to inframesenteric lymphadenectomy the number of removed lymph nodes can be doubled.

Detection of micrometastatic breast cancer by means of real time quantitative RT-PCR and immunostaining in perioperative blood samples and sentinel nodes

The aim of our study was to detect micrometastatic breast cancer by epithelial glycoprotein-2 (EGP-2) and cytokeratin 19 (CK19), using immunostaining and real time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Fifty-eight breast cancer patients, 52 primary tumors, 75 sentinel nodes (SN) and 149 peripheral blood (PB) samples (from before, during and 4 days after operation) were examined. Immunostaining was performed with antibodies directed against EGP-2 and CK19. Detection limits were one Michigan Cancer Foundation-7 (MCF-7) breast cancer cell line cell/2.10(6) leukocytes (immunostaining) and one MCF-7 cell/10(6) leukocytes qRT-PCR. Control noncancer lymph nodes (n = 10) showed nonspecific CK19 staining, but were qRT-PCR negative; control healthy volunteer PB (n = 11) was always negative. Primary tumor samples, all positive with immunostaining, showed a wide variation of EGP-2 (>10(4) fold) and CK19 mRNA expression (>10(3) fold). SN (n = 19) from 16 patients were tumor-positive with routine haematoxylin-eosin (H&E) and/or immunostaining. SN tumor presence was positively correlated to qRT-PCR expression, but 3 tumor-positive SN were false negative with qRT-PCR. Three SN were qRT-PCR positive, while tumor negative with H&E and/or immunostaining. No immunostaining positive PB was observed, but 19 patients (33%) had one or more qRT-PCR positive PB samples. We concluded that primary tumors have varying expressions of EGP-2 and CK19 mRNA. Both markers can be used in qRT-PCR to obtain adequate sensitivity for single tumor cell detection. In SN, immunostaining appears more sensitive/specific than H&E or qRT-PCR for tumor detection. No immunostaining positivity was found in PB, while 33% of patients had qRT-PCR positive PB. The clinical value of these findings will have to be clarified.

Laparoscopic detection of sentinel lymph nodes followed by lymph node dissection in patients with early stage cervical cancer

OBJECTIVE

The purpose of this study was to investigate the feasibility of sentinel node detection through laparoscopy in patients with early cervical cancer. Furthermore, the results of laparoscopic pelvic lymph node dissection were studied, validated by subsequent laparotomy.

METHODS

Twenty-five patients with early stage cervical cancer who planned to undergo a radical hysterectomy and pelvic lymph node dissection received an intracervical injection of technetium-99m colloidal albumin as well as blue dye. With a laparoscopic gamma probe and with visual detection of blue nodes, the sentinel nodes were identified and separately removed via laparoscopy. If frozen sections of the sentinel nodes were negative, a laparoscopic pelvic lymph node dissection, followed by radical hysterectomy via laparotomy, was performed. If the sentinel nodes showed malignant cells on frozen section, only a laparoscopic lymph node dissection was performed.

RESULTS

One or more sentinel nodes could be detected via laparoscopy in 25/25 patients (100%). A sentinel node was found bilaterally in 22/25 patients (88%). Histological positive nodes were detected in 10/25 patients (40%). One patient (11%) had two false negative sentinel nodes in the obturator fossa, whereas a positive lymph node was found in the parametrium removed together with the primary tumor. In seven patients (28%), the planned laparotomy and radical hysterectomy were abandoned because of a positive sentinel node. Bulky lymph nodes were removed through laparotomy in one patient, and in six patients only laparoscopic lymph node dissection and transposition of the ovaries were performed. These patients were treated with chemoradiation. In two patients, a micrometastasis in the sentinel node was demonstrated after surgery. Ninety-two percent of all lymph nodes was retrieved via laparoscopy, confirmed by laparotomy. Detection and removal of the sentinel nodes took 55 +/- 17 min. Together with the complete pelvic lymph node dissection, the procedure lasted 200 +/- 53 min.

