How should we view the results of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1)?

External validation of the Melanoma Institute Australia Sentinel Node Metastasis Risk Prediction Tool using the National Cancer Database

BACKGROUND

To improve patient selection for sentinel node (SN) biopsy, the Melanoma Institute of Australia (MIA) created a predictive model based on readily available clinicopathologic factors.

OBJECTIVES

Validation of the MIA nomogram using the National Cancer Database (NCDB), a nationwide oncology outcomes database for >1500 Commission-accredited cancer programs in the United States.

METHODS

A total of 60,165 patients were included in the validation. The probability of SN positivity was calculated for each patient. Using calculated probabilities, a receiver operating characteristic curve was generated to assess the model's discrimination ability.

RESULTS

At baseline, the NCDB cohort had different clinicopathologic characteristics compared with the original MIA data set. Despite these differences, the MIA nomogram retained high-predictive accuracy within the NCDB dataset (C-statistic, 0.733 [95% CI, 0.726-0.739]), although calibration weakened for the highest risk decile.

LIMITATIONS

The NCDB collects data from hospital registries accredited by the Commission on Cancer.

CONCLUSIONS

In conclusion, this study validated the use of the MIA nomogram in a nationwide oncology outcomes database collected from >1500 Commission-accredited cancer programs in the United States, demonstrating the potential for this nomogram to predict SN positivity and reduce the number of negative SN biopsies.

Sentinel Node Biopsy for Head and Neck Cutaneous Melanoma

Sentinel lymph node biopsy is the most precise and accurate staging technique for malignant melanoma. This resulted from international collaborations and technical innovations across subspecialties and systematic and methodical study of real-time clinical problems. This article describes sentinel node biopsy from conception to current techniques. Indications for the procedure and evidence of its prognostic value are discussed. Controversies surrounding results of Multicenter Selective Lymphadenectomy Trial I and II and German Dermatologic Cooperative Oncology Group Selective Lymphadenectomy trial are reviewed. Head and neck melanoma is presented as a unique subsite for performing sentinel node biopsy and when considering completion cervical lymphadenectomy.

Melanoma & nuclear medicine: new insights & advances

The contribution of nuclear medicine to management of melanoma patients is increasing. In intermediate-thickness N0 melanomas, lymphoscintigraphy provides a roadmap for sentinel node biopsy. With the introduction of single-photon emission computed tomography images with integrated computed tomography (SPECT/CT), 3D anatomic environments for accurate surgical planning are now possible. Sentinel node identification in intricate anatomical areas (pelvic cavity, head/neck) has been improved using hybrid radioactive/fluorescent tracers, preoperative lymphoscintigraphy and SPECT/CT together with modern intraoperative portable imaging technologies for surgical navigation (free-hand SPECT, portable gamma cameras). Furthermore, PET/CT today provides 3D roadmaps to resect 18F-fluorodeoxyglucose-avid melanoma lesions. Simultaneously, in advanced-stage melanoma and recurrences, 18F-fluorodeoxyglucose-PET/CT is useful in clinical staging and treatment decision as well as in the evaluation of therapy response. In this article, we review new insights and recent nuclear medicine advances in the management of melanoma patients.

Completion lymph node dissection in patients with melanoma and positive sentinel lymph node biopsy

Melanoma is a highly aggressive cancer that represents a significant disease burden, making diagnosis and appropriate control of disease vital for improving morbidity and mortality. The most recent guidelines for melanoma treatment advise performing a sentinel lymph node biopsy for intermediate thickness melanomas, with subsequent completion lymph node dissection (CLND) if sentinel nodes are positive. This guideline is controversial due to the limited availability of data on this topic. CLND is an extensive surgery with known risks and complications and a small survival benefit. However, in patients without significant comorbidities and at low risk for surgery, the survival benefit outweighs the procedural risk. This article reviews CLND and the current recommendations.

Impact of Completion Lymph Node Dissection on Patients with Positive Sentinel Lymph Node Biopsy in Melanoma

BACKGROUND

Whether patients with positive SLNB should undergo complete lymph node dissection (CLND) is an important unanswered clinical question.

STUDY DESIGN

Patients diagnosed with positive SLNB at a melanoma referral center from 1991 to 2013 were studied. Outcomes of patients who underwent CLND were compared with those who did not undergo immediate CLND (observation [OBS] group).

RESULTS

There were 471 patients who had positive SLNB; 375 (79.6%) in the CLND group and 96 (20.4%) in the OBS group. The groups were similar except that the CLND group was younger and had more sentinel nodes removed. Five-year nodal recurrence-free survival was significantly better in the CLND group compared with the OBS group (93.1% vs 84.4%; p = 0.005). However, 5-year (66.4% vs 55.2%) and 10-year (59.5% vs 45.0%) distant metastasis-free survival rates were not significantly different (p = 0.061). The CLND group's melanoma-specific survival (MSS) rate was superior to that of the OBS group; 5-year MSS rates were 73.7% vs 65.5% and 10-year MSS rates were 66.8% vs 48.3% (p = 0.015). On multivariate analysis, CLND was associated with improved MSS (hazard ratio = 0.60; 95% CI, 0.40-0.89; p = 0.011) and lower nodal recurrence (hazard ratio = 0.46; 95% CI, 0.24-0.86; p = 0.016). Increased Breslow thickness, older age, ulceration, and trunk melanoma were all associated with worse outcomes. On subgroup analysis, the following factors were associated with better outcomes from CLND: male sex, nonulcerated primary, intermediate thickness, Clark level IV or lower extremity tumors.

