Sentinel lymph node biopsy and melanoma: 2010 update

Clinicopathologic features correlated with paradoxical outcomes in stage IIC versus IIIA melanoma patients

Under current AJCC staging criteria, stage IIC patients paradoxically have worse outcomes than IIIA patients despite the lack of nodal metastatic disease. This study sought to identify additional clinicopathologic characteristics correlated with worse patient outcomes. Retrospective chart review of stage IIC and IIIA melanoma patients were evaluated between 1995 and 2011 with clinical follow-up through 2015. Records were reviewed for demographics, clinical characteristics, and tumor pathology. Fisher's exact test and Wilcoxon's rank-sum test were used to assess group differences. Clinicopathologic features were evaluated relative to overall survival (OS), time to distant metastases, and local/regional recurrence. Overall, 128 patients were included (45 stage IIC and 83 stage IIIA) with a median follow-up time of 5.7 years. Compared with stage IIIA patients, stage IIC patients were older, and their melanomas were more likely to be nodular, amelanotic, thicker, have higher mitotic rate, tumor lymphocytic infiltrate, no radial growth phase, and less likely to have associated precursor lesions. Stage IIC patients had shorter OS and time to distant metastases; multivariate regression revealed that older age (>55 years) and mitotic rate (>5 mitoses/mm) were independent predictors of OS. Melanomas in stage IIC disease may be biologically distinct from those that are seen in stage IIIA. While sentinel node biopsies remain the standard-of-care, these results suggest that clinicians may want to assess the clinicopathologic characteristics described above to aggressively counsel, screen for distant disease, and consider adjuvant therapy, in particular for older patients and higher mitotic rates in thicker primary tumors, regardless of nodal status.

Lymphatic transit rate as a predictive parameter for nodal metastasis in primary limb malignant melanoma

BACKGROUND

The status of sentinel lymph node (SLN) is one of the most predictive prognostic factors in patients with clinically localized malignant melanomas (MMs). However, since the positive SLN metastatic rate is as low as 20%, it is desirable to minimize SLN biopsy performance with imaging. By dynamic lymphoscintigraphy, we have proposed the lymphatic transit rate (LTR), the value that the distance between the primary lesion and SLN is divided by scintigraphic saturation time. LTR represents the scintigraphic saturation velocity and can be used for evaluation of metastasis of skin cancers.

METHODS

Dynamic lymphoscintigraphy data from 36 lymph nodes in 36 patients with primary MM on the limb were analyzed. The initial sites of the MMs were the lower limb in 24 patients and the upper limb in 12 patients. Histopathologically, nodal metastasis was found in 10 patients.

RESULTS

In the lower limb MM, the mean LTRs were 3.49 cm/min in histologically non-metastatic SLNs and 4.49 cm/min in histologically metastatic SLNs (P = 0.0056). In the upper limb MM, the mean LTRs were 2.59 cm/min in non-metastatic SLNs and 3.94 cm/min in metastatic SLNs (P = 0.0162). Thus, significantly higher LTRs were obtained in the metastatic SLNs. All SLNs with LTR < 4.0 cm/min in the lower limb MM and those with LTR < 3.0 cm/min in the upper limb MM were non-metastatic.

CONCLUSION

LTR is a useful predictive indicator for nodal metastasis and SLN biopsy performance in MMs.

Metastatic Melanoma in Sentinel Node-Negative Patients: The Ottawa Experience

BACKGROUND

Lymph node involvement is a major independent prognostic factor for survival in patients with malignant melanoma. Sentinel lymph node biopsy (SLNB) detection of microscopic nodal melanoma has been shown to improve both 5-year survival and 5-year disease-free survival.

OBJECTIVE

To determine the rate of metastatic melanoma in SLNB-negative patients at long-term follow-up.

METHODS

Study subjects include all 152 patients who had a negative SLNB and were followed at the Ottawa Regional Cancer Centre (ORCC) between 1999 and 2004. Patients with a follow-up period less than 6 months, more than 1 primary melanoma, and metastatic melanoma at diagnosis were excluded. Age at diagnosis, sex, Breslow thickness, ulceration, mitoses, regression, Clark level, anatomical location, development of metastatic melanoma, time to detection of metastatic disease, and time to death from melanoma were studied.

RESULTS

In this retrospective study at the ORCC, 40 of 140 (28.6%) patients with a single primary melanoma developed metastatic melanoma following negative SLNB at a mean follow-up of 63 months.

