Detection of micrometastasis in sentinel lymph nodes of patients with primary cutaneous melanoma

Optimization of Sentinel Lymph Node Imaging Methodology Using Anionic Liposome and Hyaluronidase

The sentinel lymph node (SLN) is the first lymph node into which lymphatic fluid from tumor tissues flows. The development of a highly sensitive probe for detecting SLNs is desired for the lymph node dissection through intraoperative biopsy. We have previously shown that anionic liposomes tend to accumulate in lymph nodes and that macrophage uptake of liposomes contributes to their accumulation. In the present study, we found that among anionic lipids, phosphatidylserine (PS)-containing liposomes were substantially taken up by macrophages. We identified a new lipid composition to improve the SNL-selectivity of liposome accumulation based on Design-of-Experiment. The optimized PS-containing particles were more selectively accumulate to SLN lymph nodes than existing imaging agents indocyanine green. These results indicate the effectiveness of PS-containing anionic particles in SLN imaging.

Pemphigus vulgaris antigen mRNA quantification for the staging of sentinel lymph nodes in head and neck cancer

Background:

Molecular diagnosis has been proposed to enhance the intra-operative diagnosis of sentinel lymph node (SLN) invasion in head and neck squamous cell carcinoma (HNSCC). Although cytokeratin (CK) mRNA quantification with real-time reverse transcriptase-PCR (QRT–PCR) has produced encouraging results, the more discriminating markers remain to be identified.

Methods:

Pemphigus vulgaris antigen (PVA), squamous cell carcinoma antigen (SCCA), and CK17 mRNA were quantified using QRT–PCR, and the results were compared with an extensive histopathological examination of the entire SLNs on 78 SLNs harvested from 22 patients with HNSCC.

Results:

SCCA and CK17 quantification showed significantly higher mRNA values for macrometastases (MAs) than for either negative or isolated tumour cell (ITC) SLNs (P<0.01). Pemphigus vulgaris antigen allowed the discrimination of all MAs and micrometastases from both negative and ITC SLNs (P<0.001). For the neck staging of patients, considering metastatic vs non-metastatic status, receiver-operating characteristic curve analysis found areas under the curve of 93.8, 97.9, and 100% for CK17, SCCA, and PVA, respectively. With PVA, a cutoff value of 562 copies per 100 ng of cDNA permitted the correct distinction between patients with positive as opposed to negative neck nodes in all cases.

Conclusion:

PVA seems to be a highly promising marker for accurate intra-operative SLN staging in HNSCC by QRT–PCR.

Extralesional detection and load of human papillomavirus DNA: a possible marker of preclinical tumor spread in cervical cancer

OBJECTIVE

Because the interaction between viral DNA products and cellular regulatory mechanisms is the first step leading to cancerous transformation, the detection of its presence in histologically negative lymph nodes may represent a very early biological step in cancer spread. The quantitative estimate may represent and an indirect sign of active cellular replication.

MATERIALS AND METHODS

Cervical and lymph nodes tissues of 13 cases of invasive cervical cancer were analyzed for human papillomavirus (HPV)-DNA presence and viral load by HPV typing and quantification by real-time polymerase chain reaction.

RESULTS

HPV-DNA was demonstrated in all tissue samples (primary tumor, positive lymph nodes, negative lymph nodes) with the most prevalence of HPV 16 (61.5%) and single-type infection (69.3%), whereas viral load (mean quantity of DNA copies) is statistically different in negative versus positive lymph nodes (p =.005).

CONCLUSIONS

Concordance of viral type and lymph nodes viral load may represent as a useful tool in identifying early metastatic risk of tumor spread.

Laparoscopic Sentinel Node Biopsy in Cervical Cancer Using a Combined Detection: 5–Years Experience

BACKGROUND

To evaluate the feasibility after 5 years experience of a laparoscopic sentinel node (SN) procedure with combined radioisotopic and patent blue labeling in patients with cervical cancer.