CONCLUSIONS

Treatment of positive SLNB with CLND was associated with improved MSS and nodal recurrence rates. Follow-up beyond 5 years was needed to see a significant difference in MSS rates.

Melanoma and nuclear medicine

Supported by a large body of published work, the contribution of nuclear medicine technologies to the assessment of melanoma has been increasing in recent years. Lymphoscintigraphy-assisted sentinel lymph node biopsy and PET are in continuous evolution with the aid of technological imaging advances, making it possible to fuse functional and anatomic images (e.g., with SPECT/CT, PET/CT and 3D rendering systems). The development of hybrid fluorescent-radioactive tracers that enable high-quality preoperative lymphoscintigraphy and SPECT/CT, and the optimization of modern intraoperative portable imaging technologies, such as free-hand SPECT and portable γ-cameras, are important innovations that have improved sentinel lymph node identification in complex anatomical areas, such as the pelvis and head and neck. Concurrently, ¹⁸F-fluorodeoxyglucose-PET has proved its usefulness in the clinical staging and treatment decision-making process, and there is also emerging evidence regarding its utility in the evaluation of therapeutic response. The potential uses of other novel PET radiotracers could open up a new field of use for this technique. In this article, we review the current and future role of nuclear medicine in the management of 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 should not be recommended for patients with thick melanoma

OBJECTIVE

To ascertain whether there is any relationship between the state of the sentinel lymph node histopathology, recurrence and mortality from thick melanoma in patients undergoing SLNB over a long follow-up.

METHODS

Eighty-six patients with thick melanoma undergoing SLNB were selected from a prospective database. Lymphoscintigraphy, lymphatic mapping and intraoperative gamma probe detection were performed in all patients. The sentinel lymph node (SLN) was analyzed by HE and immunohistochemistry. Complete lymphadenectomy was indicated for patients with positive sentinel node. The histopathological SLN status was related to the rate of recurrence and mortality from melanoma.

RESULTS

One hundred and sixty-six SLNs were taken from the 86 patients. Ages ranged from 18 to 73 years. There were 47 women and 39 men. Micrometastases were found in 44 patients. Forty-two patients underwent complete lymphadenectomy. Seven other patients had positive lymph node. Among the 44 patients with positive sentinel node, there were 20 recurrences and 15 deaths. There were 18 recurrences and 12 deaths in the group with negative SLN. The Breslow thickness was not correlated with the histopathological SLN status. The histopathological SLN status did not affect the rates of recurrence and mortality (Fisher test, p = 1.00). The median follow-up was 69 months.

CONCLUSION

Considering the lack of evidence of benefit, SLNB should not be indicated for patients with thick melanoma outside of clinical studies.

Surgeons' opinions on lymphadenectomy in melanoma patients with positive sentinel nodes: a worldwide web-based survey

PURPOSE

A worldwide web-based survey was conducted among melanoma surgeons to investigate opinions about completion lymph node dissection (CLND) in patients with positive sentinel nodes (SN).

METHODS

A questionnaire was designed following input from a group of melanoma surgeons. Cognitive interviews and pilot testing were performed. Surgeons identified through a systematic-review of the SN and CLND literature were invited by email.

RESULTS

Of 337 surgeons, 193 (57.2 %) from 25 countries responded (January-July 2011). Most respondents work in melanoma (30.1 %) and surgical oncology (44.6 %) units. In patients with a positive SN, 169 (91.8 %) recommend CLND; the strength of the recommendation is mostly influenced by patient comorbidities (64.7 %) and SN tumor burden (59.2 %). Seventy-one responders enroll patients in the second Multicenter Selective-Lymphadenectomy Trial (MSLT-2), and 64 of them (76 %) suggest entering the trial to majority of patients. In cases requiring neck CLND, level 1-5 dissection is recommended by 35 % of responders, whereas 62 % base the extent of dissection on primary site and lymphatic mapping patterns. Only inguinal dissection or ilioinguinal dissection is performed by 36 and 30 % of surgeons, respectively. The remaining 34 % select either procedure according to number of positive SNs, node of Cloquet status, and lymphatic drainage patterns. Most surgeons (81 %) perform full axillary dissections in positive SN cases.

CONCLUSIONS

The majority of melanoma surgeons recommend CLND in SN-positive patients. Surgeons participating in the MSLT-2 suggest entering the trial to the majority of patients. More evidence is needed to standardize the extent of neck and groin CLND surgeries.

