Identification of the sentinel lymph node in patients with malignant melanoma: what are the reasons for mistakes?

Prognostic Role of Non-Identification of Sentinel Lymph Node in Cutaneous Melanoma Patients: An Observational Retrospective Study

Simple Summary

Sentinel lymph node status is the most important prognostic factor for patients with cutaneous melanoma, but occasionally it is not possible to identify the sentinel lymph node. Little is known in cutaneous melanoma literature about the phenomenon of non-identification of sentinel lymph node and its prognostic implications. In this study we observed that not identifying the sentinel lymph node involves a worse nodal disease-free survival, but not a worse melanoma-specific survival than a negative sentinel lymph node. Potentially, patients with non-identified SLN should receive a follow-up schedule like that of patients with positive SLN.

Abstract

Background: Sentinel lymph node (SLN) status is recognized as the most important prognostic factor for patients with cutaneous melanoma. However, sometimes it is not possible to identify SLN. The phenomenon of non-identification of SLN and its prognostic role have not been thoroughly evaluated in melanoma literature. The objective of this study was to identify which patient or tumor variables may be associated to non-identification of SLN and to evaluate the prognostic role of non-identification of SLN. Methods: Observational retrospective study of 834 cutaneous melanoma patients who underwent SLN biopsy at Instituto Valenciano de Oncología. Results: Forty-two patients (5%) presented non-identification of SLN. Patients with age at diagnosis of ≥ 64 years, obesity (BMI ≥ 30), and head and neck localization were at higher risk of non-identification of SLN. Non-identified SLN patients had worse nodal disease-free survival with respect to negative SLN patients, but not worse melanoma-specific survival. Conclusions: Our findings suggest a need to follow-up patients with non-identified SLN in the same way as patients with positive SLN.

High nevus counts confer a favorable prognosis in melanoma patients

A high number of nevi is the most significant phenotypic risk factor for melanoma and is in part genetically determined. The number of nevi decreases from middle age onward but this senescence can be delayed in patients with melanoma. We investigated the effects of nevus number count on sentinel node status and melanoma survival in a large cohort of melanoma cases. Out of 2,184 melanoma cases, 684 (31.3%) had a high nevus count (>50). High nevus counts were associated with favorable prognostic factors such as lower Breslow thickness, less ulceration and lower mitotic rate, despite adjustment for age. Nevus count was not predictive of sentinel node status. The crude 5- and 10-year melanoma-specific survival rate was higher in melanomas cases with a high nevus count compared to those with a low nevus count (91.2 vs. 86.4% and 87.2 vs. 79%, respectively). The difference in survival remained significant after adjusting for all known melanoma prognostic factors (hazard ratio [HR] = 0.43, confidence interval [CI] = 0.21-0.89). The favorable prognostic value of a high nevus count was also seen within the positive sentinel node subgroup of patients (HR = 0.22, CI = 0.08-0.60). High nevus count is associated with a better melanoma survival, even in the subgroup of patients with positive sentinel lymph node. This suggests a different biological behavior of melanoma tumors in patients with an excess of nevi.

Probabilistic issues with sentinel lymph nodes in malignant melanoma

OBJECTIVES

To address issues of probability for sentinel lymph node results in melanoma and provide details about the probabilistic nature of the numbers of sentinel nodes as well as to address how these issues relate to tumor thickness and patient outcomes.

METHODS

Analysis of the probability of observing sentinel node metastases uses the discrete exponential probability distribution to address the number of observed positive sentinel nodes. In addition, mathematical functions derived from survival analysis are used. Data are then chosen from the literature to illustrate the approach and to derive results.

RESULTS

Observations about the numbers of positive and negative sentinel nodes closely follow discrete exponential probability distributions, and the relationship between the probability of a positive sentinel node and tumor thickness follows closely a function derived from survival analysis. Sentinel node results relate to tumor thickness as well as to the total number of nodes harvested but fall short of identifying all those who eventually develop metastatic melanoma.