CONCLUSION

Laparoscopic removal of sentinel nodes in cervical cancer is a feasible technique. If radical hysterectomy is aborted in the case of positive lymph nodes, sentinel node detection via laparoscopy, followed by laparoscopic lymph node dissection, prevents potentially harmful and unnecessary surgery.

Combination of microdissection and microarray analysis to identify gene expression changes between differentially located tumour cells in breast cancer

Comparison of gene expression changes between cancer cells at the periphery and in the centre of breast cancers was performed using a combination of microdissection and microarray analysis. Cancer cells from the two areas were pooled separately from five patients with ductal carcinoma in situ and separately from five patients with frankly invasive cancer. Limited total RNA, 100-200 ng, from this microdissected tissue required use of the Atlas SMART trade mark Probe Amplification Kit to synthesize and amplify cDNA and make (33)P-labelled probes. Probes were then hybridized to Atlas Human Cancer 1.2 Arrays containing 1176 known genes. Triplicate analysis revealed that 22 genes changed their expression levels in the periphery relative to the central region: 15 upregulated and seven downregulated (arbitrary threshold of 1.5-fold or greater). Differences in RNA levels were confirmed by quantitative real-time PCR for two of the genes and by changes in protein levels, detected by immunohistochemistry, for a couple of representative gene products. Thus, changes in gene expression associated with variation in microanatomical location of neoplastic cells can be detected within even small developing tumour masses.

Molecular detection of von Hippel-Lindau gene mutations in urine and lymph node samples in patients with renal cell carcinoma: potential biomarkers for early diagnosis and postoperative metastatic status

PURPOSE

Organ confined renal cell carcinoma can be cured in the majority of patients, whereas more extensive lesions have a poor prognosis. Therefore, the development of a useful biomarker for early diagnosis as well as postoperative metastatic status would contribute to the appropriate therapy for renal cell carcinoma. To diagnose renal cell carcinoma preoperatively we developed a novel urinary test and detected occult lymph node micrometastasis using a molecular approach.

MATERIALS AND METHODS

Urine samples were obtained preoperatively from 27 patients with renal cell carcinoma and von Hippel-Lindau (VHL) gene mutations in the tumors, and were analyzed for VHL gene mutations using a nested single strand conformational polymorphism analysis. Lymph nodes without evidence of histological metastasis were obtained from 15 patients with renal cell carcinoma and VHL gene mutations, and analyzed for VHL gene mutations using mutation specific nested reverse transcription polymerase chain reaction method.

RESULTS

In urine samples 5 of 27 VHL gene mutations (18.5%) were found and each mutation pattern was the same as that detected in each renal cell carcinoma. One lymph node micrometastasis was found.

CONCLUSIONS

These data indicate the presence of detectable levels of tumor derived DNA in the urine of patients with renal cell carcinoma and suggest that nested single strand conformational polymorphism analysis of VHL gene of urine samples provides a possible tool for the early detection of renal cell carcinoma. Furthermore, mutation specific nested reverse transcription polymerase chain reaction is useful to detect occult lymph node micrometastasis and may predict patients at risk for local recurrence. These 2 combined approaches using VHL gene mutations may contribute to the total therapy for and prognosis of renal cell carcinoma.

Quantitative real-time PCR: a powerful ally in cancer research

In this era of the Human Genome Project, quantitation of gene expression in tumor or host cells is of paramount importance for investigating the gene patterns responsible for cancer development, progression and response or resistance to treatment. Quantitative real-time PCR (qrt-PCR) technology has recently reached a level of sensitivity, accuracy and practical ease that supports its use as a routine bioinstrumentation for gene level measurement. Several applications have already been implemented in the field of cancer research, and others are being validated, showing that this molecular biology tool can provide both researchers and clinicians with precious information concerning the behavior of tumors. Knowledge of the biochemical principles underlying this biotechnology can be of great value to interpret correctly qrt-PCR data.

