Sentinel Node Tumor Burden Research Articles

Enhancing the prognostic role of melanoma sentinel lymph nodes through microscopic tumour burden characterization: clinical usefulness in patients who do not undergo complete lymph node dissection.

This study aimed to investigate the sentinel lymph node (SLN) tumour burden to predict the non-SLN positivity rate and the survival of melanoma patients to evaluate whether SLN microstaging could predict the prognosis, similar to what is currently performed by examining the lymph nodes excised by complete lymph node dissection. Of 1130 consecutive melanoma patients who underwent SLN biopsy, 226 were tumour-positive and 204 were included in this study. SLN metastases were classified on the basis of dimensional (Rotterdam) and topographic (Dewar) criteria either separately or combined. SLN metastases more than 1 mm in diameter had the highest non-SLN positivity rate (31%) compared with metastases 0.1-1 mm (10%) and less than 0.1 mm (4%). The non-SLN positivity rate was 45% for extensive metastases, 5% for subcapsular metastases and 23-29% for parenchymal, combined and multifocal classes, therefore suggesting a simplification of the parenchymal SLN metastases into only two classes: extensive and 'not extensive'. The dimension of the metastasis was correlated with a different non-SLN positivity rate only when the metastasis was in the parenchyma (20-36%) and not when it was in the subcapsular location (4-7%). Interestingly, the 5-year melanoma-specific survival (MSS) was 89% for patients with subcapsular less than 0.1 mm metastases and 45% for patients with nonsubcapsular more than 1 mm metastases (P=0.017). In the parenchyma, larger metastases (>1 mm) were related to a lower 5-year MSS (46%) than smaller (<1 mm) metastases (MSS 77%). SLN tumour burden characterization can be simplified and it can provide prognostic information on non-SLN positivity and survival, which is especially useful in patients who do not undergo complete lymph node dissection.

Sentinel node for malignant melanoma: An observational study of a consecutive single centre experience

IntroductionSentinel node biopsy (SNB) for melanoma gives prognostic information, however the success is dependent on several factors. The aim of this study was to describe outcome data after the introduction of the technique at our centre, including analysis of false negative rate (FNR), predictive factors for positive sentinel node (SN) and non-sentinel node (NSN), as well as prognostic factors for melanoma-specific survival (MSS). Materials and methodsThis is a retrospective observational study of a prospectively kept database at Sahlgrenska University Hospital. Between March 2000 and December 2013, 769 consecutive patients with cutaneous malignant melanoma undergoing SNB were included. The median follow-up time was 55 months (2–179 months). Tumour load in the SN was categorized according to the largest tumour deposit, low when ≤1 mm and high when >1 mm. ResultsThe FNR was 20% and the SN positivity rate was 14% with a decrease in both FNR and SN positivity rate during the study period. In multivariate analysis the only predictive factor for a positive SN was Breslow thickness. The 5-year melanoma specific survival (MSS) was 81% and in multivariate analysis the prognostic factors were SN-status (low metastatic load HR = 2.6, p = 0.001; high metastatic load HR = 2.7, p = 0.004) followed by Breslow thickness and ulceration. ConclusionsIn this study Breslow thickness was the only independent predictive factor for a positive SN, no predictive factors were identified for NSN. Independent prognostic factors for MSS were SN status, Breslow thickness and ulceration. Interestingly, there was no survival difference depending on SN tumour burden when using 1 mm as cut-off.

A model for predicting low probability of nonsentinel lymph node positivity in melanoma patients with a single positive sentinel lymph node.

Identifying factors associated with nonsentinel lymph node (NSN) metastases in melanoma patients with a single positive sentinel lymph node (SLN) could aid decision making regarding adjuvant therapy. We describe a model for identifying patients with a single positive SLN at low risk for NSN metastasis. Factors associated with NSN metastasis in patients with a primary cutaneous melanoma and a single positive SLN who underwent completion lymph node dissection (CLND) were identified. These factors were used to construct a model for predicting the NSN status. The model was validated using a separate data set from another tertiary referral cancer center. In the training data set, 111 patients had a single positive SLN. Of these, 27 had positive NSN. SLN tumor deposit diameter ≥0.75 mm (OR, 3.43; P = 0.047), age ≥40 (OR, 12.14; P = 0.024), and multifocal SLN tumor deposit location (OR, 4.16; P = 0.0096) were independently associated with NSN positivity. Patients with 0 to 1 of these risk factors had a low risk of NSN metastasis in both the training (7.5%) and validation (4.6%) data sets. A combination of patient and SLN tumor burden characteristics can help to identify patients with a single positive SLN who are at a low risk of NSN metastasis.