CONCLUSIONS

Probability analyses provide useful insight into the success and failure of the sentinel node biopsy procedure in patients with melanoma.

EANM practice guidelines for lymphoscintigraphy and sentinel lymph node biopsy in melanoma

PURPOSE

Sentinel lymph node biopsy is an essential staging tool in patients with clinically localized melanoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with melanoma.

METHODS

These practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, national nuclear medicine societies, the European Society of Surgical Oncology (ESSO) and the European Association for Research and Treatment of Cancer (EORTC) melanoma group. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI).

CONCLUSION

The present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of melanoma patients.

Dermoscopy structures as predictors of sentinel lymph node positivity in cutaneous melanoma

BACKGROUND

Histological features such as Breslow thickness, ulceration and mitosis are the main criteria to guide sentinel lymph node biopsy (SLNB) in melanoma. Dermoscopy may add complementary information to these criteria.

OBJECTIVES

To evaluate the correlation between dermoscopy structures and SLNB positivity.

METHODS

Retrospective analysis of 123 consecutive melanomas with Breslow thickness > 0·75 mm, SLNB performed during follow-up and dermoscopic images.

RESULTS

Men were more likely to have a positive SLNB. The presence of ulceration and blotch and the absence of a pigmented network in dermoscopy correlated with positive SLNB. Histological ulceration also correlated with positive SLNB. A dermoscopy SCORE predicted SLN status with a sensitivity of 96·3% and a specificity of 30·2%. When sex and Breslow thickness were added (SCOREBRESEX), the sensitivity remained at 96·3% but the specificity increased to 52·1%. This study is limited by the number of patients and was performed in only one institution.

CONCLUSIONS

Dermoscopy allowed a more precise prediction of SLN status. If a combined SCOREBRESEX was used to select patients for SLNB, 41·5% of procedures might be avoided.

Contribution of dynamic sentinel lymphoscintigraphy images to the diagnosis of patients with malignant skin neoplasms in the upper and lower extremities

The aim of the present study was to confirm the contribution of dynamic images in sentinel lymphoscintigraphy in malignant skin neoplasms: precisely, to investigate if dynamic images were necessary and to observe if dynamic images could reduce the areas needed for biopsy and dissection. Twenty-five patients with malignant skin neoplasms of the lower (n = 21) and upper (n = 4) extremities were retrospectively investigated. Images were evaluated by two independent reviewers, an expert in diagnostic radiology and nuclear medicine and a diagnostic radiologist in training. Visualized hot spots were assessed to be sentinel nodes using only static planar images. Next, both static planar and dynamic images were assessed. Reviewers scored diagnostic confidence values of determined sentinel nodes as follows: 0, cannot be decided; 1, possible; 2, probable; and 3, definitive. Patterns of lymphatic drainage were categorized into six different pathways: (1) inguinal type, (2) popliteal type, (3) inguinal and popliteal type, (4) axillary type, (5) cubital type, and (6) axillary and cubital type. In cases in the lower extremities, with dynamic images, the expert reviewer changed assessment in three cases and the trainee reviewer changed it in one case. There were no cases in which a decision was changed to be the same between both reviewers. Although the average diagnostic confidence value of assessment is usually higher with dynamic images, significant differences were not present. In cases of the upper extremities, both reviewers changed their assessment in one patient. By mutual agreement, cases in which assessment was changed with dynamic images were the inguinal and popliteal type, and the axillary and cubital type. The expert reviewer noticed lymphatic channels only visualized on dynamic images and changed assessment. Determination of whether or not a lymph node is a sentinel node depends on visualization of the lymphatic network. In the present circumstances, all biopsies of hot spots determined to be lymph nodes should not be excluded. However, excessive biopsies should be avoided as much as possible. It is necessary to use dynamic images alongside skillful observation.

Management of popliteal sentinel nodes in melanoma

BACKGROUND

Although most melanomas on the distal lower extremity drain exclusively to inguinal lymph nodes, a small percentage (<5%) drain to interval nodes in the popliteal basin. We investigated a possible relationship between tumor-draining popliteal and inguinal nodes in patients with lower-extremity melanoma.