METHODS

Sixty-seven patients (median age 48.9 years) with cervical cancer underwent a laparoscopic SN procedure using an endoscopic gamma probe, after both radioactive and patent blue injections. After the procedure, all the patients underwent complete laparoscopic pelvic/para-aortic lymphadenectomy.

RESULTS

At least one SN was identified in 57 patients (85.1%). According to the Stage, the SN identification rate was 91.2% in early-stage cervical cancer and 78.5% in locally advanced cervical cancer. The mean number of SN was 2.3 per patient (range 1-5). A total of 129 SNs were removed. Lymph node metastasis involvement was identified in the 20 SNs (15.5%) from 14 patients (24.6%). Nine of the 14 patients had at least one macrometastases, three patients presented micrometastases in H&S, and two patients presented isolated single cells. Six patients presented a pelvic non-SN involvement including two patients whose SNs were uninvolved. The false-negative SNs rate was 12.5% (two patients out of 16). Both patients have locally advanced cervical cancer.

CONCLUSION

This study confirms that laparoscopic SN detection with a combination of radiocolloid and patent blue is accurate in patients with early cervical cancer to assess pelvic lymph node status.

Assessment of pelvic lymph node micrometastatic disease in stages IB and IIA of carcinoma of the uterine cervix

The objective of this study was to assess the frequency of micrometastatic disease (MID) in pelvic lymph nodes (PLNs) in carcinoma of the uterine cervix (CUC) and to determine the risk of recurrence. The PLNs from 289 patients with CUC (IB and IIA) were studied. Each PLN was assessed via immunohistochemistry using a single histologic section (AE1/AE3). Metastatic deposits were measured and the disease status was classified into three groups: 1) absence of metastatic disease (MOD); 2) MID, one or more metastatic PLN with only isolated tumor cells and/or micrometastases (up to 2 mm); and 3) macrometastatic disease (MAD), presence of one or more metastatic PLN with macrometastases (more than 2 mm). Eleven patients (3.8%) were classified as having MID and 37 (12.8%) as having MAD. The 5-year disease-free survival (DFS) rates for MOD, MAD, and MID were 88.7%, 80.4%, and 50.0%, respectively (P < 0.001). The Cox proportional hazards model showed that MID was an independent variable for recurrence when adjusted for MAD, depth of tumor invasion, severity of inflammatory reaction, and use of adjuvant radiotherapy. We conclude that the frequency of MID in PLN was low. However, patients with MID presented a high risk of recurrence and reduced DFS.

The Diagnostic Accuracy of Reverse Transcription-PCR Quantification of Cytokeratin mRNA in the Detection of Sentinel Lymph Node Invasion in Oral and Oropharyngeal Squamous Cell Carcinoma: A Comparison with Immunohistochemistry

PURPOSE

The main goal of sentinel lymph node (SLN) detection in head and neck squamous cell carcinomas is to limit neck dissections to pN+ cases only. However, intraoperative + diagnosis cannot be routinely done using the current gold standard, serial step sectioning with immunohistochemistry. Real-time quantitative reverse transcription-PCR (RT-PCR) is potentially compatible with intraoperative use, proving highly sensitive in detecting molecular markers. This study postoperatively assessed the accuracy of quantitative RT-PCR in staging patients from their SLN.

EXPERIMENTAL DESIGN

A combined analysis on the same SLN by serial step sectioning with immunohistochemistry and quantitative RT-PCR targeting cytokeratins 5, 14, and 17 was done in 18 consecutive patients with oral or oropharyngeal squamous cell carcinoma and 10 control subjects.