Tumor size, axillary lymph node status and steroid receptor expression in breast cancer: prognostic relevance 5 years after surgery

Tumor size, axillary lymph node status and expression of steroid receptors are well-established prognostic factors in breast cancer. However, it is not clear if these prognostic factors are time-dependent variables and lose their significance after several years of disease-free survival. To analyse how long these factors keep their prognostic relevance survival of 1162 breast cancer patients was analysed retrospectively. The post-operative follow-up period was split into consecutive 2-year intervals and each interval was analysed for rate of recurrence and rate of tumor depending deaths. Furthermore, a multivariate analysis was performed for the total follow-up time and for the follow-up period starting 5 years after surgery. Multivariate analysis revealed tumor size, axillary lymph node status and estrogen receptor status as independent prognostic parameters. Analysing separately the rate of recurrences and tumor-related deaths during consecutive 2-year intervals, only the tumor size was a constant prognostic parameter, whereas prognostic relevance of lymph node status decreased. Estrogen receptor status associated with favourable prognosis during the first years after surgery changed to an unfavourable prognostic factor 4 years after surgery. To summarize, prognostic factors obtained at the time of surgery can lose their significance with increasing disease-free survival.

Patterns of disease recurrence influenced by hematogenous tumor cell dissemination in patients with cervical carcinoma of the uterus

BACKGROUND

The presence of isolated tumor cells (ITC) in the bone marrow at the time of primary diagnosis indicates an increased risk for subsequent development of distant metastases in various solid tumors. This study evaluates the prevalence and prognostic significance of ITC in patients with primary carcinoma of the cervix uteri.

METHOD

We immunocytochemically analyzed bone marrow aspirates of 130 patients with newly diagnosed carcinoma of the cervix uteri for the presence of cytokeratin(CK)-positive cells from May 1994 to January 2001. We used a quantitative immunoassay with the monoclonal anti-CK antibody A45-B/B3 and evaluated 2 x 10(6) bone marrow cells per patient. Patients were followed prospectively for a median of 43 (range, 1-85) months.

RESULTS

Isolated tumor cells were found in the bone marrow of 38 patients (29%). The presence of ITC did not correlate with the International Federation of Gynecology and Obstetrics (FIGO) tumor stage (P = 0.61), pelvic and paraaortal lymph node involvement (P = 0.41), histopathologic grading (P = 0.67), the histologic type of the carcinoma (P = 0.93), invasion of lymph nodes (P = 0.93) and blood vessels (P = 0.92), or with menopausal status (P = 0.17). The bone marrow status at the time of primary diagnosis did not correlate with the overall survival as estimated by Kaplan-Meier analysis (P = 0.30). However, distant metastases occurred in 5% of the patients (n = 5) with negative bone marrow status and in 15% of the patients (n = 6) with positive bone marrow status (P = 0.054). The median distant disease-free survival period was 78 months (95% confidence interval 73-82) in patients with negative bone marrow status and 72 months (95% CI 61-82) in patients with positive bone marrow status (P = 0.051). Multivariate analysis revealed the presence of ITC as a significant, independent risk factor for the subsequent development of distant metastases (relative risk 3.6, P = 0.046).

CONCLUSION

Despite the locoregional predominance of cervical carcinoma at the time of primary diagnosis, the presence of ITC in the bone marrow indicates an increased risk for the development of distant metastases. This information may prove useful to stratify patients for systemic treatment.

Substantial changes in gene expression level due to the storage temperature and storage duration of human whole blood

Blood is a valuable clinical sample for high-throughput analysis of gene expression and is likely to become more popular as a diagnostic tool and as a predictive measure of disease progression and drug responsiveness. Gene expression data from blood that has been stored at ambient temperature for greater than 1 h vs. blood samples that have been lysed immediately post-collection shows dramatic changes in relative gene expression for a number of cytokines, chemokines, and transcription factors. Results indicate significant changes in the relative expression of several genes, many of which were either up-regulated or down-regulated, because of storage at ambient temperature: (1) In only 4 h of storage at ambient temperature, greater than 10-fold increases in relative gene expression were observed for interleukin-8 (IL-8), c-myc, and c-fos; (2) Up-regulation of IL-8, a chemokine that mediates inflammatory cell migration, took place only 1-h after collection and increased nearly 100-fold by 4 h; (3) Down-regulation of several anti-inflammatory genes was observed for blood stored at ambient temperature; and (4) A general trend toward selective enhancement of inflammatory responses was observed, mediated by possible mRNA transcription and turnover. These results validate the need for the rapid lysis of whole blood after removal from the source.