STUDY DESIGN

We queried our melanoma database to identify patients who underwent sentinel node biopsy (SNB) for an infrapopliteal melanoma. Patterns of nodal drainage and nodal metastasis were analyzed.

RESULTS

Of 461 patients who underwent SNB for a primary infrapopliteal melanoma, 15 (3.2%) had drainage to the popliteal basin. Thirteen melanomas were on the posterior leg and foot, and 2 were on the anterior lower leg. Mean Breslow thickness was 2.4 mm. All 15 patients with popliteal drainage also had inguinal drainage and therefore underwent concurrent inguinal and popliteal SNB. The average number of popliteal sentinel nodes was 1.4 (range 1 to 3). Eight patients (53%) had a tumor-positive popliteal sentinel node, and 6 of the 8 underwent completion popliteal lymphadenectomy. Four of the 8 patients (50%) also had tumor-positive inguinal sentinel nodes; all underwent complete inguinal lymphadenectomy. We also identified 9 additional patients who underwent SNB for locoregional recurrent melanomas of the infrapopliteal leg. Three (33%) of these patients had concurrent inguinal and popliteal SNB, with 1 isolated tumor-positive popliteal node found.

CONCLUSIONS

In our series, a high percentage of popliteal sentinel lymph nodes contained metastases, and these patients frequently also had inguinal metastases. In our patients, all inguinal metastases were associated with concomitant popliteal metastases. Although it is anatomically separate, the inguinal basin appears to be a functional extension of the popliteal basin.

Lymphatic mapping and sentinel lymph node biopsy in patients with melanoma: a meta-analysis

PURPOSE

To perform a meta-analysis of all published studies of sentinel lymph node (SLN) biopsy for staging patients with melanoma.

METHODS

Published literature in all languages between 1990 and 2009 was critically appraised. Primary outcomes evaluated included the proportion successfully mapped (PSM) and test performance including false-negative rate (FNR), post-test probability negative (PTPN), and positive predictive value in the same nodal basin recurrence.

RESULTS

A total of 71 studies including 25,240 patients met full eligibility criteria. The average PSM was 98.1% (95% CI, 97.3% to 98.6%) and increased with the year of publication, female sex, ulceration, age, and the quality score of the studies. The FNR ranged from 0.0% to 34.0%, averaging 12.5% overall (95% CI, 11% to 14.2%). FNR increased with the length of follow-up (P = .002) but decreased with greater PSM (P = .001). PTPN averaged 3.4% (95% CI, 3.0% to 3.8%), which also increased in studies with longer follow-up, younger age, female sex, deeper Breslow thickness, and with tumor ulceration while decreasing with greater PSM (P < .001). Approximately 20% of the patients with a positive SLN had additional lymph nodes in the complete lymph node dissection and 7.5% of the patients with positive SLN developed recurrence in the same nodal basin which was greater in studies that also reported higher FNR (P = .01).

CONCLUSION

The estimated risk of nodal recurrence after a negative SLN biopsy was ≤ 5% supporting the use of this technology for staging patients with melanoma.

EANM-EORTC general recommendations for sentinel node diagnostics in melanoma

The accurate diagnosis of a sentinel node in melanoma includes a sequence of procedures from different medical specialities (nuclear medicine, surgery, oncology, and pathology). The items covered are presented in 11 sections and a reference list: (1) definition of a sentinel node, (2) clinical indications, (3) radiopharmaceuticals and activity injected, (4) dosimetry, (5) injection technique, (6) image acquisition and interpretation, (7) report and display, (8) use of dye, (9) gamma probe detection, (10) surgical techniques in sentinel node biopsy, and (11) pathological evaluation of melanoma-draining sentinel lymph nodes. If specific recommendations given cannot be based on evidence from original, scientific studies, referral is given to "general consensus" and similar expressions. The recommendations are designed to assist in the practice of referral to, performance, interpretation and reporting of all steps of the sentinel node procedure in the hope of setting state-of-the-art standards for good-quality evaluation of possible spread to the lymphatic system in intermediate-to-high risk melanoma without clinical signs of dissemination.