RESULTS

From 71 lymph nodes examined, mRNA levels (KRT) were linked to metastasis size for the three cytokeratins studied (Pearson correlation coefficient, r = 0.89, 0.73, and 0.77 for KRT 5, 14, and 17 respectively; P < 0.05). Histopathology-positive SLNs (macro- and micrometastases) showed higher mRNA values than negative SLNs for KRT 17 (P < 10(-4)) and KRT 14 (P < 10(-2)). KRT 5 showed nonsignificant results. KRT 17 seemed to be the most accurate marker for the diagnosis of micrometastases of a size >450 mum. Smaller micrometastases and isolated tumor cells did not provide results above the background level. Receiver operating characteristic curve analysis for KRT 17 identified a cutoff value where patient staging reached 100% specificity and sensitivity for macro- and micrometastases.

CONCLUSION

Quantitative RT-PCR for SLN staging in cN(0) patients with oral and oropharyngeal squamous cell carcinoma seems to be a promising approach.

Clinical significance of lympho vascular space involvement and lymph node micrometastases in early-stage cervical cancer: A retrospective case-control surgico-pathological study

OBJECTIVE

Several studies have shown that lympho vascular space involvement (LVSI) and lymph node micrometastases (LNmM) may be risk factors for recurrence in early-stage cervical cancer with no apparent lymph node metastases. We performed a retrospective case-control study to reassess whether the presence of lymph node micrometastases and LVSI is predictive of subsequent recurrence following surgical resection of early-stage cervical cancer.

METHODS

In a series of 292 patients diagnosed with early cervical cancer and treated by the same surgical procedure (laparoscopic-vaginal radical hysterectomy) during the same time period, two paired series were selected. The first series consisted of 26 cases who recurred in a median time of 36.8 months and the second series were 26 cases matched for age, histological sub-type, surgico-pathological stage and maximal tumor diameter, who did not recur after a median follow-up of 122 months. Sections taken from the hysterectomy specimens were reassessed for LVSI. All the lymph node blocks which have initially been considered as uninvolved were submitted to serial sectioning. Immunohistochemical staining using anti-cytokeratins AE1 and AE3 was used for identifying LNmM.

RESULTS

LVSI was twice more frequent and LNmM ten-fold more frequent in the group of patients who recurred: 20/26 (77%) versus 9/26 (35%) and 11/26 (42%) versus 1/26 (4%) respectively. The relative risk of recurrence is 2.64 (1.67-5.49, P < 0.01) in the presence of LVSI and 2.44 (1.58-3.78, P < 0.01) in the presence of LNmM. All the patients with LNmM were LVSI positive. At bivariate analysis, the true LNmM (deposits more than 200 um in size) was the only independent risk factor.

CONCLUSIONS

LNmM is an important risk factor of tumor recurrence in patients with early cervical cancer with no apparent lymph node metastases. LNmM seems to occur only in LVSI positive tumors. These data may lead to improve management of early-stage cervical cancer to reduce the risk of recurrence in those cases.

Systematic Identification of Human Melanoma Antigens Using Serial Analysis of Gene Expression (SAGE)

To identify new melanoma antigens using systematic gene expression analysis combined with rapid screening of patient sera for immunogenicity, a serial analysis of gene expression (SAGE) method was applied to profile transcripts in a highly pigmented melanoma cell line SKmel23. 25,997 SAGE tags consisting of 10,382 unique transcripts were sequenced. This melanoma SAGE library was compared with a testis SAGE library and the colon SAGE database, and to the cDNA database obtained by random sequencing of a melanocyte cDNA library. Among the 15 tags finally selected with criteria of preferential expression on melanoma and melanocytes at relatively high frequency, two tags were further analyzed for their structure and immunogenicity. One was identified as PAX3, and its isoform, PAX3d, was found to be dominantly expressed in melanoma and melanocytes. The other was derived from a novel gene and its full-length cDNA clone was isolated. Preferential expression of these genes in melanoma and melanocytes was confirmed by RT-PCR and Northern blot analysis. The recombinant bacterial PAX3d protein was recognized by serum IgG from some patients with melanoma and Vogt-Koyanagi-Harada (VKH) disease but not from healthy individuals, indicating that PAX3d is a new melanocyte-specific antigen immunogenic in patients with melanoma or VKH disease. The authors report two melanocyte/melanoma-specific molecules, which may be useful for development of diagnosis or treatment of these pigment disorders. In addition, a system using SAGE and immunoscreening with patients' sera is shown to be an efficient method for the systematic identification of tumor antigens.

