Factors predictive of pelvic lymph node involvement and outcomes in melanoma patients with metastatic sentinel lymph node of the groin: A multicentre study

Extent of Groin Dissection in Melanoma: A Mixed-Methods, Population-Based Study of Practice Patterns and Outcomes

Melanoma metastases to the groin are frequently managed by therapeutic lymph node dissection. Evidence is lacking regarding the extent of dissection required. Thus, we sought to describe practice patterns for the use of inguinal vs. ilioinguinal dissection, as well as the perioperative/oncologic outcomes of each procedure. A mixed-methods approach was employed to evaluate surgical practice patterns. A retrospective review of three multi-site databases was carried out, together with semi-structured interviews of melanoma surgeons. A total of 347 patients who underwent dissection were reviewed. The main indications stated for adding a “deep” ilioinguinal dissection were palpable or radiologically positive disease. There was no significant difference in complications, length of stay or lymphedema between patients having inguinal vs. ilioinguinal dissection, irrespective of method of diagnosis. There was also no significant difference in recurrence, cancer-specific survival or overall survival between groups. In conclusion, ilioinguinal dissection is a safe and well-tolerated procedure, with no significant added morbidity relative to an inguinal dissection. The indications for ilioinguinal dissection currently in use produce an appropriate deep node positivity rate and ilioinguinal dissection should continue to be used selectively. Randomized data are needed to clarify the impact of ilioinguinal dissection on regional control and survival.

Pelvic sentinel lymph nodes have minimal impact on survival in melanoma patients

Background

Lower limb or trunk melanoma often presents with femoral and pelvic sentinel lymph nodes (SLNs). The benefits of harvesting pelvic lymph nodes remain controversial. In this retrospective study, the frequency and predictors of pelvic SLNs (PSLNs), and the impact of PSLNs on survival and staging was investigated.

Methods

Altogether 285 patients with cutaneous melanoma located in the lower limb or trunk underwent sentinel lymph node biopsy of the inguinal/iliac lymph node basin at Helsinki University Hospital from 2009–2013. Patient characteristics, detailed pathology reports and follow-up data were retrieved from hospital files. Subgroups of patients categorized by presence of PSLNs were compared for outcome parameters including progression-free survival, melanoma-specific survival and groin recurrence.

Results

Superficial femoral/inguinal SLNs were present in all patients and 199 (69.8 per cent) also had PSLNs removed. Median number of SLNs per patient was five and median number of PSLNs was two. Sixty-three patients (22.1 per cent) had metastases in their SLNs and seven (2.5 per cent) had metastases in PSLNs. A single patient had metastases solely in PSLNs, while superficial SLNs remained negative. Harvesting PSLNs or the number of PSLNs retrieved had no impact on progression-free survival or overall survival. The removal of PSLNs did not affect the risk of postoperative seroma or lymphoedema. The only predictor of positive PSLNs was radioactivity count equal to or more than that of the hottest superficial SLNs.

Conclusion

Pelvic SLNs have minimal clinical impact on the outcome of melanoma patients especially in cases with negative superficial femoral/inguinal SLNs. Removal of PSLNs should be considered when they are the most radioactive nodes or equal to the hottest superficial femoral/inguinal SLNs in lymphoscintigraphy or during surgery.

Preliminary results were presented in part at the International Sentinel Node Society Biennial Meeting, Tokyo, Japan, 11–13 October 2018.

A novel predictive model for pelvic lymph node metastasis in patients with penile cancer: A multi-institutional study

PURPOSE

We determined whether a clinicopathological nomogram is able to predict the risk of pelvic lymph node metastasis (LNM) in penile cancer patients after inguinal lymph node dissection (ILND).

METHODS

Ninety-eight patients with bilateral ILND who underwent pelvic lymphadenectomy at 10 centers were retrospectively analyzed. The most predictive features in the nomogram were selected by the stepwise logistic regression method and then tested and verified by multivariate logistic regression analyses. The nomogram was assessed using concordance indices and calibration curves.