A model for co-expression pattern analysis of genes implicated in angiogenesis and tumour cell invasion in cervical cancer

To date, numerous genes have been identified which are involved in both tumour neovascularisation (angiogenesis) and tumour cell invasion, and most of them are also expressed to some extent under normal physiological conditions. However, little is known about how these genes co-express in these settings. This study was undertaken to quantitate mRNA levels in normal and malignant cervical tissues of nine selected genes (VEGF(121), VEGF(165), VEGF(189), VEGF-C, eIF-4E, b-FGF, TSP-2, MMP-2 and MMP-9) implicated in the above processes using real-time quantitative RT-PCR. In addition, the Spearman's rank correlation was used to determine their co-expression patterns. The transcript levels for the different VEGF-A splice variants (VEGF(121), VEGF(165), VEGF(189)) were at least 10-fold higher in the cancer cases, with the highest levels in the primary tumours demonstrating lympho-vascular space involvement. The lymphangiogenic factor VEGF-C and MMP-9 were upregulated 130- and 80-fold respectively in cervical cancers. The highest levels of VEGF-C mRNA were found in the lymph-node positive group. The transcript levels for b-FGF were similar in normal cervical tissue and early-stage cervical cancer, however, higher levels were found in the cervical cancers with advanced stage disease. Comparing gene transcript levels between recurrent and non-recurrent cervical cancer patients revealed significant differences (P=0.038) in transcript levels for the angiogenesis inhibitor TSP-2, with the highest levels in non-recurrent cases. Co-expression pattern analysis in normal cervical tissue revealed highly significant co-expressions (P<0.0001) between TSP-2 and most other genes analysed (VEGF(121), VEGF(165), VEGF-C, b-FGF and MMP-2). In cervical cancer, TSP-2 appears only to be highly co-expressed with MMP-2 (P<0.0001). In contrast to normal cervical tissue, we found a highly significant co-expression (P<0.0001) between MMP-9 and VEGF(189) in cervical cancer. The combined application of real-time quantitative RT-PCR and Spearman's rank correlation identifies gene transcripts which are simultaneously co-expressed. Our results revealed a significant co-expression between the angiogenesis inhibitor TSP-2 and most other genes analysed in normal cervical tissue. In cervical cancer, we found a strong upregulation of VEGF-C and MMP-9 mRNA, with a highly significant co-expression between MMP-9 and VEGF(189).

Molecular profiling of angiogenesis markers

The goal of this study was to develop a sensitive, simple, and widely applicable assay to measure copy numbers of specific mRNAs using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), and identify a profile of gene expression closely associated with angiogenesis. We measured a panel of nine potential angiogenesis markers from a mouse transgenic model of prostate adenocarcinoma (TRAMP) and a mouse skin model of vascular endothelial growth factor (VEGF)-driven angiogenesis. In both models, expression of VEGF correlated with expression of mRNAs encoding other angiogenic cytokines (angiopoietin-1 and angiopoietin-2), endothelial cell receptor tyrosine kinases (Flt-1, KDR, Tie-1), and endothelial cell adhesion molecules (VE-cadherin, PECAM-1). Relative to control, in dermis highly stimulated by VEGF, the Ang-2 mRNA transcript numbers increased 35-fold, PECAM-1 and VE-cadherin increased 10-fold, Tie-1 increased 8-fold, KDR and Flt-1 each increased 4-fold, and Ang-1 increased 2-fold. All transcript numbers were correspondingly reduced in skin with less VEGF expression, indicating a relationship of each of these seven markers with VEGF. Thus, this study identifies a highly efficient method for precise quantification of a panel of seven specific mRNAs that correlate with VEGF expression and VEGF-induced neovascularization, and it provides evidence that real-time quantitative RT-PCR offers a highly sensitive strategy for monitoring angiogenesis.