National practice patterns of completion lymph node dissection for sentinel node-positive melanoma.

Close observation may be an appropriate alternative to completion lymph node dissection (CLND) for selected patient populations, especially those with minimal tumor burden in the sentinel lymph node (SLN). In this study, we examined the practice patterns of CLND utilization. Using the National Cancer Database, we examined CLND utilization in SLN-positive patients diagnosed with clinically node-negative Stage III melanoma from 2012 to 2015. Hierarchical logistic regression models were constructed to assess the factors associated with observation after positive SLN biopsy (SLNB). Of the 131 171 patients identified, 55 688 (42.5%) underwent SLNB and 7200 (12.9%) had an SLN with a metastatic disease. CLND was performed in 57.0% of the patients with a positive SLNB. Patients were more likely to forgo CLND if the primary tumor was located on the lower extremity (odds ratio [OR], 1.65, 95% confidence interval [CI], 1.40-1.94), were older (P < 0.001), had multiple comorbidities (OR, 1.61, 95% CI, 1.19-2.20), or were diagnosed with melanoma in 2015 (OR, 1.33, 95% CI, 1.13-1.56 vs 2012). CLND utilization varied based on patient factors and decreased over time. As evidence supports close observation in selected patient populations with low SLN tumor burden, monitoring is needed to ensure that CLND is performed in the appropriate patient populations. However, this will require improvements in the data collected by cancer registries.

Application of sentinel lymph node biopsy in patients with melanoma

Objective: To investigate the difference between routine hematoxylin-eosin (HE) staining and immunohistochemistry in diagnosing metastatic melanoma in sentinel lymph node (SLN) metastases, and to evaluate the association of SLN tumor burden with the status of non-sentinel lymph nodes (NSLN). Methods: 126 melanoma patients were treated with SLN biopsy and further examined with immunohistochemistry at Fudan University Shanghai Cancer Center between 2010 and 2016, and the status of SLN was respectively estimated by HE stain and immunohistochemistry (S-100 protein, HMB45, Melan A and SOX10). In 39 patients who were treated with complete lymph node dissection, characteristics of SLN tumor burden (maximum diameter of the tumor deposit, tumor penetrative depth and the microanatomic location of the metastasis) and the associations of SLN tumor burden with the involvement of NSLN were all evaluated. Results: Of the total 126 cases, 33 (26.2%) were positive by HE staining and 49 (38.3%) were positive by immunohistochemistry. S-100 protein was positive in 48 out of 49 cases (98.0%). HMB45 was positive in 46 out of 49 cases (93.9%). Melan A was positive in 47 out of 49 cases (96.0%). SOX10 was positive in 8 out of 8 cases. The outcome indicated that the application of immunohistochemistry identified positive SLN missed by HE stain in about 12.1% of cases. Of the 39 patients who were treated with complete lymph node dissection, six showed metastases in NSLN. The frequency of metastases in NSLN was 15.4% (6/39) when SLN was positive. Additionally, the frequency of metastases in NSLN in cases with SLN metastatic deposits ≤2 mm was significantly lower than that in cases with SLN metastatic deposits >2 mm; eight cases with SLN metastatic deposits <0.2 mm had no additional positive NSLN. Conclusions: The findings suggest that immunohistochemistry could effectively improve the detection of positive SLN in melanoma. Cases with SLN metastatic deposits ≤2 mm are less likely to have further metastases in NSLN. There is a need for prospective large-population based studies to identify a subgroup of SLN positive patients who can safely be spared complete lymph node dissection.

Risk stratification of sentinel node–positive melanoma patients defines surgical management and adjuvant therapy treatment considerations