RESULTS

Of the 181 pelvic basins, pelvic LNM was observed in 52 packages (43 patients). Bilateral pelvic LNM was present in 9 patients (9/43, 20.9%). There was no crossover metastatic spread from one inguinal side to the other pelvic side. Age, previous resection, the biopsy procedure for inguinal lymph nodes, vascular invasion, and ipsilateral inguinal lymph node status were all independent risk factors for pelvic LNM (all P < 0.05) in the multivariate logistic regression analysis. The nomogram exhibited a good probability for survival agreement, with a concordance index of 0.868 (95% CI: 0.813-0.922).

CONCLUSIONS

A novel nomogram suggests that the risk of pelvic LNM can be effectively predicted in penile carcinoma patients and may provide a useful guide for clinicians. Further external validation is needed.

Robotic-Assisted Pelvic Lymphadenectomy for Metastatic Melanoma Results in Durable Oncologic Outcomes

BACKGROUND

Robotic pelvic lymphadenectomy (rPLND) has been demonstrated to be a safe and effective minimally invasive approach for patients with metastatic melanoma to the iliac nodes. However, the long-term oncologic benefit of this procedure remains poorly defined.

METHODS

A single-institutional study comparing perioperative outcomes and survival [recurrence-free (RFS) and overall survival (OS)] between rPLND and open PLND (oPLND) for metastatic melanoma was conducted.

RESULTS

From 2006 to 2018, a total of 63 PLND cases were identified: 22 rPLND and 41 oPLND. Evidence of isolated pelvic metastasis was the most common indication for PLND in both groups (rPLND: 64%, oPLND: 85%). There was no difference in median pelvic lymph node yield (11 vs. 9 nodes, p = 0.65). Neither treatment group experienced a Clavien-Dindo complication ≥ 3. rPLND was associated with a shorter length of stay compared with oPLND (2 vs. 4 days, p < 0.001). With a median follow-up of 37 months, there was no difference in RFS (14.4 vs. 9.6 months, p = 0.47) and OS (43 vs. 50 months, p = 0.58) between rPLND and oPLND, respectively. In basin recurrence was low with 1 (4.5%) and 3 (7.3%) patients in the rPLND and oPLND cohorts, respectively, experiencing an event (p = 0.9).

CONCLUSIONS

rPLND for metastatic melanoma is a safe, minimally invasive treatment strategy that appears to result in similar intermediate term recurrence and survival rates as oPLND but shorter hospital stays.

Routine retrieval of pelvic sentinel lymph nodes for melanoma rarely adds prognostic information or alters management

Pelvic sentinel lymph nodes (SLNs) are commonly identified during inguinal SLN biopsy for melanoma, but retrieval is not uniform among surgeons/centers. Few studies have assessed rates of micrometastases in pelvic versus superficial inguinal SLNs. Previous studies suggested that presence of pelvic SLNs was predicted by aggressive pathologic features and that their presence portended a worse prognosis. The objectives of this study were to examine presurgical predictors of pelvic SLNs among patients undergoing inguinal SLN biopsy, assess rates of micrometastases in superficial inguinal versus pelvic SLNs, and determine whether presence of pelvic SLNs was associated with long-term outcomes. Multivariable regression was used to assess presurgical factors associated with presence of pelvic SLNs. Rates of micrometastases in superficial inguinal versus pelvic SLNs in patients who had a pelvic SLN were compared with McNemar's test. Groin recurrence, disease-free survival (DFS), and disease-specific survival were analyzed by Kaplan-Meier method. A multivariable Cox model for DFS was performed. Pelvic SLNs were retrieved in 100/537 (18.6%) superficial inguinal SLN biopsies and no preoperative factors predicted their presence. In patients with a pelvic SLN, micrometastases were present in 3.0% of pelvic versus 34.0% of superficial inguinal SLN biopsies (P<0.001). There were no differences in groin recurrence, DFS, and disease-specific survival for patients with/without pelvic SLNs in univariate analyses (all P>0.2) or in the multivariable Cox model for DFS (hazard ratio: 1.1, 95% confidence interval: 0.6-2.1). In conclusion, pelvic SLNs harbor micrometastases less frequently than superficial inguinal SLNs do, suggesting that omission of pelvic SLN biopsy may be reasonable.

