Inguinal or inguino-iliac/obturator lymph node dissection after positive inguinal sentinel lymph node in patients with cutaneous melanoma

Optimal extent of completion lymphadenectomy for patients with melanoma and a positive sentinel node in the groin

BACKGROUND

The optimal extent of groin completion lymph node dissection (CLND) (inguinal or ilioinguinal dissection) in patients with melanoma is controversial. The aim of this study was to evaluate whether the extent of groin CLND after a positive sentinel node biopsy (SNB) is associated with improved outcome.

METHODS

Data from all sentinel node-positive patients who underwent groin CLND at four tertiary melanoma referral centres were retrieved retrospectively. Baseline patient and tumour characteristics were collected for descriptive statistics, survival analyses and Cox proportional hazards regression analyses.

RESULTS

In total, 255 patients were included, of whom 137 (53·7 per cent) underwent inguinal dissection and 118 (46·3 per cent) ilioinguinal dissection. The overall CLND positivity rate was 18·8 per cent; the inguinal positivity rate was 15·5 per cent and the pelvic positivity rate was 9·3 per cent. The pattern of recurrence, and 5-year melanoma-specific survival, disease-free survival and distant-metastasis free survival rates were similar for both dissection types, even for patients with a positive CLND result. Cox regression analysis showed that type of CLND was not associated with disease-free or melanoma-specific survival.

CONCLUSION

There was no significant difference in recurrence pattern and survival rates between patients undergoing inguinal or ilioinguinal dissection after a positive SNB, even after stratification for a positive CLND result. An inguinal dissection is a safe first approach as CLND in patients with a positive SNB.

Is pelvic sentinel node biopsy necessary for lower extremity and trunk melanomas?

OBJECTIVE

There is currently no consensus regarding how to address pelvic sentinel lymph nodes (PSLNs) in melanoma. Thus, our objectives were to identify the incidence and clinical impact of PSLNs.

METHODS

Retrospective review of a prospectively collected multi-institutional melanoma database.

RESULTS

Of 2476 cases of lower extremity and trunk melanomas, 227 (9%) drained to PSLNs (181 to both PSLNs and superficial (inguinal or femoral) sentinel lymph nodes (SSLN) and 46 to PSLNs alone). Seventeen (7.5%) of 227 PSLN cases were positive for nodal metastasis, 8 of which drained to PSLNs only while 9 drained to both PSLNs and SSLNs. Complication rates between PSLN and SSLN biopsy were similar (15% vs. 14% respectively). In 181 cases with drainage to both SSLNs and PSLNs, PSLN biopsy upstaged one patient (0.6%), and completion dissection based on a positive PSLN did not upstage any.

CONCLUSIONS

PSLN biopsy is safe, however in the setting of negative SSLNs there is minimal clinical impact. We therefore recommend PSLN biopsy when the SSLNs are positive or when the tumor drains to PSLNs alone.