The management of cervical lymph nodes in patients with cutaneous melanoma

BACKGROUND

The aim of this study was to review the management of cervical lymph nodes in patients with cutaneous melanoma and to analyze factors influencing prognosis.

METHODS

This was a retrospective cohort study of patients who had cervical node surgery at the Sydney Melanoma Unit from 1990 to 2004.

RESULTS

Of 716 patients who met the study criteria, 339 had a sentinel node biopsy (SNB) and 396 had a neck dissection. Locoregional recurrence occurred in 27.6 % of those undergoing therapeutic neck dissection and 60 % eventually developed distant metastases. Radiotherapy was given as adjuvant treatment in 110 of the patients who had a therapeutic neck dissection (41 %), but this was not associated with improved regional control (p = .322). Multivariate analysis showed that nodal positivity (p < .001) and primary tumor ulceration (p = < .027) were the most important predictors of locoregional recurrence and that primary tumor Breslow thickness (p = .009) and node positivity (p = .046) were the most important factors predicting survival. SNB-positive patients who underwent immediate completion lymphadenectomy had a 5-year survival advantage over those who had a therapeutic neck dissection for macroscopic disease (54 % vs 47 %, p = .028).

CONCLUSIONS

Nodal status was the most important factor predicting disease-free and overall survival in patients with melanoma of the head and neck. Adjuvant radiotherapy was not associated with better locoregional control in the non-randomized cohorts of patients in this study.

Risk evaluation in cutaneous melanoma patients undergoing lymph node dissection: impact of POSSUM

INTRODUCTION

When lymphatic metastasis occurs, surgery is the primary treatment modality in melanoma patients. Depending on the tumour stage, patients receive a completion lymph node dissection (CLND) when a positive sentinel node is detected. Patients with clinically evident disease of the regional lymph nodes are recommended to undergo a therapeutic lymph node dissection (TLND). The aim of this study was to assess the morbidity of CLND and TLND and to evaluate the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) for preoperative risk adjustment of postoperative morbidity.

METHODS

The hospital files of 143 patients who underwent CLND and TLND for malignant melanoma were analysed. The POSSUM score was used to predict morbidity rates after surgery for the total patient group as well as separated for CLND and TLND patients.

RESULTS

The overall complication rate was 28.0% and the mortality rate was 0%. The morbidity rate predicted by POSSUM was 32.9%, the mortality 8.3%. Morbidity in patients undergoing CLND was significantly higher with regard to overall wound complications compared with patients with TLND. In these subgroups, POSSUM failed to predict the rates precisely.

CONCLUSIONS

The POSSUM score predicted the morbidity of the total patient group accurately but failed to predict the rates in the TLND and CLND subgroups. Patients receiving CLND showed the highest morbidity rates. Preoperative sentinel lymph node biopsy therefore has more influence on postoperative morbidity than the physiological parameters represented in the POSSUM physiological score.

Sentinel node biopsy for melanoma: an update after two decades of experience

When detected and treated early, melanoma has an excellent prognosis. Unfortunately, as the tumor invades deeper into tissue the risk of metastatic spread to regional lymph nodes and beyond increases and the prognosis worsens significantly. Therefore, accurately detecting any regional lymphatic metastasis would significantly aid in determining a patient's prognosis and help guide his or her treatment plan. In 1991, Don Morton and colleagues presented new paradigm in diagnosing regional lymphatic involvement of tumors termed sentinel lymph node biopsy (SLNB). By mapping the regional lymph system around a tumor and tracing the lymphatic flow, a determination of the most likely lymph node or nodes the cancer will spread to first is made. Then, a limited biopsy of the most likely nodes is performed rather than a more-invasive removal of the entire local lymphatic chain. In 20 years that have followed, a great deal of information has been gained as to its accuracy, prognostic value, appropriate candidates, and its impact on regional disease control and survival. The SLNB has been shown to accurately stage regional lymph node basins in stage I and II melanoma patients with minimal morbidity. More sensitive histologic techniques are now being applied that may allow even greater accuracy in the staging of melanoma patients. Although specific percent risk thresholds are still in question, recommendation for SLNB when melanomas are 1 mm or thicker has gained wide acceptance. SLNB may also be appropriate for patients with melanomas that are between 0.76 and 1 mm thick and have ulceration, high mitotic rates, or reach a Clark level IV. Therefore, melanomas with IB or greater staging should be considered for SLNB.

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 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.

Sentinel node biopsy and standard of care for melanoma

An international panel was convened by the organizing committee of the International Sentinel Node (SN) Society (ISNS) at their meeting in Sydney, Australia, on February 21, 2008, to address questions about SN biopsy (SNB) for melanoma. The panelists subsequently wrote this consensus statement, based on their interpretation of current evidence, as a guide to clinical treatment of patients with clinically localized melanoma. The panel comprised a cross section of expert melanoma surgeons who have contributed data and leadership to investigations of SNB.