Identification of micrometastases in histologically negative lymph nodes of early-stage cervical cancer patients

OBJECTIVE

Despite histologically negative lymph nodes, approximately 15% of patients with early-stage cervical cancer will develop recurrence. Micrometastases have been shown to be important in staging and treatment of breast cancers and melanoma and have been identified by polymerase chain reaction analysis in cervical cancers. This study sought to estimate the frequency of micrometastases identified by immunohistochemistry in histologically negative lymph nodes and compare this to other known risk factors for recurrence of cervical cancer.

METHODS

Early-stage (stages IA2, IB1, and IB2) cervical cancer patients of all histologic subtypes were identified from the surgical logs of the Los Angeles County-University of Southern California Medical Center for the period 1994-2000. One hundred thirty-two patients had histologically negative lymph nodes. Immunohistochemical assay was performed on 3,106 lymph nodes by using antibodies against cytokeratins AE-1 and CAM 5.2 in combination according to standard protocols. The stained nodes were then evaluated for the presence of micrometastases and compared against the respective clinicopathologic information in each case.

RESULTS

Micrometastases were detected in 19 of 132 (15%, 95% confidence interval [CI] 9%, 22%) patients, found in 29 of the 3,106 (0.9%) lymph nodes evaluated. Vascular space invasion was seen in 50 of 132 cases (38%, 95% CI 30%, 47%) and in 8 of 19 (42%, 95% CI 21%, 66%) cases with micrometastases. Surgical margins of the resected specimen were negative in 120 of 132 cases (91%, 95% CI 84%, 95%) and in 16 of 19 (84%, 95%CI 60%, 96%) of those cases with micrometastases. Micrometastases were seen most frequently in pelvic lymph nodes (25 of 29, 86%). Patients with more than 20 lymph nodes removed were more likely to demonstrate metastasis (P <.001). There was no statistically significant association between micrometastasis and vascular space invasion or tumor volume.

CONCLUSION

Micrometastases are identifiable in histologically negative lymph nodes in 15% (95% CI 9%, 22%) of early-stage cancer patients, a frequency which approximates the recurrence rate for patients with negative nodes. In this series, patients with greater numbers of lymph nodes analyzed were more likely to have lymph node micrometastasis identified. There appears to be no relationship between tumor volume and the identification of micrometastases. Although micrometastases can be identified in histologically negative lymph nodes, their presence is not strongly associated with other known factors of cervical cancer recurrence. Further research is needed to determine whether the presence of lymph node micrometastases is associated with an unfavorable prognosis.

LEVEL OF EVIDENCE

II-3

Rapid immunohistochemistry of sentinel lymph nodes for metastatic melanoma

Sentinel lymph node (SLN) biopsy is performed on patients with malignant melanoma (MM) to assess the need for selective complete lymphadenectomy. Melanoma metastasis to regional lymph nodes is an important prognostic indicator in patients with MM. This study assesses the sensitivity and specificity of rapid immunohistochemistry (RIHC) in intraoperative delineation of melanoma metastasis to SLN. RIHC for S-100 protein, HMB45, and a melanoma marker cocktail (melan A, HMB45, and tyrosinase) was performed on 71 SLNs obtained from 28 patients with MM. Frozen sections (6 micro thick) on plus slides were fixed for 2 to 3 minutes in cold acetone and then stored at -70 degrees C. The EnVision kit (Dako, Carpinteria, CA) for rapid immunohistochemistry (RIHC) on frozen tissue sections was used, and the staining technique took 19 minutes. Together with preparation of the frozen sections and fixation in acetone, immunostained slides were available in approximately 25 minutes. Of the 71 SNLs examined, 7 showed melanoma metastasis in permanent sections. RIHC of frozen sections detected metastatic melanoma in 6 SLNs, with a sensitivity of 86% for HMB45 and 71% for S-100 protein and the melanoma cocktail and a specificity of 97% for HMB45 and 100% for S-100 and the melanoma cocktail. We conclude that RIHC for HMB45, S-100 protein, and the melanoma cocktail may help detect melanoma metastasis in SLN intraoperatively, leading to total lymph node dissection and obviating the need for 2 surgical procedures. Section folds and background stain can make interpretation difficult. Intraoperative time constraints require a more rapid technique. A recent consensus group has discouraged frozen-section examination of SLN.