Imaging of lymph node micrometastases using an oncolytic herpes virus and [F]FEAU PET

Background

In patients with melanoma, knowledge of regional lymph node status provides important information on outlook. Since lymph node status can influence treatment, surgery for sentinel lymph node (SLN) biopsy became a standard staging procedure for these patients. Current imaging modalities have a limited sensitivity for detection of micrometastases in lymph nodes and, therefore, there is a need for a better technique that can accurately identify occult SLN metastases.

Methodology/Principal Findings

B16-F10 murine melanoma cells were infected with replication-competent herpes simplex virus (HSV) NV1023. The presence of tumor-targeting and reporter-expressing virus was assessed by [¹⁸F]-2′-fluoro-2′-deoxy-1-β-D-β-arabinofuranosyl-5-ethyluracil ([¹⁸F]FEAU) positron emission tomography (PET) and confirmed by histochemical assays. An animal foot pad model of melanoma lymph node metastasis was established. Mice received intratumoral injections of NV1023, and 48 hours later were imaged after i.v. injection of [¹⁸F]FEAU. NV1023 successfully infected and provided high levels of lacZ transgene expression in melanoma cells. Intratumoral injection of NV1023 resulted in viral trafficking to melanoma cells that had metastasized to popliteal and inguinal lymph nodes. Presence of virus-infected tumor cells was successfully imaged with [¹⁸F]FEAU-PET, that identified 8 out of 8 tumor-positive nodes. There was no overlap between radioactivity levels (lymph node to surrounding tissue ratio) of tumor-positive and tumor-negative lymph nodes.

Conclusion/Significance

A new approach for imaging SLN metastases using NV1023 and [¹⁸F]FEAU-PET was successful in a murine model. Similar studies could be translated to the clinic and improve the staging and management of patients with melanoma.

Imaging in cutaneous melanoma

Cutaneous melanoma (CM) is a common malignancy and imaging, particularly lymphoscintigraphy (LS), positron-emission tomography with 2-fluoro-2-deoxyglucose (FDG-PET), ultrasound, radiography computed tomography (CT) and magnetic resonance imaging have important roles in staging and restaging, surgical guidance, surveillance and assessment of recurrent disease. This review aims to summarize the available data regarding these and other imaging modalities in CM and provide the basis for subsequent formulation of guidelines regarding the use of imaging in CM. PubMed and Medline searches were performed and reference lists from publications were also searched. The published data were reviewed and tabulated. There is level I evidence supporting the use of LS and sentinel lymph node biopsy in nodal staging for CM. There is level III evidence demonstrating the superiority of ultrasound to palpation in the assessment of lymph nodes in CM. There is level IV evidence supporting FDG-PET in American Joint Committee on Cancer stage III/IV and recurrent CM and that FDG-PET/CT may be superior to FDG-PET. Level IV evidence also supports the use of CT in the same group of patients and the role of CT appears to be complementary to FDG-PET. Various imaging modalities, especially LS/sentinel lymph node biopsy and FDG-PET/CT, add incremental information in the management of CM and the various modalities have complementary roles depending on the clinical situation.

Slow dynamic lymphoscintigraphy is not a reliable predictor of sentinel-node negativity in cutaneous melanoma