CONCLUSION

The rate of metastatic melanoma following negative SLNB at long-term follow-up at the ORCC is higher than the upper limit of rates reported in the literature (6%-24%). The reason for this is multifactorial, and the long follow-up period of 5 years allowed for detection of metastatic disease at a mean of 3.9 years. Long-term prognosis may be guarded in node-negative patients with a primary cutaneous melanoma, and surveillance by a multidisciplinary team is crucial.

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.

[Sentinel node in melanoma and breast cancer. Current considerations]

The main objectives of sentinel node (SN) biopsy is to avoid unnecessary lymphadenectomies and to identify the 20-25% of patients with occult regional metastatic involvement. This technique reduces the associated morbidity from lymphadenectomy and increases the occult lymphatic metastases identification rate by offering the pathologist the or those lymph nodes with the highest probability of containing metastatic cells. Pre-surgical lymphoscintigraphy is considered a "road map" to guide the surgeon towards the sentinel nodes and to localize unpredictable lymphatic drainage patterns. The SPECT/CT advantages include a better SN detection rate than planar images, the ability to detect SNs in difficult to interpret studies, better SN depiction, especially in sites closer to the injection site and better anatomic localization. These advantages may result in a change in the patient's clinical management both in melanoma and breast cancer. The correct SN evaluation by pathology implies a tumoral load stratification and further prognostic implication. The use of intraoperative imaging devices allows the surgeon a better surgical approach and precise SN localization. Several studies reports the added value of such devices for more sentinel nodes excision and a complete monitoring of the whole procedure. New techniques, by using fluorescent or hybrid tracers, are currently being developed.

Histopathologic evaluation of the sentinel lymph node for malignant melanoma: the unstandardized process

Metastasis from malignant melanoma (MM) usually first presents in the draining lymph node basin and thus sentinel lymph node (SLN) biopsy is a staging tool used to predict risk of metastases and death in higher risk tumors and has become the standard of care. Differences in the processing and methods used in the histopathological examination of SLNs can affect the positivity rate for metastatic MM because isolated MM deposits may be small and variably distributed in the SLN. The examination of SLNs is not standardized. The authors surveyed institutions across the United States who process SLNs for MM to better characterize the current methods used and to suggest a standardized approach to improve the reliability of the SLN biopsy. A survey of 142 academic institutions in the United States regarding the methods used in the evaluation of the SLN biopsy for MM was conducted. Thirty-two institutions responded. Eighty-one percent of the institutions (26 of 32) had a protocol that they used for SLN examination. In regards to gross dissection, 28% of the responders (9 of 32) initially bivalve (cut the SLN in half), whereas 59% (19 of 32) use a bread loaf technique, cutting the SLN at even intervals without specifically commenting about orientation to the hilum. The number of levels initially cut from the SLN block varied from 1 to 8 levels per block. Thirty-nine percent of the respondents (12 of 31) routinely order immunohistochemistry before evaluation of the initial hematoxylin- and eosin-stained sections. Eighty percent of the respondents (24 of 30) report the maximum dimension of the metastatic tumor deposit. The response rate was low (22%), and most respondents did not indicate how many SLN accessions were performed at their institution each year. Histologic protocols for processing SLNs for MM vary among institutions. Different methods of handling SLNs result in varying sensitivities for detection of metastases. Data derived from these varied approaches to develop and determine prognostic and staging categories may be inconsistent. A standardized yet practical approach is needed to provide reliable information on which prognosis can be determined and therapeutic guidelines can be based. The hope is for dermatologists and those treating patients with MM to understand the intricacies and inconsistencies involved in performance and interpretation of this key staging tool.

Breslow thickness, clark index and ulceration are associated with sentinel lymph node metastasis in melanoma patients: a cohort analysis of 612 patients

BACKGROUND

Sentinel lymph node biopsy (SLNB) is the most sensitive procedure for assessing nodal status in patients with primary melanoma.

OBJECTIVE

To evaluate the predictive ability of usual primary melanoma prognosis factors of detecting sentinel lymph node (SLN) metastasis in patients with melanoma.

PATIENTS AND METHODS

A cohort of 612 consecutive patients presenting with primary skin melanoma who underwent a SLNB was evaluated. Assessment of the determinants of SLN metastasis was based on general linear model analysis. The model performance was studied using the concordance statistic and the net reclassification index. The calibration was estimated using the Hosmer-Lemeshow test.

