Importance of sentinel lymph node biopsy in patients with thin melanoma

The influence of sentinel lymph node biopsy on survival for intermediate-thickness melanoma

BACKGROUND

The Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) failed to demonstrate a survival advantage for sentinel lymph node biopsy (SNB) in melanoma. This may have been secondary to inadequate statistical power. This study was designed to determine the impact of SNB on melanoma-specific survival (MSS) in a larger patient cohort.

METHODS

From 2003-2008, patients with tumors 1-4 mm in thickness and clinically negative nodes were identified within the SEER registry. Propensity score was used to create two matched cohorts: those who underwent a wide excision with SNB or wide excision alone.

RESULT

A total of 15,274 met inclusion criteria and 7,910 comprised the match cohort. Average age was 67.4 years. The majority were male (62.3 %) and white (97.2 %). Primary tumors were most frequently nonulcerated (77.1 %), located on the extremity (42.3 %), and T2 (64.1 %). There were 3,955 patients in both the SNB and observation groups. There was no significant difference in gender, ethnicity, ulceration status, primary site, or T-classification between the groups. Improved 5-year MSS was associated with SNB (85.7 vs. 84.0 %), female gender (88.3 vs. 82.7 %), absence of ulceration (87.5 vs. 75.7 %), extremity location (87.4 %), T2 disease (88.6 vs. 77.9 %), and a negative SNB (88.9 vs. 64.8 %). The relationships between observation [hazard ratio (HR) 1.18], male gender (HR 1.33), ulceration (HR 1.77), head-and-neck location (HR 1.34), and T3 disease (HR 1.82) persisted on multivariate analysis.

CONCLUSIONS

Status of the sentinel node is the strongest predictor of survival in patients with intermediate thickness melanoma. SNB compared with observation was associated with a modest survival advantage.

Sentinel node biopsy improves prognostic stratification in patients with thin (pT1) melanomas and an additional risk factor

BACKGROUND

Sentinel lymph node (SLN) biopsy (SLNB) for pT1 melanomas is not generally recognized as a clinical standard. We studied the value of SLNB for pT1 melanoma patients having at least one additional risk factor.

PATIENTS

Among 931 patients with SLNB, 210 had pT1 melanomas. All of the latter showed at least one of the following risk factors: ulceration (4 %) Clark level IV (44 %), nodular growth pattern (11 %), mitoses (59 %), regression (38 %) or age ≤ 40 years (27 %).

RESULTS

In this selected pT1 population, we observed a surprisingly high SLN positivity rate of 18 %. The melanoma-specific overall survival significantly depended on SLN status. Compared with Clark IV, a lower invasion level (Clark II/III) was associated with a higher proportion of positive SLNs (25 vs. 10 %; p < 0.01). There was a trend towards a higher SLN positivity rate in younger patients (p = 0.06). Breslow, ulceration, mitoses, nodular growth pattern, and sex did not reach significance. Regression was significantly more frequently found in very thin melanomas (≤ 0.75 mm) and tended to be significant in this subgroup (p = 0.075).

CONCLUSIONS

SLNB improves prognostic stratification in patients with thin melanomas having an additional risk factor. Clark level IV most likely does not belong to these risk factors. The impact of regression deserves further consideration. Our data suggest that SLNB should be offered to patients with thin melanomas, if ulceration, nodular growth pattern, mitoses, or regression are present, or if the patient is younger than 40 years of age.

The role of sentinel lymph node biopsy for thin cutaneous melanomas of the head and neck

From 18% to 35% of cutaneous melanomas are located in the head and neck, and nearly 70% are thin (Breslow thickness ≤ 1 mm). Sentinel lymph node biopsy (SLNB) has an established role in staging of intermediate-thickness melanomas, however its use in thin melanomas remains controversial. In this article, we review the literature regarding risk factors for occult nodal metastasis in thin cutaneous melanoma of the head and neck (CMHN). Based on the current literature, we recommend SLNB for all lesions with Breslow thickness ≥ 0.75 mm, particularly when accompanied by adverse features including mitotic rate ≥ 1 per mm(2), ulceration, and extensive regression. SLNB should also be strongly considered in younger patients (e.g. < 40 years old), especially in the presence of additional adverse features. All patients who do not proceed with sentinel lymph node biopsy must be carefully followed to monitor for regional relapse.

Impact of the 2009 (7th edition) AJCC melanoma staging system in the classification of thin cutaneous melanomas

CONTEXT

The 7th (2009) edition of the AJCC melanoma staging system incorporates tumor (Breslow) thickness, MR, and ulceration in stratifying T1 primary melanomas. Compared to the prior 6th (2001) edition, MR has replaced CL for thin melanomas.

OBJECTIVE

We sought to identify and report differences of the classification of thin melanomas as well as outcome of SLNB in patients according to the 6th and 7th editions at our institution.