BackgroundIn light of the evolving landscape of adjuvant therapy in melanoma and the recently confirmed absent survival benefit of completion lymph node dissection (CLND), it becomes important to explore possible consequences of omitting CLND, and whether it is possible to adequately stratify positive sentinel node (SN) patients solely based on information retrieved from the melanoma up to the sentinel lymph node biopsy (SLNB). MethodsA retrospective cohort from nine European Organization for Research and Treatment of Cancer Melanoma Group centres was used. Patients were staged based on SLNB and CLND result according to the American Joint Committee on Cancer (AJCC) criteria and stratified by ulceration and SN tumour burden. These were incorporated in Cox regression models. Predictive ability was assessed using Harrell's concordance index (c-index) and the Akaike information criterion (AIC). ResultsIn total, 1015 patients were eligible. CLND led to upstaging in N-category in 19% and in AJCC stage in 5–6%. The model incorporating only ulceration and SN tumour burden performed equally well as the model incorporating substages after CLND. The model incorporating substages based on SLNB had the lowest predictive ability. Stratifying by ulceration and SN tumour burden resulted in four positive SN groups from which low-, intermediate- and high-risk prognostic classes could be derived. ConclusionsAdequate stratification of positive SN patients was possible based on ulceration and SN tumour burden category. The identification of low-, intermediate- and high-risk patients could guide adjuvant therapy in clinical practice. Omitting CLND seems to have little consequences.

A new molecular-based lymph node staging classification determines the prognosis of breast cancer patients

Background:The one-step nucleic acid amplification (OSNA) assay is a novel molecular method that can detect metastasis in a whole lymph node based on cytokeratin 19 mRNA copy number. This cohort study aimed to establish an OSNA-based nodal staging (pN(mol)) classification for breast cancer.Methods:The cohort consisted of 1039 breast cancer patients who underwent sentinel node (SN) biopsy using the OSNA assay. Cutoff value of the SN tumour burden stratifying distant disease-free survival (DDFS) was determined, and predictive factors for DDFS and breast cancer-specific survival (BCSS) were investigated. pN(mol) classification of the SN status was defined as: pN0(mol)(sn), SN negative; pN1mi(mol)(sn), SN positive and tumour burden <cutoff-value; and pN1(mol)(sn), tumour burden ⩾cutoff-value. Median follow-up time; 68.3 months.Results:Cutoff value of the SN tumour burden was 2810 copies per μl. Of the 1039 patients, 798, 95, and 146 had pN0(mol)(sn), pN1mi(mol)(sn), and pN1(mol)(sn) status, respectively. Five-year DDFS and BCSS rates were lower for pN1(mol)(sn) patients than for pN1mi(mol)(sn) patients (87.7% vs 98.8%, P=0.001 and 93.1% vs 98.8%, P=0.044, respectively). Multivariate analyses revealed the pN(mol) classification was most significant predictor for DDFS and BCSS.Conclusions:The molecular-based pN classification determines the prognosis of breast cancer patients and could guide therapeutic decision making.

The interval between primary melanoma excision and sentinel node biopsy is not associated with survival in sentinel node positive patients – An EORTC Melanoma Group study

BackgroundWorldwide, sentinel node biopsy (SNB) is the recommended staging procedure for stage I/II melanoma. Most melanoma guidelines recommend re-excision plus SNB as soon as possible after primary excision. To date, there is no evidence to support this timeframe. AimTo determine melanoma specific survival (MSS) for time intervals between excisional biopsy and SNB in SNB positive patients. MethodsBetween 1993 and 2008, 1080 patients were diagnosed with a positive SNB in nine Melanoma Group centers. We selected 1015 patients (94%) with known excisional biopsy date. Time interval was calculated from primary excision until SNB. Kaplan–Meier estimated MSS was calculated for different cutoff values. Multivariable analysis was performed to correct for known prognostic factors. ResultsMedian age was 51 years (Inter Quartile Range (IQR) 40–62 years), 535 (53%) were men, 603 (59%) primary tumors were located on extremities. Median Breslow thickness was 3.00 mm (IQR 1.90–4.80 mm), 442 (44%) were ulcerated. Median follow-up was 36 months (IQR 20–62 months). Median time interval was 47 days (IQR 32–63 days). Median Breslow thickness was equal for both <47 days and ≥47 days interval: 3.00 mm (1.90–5.00 mm) vs 3.00 mm (1.90–4.43 mm) (p = 0.402). Sentinel node tumor burden was significantly higher in patients operated ≥47 days (p = 0.005). Univariate survival was not significantly different for median time interval. Multivariable analysis confirmed that time interval was no independent prognostic factor for MSS. ConclusionsTime interval from primary melanoma excision until SNB was no prognostic factor for MSS in this SNB positive cohort. This information can be used to counsel patients.

Is there a therapeutic benefit of complete lymph node dissection in melanoma patients with low tumor burden in the sentinel node?