RESULTS

The discrimination ability did not differ significantly between Breslow thickness (0.57), Clark index (0.61), ulceration (0.57) and histological subtype (0.55). Clark index, ulceration and Breslow thickness were all significant and independent determinants of SLN metastasis. The predictive ability of the final model was 0.657.

CONCLUSION

Breslow thickness, Clark index and ulceration are independent predictors of a SLN metastasis.

Long-term survival analysis and clinical follow-up in acral lentiginous malignant melanoma undergoing sentinel lymph node biopsy in korean patients

BACKGROUND

In cutaneous malignant melanoma (MM) with clinically uninvolved regional lymph nodes, sentinel lymph node (SLN) status is the most powerful indicator of both overall survival (OS) and disease-free survival (DFS). However, no studies on the long-term survival and clinical follow-up of Korean patients with acral lentiginous MM (ALM) undergoing SLN biopsy (SLNB) have been published.

OBJECTIVE

The purpose of this study was to investigate the clinical prognosis and long-term survival of Korean patients with ALM according to SLN status.

METHODS

Thirty-four ALM patients undergoing SLNB were included in this study. We evaluated clinical and histopathological follow-up data such as the stage of disease, treatment, recurrence, and metastasis, and analyzed OS and DFS according to SLN status.

RESULTS

The median follow-up time was 60.5 months (range 3~127 months). Positive SLNs were noted in 14 patients (41.2%). Patients with negative SLNs had better OS and DFS than those with positive SLNs (p<0.05). Increased Breslow thickness was associated with short OS and DFS (p<0.05), and female patients showed better DFS than male patients (p<0.05).

CONCLUSION

To our knowledge, this is the first study on the long-term survival and clinical follow-up of patients undergoing SLNB for ALM in Korea. Our findings show that SLN status is an important prognostic factor for predicting OS and DFS.

Sentinel lymph node biopsy for cutaneous melanoma: a 6 years study

Background:

The aim of this study was to evaluate the results of sentinel lymph node biopsy (SLNB) in cutaneous melanoma at our institution.

Materials and Methods:

128 patients with primary cutaneous melanoma who underwent SLNB between April, 2004, and August, 2010 were studied. Univariate and multivariate analysis was performed to explore the effect of variables on mortality and sentinel node status. Survival analysis was performed using the Kaplan-Meier approach.

Results:

Positive SLNB were detected in 35 (27.3%) of 128 cases. Mean Breslow depths were 3.7 mm for SLNB positive patients and 1.99 mm for SLNB negative patients. False negative rate was 1%. The recurrence rate was 40% for positive patients and 6.5% for negative patients (odds ratio 9.7 [confidence interval 95 % 3.3-28.1]). 33 patients (29%) had an ulcerated melanoma, 12 (10.5%) in the positive group and 21 (18.5%) in the negative group. The disease recurred in a 48.5% of patients with ulcerated melanoma, but only in a 2.5% of patients with non-ulcerated melanoma. Upon multivariate analysis, only Breslow thickness (P = 0.005) demonstrate statistically significance for SLNB status. Multivariate analysis for clinicopathologic predictors of death demonstrate statistically significance for Breslow thickness (P = 0.020), ulceration (P = 0.030) and sentinel node status (P = 0.020).

Conclusions:

This study confirms that the status of the sentinel node is a strong independent prognostic factor with a higher risk of death and lower survival. Patients with ulcerated melanoma are more likely to develop recurrence, and also higher risk of death than patients with non-ulcerated melanoma.

Accuracy of intraoperative pathological examination of SLN in cervical cancer

OBJECTIVE

Early cervical cancer patients with pelvic lymph node metastasis do not benefit from radical hysterectomy. Assessment of the SLN status is thus crucial before deciding to perform a radical hysterectomy as opposed to aortic dissection only followed by definitive radiation therapy. Accuracy of frozen section of SLN has been questioned and deserves further investigation.

METHODS

Stage IA-IB1 cervical cancer patients who underwent SLN then full pelvic dissection at the Claudius Regaud Cancer Center in Toulouse, France, were included.