RESULTS

106 patients were identified with thin melanomas verified by wide excision. 31 of 106 thin melanomas were reclassified according to the 7th edition of the AJCC. Of those 31, 15 CL II/III patients (6th edition T1a) were reclassified as T1b based on the presence of mitoses while 16 CL IV patients (6th edition T1b) were categorized as T1a based on the absence of mitoses. 26/31 reclassified patients underwent SLNB, and all were negative. Patients with thin melanoma and a +SLNB (N = 3) were all classified as T1b according to both staging systems.

CONCLUSIONS

In our experience, 29% of thin melanomas were reclassified according to the 7th edition with similar proportions of patients re-distributed as T1a (14%) and T1b (15%). Cases with +SLN corresponded with T1b lesions in both 6th and 7th editions.

Clinicopathologic predictors of sentinel lymph node metastasis in thin melanoma

PURPOSE

Indications for sentinel lymph node biopsy (SLNB) for thin melanoma are continually evolving. We present a large multi-institutional study to determine factors predictive of sentinel lymph node (SLN) metastasis in thin melanoma.

PATIENTS AND METHODS

Retrospective review of the Sentinel Lymph Node Working Group database from 1994 to 2012 identified 1,250 patients who had an SLNB and thin melanomas (≤ 1 mm). Clinicopathologic characteristics were correlated with SLN status and outcome.

RESULTS

SLN metastases were detected in 65 (5.2%) of 1,250 patients. On univariable analysis, rates of Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, ulceration, and absence of regression differed significantly between positive and negative SLN groups (all P < .05). These four variables and mitotic rate were used in multivariable analysis, which demonstrated that Breslow thickness ≥ 0.75 mm (P = .03), Clark level ≥ IV (P = .05), and ulceration (P = .01) significantly predicted SLN metastasis with 6.3%, 7.0%, and 11.6% of the patients with these respective characteristics having SLN disease. Melanomas < 0.75 mm had positive SLN rates of < 5% regardless of Clark level and ulceration status. Median follow-up was 2.6 years. Melanoma-specific survival was significantly worse for patients with positive versus negative SLNs (P = .001).

CONCLUSION

Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, and ulceration significantly predict SLN disease in thin melanoma. Most SLN metastases (86.2%) occur in melanomas ≥ 0.75 mm, with 6.3% of these patients having SLN disease, whereas in melanomas < 0.75 mm, SLN metastasis rates are < 5%. By using a 5% metastasis risk threshold, SLNB is indicated for melanomas ≥ 0.75 mm, but further study is needed to define indications for SLNB in melanomas < 0.75 mm.

Clark level risk stratifies patients with mitogenic thin melanomas for sentinel lymph node biopsy

BACKGROUND

The role for sentinel lymph node biopsy (SLNB) in patients with thin melanoma (≤1 mm) remains controversial. We examined a large cohort of patients with thin melanoma to better define predictors of SLN positivity.

METHODS

From 1995 to 2011, 781 patients with thin primary melanoma and evaluable clinicopathologic data underwent SLNB at our institution. Predictors of SLN positivity were determined using univariate and multivariate regression analyses, and patients were risk-stratified using a classification and regression tree (CART) analysis.

RESULTS

In the study cohort (n = 781), 29 patients (3.7%) had nodal metastases. In the univariate analysis, mitotic rate [odds ratio (OR) = 8.11, p = 0.005], Clark level (OR 4.04, p = 0.003), and thickness (OR 3.33, p = 0.011) were significantly associated with SLN positivity. In the multivariate analysis, MR (OR 7.01) and level IV-V (OR 3.45) remained significant predictors of SLN positivity. CART analysis initially stratified lesions by mitotic rate; nonmitogenic lesions (n = 273) had a 0.7% SLN positivity rate versus 5.6% in mitogenic lesions (n = 425). Mitogenic lesions were further stratified by Clark level; patients with level II-III had a 2.9% SLN positivity rate (n = 205) versus 8.2% with level IV-V (n = 220). With median follow-up of 6.3 years, five SLN-negative patients developed nodal recurrence and four SLN-positive patients died of disease.

CONCLUSIONS

SLN positivity is low in patients with thin melanoma (3.7%) and exceedingly so in nonmitogenic lesions (0.7%). Appreciable rates of SLN positivity can be identified in patients with mitogenic lesions, particularly with concurrent level IV-V regardless of thickness. These factors may guide appropriate selection of patients with thin melanoma for SLNB.

Transferring innovative freehand SPECT to the operating room: first experiences with sentinel lymph node biopsy in malignant melanoma

PURPOSE

The purpose of this study was to report on the first experiences with freehand single-photon emission-computed tomography (freehand SPECT) in sentinel lymph node biopsy (SLNB) in patients with malignant melanoma. Freehand SPECT is a novel imaging modality combining gamma probes, surgical navigation systems, and emission tomography algorithms, designed to overcome some of the limitations of conventional gamma probes.

