Sentinel lymph node biopsy for evaluation and treatment of patients with Merkel cell carcinoma: The Dana-Farber experience and meta-analysis of the literature.
OBJECTIVE
To determine the diagnostic accuracy and usefulness of sentinel lymph node biopsy (SLNB) and computed tomographic scans in the initial evaluation and treatment of patients with Merkel cell carcinoma (MCC).


METHODS
Single-institution case series and literature-based case-level meta-analysis.


METHODS
Academic cutaneous oncology clinic.Patients Sixty-one adults with biopsy-proven MCC (30 who had undergone SLNB) plus 92 cases from the literature of patients who had undergone SLNB.


METHODS
Relapse-free survival.


RESULTS
In 122 patients with no nodal disease found by physical examination, SLNB findings revealed nodal involvement in 39 cases (32%). At 3 years, the recurrence rate for those with a positive SLNB was 3 times (60%) higher than for those with a negative SLNB (20%; P = .03). Patients with a positive SLNB who received adjuvant nodal therapy had a relapse-free survival rate of 51% at 3 years (n = 26) compared with 0% for patients who did not receive nodal therapy (n = 3; P < .01). In contrast, among patients with a negative SLNB there was no significant difference in 3-year relapse-free survival rates for those who did (90%; n = 24) or did not (70%; n = 19; P = .26) receive adjuvant nodal therapy. Using SLNB plus clinical follow-up as a gold standard, computed tomographic scans had low sensitivity (20%) for detecting MCC that had spread to the lymph node basin and low specificity for distant disease (only 4 of 21 "positive" scans were confirmed during 6 months of follow-up).


CONCLUSIONS
Sentinel lymph node biopsy detects MCC spread in one third of patients whose tumors would have otherwise been clinically and radiologically understaged and who may not have received treatment to the involved node bed. There was a significant benefit of adjuvant nodal therapy, but only when the SLNB was positive. Thus, SLNB is important for both prognosis and therapy and should be performed routinely for patients with MCC. In contrast, computed tomographic scans have poor sensitivity in detecting nodal disease as well as poor specificity in detecting distant disease.
Gupta
Sheela G
SG
Cutaneous Oncology Disease Center, Dana-Farber/Brigham and Women's Cancer Center, Boston, Mass., USA.
Wang
Linda C
LC
Peñas
Pablo F
PF
Gellenthin
Martina
M
Lee
Stephanie J
SJ
Nghiem
Paul
P
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001900:Boston; D015266:Carcinoma, Merkel Cell / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy; D011237:Predictive Value of Tests; D021701:Sentinel Lymph Node Biopsy / Q000592:standards*; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy; D014057:Tomography, X-Ray Computed / Q000592:standards