We reviewed data from 160 consecutive patients (89 M/71 F; 53.5 [range, 9-88] years) who had under-gone lymphoscintigraphy and sentinel lymph node biopsy (SNB) in our hospital for histologically proven cutaneous malignant melanoma (CMM) (located on the upper limb: 33; lower limb: 57; trunk: 44; and head and neck: 26 patients), with a Breslow index > 1 mm and without clinical or radiologic evidence of metastatic spread. Colloidal (99m)Tc-rhenium sulfide (36-76 MBq) was injected intradermally in the four quadrants around the tumorectomy scar, followed by dynamic acquisition and static imaging. SN(s) were identified in 157 patients (overall identification rate, 98%). Fast (< 20 minutes), intermediate (20-30 minutes), or slow (> 30 minutes) lymphatic drainage was observed, respectively, in 122 (78%), 24 (15%), or 11 (7%) cases. Overall malignancy rate was 15%, respectively found in 19 (16%), 2 (8%), and 2 (18 %) patients with fast, intermediate, or slow drainage. No statistical difference between SN-positivity rates of patients with fast (19/122 = 16%) versus intermediate or slow drainage (4/35 = 11.4%) was observed (p = 0.69). Therefore, lymphoscintigraphic SN appearance time in CMM patients is unable both to predict SN metastasis and spare them from undergoing SN excision.

The sentinel node in breast cancer

Biopsy of the sentinel lymph node now forms part of routine management in many centres dealing with early stage breast cancer. This article seeks to discuss developments over the past number of years and to summarise current practice.

Sentinel lymph node biopsy for melanoma: aspects of pathologic assessment

Sentinel lymph node (SLN) biopsy affords an accurate, minimally invasive means of staging and determining prognosis in patients with melanoma and for identifying those patients who may benefit from complete regional lymph node dissection. Careful and accurate histopathologic assessment of SLNs is critical to achieving optimal reliability of the technique. Micromorphometric parameters of melanoma deposits in SLNs have been shown to be predictive of regional non-SLN involvement and of clinical outcomes. Several non-histopathologic methods of SLN evaluation have been investigated, and while some of them show promise for the future, excision and histopathologic examination currently remains the gold standard for the evaluation of SLNs.

Tumour lymphangiogenesis is a possible predictor of sentinel lymph node status in cutaneous melanoma: a case-control study

BACKGROUND

Cutaneous melanoma spreads preferentially through the lymphatic route and sentinel lymph node (SLN) status is regarded as the most important predictor of survival.

AIMS

To evaluate whether tumour lymphangiogenesis and the expression of vascular endothelial growth factor C (VEGF-C) is related to the risk of SLN metastasis and to clinical outcome in a case-control series of patients with melanoma.

METHODS

Forty five invasive melanoma specimens (15 cases and 30 matched controls) were investigated by immunostaining for the lymphatic endothelial marker D2-40 and for VEGF-C. Lymphangiogenesis was measured using computer assisted morphometric analysis.

RESULTS

Peritumorous lymphatic vessels were more numerous, had larger average size, and greater relative area than intratumorous lymphatics. The number and area of peritumorous and intratumorous lymphatics was significantly higher in melanomas associated with SLN metastasis than in non-metastatic melanomas. No significant difference in VEGF-C expression by neoplastic cells was shown between metastatic and non-metastatic melanomas. Using logistic regression analysis, intratumorous lymphatic vessel (LV) area was the most significant predictor of SLN metastasis (p = 0.04). Using multivariate analysis, peritumorous LV density was an independent variable affecting overall survival, whereas the intratumorous LV area approached significance (p = 0.07).

CONCLUSIONS

This study provides evidence that the presence of high peritumorous and intratumorous lymphatic microvessel density is associated with SLN metastasis and shorter survival. The intratumorous lymphatic vessel area is the most significant factor predicting SLN metastasis. The tumour associated lymphatic network constitutes a potential criterion in the selection of high risk patients for complementary treatment and a new target for antimelanoma therapeutic strategies.

Biopsia selectiva de ganglio centinela en tumores cutáneos no melanoma

PURPOSE

To assess the feasibility of the Sentinel lymph node biopsy (SLNB) technique in cutaneous non-melanoma malignancies.

MATERIALS AND METHODS

Nine patients were retrospectively evaluated performing a scintigraphy with 99mTc-nanocolloid. On the day of the surgery, an initial dynamic study and static images were obtained. The first drainage station visualized was considered the sentinel node (SLN). The SLN position was marked on the skin and after a correct localization in the surgical field with a gamma probe the SLN was obtained. Patients of this study have been followed up for 8 to 48 months.