METHODS

In this study 20 patients with malignant melanoma underwent conventional planar scintigraphy prior to surgery. In the operating room, the number and location of separable SLNs were detected first by a pre-incisional scan with freehand SPECT to render a 3D-image of the target site and afterwards by a scan with a conventional gamma probe. After SLNB another scan was performed to document the removal of all targeted SLNs.

RESULTS

Planar scintigraphy identified 40 SLNs in 26 nodal basins. Pre-incisional freehand SPECT mapped 38 of these nodes as well as one additional node in one patient (95.0% node based sensitivity). The results of freehand SPECT were identical to those of planar scintigraphy in 25 basins, while it missed one basin (96.2% basin based sensitivity). In comparison, the gamma probe failed to detect 7 nodes in 4 basins (82.5% node based sensitivity and 84.6% basin based sensitivity). After resection freehand SPECT detected 9 remaining radioactive spots, two of whichwere resected as they matched the position of SLNs detected on preoperative planar scintigraphy.

CONCLUSIONS

Freehand SPECT provides a real-time, intraoperative 3D-image of the radioactive labelled SLNs, facilitating their detection and resection.

Sentinel node biopsy in thin and thick melanoma

BACKGROUND

Although sentinel node biopsy (SNB) has become standard of care in patients with melanoma, its use in patients with thin or thick melanomas remains a matter of debate.

METHODS

This was a retrospective analysis of patients with thin (≤1 mm) or thick (≥4 mm) melanomas who underwent SNB at two Italian centers between 1998 and 2011. The associations of clinicopathologic features with sentinel lymph node positive status and overall survival (OS) were analyzed.

RESULTS

In 492 patients with thin melanoma, sentinel node was positive for metastatic melanoma in 24 (4.9 %) patients. No sentinel node positivity was detected in patients with primary tumor thickness <0.3 mm. Mitotic rate was the only factor significantly associated with sentinel node positivity (p = 0.0001). Five-year OS was 81 % for patients with positive sentinel node and 93 % for negative sentinel node (p = 0.001). In 298 patients with thick melanoma, 39 % of patients had positive sentinel lymph nodes (median Breslow thickness 5 mm). In patients with positive sentinel node, 93 % had mitotic rate >1/mm(2). Five-year OS was 49 % for patients with positive sentinel lymph nodes and 56 % for patients with negative sentinel nodes (p = 0.005).

CONCLUSIONS

The rate of sentinel node positivity in patients with thin melanoma was 4.9 %. The only clinicopathologic factor related to node positivity was mitotic rate. Given its prognostic importance, SNB should be considered in such patients. SNB should also be the standard method for melanoma ≥4 mm, not only for staging, but also for guiding therapeutic decisions.

Evidence-based clinical practice guidelines on the use of sentinel lymph node biopsy in melanoma

Sentinel lymph node biopsy (SLNB) was introduced in 1992 to allow histopathologic evaluation of the "sentinel" node, that is, the first node along the lymphatic drainage pathway from the primary melanoma. This procedure has less risk of complications than a complete lymphadenectomy, and if the sentinel node is uninvolved by tumor the likelihood a complete lymphadenectomy would find metastatic disease in that nodal basin is very low. SLNB is now widely used worldwide in the staging of melanoma as well as breast and Merkel cell carcinomas. SLNB provides safe, reliable staging for patients with clinically node-negative melanomas 1 mm or greater in thickness, with an acceptably low rate of failure in the sentinel node-negative basin. Evidence-based guidelines jointly produced by ASCO and the Society of Surgical Oncology (SSO) recommend SLNB for patients with intermediate-thickness melanomas and also state that SLNB may be recommended for patients with thick melanomas. Major remaining areas of uncertainty include the indications for SLNB in patients with thin melanomas, pediatric patients, and patients with atypical melanocytic neoplasms; the optimal radiotracers and dyes for lymphatic mapping; and the necessity of complete lymphadenectomy in all sentinel node-positive patients.

[Melanoma in children: diagnosis and treatment specificities]

Skin melanoma is an extremely rare disease at pediatric age and its incidence increases with age. Links with predisposition syndrome exists (giant congenital naevus, xeroderma pigmentosum). Diagnosis is often difficult and distinction between benign or malignant lesion is sometime impossible (Spitzoid naevus, melanocytic neoplasms) leading to the diagnosis of "melanocytic tumor of uncertain malignant potential" (MELTUMP). Atypical features (amelanotic or raised lesions, atypical histotype) are frequent leading to delay in treatment. Diagnosis and treatment require expertise for pathologists and dermatologists pediatricians. Invasive melanomas are of poor prognosis despite recent progress in adult treatment. Early and rigorous treatment of suspect skin lesions is necessary.