In the case of a positive sentinel lymph node (SLN), melanoma patients are recommended to proceed to complete lymph node dissection (CLND). However, CLND for SLN-positive patients - especially with minimal tumor burden in SLN - is becoming more controversial. We analyzed the clinical course of 305 SLN-positive patients with a mean follow-up of 51.1 months by Kaplan-Meier analyses. Overall, 58/305 (17%) patients did not undergo CLND. These were compared with a matched selection of 58 comparable patients who underwent CLND. Moreover, 106/305 patients with minimal tumor burden in SLN (<0.1 mm diameter of the largest tumor deposit) were analyzed separately. Of these 106 patients, 34 did not undergo CLND, whereas 72/106 patients were treated by CLND. In the matched groups, the CLND group and the non-CLND group did not differ significantly with respect to clinical characteristics, characteristics of the primary melanoma, and histopathological parameters of SLN. There were no differences in recurrence-free survival (P=0.765) and overall survival (P=0.844). The total number of regional lymph node metastases and time to regional lymph node metastases were not significantly higher for non-CLND patients. The subgroup of patients with minimal tumor burden in SLN also did not benefit significantly from CLND. In our analyses from a single German center, we could not find any evidence for a therapeutic survival benefit for CLND after positive SLN. However, future prospective randomized trials should confirm these data.

Impact of sentinel node tumor burden on outcome of invasive breast cancer patients

BackgroundThe tumor status of the axillary lymph nodes is one of the most important prognostic factors in women with early breast cancer (BC). Sentinel lymph node (SLN) biopsy has become the standard staging procedure for patients with invasive BC, largely replacing axillary lymph nodes dissection (ALND). The exact impact on prognosis of SLN tumor burden is still object of controversy. The aim of this study was to correlate the tumor burden in the SLN with the outcome in a large cohort of women. Patients and methods1040 consecutive patients with clinical stage I–III invasive BC were prospectively collected on our Institutional BC database from January 2001 to January 2007. Patients were stratified into the following four groups based on the tumor burden of the SLN: macrometastases, tumor deposit ≥2 mm; micrometastases, tumor deposit ≥0.2 mm and <2 mm; isolated tumor cells (ITC), isolated tumor cells or tumor deposit <0.2 mm; negative, in case of patients with no evidence of tumor. ResultsAt a median follow-up of 8.5 years, the tumor burden of SLN metastases resulted significant predictor of DFS (P < 0.0001) and OS (P = 0.042). Multivariate analysis showed that the tumor burden of SLN metastases and Ki 67 proliferative index maintained the statistical significance. ConclusionPatients with SLN micrometastases or ITC, do not seem to have a worse DFS or OS compared with SLN negative cases. There is a significant decrease in DFS and OS in patients with macrometastatic disease in the SLN.

Observation after a positive sentinel lymph node biopsy in patients with melanoma.

The benefit of completion lymph node dissection (CLND) in melanoma patients with a positive sentinel lymph node (SLN) remains unknown. We identified patients with a positive SLN from 1994 to 2012. Patient and tumor characteristics, reasons for not undergoing CLND, patterns of recurrence, and melanoma-specific survival data were analyzed. Of 4,310 patients undergoing SLN biopsy (SLNB), 495 (11 %) had a positive SLN-167 (34 %) patients underwent nodal observation and 328 (66 %) had immediate CLND. Patients in the no-CLND group were older (66 vs. 56 years; p < 0.001) and more likely to have lower extremity lesions (57 vs. 42 %; p = 0.006). There were no differences in tumor thickness, Clark level of invasion, ulceration, or SLN tumor burden. Median follow-up was 23 and 80 months for the no-CLND and CLND groups, respectively, and median time to recurrence was similar at 9 and 12 months, respectively (p = 0.48). There was no difference in local and in transit recurrence rates between groups (16 %, no CLND, and 18 %, CLND; p = 0.48). Nodal disease as a site of first recurrence occurred in 15 % of patients in the no-CLND group and 6 % of CLND patients (p = 0.002). In contrast, systemic recurrences occurred in 8 % of no-CLND patients compared with 27 % of CLND patients (p < 0.001). While median recurrence-free survival was higher after CLND (34.5 vs. 20.9 months; p = 0.02), melanoma-specific survival was similar (not reached, no CLND vs. 110 months, CLND; p = 0.09). Immediate CLND after a positive SLNB is associated with fewer initial nodal basin recurrences but similar melanoma-specific survival. These results support ongoing equipoise in the Multicenter Selective Lymphadenectomy Trial II (MSLT-II).