Modified radical vaginal hysterectomy with or without laparoscopic nerve-sparing dissection: a comparative study

OBJECTIVE

Nerve-sparing dissection of the lateral portion of the cardinal ligament (paracervical lymphadenectomy) has been recently developed with the goal of reducing the late urinary adverse effects of radical hysterectomy without impairing the outcome. This work has been carried out in order to investigate the influence of additional paracervical lymph node dissection at the time of laparoscopically assisted modified radical hysterectomy on outcome and urinary sequelae.

METHODS

A total of 95 patients underwent a modified radical hysterectomy using a combined laparoscopic and vaginal approach since 1991. In 47 of these patients treated since 1996 an additional laparoscopic paracervical lymphadenectomy was performed. The operative, postoperative, and survival outcomes were assessed. In 60 patients, 32 and 28 in the groups of patients with or without paracervical dissection, respectively, a careful interview on urinary symptoms was conducted by an independent investigator.

RESULTS

Paracervical dissection involves no operative complication and lenghthens the postoperative urinary retention, but has no adverse influence on long-term urinary discomfort. The yield of paracervical dissection is negligible for small tumors: no positive node was found in 38 patients with tumors less than 2 cm in diameter. The outcome of patients after minimal access surgery for tumors less than 2 cm is excellent whether or not a paracervical dissection has been performed.

CONCLUSION

Paracervical dissection does not worsen the late urinary symptoms after vaginal radical hysterectomy. It has a limited value in the surgical management of small-size (less than 2 cm) cervical cancers, although it may prevent long-term lateropelvic recurrences.

Polymerase chain reaction in the staging of solid tumors

Polymerasechain reaction (PCR) is a molecular biology technique that holds great promise as a way to perform molecular staging of cancer by detecting very early metastatic disease. Significant data suggest that PCR analysis may play an important role in the management of colorectal cancer in the future. However, for PCR staging of breast cancer, progress awaits identification of gene markers that have sufficient sensitivity and specificity. Within the next few years, the results of the Sunbelt Melanoma Trial and other ongoing studies will determine whether PCR evaluation of sentinel lymph nodes and peripheral blood cells has prognostic relevance in melanoma. The future of cancer management will likely revolve around the molecular staging of tumors, and PCR is but one method that may better define subgroups of patients that are appropriate candidates forvarious anticancer therapies.

Circulating tumor cells in the peripheral blood and bone marrow of patients with ovarian carcinoma do not predict prognosis

BACKGROUND

Ovarian carcinoma is apparently restricted for a long time to the peritoneal cavity. However, about 50% of patients with a surgically documented complete intraabdominal response experience later recurrence. Occult hematogenous micrometastases are common to most epithelial malignancies and have recently been found in 30% of bone marrow samples of ovarian carcinoma patients, as examined by immunocytochemistry. Moreover, these findings were associated with poor progression-free and overall survival. The aim of the current study was to evaluate the possible prognostic significance of tumor cells detected in the peripheral blood and bone marrow of ovarian carcinoma patients by an immunomagnetic method.

METHODS

In a total of 90 patients with histologically proven epithelial ovarian carcinoma, blood and (in 73 cases) bone marrow samples were taken. Tumor cells were identified by a microbead coated with the antibody MOC-31, which recognizes an epitope regularly expressed on ovarian carcinoma cells.

RESULTS

The authors detected carcinoma cells in the bone marrow in 21% of ovarian carcinoma patients, and in the peripheral blood in 12% of patients. Mean overall survival was 25 and 28 months for patients with or without circulating tumor cells, respectively.

CONCLUSIONS

Ovarian carcinoma cells seem to reach peripheral circulation more frequently than expected. However, in contrast to an earlier report, detection of tumor cells in the bone marrow and/or blood was not associated with poor prognosis in ovarian carcinoma patients. This discrepancy remains unexplained, but characterization of circulating ovarian carcinoma cells for their malignant and metastatic capacity is clearly warranted.