Sentinel node biopsy is indicated for thin melanomas ≥0.76 mm

BACKGROUND

A consensus for which patients with thin melanomas (≤1 mm) should undergo sentinel lymph node biopsy (SLNB) is not established. We describe a large single institution experience with SLNB for thin melanomas to determine factors predictive of nodal metastases.

METHODS

Retrospective review from 2005 to 2010 identified 271 patients with thin melanomas who underwent SLNB, along with 13 additional patients not treated with SLNB who developed a nodal recurrence as first site of recurrence. Clinicopathologic characteristics were correlated with nodal status and outcome.

RESULTS

Median age was 55 years, and 53% of patients were male. Median Breslow thickness was 0.85 mm. Overall, a positive sentinel lymph node (SLN) was found in 22 (8.1%) of 271 cases; 8.4% of melanomas ≥0.76 mm were SLN positive with 5% of T1a melanomas ≥0.76 mm and 13% of T1b melanomas ≥0.76 mm having SLN metastases. Only two of 33 highly selected patients with melanomas <0.76 mm (both T1b) had a positive SLN. Logistic regression analysis demonstrated that mitotic rate ≥1/mm(2) significantly correlated with nodal disease (p < 0.05) and ulceration correlated with SLN metastases (p < 0.05). Median follow-up was 2.1 years. Overall survival did not differ between positive and negative SLN patients (p = 0.53) but was worse for patients presenting with a nodal recurrence (p < 0.01).

CONCLUSIONS

SLN metastases were seen in 8.4% of thin melanomas ≥0.76 mm, including 5% of T1a melanomas ≥0.76 mm. We believe these rates are sufficient to justify consideration of SLNB in these patients, while the indications for SLNB in melanomas <0.76 mm remain to be defined.

Guidelines of care for the management of primary cutaneous melanoma. American Academy of Dermatology

The incidence of primary cutaneous melanoma has been increasing dramatically for several decades. Melanoma accounts for the majority of skin cancer-related deaths, but treatment is nearly always curative with early detection of disease. In this update of the guidelines of care, we will discuss the treatment of patients with primary cutaneous melanoma. We will discuss biopsy techniques of a lesion clinically suspicious for melanoma and offer recommendations for the histopathologic interpretation of cutaneous melanoma. We will offer recommendations for the use of laboratory and imaging tests in the initial workup of patients with newly diagnosed melanoma and for follow-up of asymptomatic patients. With regard to treatment of primary cutaneous melanoma, we will provide recommendations for surgical margins and briefly discuss nonsurgical treatments. Finally, we will discuss the value and limitations of sentinel lymph node biopsy and offer recommendations for its use in patients with primary cutaneous melanoma.

The Impact of Shave Biopsy on The Management of Patients with Thin Melanomas

Disagreement persists regarding the role that various biopsy methods should play in the diagnosis of primary cutaneous melanoma. We analyzed the indications for sentinel lymph node (SLN) biopsy and the rates of SLN involvement among biopsy techniques and deep margin status to attempt to determine impact of shave biopsy on surgical management of patients with thin melanoma. All patients who underwent SLN biopsy for melanoma with Breslow thickness less than 1 mm between 1998 and 2006 were identified. Patient and tumor characteristics were compared using χ2 tests for categorical variables. Continuous variables were reported as a mean ± standard deviation and analyzed using t test. Of the 260 patients diagnosed with thin melanomas, 159 (61.2%) were diagnosed by shave biopsy; 101 (38.8%) were diagnosed by other techniques. Of the 159 patients diagnosed by shave biopsy, 18.2 per cent (n = 29) underwent SLN biopsy with the only indication being positive deep margin. The frequency of SLN positivity did not differ between the biopsy groups (3.1% vs 4.0%, P = 0.726) or between groups that had positive or negative deep margins (3.0% vs 3.3%, P = 0.839, respectively). For patients unable to undergo general anesthesia, the increased rate of performing SLN biopsy resulting from shave biopsy should limit its use in these patients. However, shave biopsy is a reasonable diagnostic method for patients at low risk for general anesthesia, particularly because it results in comparably low rates of positive SLN. Thus each patient's unique clinical situation should be considered when deciding which biopsy technique is appropriate.

False-Negative Sentinel Lymph Node Biopsy in Head and Neck Melanoma

Objective. The results of sentinel lymph node biopsy (SLNB) can be useful for staging and deciding on adjuvant treatment for patients with head and neck melanoma. False-negative SLNB can result in treatment delay. This study aimed to evaluate the characteristics and outcome of patients with false-negative SLNB in cutaneous melanoma of the head and neck.

Study Design. Longitudinal cohort study using a prospective institutional tumor registry.

Setting. Academic health center.