Pigmentation in the sentinel node correlates with increased sentinel node tumor burden in melanoma patients

The prognosis of sentinel node (SN)-positive melanoma patients is predicted by a number of characteristics such as size and site of the metastases in the SN. The pathway and prognosis of strong pigmentation of melanoma metastases in the SN is unclear. The aim of this study is to evaluate the role of pigmentation and growth pattern of metastases in the SN with respect to survival. A total of 389 patients underwent an SN procedure (1997-2011). Ninety-five patients had a positive SN and material from 75 patients was available for review. The median follow-up time was 75 months (range 6-164). Pigmentation was scored from 0 to 2 using the following scale: 0=absent, 1=slight, and 2=strong. Growth pattern was scored as either eccentric (1) or infiltrative (2). SN tumor burden was measured according to the Rotterdam criteria. The primary melanoma had a median Breslow thickness of 2.90 mm (0.8-12.00 mm). Ulceration was present in 34 patients (45.3%). There was a median SN tumor burden of 0.5 mm (0.05-7.00 mm). In a total of 75 patients, 59 patients (79%) had no pigmentation, 13 patients (17%) had slight pigmentation, and three patients (4%) had strong pigmentation in the SN. Because of the small numbers, the classification was modified to either absent 59 (79%) or present 16 (21%) pigmentation, respectively. The SN tumor burden was significantly higher (P=0.031) for patients with pigmentation. Patients with pigmentation had a 5-year melanoma-specific survival (MSS) of 47% and a 10-year MSS of 33%. Patients without pigmentation had a 5-year MSS of 70% and a 10-year MSS of 59% (P=0.06). There was no difference in MSS for patients with an eccentric or an infiltrative growth pattern, nor did it correlate with other prognostic factors. Multivariate analysis for MSS showed five significant factors associated with worse prognosis: male sex (P=0.036), nodular melanoma (P=0.001), truncal site (P=0.0001), SN tumor burden more than 1.0 mm (P=0.022), and positive completion lymph node dissection (P=0.004). The 5-year MSS for SN tumor burden is 94% for 0.1 mm or less, 66% for 0.1-1.0 mm, and 41% for more than >1.0 mm (P<0.001). The 10-year MSS for SN tumor burden is, respectively, 94, 51, and 35% (P<0.001). This preliminary exploratory retrospective study showed that pigmentation within the SN seems to correlate with increased SN tumor burden.

Is complete lymph node dissection after a positive sentinel lymph node biopsy for cutaneous melanoma always necessary? A meta-analysis

The current recommendation for patients with cutaneous melanoma and a positive sentinel lymph node (SLN) biopsy is a complete lymph node dissection (CLND). However, metastatic melanoma is not present in approximately 80% of CLND specimens. A meta-analysis was performed to identify the clinicopathological variables most predictive of non-sentinel node (NSN) metastases when the sentinel node is positive in patients with melanoma. A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google scholar, Science Direct, and Web of Science. The search identified 54 relevant articles reporting the frequency of NSN metastases in melanoma. Original data was abstracted from each study and used to calculate a pooled odds ratio (OR) and 95% confidence interval (95% CI). The pooled estimates that were found to be significantly associated with the high likelihood of NSN metastases were: ulceration (OR: 1.88, 95% CI: 1.53-2.31), satellitosis (OR: 3.25, 95% CI: 1.86-5.66), neurotropism (OR: 2.51, 95% CI: 1.39-4.53), >1 positive SLN (OR: 1.77, 95% CI: 1.2-2.62), Starz 3 (old) (OR: 1.83, 95% CI: 0.89-3.76), Angiolymphatic invasion (OR: 2.46, 95% CI: 1.34-4.54), extensive location (OR: 2.22, 95% CI: 1.74-2.81), macrometastases >2 mm (OR: 1.95, 95% CI: 1.61-2.35), extranodal extension (OR: 3.38, 95% CI: 1.79-6.40) and capsular involvement (OR: 3.16, 95% CI: 1.37-7.27). There were 3 characteristics not associated with NSN metastases: subcapsular location (OR: 0.51, 95% CI: 0.38-0.67), Rotterdam Criteria <0.1 mm (OR: 0.29, 95% CI: 0.17-0.50) and Starz I (new) (OR: 0.44, 95% CI: 0.22-0.91). Other variables including gender, Breslow thickness 2-4 mm and extremity as primary site were found to be equivocal. This meta-analysis provides evidence that patients with low SLN tumor burden could probably be spared the morbidity associated with CLND. We identified 9 factors predictive of non-SLN metastases that should be recorded and evaluated routinely in SLN databases. However, further studies are needed to confirm the standard criteria for not performing CLND.