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.

Metastasectomy in cutaneous melanoma

Metastasectomy remains the only treatment in malignant melanoma to offer complete pathologic response within a few days of in-hospital stay. It has been historically associated with the highest survival rates in the literature reported for patients of this stage. However, only a minority of patients are amenable to curative resection of distant metastatic disease. This patient group exhibit slow growing oligometastases as indicated by: a. Long disease free interval after treatment of their primary tumours and b. An exhaustive preoperative work up with the use of PET/CT and MRI scans. Only complete resection of all metastases is associated with long term survival and debulking should not be attempted. Metastasectomy has also been shown to offer significant palliation in cases of gastrointestinal bleeding or obstruction. The timing and the sequencing of surgery in the modern multimodal targeted treatment of melanoma is still unclear and warrants further investigation.

Measuring the quality of melanoma surgery - Highlighting issues with standardization and quality assurance of care in surgical oncology

In an attempt to ensure high standards of cancer care, there is increasing interest in determining and monitoring the quality of interventions in surgical oncology. In recent years, this has been particularly the case for melanoma surgery. The vast majority of patients with melanoma undergo surgery. Usually, this is with combinations of wide excision, sentinel lymph node biopsy and lymphadenectomy. The indications for these procedures evolved during a time when no effective systemic adjuvant therapy was available, and whilst the rationale has been sound, the justification for differences in extent and thoroughness has generally been supported by inadequate or low-level evidence. This has led to a substantial variation among melanoma centres or even among surgeons within a centre in how these procedures are done. With recent rapid progress in the efficacy of systemic treatments that are impacting on overall survival, the prospect of long-term survival in these previously high risk patients means that more than ever long-term locoregional control of melanoma is imperative. Furthermore, the understanding of effects of systemic therapy on locoregional disease will only be interpretable if surgeons use standardized, high quality techniques. This article focuses on standardization and evolution of quality indicators for melanoma surgery and how these might have a positive impact on patient care.

Robotic-Assisted Transperitoneal Pelvic Lymphadenectomy for Metastatic Melanoma: Early Outcomes Compared with Open Pelvic Lymphadenectomy

BACKGROUND

In the absence of iliac or obturator nodal involvement, the role of pelvic lymphadenectomy (PLND) for melanoma is controversial, but for select patients, long-term survival can be achieved with the combination of superficial inguinal (inguinofemoral) and PLND. Open PLND (oPLND) is often limited in visual exposure and can be associated with considerable postoperative pain. Robotic PLND (rPLND) is a minimally invasive technique that provides excellent visualization of the iliac and obturator nodes. Outcomes comparing the open and robotic techniques have not been reported previously for patients with melanoma.

STUDY DESIGN

We reviewed our experience with rPLND for melanoma and compared clinical and pathologic results with oPLND. We evaluated operative times, nodal yield, and short-term oncologic outcomes.

RESULTS

Thirteen rPLND (2013 to 2015) (15 attempted, 87% success rate) and 25 oPLND (2010 to 2015) consecutive cases were completed. Pelvic lymphadenectomy was combined with an open inguinofemoral dissection in 8 of 13 (62%) robotic and 17 of 25 (68%) open cases. Median length of stay was shorter in the rPLND group, with 1.0 vs 3.5 days for pelvic-only cases (p < 0.001) and 2.5 vs 4.0 days (p < 0.001) for combined ilioinguinal cases. Median operative time (227 vs 230 minutes; p = 0.96) and nodal yield (11 vs 10 nodes; p = 0.53) were not different between rPLND and oPLND.

CONCLUSIONS

Robotic PLND offers a safe, effective, minimally invasive approach to resect the pelvic lymph nodes in patients with melanoma, with no significant difference in nodal yield or operative times, but a shorter length of stay compared with oPLND.