Subjects and Methods. Data from 153 patients who underwent SLNB for melanoma of the head and neck were analyzed. False-negative biopsy was defined as recurrence of tumor in a previously identified negative nodal basin. Statistical analysis was performed on registry data.

Results. Positive sentinel lymph nodes were identified in 19 (12.4%) patients. False-negative SLNB was noted in 9 (5.9%) patients, with a false-negative SLNB rate of 32.1%. Using multivariate regression analysis, only examination of a single sentinel lymph node was a significant predictor of false-negative SLNB ( P = .01). The mean treatment delay for the false-negative SLNB group was 470 days compared with 23 days in the positive SLNB group ( P < .001). The 2-year overall survival of patients with false-negative SLNB was 75% compared with 84% and 98% in positive and negative SLNB groups, respectively ( P = .02).

Conclusions. False-negative SLNB is more likely to occur when a single sentinel lymph node is harvested. There is significant treatment delay in patients with false-negative SLNB. False-negative SLNB is associated with poor outcome in patients with melanoma of the head and neck.

Histopathological diagnostics of malignant melanoma in accordance with the recent AJCC classification 2009: Review of the literature and recommendations for general practice

BACKGROUND

TNM classifications are the basis for diagnostic and therapeutic procedures in oncology. Histopathological reports have to enable a proper indexing of tumor specific findings into recent classifications.

METHODS

A systematic review of the literature was performed to identify reports dealing with the assessment of mitotic rate and the processing and evaluation of sentinel node biopsies in malignant melanoma. On the basis of this review an expert panel of dermatopathologists and general pathologists discussed and agreed recommendations for general practice.

RESULTS

Following recommendations were agreed with a broad consensus (93-100 % agreement): The determination of the mitotic rate in primary melanoma is performed on HE slides. The evaluation of an area of 1 mm(2) is sufficient. Only dermal mitoses are considered. The counted number of mitoses is provided as an integer value. The mitotic rate shall be determined in primary melanomas of ≤1.00 mm vertical tumor thickness according to the hot-spot method and provided as an integer value in relation to an area of 1 mm(2) . The determination of the mitotic rate in the case of thicker primary melanomas is desirable. In general, for the evaluation of each sentinel lymph node, 4 slides should be prepared. For diagnostic purposes, immunohistochemistry (preferably with antibodies against S100ß, Melan A and HMB-45) should be performed in addition to HE staining. The pathology report should provide information about micro-metastases and their longest extension (one-tenth of a millimeter).

CONCLUSIONS

These recommendations are suitable for standardizing the histopathological diagnosis of malignant melanoma and for providing a common basis for clinical decisions and scientific research.

Sentinel lymph nodes in cutaneous melanoma: handling, examination, and clinical repercussion

CONTEXT

Within the last 15 years, evaluation of sentinel lymph nodes (SLNs) has become the most popular method of early staging of several malignancies, including melanoma. Sentinel lymph nodes are usually examined on formalin-fixed, paraffin-embedded sections and by routine histology/immunohistochemistry (research protocols have used other techniques such as polymerase chain reaction). Approximately 20% of patients with cutaneous melanoma have metastasis in the SLN. In most studies, detection of positive SLN conveys a poorer prognosis for patients with cutaneous melanoma.

OBJECTIVE

To review the morphologic patterns of melanoma metastasis in the SLN, the differential diagnosis, and the quantification of tumor burden as a prognostic factor.

DATA SOURCES

Personal observations and review of the pertinent literature.

CONCLUSIONS

Evaluation of sentinel lymph nodes is certainly becoming a widespread technique and most authors agree on its prognostic power for staging patients with cutaneous melanoma. Current studies are evaluating the possible therapeutic value of removal of positive SLNs.

Sentinel lymph node biopsy in melanoma: Facts and controversies

Three decades after its introduction in the 1990s, the sentinel lymph node biopsy for patients with localized cutaneous melanoma is still the subject of great debate in dermatology. Many questions remain unanswered, and studies currently in progress may or may not bring us any closer to determining the truth about sentinel lymph node biopsy and melanoma. We discuss the effect of sentinel lymph node biopsy on overall survival, the clinical and therapeutic implications of sentinel lymph node biopsy, and the melanoma patients who might be candidates for sentinel lymph node biopsy.