RESULTS

Lymphoscintigraphy detected the sentinel node in 88,8 % of our studies (the SLN was not observed in a patient with a Merkel's tumour on the back). The SLN was identified intraoperatively in those patients with positive imaging. Those cases without scintigraphic demonstrated migration were also not found intraoperatively. Histopathological analysis of the SLN showed non metastatic disease and none patient developed metastases or local recurrence in the monitoring period.

CONCLUSIONS

Sentinel node biopsy can be applied to certain cutaneous non-melanoma malignancies. In patients with unclear drainage and to avoid unnecessary lymphadenectomy, the technique offers clear advantages. In our study the SLN analysis was related to the clinical progress. A large number of patients should be examined to truly assess the benefit of this technique in this kind of malignancies and to determinate when the technique must be performed.

The sentinel node in breast cancer: an update

There has been rapid acceptance of sentinel lymph node biopsy into the management of breast cancer over the past 10 years. This article seeks to highlight the controversies and to summarise its current status.

Outcome in 846 Cutaneous Melanoma Patients From a Single Center After a Negative Sentinel Node Biopsy

BACKGROUND

A negative sentinel node biopsy (SNB) implies a good prognosis for melanoma patients. The purpose of this study was to determine the long-term outcome for melanoma patients with a negative SNB.

METHODS

Survival and prognostic factors were analyzed for 836 SNB-negative patients. All patients with a node field recurrence were reviewed, and sentinel node (SN) tissue was reexamined.

RESULTS

The median tumor thickness was 1.7 mm, and 23.8% were ulcerated. The median follow-up was 42.1 months. Melanoma specific survival at 5 years was 90%, compared with 56% for SN-positive patients (P < .001). On multivariate analysis, only thickness and ulceration retained significance for disease-free and disease-specific survival. Five-year survival for patients with nonulcerated lesions was 94% vs. 78% with ulceration. Eighty-three patients (9.9%) had a recurrence. Twenty-seven patients developed recurrence in the regional node field, and in 22 of these, it was the first recurrence site. Six developed local recurrence, 17 an in-transit metastasis, and 58 distant disease. The false-negative rate was 13.2%. SN slides and tissue blocks were further examined in 18 patients with recurrence in the node field, and metastatic disease was found in 3 of them.

CONCLUSIONS

This large, single-center study confirms that patients with a negative SNB have a significantly better prognosis than those with positive SNs. In those with a negative SNB, primary tumor thickness and ulceration are independent predictors of survival. Incorrect pathologic diagnosis contributed to only a minority of the false-negative results in this study.

Update on detection of sentinel lymph nodes in patients with breast cancer

Sentinel lymph node biopsy is now the practice of choice for the management of many patients with breast cancer. This was not true in the early 1990s, when the first such procedures were performed and protocols for such were refined often. This was also not true in the first years of the 21st century, when a decade of collective experience and information acquired from numerous clinical investigations dictated additional subtle and not-so-subtle refinements of the procedures. However, it is true today; reports of the latest round of clinical investigations indicate that there are several breast cancer sentinel node procedures that result in successful identification of potential sentinel nodes in nearly all patients who are eligible for such procedures. A significant component of many of these successful sentinel node procedures is a detection and localization protocol that involves radiotracer methodologies, including radiopharmaceutical administration, preoperative nuclear medicine imaging, and intraoperative gamma counting. The present state and roles of nuclear medicine protocols used in breast cancer sentinel lymph node biopsy procedures is reviewed with emphasis on discussion of recent results, unresolved issues, and future considerations. Included are brief reviews of present radiotracer and blue-dye techniques for node localization, including remarks about injection strategies, counting probe technology, and radiation safety. Included also are discussions of on-going investigations of the implications of the presence of micrometastases; of the management value of detection, localization, and excision of extra-axillary nodes such as internal mammary nodes; and of the broad range of recurrence rates presently being reported. Remarks on the present and possible near- and long-term roles for nuclear medicine in the staging of breast cancer patients including comments on positron emission tomography and intraoperative imaging conclude the article.