Sentinel lymph node biopsy for the T1 (thin) melanoma: is it necessary?

The use of sentinel lymph node biopsy for the T1 melanoma is controversial. Recent reports have demonstrated that certain T1 melanomas are at increased risk for early regional metastases and late recurrence when compared with all thin melanomas. The purpose of this study was to review the authors' experience with wide excision and sentinel lymph node biopsy for certain patients with T1 melanoma. A retrospective analysis of 34 patients with T1 melanoma was completed over a 3-year period. Indications for sentinel lymph node biopsy included a Breslow thickness of less than or equal to 1 mm a Clark level of III or IV tumor ulceration, or tumor regression. Twenty-four patients met these criteria (13 men and 11 women). Mean age was 47.6 years (range, 23-88 years). Mean tumor thickness for all patients was 0.69 mm (range, 0.3-1.0 mm), 0.61 mm for the Clark level III patients (N = 15), and 0.72 mm for the Clark level IV patients (N = 9). Tumor ulceration was present in 1 patient and histological regression was present in 2 patients. Regional lymph node metastases were confirmed histologically in 2 of 24 patients (8.3%) in whom the thickness of the melanoma was 0.9 mm and 1 mm. Both patients have died of metastatic melanoma. No recurrence has been demonstrated in the remaining 22 patients at the 2 to 5-year follow-up. Current indications for sentinel lymph node biopsy for patients with T1 melanoma include tumors associated with Clark level IV or V invasion, ulceration, regression, a positive deep margin on initial biopsy, or previous melanoma. Acral lentiginous melanoma associated with at least a Clark level III invasion warrant sentinel lymph node biopsy. Superficial spreading or nodular melanoma larger than 0.9 mm should include sentinel lymph node biopsy regardless of other associated histological factors.

Biomarkers in melanoma: staging, prognosis and detection of early metastases

Currently, melanoma remains a surgical disease since early detection and excision of thin melanomas offers the best chance of a cure. Despite intensive clinical investigation, no effective systemic therapies exist for metastatic melanoma. Sentinel lymph node biopsy has greatly aided the staging and prognostic evaluation of primary cutaneous melanoma, however, approximately a third of patients diagnosed with metastatic melanomas present without prior regional lymph node involvement. Additional prognostic biomarkers exist which help determine the risk of advanced melanoma but the accuracy for each current marker is less than 100%. A greater understanding of the biology of melanomas and the development of new methods to identify patients with early (subclinical) metastatic disease may allow for selective and more effective therapy for patients at-risk for advanced disease. In this paper, current and novel potentially more accurate biomarkers for the staging and prognostic evaluation of melanoma patients, and for the detection of subclinical metastases are reviewed.

New diagnostic techniques in staging in the surgical treatment of cutaneous malignant melanoma

The emphasis of the research on the surgical treatment of melanoma has been on the resection margins, the role of elective lymph node dissection in high risk patients and the value of adjuvant regional treatment with hyperthermic isolated lymph perfusion with melphalan. Parallel to this research, new diagnostic techniques, such as Positron Emission Tomography and the introduction of the sentinel lymph node biopsy with advanced laboratory methods such as immuno-histochemical markers, and reverse transcriptase polymerase chain reaction, have been developed to facilitate early detection of metastatic melanoma. The role of these new techniques on the staging and surgical treatment of melanoma is discussed in this paper.

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.