Importance of tumor load in the sentinel node in melanoma: clinical dilemmas

There are two hypotheses to explain melanoma dissemination: first, simultaneous lymphatic and hematogeneous spread, with regional lymph nodes as indicators of metastatic disease; and second, orderly progression, with regional lymph nodes as governors of metastatic disease. The sentinel node (SN) has been defined as the first draining lymph node from a tumor and is harvested with the use of the triple technique and is processed by an extensive pathology protocol. The SN status is a strong prognostic factor for survival (83-94% for SN negative, 56-75% SN-positive patients). False-negative rates are considerable (9-21%). Preliminary results of the MSLT-1 trial did not demonstrate a survival benefit for the SN procedure, although a subgroup analysis indicates a possible benefit. A mathematical model has demonstrated 24% prognostic false positivity. SN tumor burden represents a heterogeneous patient population and is classified most frequently with the Starz, Dewar or Rotterdam Criteria. A completion lymph-node dissection might not be indicated in all SN-positive patients. Patients classified with metastases <0.1 mm by the Rotterdam Criteria have excellent survival rates. Ultrasound-guided fine-needle aspiration cytology is emerging as a staging tool for high-risk patients, but more research is necessary before this can change clinical practice.

Sentinel node biopsy in melanoma: technical considerations of the procedure as performed at the John Wayne Cancer Institute

Since its first description in 1990, sentinel node (SN) biopsy has become the standard for accurate staging of a melanoma-draining regional lymphatic basin. This minimally invasive, multidisciplinary technique can detect occult metastases by selective sampling and focused pathologic analysis of the first nodes on the afferent lymphatic pathway from a primary cutaneous melanoma. An understanding of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and the definition of SN are critical for surgical expertise with SN biopsy.

Lymphatic mapping and sentinel lymphadenectomy in primary cutaneous melanoma

The management of clinically normal regional lymph nodes in early-stage melanoma has been controversial for over a century. Lymphatic mapping and sentinel lymphadenectomy (LM/SL) has been developed as a minimally invasive surgical technique to stage the regional lymph nodes without the associated morbidity of elective complete lymph node dissection. Multiple retrospective studies have validated the accuracy of LM/SL and the importance of the sentinel nodes as a staging tool for melanoma. Two multicenter, prospective, randomized trials have been performed to validate the data from the Phase II studies and determine if a therapeutic benefit exists for LM/SL.

Sentinel lymph node biopsy and melanoma: 2010 update Part II

This article will discuss the evidence for and against the therapeutic efficacy of early removal of potentially affected lymph nodes, morbidity associated with sentinel lymph node biopsy and completion lymphadenectomy, current guidelines regarding patient selection for sentinel lymph node biopsy, and the remaining questions that ongoing clinical trials are attempting to answer. The Sunbelt Melanoma Trial and the Multicenter Selective Lymphadenectomy Trials I and II will be discussed in detail.

LEARNING OBJECTIVES

At the completion of this learning activity, participants should be able to discuss the data regarding early surgical removal of lymph nodes and its effect on the overall survival of melanoma patients, be able to discuss the potential benefits and morbidity associated with complete lymph node dissection, and to summarize the ongoing trials aimed at addressing the question of therapeutic value of early surgical treatment of regional lymph nodes that may contain micrometastases.

Predictors of occult nodal metastasis in patients with thin melanoma

HYPOTHESIS

Thin primary lesions are largely responsible for the rapid increase in melanoma incidence, making identification of appropriate candidates for nodal staging in this group critically important. We hypothesized that common clinical variables may accurately estimate the risk of nodal metastasis after wide excision and determine the need for sentinel node biopsy.

DESIGN

Review of prospectively acquired data in a large melanoma database.

SETTING

A tertiary referral center.

PATIENTS

A total of 2211 patients with thin melanoma treated by wide local excision alone were identified in the database between January 1, 1971, and December 31, 2005. Of those, 1732 met entry criteria.

MAIN OUTCOME MEASURES

We examined the rate of regional nodal recurrence and the impact of clinical and demographic variables by univariate and multivariate analyses.

RESULTS

The overall nodal recurrence rate was 2.9%; median time to recurrence was 38.3 months. Univariate analysis of 1732 patients identified male sex (P < .001), increased Breslow thickness (P < .001), and increased Clark level (P < .001) as significant for nodal recurrence. Multivariate analysis identified male sex (hazard ratio, 3.5; 95% confidence interval, 1.8-7.0; P < .001), younger age (0.45; 0.24-0.86; P = .001), and increased Breslow thickness (2.5; 1.6-3.7; categorical P < .001) as significant for nodal recurrence. The Clark level was no longer significant (P = .63). Breslow thickness, age, and sex were used to develop a scoring system and nomogram for the risk of nodal involvement. Predictions ranged from 0.1% in the lowest-risk group to 17.4% in the highest-risk group.

CONCLUSIONS

Many patients with thin melanoma will have nodal recurrence after wide excision alone. Three simple clinical variables may be used to estimate recurrence risk and select patients for sentinel node biopsy.