Small cell melanoma and ulceration as predictors of positive sentinel lymph node in malignant melanoma patients

Malignant melanoma (MM) early lymph node (LN) metastasis usually appears first in the sentinel LN (SLN). Breslow thickness is the main factor considered in the selection of patients to be submitted to SLN biopsy. The present study aimed to describe other independent prognostic factors useful in SLN candidate selection. During one year, 94 MM patients (90 primary cutaneous MM with Breslow thickness > or = 0.76 mm, and four cutaneous relapses), were submitted to SLN biopsy in the Melanoma Unit at the Hospital Clinic, Barcelona, Spain. The prognostic factors studied were: Breslow thickness, Clark's level of invasion, mitotic rate, cellular type (small, epithelioid, fusocellular, sarcomatoid), vertical growth phase, regression > 50%, severe vascularization, infiltrate (lymphocytic, plasmocytic), ulceration, neurotropism, intravascular/intraneural invasion, protein p16 expression and recurrence. Nineteen SLN (20.2%) were positive and 75 (79.8%) negative. No positive SLN occurred in MM with Breslow thickness < or = 1.0 mm. Breslow thickness > or = 2 mm (P = 0.005), severe vascularization (P = 0.005), small cell (P = 0.000) and ulceration (P = 0.005) were significant prognostic factors by univariate analysis. Small cell (P = 0.008) and ulceration (P = 0.05) were also significant prognostic factors in a multivariate analysis. The probability of finding a positive SLN for small cell was 56.9% [95% confidence interval (CI), 26.8-82.6%]. The probability of positive SLN for ulceration was 35.5% (95% CI, 14.2-64.7%). For small cell and ulceration together the probability increased to 86.3% (95% CI, 54.3-97.1%). The results of this study corroborated ulceration as a prognostic factor for SLN candidate selection and for the first time we have described small cell melanoma morphology as a significant factor associated with positive SLN.

Cooperation between surgical oncologists and pathologists: a key element of multidisciplinary care for patients with cancer

For patients with cancer it is essential to reach a definite diagnosis, obtain accurate staging and provide appropriate initial treatment if a successful outcome is to be achieved. These fundamental first steps in multidisciplinary care require close cooperation between surgical oncologists and pathologists. The most important aspect of this cooperation is clear and free exchange of information between them. The surgeon should provide the pathologist not only with an adequate tissue sample for examination, but also with clinical details that will assist in establishing a diagnosis. The location and orientation of specimens, and areas of particular concern, should always be indicated. Operative digital photographs may assist this process. The pathologist, in return, should provide the surgeon with a report containing sufficient information to allow an evidence-based management plan to be made for the patient, and to permit an accurate indication of prognosis to be determined. Use of a disease-specific synoptic report format will ensure that potentially important information is not overlooked. When there is diagnostic uncertainty, the pathologist should make this clear, but provide a preferred diagnosis. Further opinions may be helpful. If doubt exists, medico-legal considerations should not encourage a pathologist to issue a report with a diagnosis of malignancy. The pathologist should refrain from making management recommendations, because there may be valid reasons for the surgeon not providing this management. By cooperating fully and communicating freely with each other, surgical oncologists and pathologists can ensure high standards of initial and subsequent care for cancer patients.

Sentinel node biopsy procedures with an analysis of recurrence patterns and prognosis in melanoma patients: technical advantages using computer-assisted gamma probe with adjustable collimation