RESULTS

At least one SLN was identified in all 94 patients. Bilateral detection rate was 80.8%. Ectopic drainage area was found in 19 patients (20.2%). Sentinel lymph node involvement was found in 11 patients (11.7%). Sensitivity and NPV of frozen section pathological examination for the detection of macrometastatic disease was 100%, sensitivity for the detection of macro and micrometastatic disease, excluding ITC, was 88.9%, and NPV was 98.8%. Micrometastasis and isolated tumor cells (ITC) undetected at frozen section examination were found in 1 patient (1.06%) and 2 lymph nodes (1.24%), and in 2 patients (2.13%) and 2 lymph nodes (1.24%), respectively. Final pathology sensitivity of SLN was 100% for both macro and micrometastatic disease, including ITC.

CONCLUSION

In our institution, intraoperative frozen examination of SLN accurately predicts the status of pelvic lymph nodes and is effective for selecting intraoperatively the group of patients who benefit from radical hysterectomy. In addition, our results suggest that patients with small tumors and bilateral detection of SLN can be spared full pelvic lymphadenectomy.

Secondary review of external histopathology on cutaneous oncology patients referred for sentinel lymph node biopsy: how often does it happen and is it worth it?

BACKGROUND

We reviewed the data on external histopathology review for patients referred to our institution for sentinel lymph node biopsy (SLNB) associated with melanoma, Merkel cell carcinoma and adnexal carcinoma.

METHODS

We calculated the incidence of external histopathology review and the rate of discordance between internal and external histopathology diagnoses between January 1, 2010 and February 28, 2011. We conducted an anonymous poll of our community pathologists' experience with external histopathology review prior to SLNB. Financial charges and payments from 10 Medicare patients who underwent SLNB were obtained from our hospital's finance department.

RESULTS

Sixty-eight cases were identified (63 melanomas, 4 Merkel cell carcinomas and 1 spiradenocarcinoma). The external histopathology was reviewed as part of the patient's care in 14 of 68 cases. In 3 of 14 reviewed cases, SLNB was deemed unnecessary. Nine of eleven community pathologists reported reviewing external histopathology material in less than 11% SLNB patients in their hospitals. The average Medicare reimbursement for SLNB and secondary pathology review was $5738 and $80 respectively.

CONCLUSIONS

Our data show that review of external cutaneous histopathology diagnoses on patients referred for SLNB is uncommon in our practice area, but is cost-effective and should be required to reduce unnecessary treatment.

Preoperative ultrasound is not useful for identifying nodal metastasis in melanoma patients undergoing sentinel node biopsy: preoperative ultrasound in clinically node-negative melanoma

BACKGROUND

Sentinel lymph node biopsy (SLNB) is widely used in melanoma. Identifying nodal involvement preoperatively by high-resolution ultrasound may offer less invasive staging. This study assessed feasibility and staging results of clinically targeted ultrasound (before lymphoscintigraphy) compared to SLNB.

METHODS

From 2005 to 2009, a total of 325 patients with melanoma underwent ultrasound before SLNB. We reviewed demographics and histopathologic characteristics, then compared ultrasound and SLNB results. Sensitivity, specificity, and positive and negative predictive value were determined.

RESULTS

A total of 325 patients were included, 58% men and 42% women with a median age of 58 (range 18-86) years. A total of 471 basins were examined with ultrasound. Only six patients (1.8%) avoided SLNB by undergoing ultrasound-guided fine-needle aspiration of involved nodes, then therapeutic lymphadenectomy. Sixty-five patients (20.4%) had 69 SLNB positive nodal basins; 17 nodal basins from 15 patients with positive ultrasounds were considered truly positive. Forty-five SLNB positive basins had negative ultrasounds (falsely negative). Seven node-positive basins did not undergo ultrasound because of unpredicted drainage. A total of 253 patients with negative SLNBs had negative ultrasounds in 240 nodal basins (truly negative) but falsely positive ultrasounds occurred in 40 basins. Overall, sensitivity of ultrasound was 33.8%, specificity 85.7%, positive predictive value 36.5%, and negative predictive value 84.2%. Sensitivity and specificity improved somewhat with increasing Breslow depth. Sensitivity was highest for the neck, but specificity was highest for the groin.

CONCLUSIONS

Routine preoperative ultrasound in clinically node-negative melanoma is impractical because of its low sensitivity. Selected patients with thick or ulcerated lesions may benefit. Because of variable lymphatic drainage patterns, preoperative ultrasound without lymphoscintigraphic localization will provide incomplete evaluation in many cases.

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.