Management of regional lymph node basins in melanoma

Of all malignancies, melanoma has the most rapid increase in incidence; in 2009 it was estimated to have had the fifth highest number of new cases overall. Surgical therapy remains the primary and most effective intervention for this disease. Over the past 20 years there has been a significant paradigm shift in the management of the regional nodal basin, driven predominantly by the introduction of sentinel lymph node biopsy (SLNB). This new technique has drastically altered the method of detecting nodal disease and has become a routine component of melanoma treatment. In addition to SLNB, a better understanding of ultrasound, fine-needle biopsy, and the considerable efforts to minimize the morbidity of surgical intervention has led to innovations in the management of patients with regional metastases. An overview of the current therapeutic options for managing patients with nodal disease follows.

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.

Significance of sentinel lymph node biopsy in malignant melanoma: overview of international data

The notion of sentinel lymph node (SLN) mapping and its use during surgery for staging cancer was initially reported in 1992, in a study involving patients with malignant melanoma. To date SLN biopsy (SLNB) has emerged as a rational approach for staging regional lymph nodes in patients with clinically node-negative melanoma (stage I and II disease). The significance of SLNB as a staging and prognostic tool in melanoma is widely accepted. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of the SLN remains very controversial. Whether SLNB improves survival in melanoma patients remains an open question.

Melanoma in pediatric, adolescent, and young adult patients

The family practitioner, pediatrician, and dermatologist all have potential roles in the primary prevention, diagnosis, and treatment of localized thin melanomas. Surgical and medical oncologists are often involved when controversy arises over the nature of the skin lesion or whether sentinel lymph node (SLN) biopsies and adjuvant therapy are to be contemplated. This overview of melanoma will deal with the primary and nodal pathology, surgery, and medical therapy of melanoma in pediatric, adolescent, and young adult patients--and will raise areas of controversy that are only recently being addressed in databases of cases from this age group.

Sentinel Lymph Nodes in Cutaneous Melanoma

Examination of sentinel lymph nodes (SLN) has probably become the most popular method of early staging of patients who have cutaneous melanoma because SLN are considered to be the lymph nodes most likely to contain metastatic deposits; they can be examined in a more intense manner than in standard lymphadenectomy. There are several protocols to examine SLN but most of them use formalin-fixed, paraffin-embedded sections stained with hematoxylin and eosin with the addition of immunohistochemistry. By using these protocols, approximately 20% of patients who have cutaneous melanoma have melanoma cells in the SLN. Current studies are evaluating the possible therapeutic value of removal of positive SLN, but it is accepted by most authors that detection of positive SLN conveys an impaired prognosis for patients who have cutaneous melanoma.

Sentinel lymph node biopsy for melanoma: indications and rationale

BACKGROUND

The disease status of regional lymph nodes is the most important prognostic indicator for patients with melanoma. Sentinel lymph node biopsy (SLNB) was developed as a technique to surgically assess the regional lymph nodes and spare node-negative patients unnecessary and potentially morbid complete lymphadenectomies.

METHODS

We reviewed the literature on SLNB for cutaneous melanoma to provide insight into the rationale for the current widespread use of SLNB.

RESULTS

Multiple studies show that the status of the SLN is an important prognostic indicator. Those with positive SLNs have significantly decreased disease-free and melanoma-specific survival compared with those who have negative SLNs. In the Multicenter Selective Lymphadenectomy Trial I (MSLT-I), in which patients with intermediate-thickness melanoma were randomized to SLNB (and immediate completion lymphadenectomy if the SLN was positive) vs observation (and a lymphadenectomy only after presenting with clinically evident recurrence), the 5-year survival rate was 72.3% for patients with positive sentinel nodes and 90.2% for those with negative sentinel nodes (P < .001). Although overall survival was not increased in patients who underwent SLNB compared with those who were randomized to observation, patients who underwent SLNB had a significantly increased 5-year disease-free survival rate compared with those who underwent observation alone (78.3% in the biopsy group and 73.1% in the observation group; P = .009). For those with nodal metastases, patients who underwent SLNB and immediate lymphadenectomy had an increased overall 5-year survival rate compared with those who had lymphadenectomy only after presenting with clinically evident disease (72.3% vs 52.4%; P = .004). Moreover, other studies show that for patients with thin melanomas <or= 1.0 mm, the overall survival rate is significantly worse for those with positive SLNs compared to those with negative SLNs. For thin melanomas, Breslow depth >or= 0.76 mm and increased mitotic rate have been shown to be associated with an increased incidence of SLN metastases.

CONCLUSIONS

SLNB provides important prognostic and staging data with minimal morbidity and can be used to identify regional node-negative patients who would not benefit from a complete nodal dissection. In our opinion, SLNB should be performed on most patients (with acceptable surgical and anesthesia risk) who have melanomas with a Breslow depth >or= 0.76 mm.