Quantitative assessment of minimal residual disease in childhood lymphoid malignancies using an allele-specific oligonucleotide real-time quantitative polymerase chain reaction

We developed an assay using a real-time quantitative polymerase chain reaction (RQ-PCR) for the quantitative assessment of minimal residual disease (MRD) in childhood lymphoid malignancies by using a consensus V-region probe combining a allele-specific oligonucleotide (ASO) reverse primer. Our strategy employs a set consisting of a consensus V-region probe, an ASO reverse primer, and a patient-specific forward primer for clonal antigen-receptor (IgH, immunoglobulin heavy chain; TCR, T-cell receptor) gene rearrangements (IgH-ASO and TCR-ASO RQ-PCR assays). The limit of detection in both assays was 5 copies of the target/10(5) cell equivalents. We tested the assays in 17 childhood malignancies (14 cases of acute lymphoblastic leukemia and 3 of non-Hodgkin's lymphoma). High correlation coefficients of the standard curves (>0.980) and PCR efficiency (>0.95) were achieved with all primer/probe sets. In 2 (12%) of the 17 patients, ASO primers could not be designed because there was no junctional N-sequence. The quantitative data suggest that the copy number of clonal antigen receptors markedly decreased after induction therapy in 15 of 17 patients and that 1 patient relapsed and died of the disease. Consensus probes make it possible to examine a large number of patients with only a limited number of probes. The strategy used for IgH-ASO and TCR-ASO RQ-PCR assays is accurate and reliable in the clinical prospective study of MRD in childhood lymphoid malignancies.

Clinical role of sentinel-lymph-node biopsy in breast cancer

The introduction of sentinel-lymph-node biopsy has brought new impetus to the early staging of cancer in general, and breast cancer in particular. This technique has rekindled the discussion on the present role and routine practice of axillary-lymph-node dissection in early breast cancer, the methods available for the histopathological assessment of lymph nodes, and the current thoughts about best surgical practice in the management of breast cancer. Sentinel-lymph-node biopsy has spread so rapidly that surgeons, pathologists, and patients are no longer willing or able to ignore the possible consequences of its implementation. A vast amount of data (over 1150 publications in the peer-reviewed literature on this subject to date) attests to the explosive interest in the past 5 years. In this article we review our own experience and discuss recommendations for clinical practice.

Lymphatic mapping and sentinel node identification in patients with cervix cancer undergoing radical hysterectomy and pelvic lymphadenectomy

PURPOSE

The purpose of this study was to determine the feasibility of sentinel node identification in patients with invasive cervix cancer undergoing radical hysterectomy and pelvic lymphadenectomy using preoperative and intraoperative lymphatic mapping.

PATIENTS AND METHODS

Thirty-nine patients at two institutions were enrolled onto this institutional review board-approved study. All underwent preoperative lymphoscintigraphy and intraoperative lymphatic mapping with blue dye and a handheld gamma probe. Radical hysterectomy was aborted in four patients because metastatic disease was discovered on frozen section analysis of the sentinel node.

RESULTS

Preoperative lymphoscintigraphy revealed at least one sentinel node in 33 patients (85%), including 21 (55%) with bilateral sentinel nodes. All 39 patients had at least one sentinel node identified intraoperatively. Eighty percent of sentinel nodes were in three pelvic locations: iliac, obturator, and parametrial (in descending order of frequency). The remaining sentinel nodes were in the common iliac and para-aortic nodal basins. A total of 132 nodes were identified clinically as sentinel nodes; 65 (49%) were both blue and hot, 35 (27%) were blue only, and 32 (24%) were hot only. Eight patients (21%) had metastatic disease. In five of these patients, sentinel nodes were the only positive lymph nodes. One patient had false-negative sentinel nodes. She had four microscopically positive parametrial nodes that were resected in continuity with the uterus. The sensitivity of the sentinel node was 87.5% and the negative predictive value was 97%.

CONCLUSION

Preoperative lymphoscintigraphy and intraoperative lymphatic mapping were highly successful at identifying sentinel nodes in patients undergoing radical hysterectomy.

