THE PLACE OF SENTINEL NODE BIOPSY IN MELANOMA AFTER THE MULTICENTER SELECTIVE LYMPHADENECTOMY TRIAL

Black sentinel lymph node and 'scary stickers'

An unusual case is presented of a young adult patient with two black-stained, radio-nucleotide tracer-active sentinel lymph nodes biopsied following her primary cutaneous melanoma treatment. This was subsequently confirmed to be secondary to cutaneous tattoos, averting the need of an elective regional node dissection. History of tattooing and tattoo removal should therefore be obtained as a routine in all melanoma patients considered for sentinel node biopsy (SLN). SLN biopsy and any subsequent completion node dissection should be strictly staged so that proper histologic diagnosis of the sentinel node is available for correct decision making and treatment.

Targeted High-Resolution Ultrasound Is Not an Effective Substitute for Sentinel Lymph Node Biopsy in Patients With Primary Cutaneous Melanoma

Purpose

To reassess traditional ultrasound descriptors of sentinel lymph node (SLN) metastases, to determine the minimum cross-sectional area (CSA) of an SLN metastasis detectable by ultrasound (US), and to establish whether targeted, high-resolution US of SLNs identified by lymphoscintigraphy before initial melanoma surgery can be used as a substitute for excisional SLN biopsy.

Methods

US was performed on SLNs identified in 871 lymph node fields in 716 patients. SLN biopsy was performed within 24 hours of lymphoscintigraphy and US examination. The CSA of each SLN metastatic deposit was determined sonographically and histologically.

Results

The sensitivity of targeted US in the detection of positive SLNs was 24.3% (95% CI, 19.5% to 28.7%), and the specificity was 96.8% (95% CI, 95.9% to 97.7%). The sensitivity was highest for neck SLNs (45.8%) and improved with greater Breslow thickness. The median histologic CSA of the SLN metastatic deposits was 0.39 mm2 (12.75 mm2 for US true-positive results and 0.22 mm2 for US false-negative results). True-positive, US-detected SLNs had significantly greater CSAs (t test P < .001) than undetected SLN metastases and were more likely to be spherical in cross-section. More than two sonographic descriptors of SLN metastases or rounding of the node alone were factors highly suggestive of a melanoma deposit.

Conclusion

US is not an appropriate substitute for SLN biopsy, but it is of value in preoperative SLN assessment and postoperative monitoring.

Fluorescence in situ hybridization (FISH) as an ancillary diagnostic tool in the diagnosis of melanoma

Although the clinical and pathologic diagnosis of some melanomas is clear-cut, there are many histopathologic simulators of melanoma that pose problems. Over-diagnosis of melanoma can lead to inappropriate therapy and psychologic burdens, whereas under-diagnosis can lead to inadequate treatment of a deadly cancer. We used existing data on DNA copy number alterations in melanoma to assemble panels of fluorescence in situ hybridization (FISH) probes suitable for the analysis of paraffin-embedded tissue. Using FISH data from a training set of 301 tumors, we established a discriminatory algorithm and validated it on an independent set of 169 unequivocal nevi and melanomas as well as 27 cases with ambiguous pathology, for which we had long-term follow-up data. An algorithm-using signal counts from a combination of 4 probes targeting chromosome 6p25, 6 centromere, 6q23, and 11q13 provided the highest diagnostic discrimination. This algorithm correctly classified melanoma with 86.7% sensitivity and 95.4% specificity in the validation cohort. The test also correctly identified as melanoma all 6 of 6 cases with ambiguous pathology that later metastasized. There was a significant difference in the metastasis free survival between test-positive and negative cases with ambiguous pathology (P=0.003). Sufficient chromosomal alterations are present in melanoma that a limited panel of FISH probes can distinguish most melanomas from most nevi, providing useful diagnostic information in cases that cannot be classified reliably by current methods. As a diagnostic aid to traditional histologic evaluation, this assay can have significant clinical impact and improve classification of melanocytic neoplasms with conflicting morphologic criteria.

Sentinel lymph node biopsy for high-risk nonmelanoma skin cancers

BACKGROUND

Although the utility of the sentinel lymph node biopsy (SLNB) in the staging of melanoma is well established, its usefulness in high-risk nonmelanoma skin cancer (NMSC) is yet to be determined.