Gray-scale contrast-enhanced ultrasonography of sentinel lymph nodes in a metastatic breast cancer model

RATIONALE AND OBJECTIVES

Previous studies showed it was possible to employ sonographic contrast agent for identification of the sentinel lymph nodes (SLNs). This study is to investigate the usefulness of SonoVue (a sonographic contrast agent) and gray-scale contrast-enhanced ultrasonography (CEUS) for detecting the SLNs in a metastatic breast cancer model.

MATERIALS AND METHODS

CEUS was performed in 12 female rabbits with breast VX2 tumor after subcutaneous administration of SonoVue. The site, number, and pattern of enhancement of the SLNs were observed and recorded. After CEUS, 0.5 mL of blue dye was injected into the same location as SonoVue and the SLNs were detected by surgical dissection. The findings of CEUS were compared with those of blue dye.

RESULTS

Of the 12 tumors assessed, a total of 17 enhanced SLNs were detected by CEUS. Among them, a single SLN was detected in eight tumors, two SLNs in three tumors, and three SLNs in one tumor. All the SLNs showed partial enhancement on CEUS. Nineteen SLNs were identified by blue dye with surgical dissection. There were no false-positive CEUS findings in terms of SLN detection. The overall sensitivity of CEUS for detecting SLNs was 89.5% (17/19). Among the 17 SLNs detected by CEUS, tumor metastases were identified histopathologically in 4 SLNs, whereas proliferation of lymphatic tissue was identified in the other 13 SLNs.

CONCLUSIONS

CEUS combined with SonoVue is useful for detecting SLNs, although it may not be helpful for detecting metastases in SLNs.

Site-specific lymphatic mapping relative to lingual septum in localizing the regional lymph nodes of tongue - an animal study

BACKGROUND AND OBJECTIVES

With technical adaptations, recent studies showed SLNB could predict cervical nodes status of head and neck carcinoma with high accuracy. However, as for tongue carcinoma, such technical adaptations seem to be not enough because the tongue has peculiar characteristic which may demand a specific procedure for accurate lymphatic mapping. This investigation explored the effect of lingual septum on lymphatic mapping of tongue to provide data for achieving an accurate lymphatic mapping for managing early tongue carcinoma.

METHODS

Four doses of Methylene Blue were injected into various parts of 64 rabbits' tongue, then diffusion range of Methylene Blue in tongue and sites of cervical nodes stained blue were noted. Finally, the tongues were resected for further histological examination and morphometric assessments.

RESULTS

There was lingual septum in the tongue and the diffusing of Methylene Blue could be terminated by lingual septum. Blue-stained nodes were identified in 84 lateral necks of 60 rabbits.

CONCLUSIONS

A site-specific way of lymphatic mapping relative to lingual septum should be developed for staging early tongue carcinoma.

Gray-scale contrast-enhanced ultrasonography in detecting sentinel lymph nodes: an animal study

OBJECTIVE

To investigate the usefulness of gray-scale contrast-enhanced ultrasonography for detecting sentinel lymph nodes.

METHODS

Contrast-enhanced ultrasonography was performed in five normal dogs (four female and one male) after subcutaneous administration of a sonographic contrast agent (Sonovue, Bracco, Milan, Italy). Four distinct regions in each animal were examined. After contrast-enhanced ultrasonography, 0.8 ml of blue dye was injected into the same location as Sonovue and the sentinel lymph nodes were detected by surgical dissection. The findings of contrast-enhanced ultrasonography were compared with those of the blue dye.

RESULTS

Twenty-one sentinel lymph nodes were detected by contrast-enhanced ultrasonography while 23 were identified by blue dye with surgical dissection. Compared with the blue dye, the detection rate of enhanced ultrasonography for the sentinel lymph nodes is 91.3% (21/23). Two patterns of enhancement in the sentinel lymph nodes were observed: complete enhancement (5 sentinel lymph nodes) and partial enhancement (16 sentinel lymph nodes). The lymphatic channels were demonstrated as hyperechoic linear structures leading from the injection site and could be readily followed to their sentinel lymph nodes. Histopathologic examination showed proliferation of lymphatic follicles or lymphatic sinus in partial enhanced sentinel lymph nodes while normal lymphatic tissue was demonstrated in completely enhanced sentinel lymph nodes.

CONCLUSIONS

Sonovue combined with gray-scale contrast-enhanced ultrasonography may provide a feasible method for detecting sentinel lymph nodes.

Multidisciplinary treatment of primary melanoma

This article covers the multidisciplinary treatment of primary melanoma. Excision margins and the need for sentinel lymphadenectomy are mainly dictated by the Breslow thickness although exceptions to this dictum do exist. Interferon is the only FDA approved adjuvant therapy for high risk melanoma although its overall survival benefit is minimal. Trials examining different doses or duration of interferon therapy have not demonstrated any promising survival data so far. There have been several randomized vaccine trials for melanoma but none have shown an overall survival benefit. Research into T-cell regulation continues and will hopefully bring promise for the future of melanoma treatment.