Lymphatic dissemination of tumour cells and the formation of micrometastases

Most human cancers show evidence of metastatic spread to regional lymph nodes, and the extent of lymph-node involvement is directly related to dinical outcome. Increased expression of vascular endothelial growth factor C in primary tumours is associated with increased dissemination of tumour cells to regional lymph nodes in various human carcinomas. Arguments favouring the activation of pre-existing lymphatic endothelium and the de novo formation of lymphatic capillaries (lymphangiogenesis) are discussed. We highlight recent advances in the molecular detection and characterisation of lymph-node micrometastases, as well as potential microenvironmental factors, such as chemokines, which may influence the migration and growth of metastatic tumour cells. Finally, we examine the clinical significance of lymphatic-mediated tumour-cell dissemination and the formation of lymph-node micrometastases.

Detection of disseminated tumor cells: strategies and diagnostic implications

Disseminated cells from primary solid tumors are considered to be the cause of metastases formation and relapse of disease. Consequently, their detection is of high importance for staging, prognosis and decisions about adjuvant therapy. Residual disease is conventionally detected by histological evaluation of biopsy specimens. Continuing efforts to increase the sensitivity to identify occult tumor cells in lymph node, bone marrow and blood have led to the development of various strategies. This review will discuss histological, immunological and molecular approaches to detect micrometastases from solid tumors.

An overview of real-time quantitative PCR: applications to quantify cytokine gene expression

The analysis of cytokine profiles helps to clarify functional properties of immune cells, both for research and for clinical diagnosis. The real-time reverse transcription polymerase chain reaction (RT-PCR) is becoming widely used to quantify cytokines from cells, body fluids, tissues, or tissue biopsies. Being a very powerful and sensitive method it can be used to quantify mRNA expression levels of cytokines, which are often very low in the tissues under investigation. The method allows for the direct detection of PCR product during the exponential phase of the reaction, combining amplification and detection in one single step. In this review we discuss the principle of real-time RT-PCR, the different methodologies and chemistries available, the assets, and some of the pitfalls. With the TaqMan chemistry and the 7700 Sequence Detection System (Applied Biosystems), validation for a large panel of murine and human cytokines and other factors playing a role in the immune system is discussed in detail. In summary, the real-time RT-PCR technique is very accurate and sensitive, allows a high throughput, and can be performed on very small samples; therefore it is the method of choice for quantification of cytokine profiles in immune cells or inflamed tissues.

The role of chemotherapy in early non-small-cell lung cancer management

Great advances have been made in chemotherapy in advanced and metastatic non-small-cell lung cancer (NSCLC), and a major milestone was reached with the administration of neoadjuvant chemotherapy in stage IIIA N2 disease. The systemic nature of lung cancer has been confirmed by many genetic analyses documenting micrometastases in negative lymph nodes and bone marrow, and mRNA gene overexpression as a surrogate of cancer cells has been identified in peripheral blood. Furthermore, serum or plasma cell-free tumor DNA has been observed even in tumors with a diameter of less than 2 cm. Pharmacogenetic screening can lead to tailored chemotherapy even in patients with early disease through the use of a genetic tool kit that will allow us to optimize the use of chemotherapy by using serial measurements of serum DNA that can help to detect residual disease and re-assess the chemosensitivity of sub-clinical micrometastatic disease. The ongoing (neo)adjuvant taxol/carboplatin hope (NATCH) trial is testing the value of three cycles of chemotherapy given pre- or post-operatively compared with surgery alone and will analyze genetic abnormalities in serum DNA at three different points during patient follow-up. Our major concern in this review is to analyze the pros and cons of chemotherapy in NSCLC. Although this review is not a formal meta-analysis, we have discussed the most relevant published studies in this field. We conclude that not only is there no evidence of detrimental effects of chemotherapy, in fact, there are many indications that chemotherapy induces response in up to 80% of patients and downgrades N2 disease in up to 50% of patients. This translates into significantly better survival when accompanied by complete resection. Since at least 50% of patients with stage IB disease develop distant metastases, it seems logical to explore the role of chemotherapy in early disease.