Completion lymph node dissection after a positive sentinel node

Sentinel node biopsy (SNB) for primary melanoma is accepted worldwide as a diagnostic procedure. When sentinel node positive, the invasive completion lymph node dissection (CLND) is usually performed. Approximately 20% of CLND patients have nonsentinel node (NSN) metastases. The therapeutic benefit is unknown. This review analyzed the necessity of CLND in sentinel node positive patients. Prognosis of sentinel node positive patients is highly heterogeneous. The Rotterdam and Dewar criteria and S-classification are important sentinel node tumor burden criteria to stratify melanoma patients for prognosis and risk of NSN metastases. Patients with less than 0.1 mm metastases seem to have similar prognosis as sentinel node negative patients, especially when located in the subcapsular area. This depends on the use of an extensive sentinel node pathology protocol identifying possibly clinically irrelevant micrometastases. Consensus on the sentinel node pathology work-up and analysis protocols are crucial for correct risk stratification and for clinical decision-making. Primary and sentinel node tumor burden parameters and patient comorbidities should be taken into consideration when offering CLND to an individual patient. In the future, prospective studies such as the MSLT-II and the EORTC 1208 (Minitub) will provide answers to whether CLND has a therapeutic benefit and to which patients might safely be spared CLND.

Detection of occult invasion in ductal carcinoma in situ of the breast with sentinel node metastasis

By definition, ductal carcinoma in situ (DCIS) - pre-invasive breast cancer - does not metastasize to the lymph nodes. However, since the introduction of molecular whole-node analysis using the one-step nucleic acid amplification assay for sentinel node (SN) biopsies, the number of patients with DCIS and SN metastasis has increased. The pathogenesis and clinical management of DCIS with SN metastasis remain controversial. In this case-control study, in order to elucidate the pathogenesis of SN metastasis in DCIS, we compared occult invasions between the SN-positive and SN-negative DCIS and investigated predictive factors of occult invasion. The subjects were 24 patients selected from 285 patients with a routine postoperative diagnosis of DCIS who had undergone SN biopsy using the one-step nucleic acid amplification whole-node assay between 2009 and 2011. Of these 24 patients, 12 were SN-positive, and 12 were SN-negative. The 12 SN-negative patients make up the control group and were selected from the 273 SN-negative patients based on patient characteristics. All paraffin blocks of the primary tumor from each patient were step-sectioned with 500-μm intervals until the block was exhausted and histopathologically examined. We analyzed 1830 step-sectioned slides and found occult invasions were more frequent in the SN-positive group (7/12, 58.3%) than in the SN-negative group (3/12, 25.0%). All occult invasions were <5mm. There was no correlation between occult invasion and SN tumor burden, non-SN metastasis, or patient characteristics. Our results suggest true metastasis from occult invasion may be a potent pathogenesis indicating nodal metastasis in postoperatively diagnosed DCIS. Patient follow-up is required to elucidate the prognostic impact of nodal metastasis and occult invasion.

The Prognostic Value of Minimally Involved Melanoma Sentinel Lymph Nodes

Background: Sentinel node (SLN) status is the most important prognostic factor for early-stage melanoma patients. It will influence follow-up and may change therapy. Positive SLNs present different degrees of involvement so that subgroups of patients may have minimal SLN invasion. The aim of this study was to evaluate survival in subgroups with minimally involved SLNs and to compare them to negative SLN patients. Method: SLN biopsy was performed in 499 consecutive clinically N0 patients between 1997 and 2008. Following updated recommendations from the Melanoma Group of the European Organization of Research and Treatment of Cancer, degrees of SLN involvement were fully reassessed for two anatomopathological parameters: tumour burden according to Rotterdam criteria ( 1.0 mm) and microanatomic location according to Dewar (subcapsular, combined subcapsular and parenchymal, parenchymal, multifocal, or extensive). Minimally involved SLNs were defined as those with tumor burden <0.1 mm and/or subcapsular metastasis location. Kaplan-Meier and multivariable logistic regression analyses were performed. Results: Out of 499 clinically N0 patients, positive SLNs were found in 123 patients (24.7 percent). With a median follow-up of 52 months (range: 9 - 146), five-year disease-free (DFS), disease-specific survival (DSS) and overall survival (OS) were 88.1, 93.9 and 89.9 percent for negative SLN patients, respectively. In minimally involved SLNs, there were 21 with tumour burden <0.1 mm, and 52 with subcapsular metastasis. Five-year DFS, DSS and OS in these sub-groups were 79.6, 86.6 and 86.6 percent, then 57.3, 69.8 and 67.8 percent respectively. DFS univariable analysis of these sub-groups compared to negative SLNs showed: (HR1.89, 95 percent CI 0.75 - 4.79; p 0.175) and (HR 3.92, 95 percent CI 2.29 - 6.71; p < 0.0001) respectively. Minimally involved sub-groups were not predictive for NSLN negativity. Conclusion: Rotterdam’s tumour burden stratification is an easy and useful prognostic factor of melanoma survival. There was a trend showing that patients with SLN tumour burden <0.1 mm have a lower survival compared to SLN negative patients. One might suggest that patients with minimally involved SLNs may not be managed similarly to negative SLN patients. Subcapsular metastasis subgroup according to the microanatomic location has statistically significant worst survival.