The purpose of this study was to investigate whether a computer-assisted gamma probe with adjustable collimation could aid in the detection of sentinel nodes (SNs) and to analyse the patterns of recurrence and prognosis in SN-positive and SN-negative cases. We analysed 385 SN biopsies. The SN identification rate was 87.2% using preoperative lymphoscintigraphy and blue dye, 93.9% using preoperative lymphoscintigraphy, blue dye and different probes, and 100% using preoperative lymphoscintigraphy, blue dye and a computer-assisted probe with adjustable collimation. The computer-assisted probe was particularly advantageous in cases where the melanoma was located very close to the SN and in cases of deep-seated nodes or nodes with low uptake, due to the possibility of changing the collimation during the procedure. The SN-positive rate according to the thickness of the primary melanoma was 1.7% for melanomas < or = 1 mm in thickness and 27.5% for melanomas > or = 1 mm. In 4.9% of cases we identified nodes outside the regional nodal basin. In one case we found a micrometastasis in a blue and hot interval node of the lateral abdominal wall. Analysing the node counts registered by the computer-assisted probe, we verified that the blue-positive node for tumour metastases was not the most radioactive node in the field in six out of 52 positive cases (11.5%). Distant metastases were present in 2.0% of SN-negative patients, and in 24% of SN-positive patients (P < 0.001). Highly statistically significant differences were found between SN-negative and SN-positive patients in both the 3 year disease-free survival (86.3% versus 49.2%) and the 3 year disease-specific survival (92.3% versus 77.1%) (P < 0.001).

Is the identification of in-transit sentinel lymph nodes in malignant melanoma patients really necessary?

The sentinel lymph node (SLN) is the first node in a nodal basin to receive the direct lymphatic flow from a malignant melanoma. However, in some patients, lymphoscintigraphic study reveals the presence of lymphatic nodes in the area between the primary melanoma and the regional basin. These nodes are called "in-transit nodes" or "interval nodes" and, by definition, are also SLNs. The purpose of this study was to determine the incidence and location of in-transit SLNs in patients with malignant melanoma and to assess whether it is really necessary to harvest them. The evaluation involved 600 consecutive malignant melanoma patients. Lymphoscintigraphy was performed on the day before surgery following intradermal injection of 74-111 MBq of (99m)Tc-nanocolloid in four doses around the primary melanoma or the biopsy scar. Dynamic and static images were obtained and revealed SLNs in 599 out of 600 patients. The SLN was intraoperatively identified with the aid of patent blue dye and a hand-held gamma probe. Lymphoscintigraphy showed in-transit SLNs in 59/599 patients (9.8%). During surgery, all these in-transit SLNs were harvested, with those in the popliteal and epitrochlear regions being the most difficult to identify and excise. Metastatic cell deposits were subsequently identified in ten (16.9%) of these in-transit SLNs. In conclusion, lymphoscintigraphy has a key role in the identification of in-transit SLNs. Although the incidence of these nodes is relatively low in malignant melanoma patients, such SLNs present metastatic deposits in a significant percentage of cases and therefore the identification of in-transit SLNs in these patients is really necessary.

The use of sentinel lymph nodes in gynaecological malignancies

PURPOSE OF REVIEW

Lymphatic mapping and sentinel node biopsy represent one of the most revolutionary advances in oncological surgery in recent years. In this review, the current state of sentinel node detection in gynaecological cancers and its use in vulvar and cervical cancer are assessed.

RECENT FINDINGS

Since the recent clinical application of sentinel node biopsy for melanomas and breast cancer, there has been extensive research on the implementation of this technique to most solid neoplasias. Studies on the feasibility of sentinel node biopsy in vulvar cancer have shown that the status of the sentinel node is an accurate predictor of the status of inguinal nodes. The clinical implementation of the procedure requires validation and is under investigation. In the last two years, several pilot studies on the feasibility of lymphatic mapping/sentinel node biopsy in cervical cancer have yielded promising results. There is minimal experience of its use in endometrial cancer. Detailed pathological study of a sentinel node biopsy with ultrastaging and immunohistochemical or polymerase chain reaction analyses can identify lymph node micrometastasis that conventional methods would identify as negative for metastatic disease. The best histopathological procedure for sentinel node biopsy, the clinical significance of micrometastases, and the appropriate management of such micrometastases are currently under investigation.

SUMMARY

Sentinel node biopsy is one of the main research interests in gynaecological oncological surgery. At present there are not enough data to permit modification of current treatment protocols. Large and multi-institutional trials are required in order to define the implementation of sentinel node biopsy in clinical practice with the objective of achieving safer and more conservative surgery.