Transcription of cytokeratins 8, 18, and 19 in bone marrow and limited expression of cytokeratins 7 and 20 by carcinoma cells: inherent limitations for RT-PCR in the detection of isolated tumor cells

The suitability of "real-time" quantitative reverse transcriptase polymerase chain reaction (RT-PCR) for the detection of isolated carcinoma cells in bone marrow was investigated by evaluating the expression of cytokeratin (CK)7, CK8, CK18, CK19, and CK20 in 17 gastrointestinal cancer cell lines, 64 control bone marrow specimens from noncancer patients, and 30 bone marrow specimens from patients with gastric or colorectal cancer. RT-PCR products for CK8 and CK18 were detected in all cancer cell lines, but only 16, 5, and 11 cell lines provided evidence for CK19, CK7, and CK20 transcription. Variable numbers of bone marrow specimens from noncancer patients demonstrated background transcription of CK8 (78.1%), CK18 (95.3%), CK19 (35.9%), CK20 (29.6%), and CK7 (16.7%). Maximal background transcription for CK8, CK18, and CK19 ranged from 52.2 to 56.1 copies/10(3) copies glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the corresponding values of 0.06 and 0.76 copies for CK7 and CK20 being distinctly lower. When maximal background values were used as a threshold value to define positivity in tumor cell dilution experiments, sensitivity levels of one tumor cell in 10(4) bone marrow cells were determined for CK7 and CK20 RT-PCR assays. Maximal background expression values of the different CKs as obtained in the control series were exceeded once (CK20), twice (CK18 and CK19), and 18 times (CK7) in bone marrow specimens from cancer patients, with none of these specimens exceeding the maximal background expression value of CK8. We conclude that RT-PCR for CK8, CK18, and CK19 cannot be recommended for the detection of isolated tumor cells in bone marrow of cancer patients. On the other side, the limited number of gastric and colorectal cancer cell lines expressing CK7 and CK20 indicates that assay sensitivity for these CKs might be limited because of their selective expression by carcinoma cells.

Sentinel nodes in gynecologic malignancies

The concept of sentinel node identification and lymphatic mapping is already established as part of standard practice in the surgical management of breast cancer and melanoma. To reduce extensive radical procedures and decrease morbidity in gynecologic malignancies, much effort is being focused on implementing less aggressive interventions. By combining the use of radioactive tracers and blue dyes, investigators are identifying sentinel nodes. In vulvar and cervical carcinomas, sentinel node identification may significantly reduce the number of patients undergoing unnecessary, extensive lymphadenectomy in the absence of disease. The addition of novel techniques, such as histopathologic ultrastaging, immunohistochemistry staining, and reverse transcriptase polymerase chain reaction assays, will help increase the accuracy and rate of detection of disease.

Epithelial cells in bone marrow of breast cancer patients at time of primary surgery: clinical outcome during long-term follow-up

PURPOSE

To evaluate the detection of epithelial cells in bone marrow of breast cancer patients as an indicator of metastatic disease.

PATIENTS AND METHODS

Between 1989 and 1994, bone marrow biopsies were performed on 393 breast cancer patients during primary surgery. Specimens were stained immunocytochemically for epithelial cells expressing cytokeratins or the epithelial membrane antigen. The long-term outcomes of these patients were analyzed in this study.

RESULTS

In 166 of 393 patients, epithelial cells were found in bone marrow (BM) aspirates. These patients were designated BM+. The rate of tumor recurrence or cancer-related death was significantly higher in BM+ patients than in BM- patients. Multivariate analysis using the Cox regression model revealed BM status as a prognostic parameter independent of tumor size and axillary lymph node status. However, tumor size and axillary lymph node status were clearly superior prognostic parameters.

CONCLUSION

Disseminated epithelial cells in BM are associated with poor clinical outcome in breast cancer patients. However, the presence of these cells is not a sufficient parameter to predict growing metastases in the majority of patients, suggesting that epithelial cells in the BM of breast cancer patients at the time of surgery have limited metastatic potential. The role of these cells needs to be further evaluated.