OBJECTIVE

The objective was to report our experience with patients who underwent SLNB for the staging of a high-risk NMSC.

MATERIALS AND METHODS

We identified 13 patients with a high-risk NMSC who underwent SLNB between 1998 and 2006 and conducted a retrospective review of their medical records and tumor pathology. Their status as regards tumor recurrence and survival was obtained when possible.

RESULTS

Of 13 patients, 9 had squamous cell carcinoma (SCC), 2 had sebaceous gland carcinoma, 1 had porocarcinoma, and 1 had atypical fibroxanthoma. All SLNB were negative for metastatic disease, but 1 appeared to be a false-negative finding.

CONCLUSION

Compared to melanoma, SCC of the skin are much less predictable as regards their tendency to metastasize to the regional lymph nodes. Although the SLNB appears to be a reliable staging procedure for NMSC (especially SCC), the yield may be too low to justify its routine use in this patient population. More data are needed to determine when a SLNB is justified in the management of NMSC.

THE ROLE OF ABDOMINAL RESECTIONAL SURGERY IN METASTATIC MELANOMA

BACKGROUND

We reviewed our experience to determine the role of resectional surgery in metastatic melanoma to the abdomen.

METHOD

An observational study of 25 patients at the Austin Hospital, Melbourne from 1997 to 2005.

RESULTS

The median survival after abdominal resectional surgery was 8.3 (range 0.4-41.1) months. Fourteen patients who underwent resection with curative intent (extra-abdominal disease controlled and complete macroscopic clearance of abdominal disease) had improved survival compared with 11 patients who underwent palliative resection (12 month survival, 89 vs 10%, respectively, P < 0.0001). Survival was also superior in patients with up to two metastases compared with more than two (P = 0.0001) and in patients with serum albumin of at least 35 g/L (P = 0.0031). Intent of surgery (curative vs palliative) was the only factor significant on multivariate analysis (P = 0.001). Of patients with preoperative symptoms, 87% had resolution of these symptoms. Operative morbidity was 12%, and 30-day mortality was 4%.

CONCLUSIONS

In a highly selected group of patients with intra-abdominal melanoma metastases, resection of intra-abdominal metastases with curative intent resulted in prolonged survival compared with patients who underwent palliative resection. Those who underwent palliative resection had good relief of symptoms with minimal morbidity.

Impact of False-Negative Sentinel Lymph Node Biopsy on Survival in Patients with Cutaneous Melanoma

BACKGROUND AND OBJECTIVES

Sentinel lymph node biopsy is widely accepted as standard care in melanoma despite lack of pertinent randomized trials results. A possible pitfall of this procedure is the inaccurate identification of the sentinel lymph node leading to biopsy and analysis of a nonsentinel node. Such a technical failure may yield a different prognosis. The purpose of this study is to analyze the incidence of false negativity and its impact on clinical outcome and to try to understand its causes.

METHODS

The Melanoma Data Base at National Cancer Institute of Naples was analyzed comparing results between false-negative and tumor-positive sentinel node patients focusing on overall survival and prognostic factors influencing the clinical outcome.

RESULTS

One hundred fifty-one cases were diagnosed to be tumor-positive after sentinel lymph node biopsy and were subjected to complete lymph node dissection. Thirty-four (18.4%)patients with tumor-negative sentinel node subsequently developed lymph node metastases in the basin site of the sentinel procedure. With a median follow-up of 42.8 months the 5-year overall survival was 48.4% and 66.3% for false-negative and tumor-positive group respectively with significant statistical differences (P < .03).

CONCLUSIONS

The sensitivity of sentinel lymph node biopsy was 81.6%, and a regional nodal basin recurrence after negative-sentinel node biopsy means a worse prognosis, compared with patients submitted to complete lymph node dissection after a positive sentinel biopsy. The evidence of higher number of tumor-positive nodes after delayed lymphadenectomy in false-negative group compared with tumor-positive sentinel node cases, confirmed the importance of an early staging of lymph nodal involvement. Further data will better clarify the role of prognostic factors to identify cases with a more aggressive biological behavior of the disease.