Sentinel node tumour burden quantified based on cytokeratin 19 mRNA copy number predicts non-sentinel node metastases in breast cancer: Molecular whole-node analysis of all removed nodes

ObjectiveThe one-step nucleic acid amplification (OSNA) assay can assess an entire lymph node and detect clinically relevant metastases quantified based on cytokeratin 19 (CK19) mRNA copy number. The OSNA assay of all sentinel lymph nodes (SNs) and non-sentinel nodes (non-SNs) allows for the accurate measurement of tumour burden in either situation. We aim to reveal the usefulness of the OSNA assay regarding the prediction of non-SN metastasis. MethodsThe subjects consisted of 185 breast cancer patients who underwent axillary dissection after a metastatic SN biopsy and whose SNs and non-SNs were examined using the OSNA whole-node assay between 2009 and 2011. The non-SN tumour burden was classified as macrometastasis (CK19 mRNA ⩾5000 copies/μl) or micrometastasis (250–5000 copies/μl). The relationship between SN and non-SN tumour burdens and predictors of non-SN metastasis were investigated. ResultsAmong these 185 patients, 38 patients (20.5%) had macrometastasis and 58 (31.4%) had micrometastasis only in the non-SNs. Non-SN macrometastasis rates increased in direct proportion to the SN copy number: approximately 5% in patients with SNs with 250–500 copies; 20%, 500–5000 copies and 30%, ⩾5000 copies. However, non-SN micrometastasis rates were approximately 30% regardless of the SN copy number. In multivariate analyses, the mean SN copy number, number of macrometastatic SN and lymphovascular invasion were significant for identifying non-SN macrometastases. ConclusionsThe SN tumour burden quantified using the OSNA assay predicts non-SN metastases. A novel mathematical model to predict the non-SN tumour burden can be generated using the results of the OSNA assay.

Prognosis in patients with sentinel node-positive melanoma without immediate completion lymph node dissection

The therapeutic value of immediate completion lymph node dissection (CLND) for sentinel node (SN)-positive melanoma is unknown. The aim of this study was to evaluate the impact of immediate CLND on the outcome of patients with SN-positive melanoma. Patients with SN metastases treated between 1993 and 2008 at ten cancer centres from the European Organization for Research and Treatment of Cancer Melanoma Group were included in this retrospective study. Maximum tumour size, intranodal location and penetrative depth of SN metastases were measured. Outcome in those who had CLND was compared with that in patients who did not undergo completion lymphadenectomy. Of 1174 patients with SN-positive melanoma, 1113 (94.8 per cent) underwent CLND and 61 (5.2 per cent) did not. Median follow-up for the two groups was 34 and 48 months respectively. In univariable survival analysis, CLND did not significantly influence disease-specific survival (hazard ratio (HR) 0.89, 95 per cent confidence interval 0.58 to 1.37; P = 0.600). However, patients who did not undergo CLND had more favourable prognostic factors. Matched-pair analysis, with matching for age, Breslow thickness, tumour ulceration and SN tumour burden, showed that CLND had no influence on survival (HR 0.86, 0.46 to 1.61; P = 0.640). After adjusting for prognostic factors in multivariable survival analyses, no difference in survival was found. In these two cohorts of patients with SN-positive melanoma and prognostic heterogeneity, outcome was not influenced by CLND.

Sentinel Lymph Nodes Containing Very Small (&lt;0.1 mm) Deposits of Metastatic Melanoma Cannot Be Safely Regarded as Tumor-Negative

Some authors have suggested that patients with very small (<0.1mm) deposits of metastatic melanoma in sentinel lymph nodes (SLNs) should be considered SLN-negative, whereas others have reported that such patients can have adverse long-term outcomes. The aims of the present study were to determine whether extensive sectioning of SLNs resulted in more accurate categorization of histologic features of tumor deposits and to assess prognostic associations of histologic parameters obtained using more intensive sectioning protocols. From patients with a single primary cutaneous melanoma who underwent SLN biopsy between 1991 and 2008, those in which the maximum size of the largest tumor deposit (MaxSize) in SLNs was <0.1mm in the original sections were identified. Five batches of additional sections were cut from the SLN tissue blocks at intervals of 250μm. The 1st batch was cut from the blocks without any trimming; these sections were therefore immediately adjacent to the original sections. Each batch included 5 sequential sections, the 1st and 5th stained with hematoxylin-eosin, and the 2nd, 3rd, and 4th stained immunohistochemically with S-100, HMB-45, and Melan-A, respectively. In each batch of sections, the following histologic features of tumor deposit(s) in the SLNs were evaluated: MaxSize; tumor penetrative depth (TPD) (defined as the maximum depth of tumor deposit(s) from the inner margin of the lymph node capsule), and intranodal location (classified as subcapsular if the tumor deposit(s) were confined to the subcapsular zone or parenchymal if there was any involvement of the nodal parenchyma beyond the subcapsular zone). The measured histologic parameters were compared in each batch of sections. The association of histologic parameters with overall survival was assessed for the parameters measured in each batch of sections. There were 20 eligible patients (15 females, 5 males, median age 60years). After a median follow-up duration of 40months, 4 patients had died from melanoma and 2 patients of unknown causes. Completion lymph node dissection (CLND) was performed in 13 cases (65%) and was negative in all cases. Relative to the measured values on the original sections, all 3 parameters were upstaged in subsequent batches of sections, but no further upstaging of MaxSize, TPD, or location was seen beyond batch 3, batch 4, and batch 2, respectively. Increasing MaxSize was associated with significantly poorer overall survival in batches 1, 2, and 3. Parenchymal involvement was significantly associated with poorer survival in batches 2-5. TPD was not significantly associated with overall survival. The results of this study indicate that very small (<0.1mm) deposits of melanoma in SLNs may be associated with adverse clinical outcomes and that this is due, at least in part, to the underestimation of SLN tumor burden in the initial sections. Our evidence does not support clinical decision-making on the assumption that patients with very small melanoma deposits in SLNs have the same outcome as those who are SLN-negative.

The Impact of Primary Melanoma Thickness and Microscopic Tumor Burden in Sentinel Lymph Nodes on Melanoma Patient Survival

The primary objectives of this work are to (1) quantitate tumor burden in sentinel lymph nodes (SLNs), and (2) assess the independent contributions of SLN tumor burden and primary melanoma thickness (PMT) with respect to progression-free survival (PFS) and overall survival (OS). Sixty-three patients (41 male and 22 female) with one or more positive SLNs were available for review in this study, with median follow-up of 6.8 years. PMT was measured and SLN metastases were assessed for size, as maximum metastasis size (MMS) in mm, by hematoxylin and eosin (H&E) and immunohistochemistry (S100 and HMB45). PFS and OS were calculated from time of SLN resection until melanoma recurrence or death. Univariate and multivariate analyses and trend test were performed. Kaplan-Meier estimates of PFS and OS differed significantly by MMS (log-rank P = 0.031 for PFS and P = 0.016 for OS) and PMT (log-rank P = 0.036 for PFS and P < 0.001 for OS). After adjusting for age and gender, the hazard ratio (HR) associated with MMS was 1.09 per mm increase (P = 0.05) for PFS, and 6.30 (P = 0.014) and 5.41 (P = 0.048) for OS in patients, respectively, with MMS of 0.6-5.5 mm and MMS ≥5.5 mm compared with those with MMS <0.6 mm. When patients were stratified by their tumor characteristics of PMT, the risk for disease progression and worse OS was substantially higher for the group with PMT ≥ 4.5 mm (HR = 13.10 and P = 0.022 for PFS; HR = 17.26 and P < 0.001 for OS) relative to the baseline group with PMT <1.6 mm. All patients had completion lymph node dissection (CLND) except for four patients. Patients with positive CLND (14, 22.2%) showed significant worse PFS (P = 0.002) and OS (P = 0.0003) than the negative CLND group (45, 71.4%). PMT and MMS were independently prognostic of PFS and OS in melanoma patients. Patients with negative CLND had significantly better PFS and OS than those with positive CLND.