Risk Of Occult Nodal Metastases Research Articles

What is the rate of occult nodal metastasis in squamous cell carcinomas of the sinonasal tract? A systematic review.

The role of elective neck dissection (END) in the management of clinical N0 (cN0) squamous cell carcinomas (SCC) of the sinonasal tract is unclear. In this systematic review, we evaluate the risk of occult nodal metastasis in sinonasal SCCs with cN0M0 tumors to support clinical decision making. A literature search was conducted in the following three electronic databases: Medline/PubMed, ScienceDirect, and Google Scholar. Articles were assessed for eligibility in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Two independent authors extracted the data. The Methodological Items for Non-Randomized Studies (MINORS) tool was used for the assessment of biases of each included study. Our systematic review included six studies that met the inclusion criteria, all retrospective in design. The rate of histologically proven metastasis of sinonasal SCC to the clinically negative neck is 12.5%. Almost half of the positive cases are pathologically staged as N2 (6.5%). Our systematic review provides the rate of sinonasal SCC occult metastasis to the neck so that the surgeons can discuss with patients the risks and possible merits of adding an elective neck management in the surgical plan.

Potential Role for Observation in Small Solid Pseudopapillary Neoplasm (SPN).

Solid pseudopapillaryneoplasms(SPN)arerare tumorsof the pancreas, typically affecting young women.Resection is the mainstay of treatment but is associated with significant morbidity and potential mortality. Weexplore the ideathat small, localized SPN could be safely observed. This retrospective review of the Pancreas National Cancer Database from 2004 to 2018 identified SPN via histology code8452. A total of 994 SPNs were identified. Mean age was 36.8 ± 0.5 years, 84.9% (n = 844) were female, and most had a Charlson-Deyo Comorbidity Coefficient (CDCC) of 0-1 (96.6%, n = 960). Patients were most often staged clinically as cT2 (69.5%, n = 457) followed by cT3 (17.6%, n = 116), cT1 (11.2%, n = 74), and cT4 (1.7%, n = 11). Clinical lymph node and distant metastasis rates were 3.0 and 4.0%, respectively. Surgical resection was performed in 96.6% of patients (n = 960), most commonly partial pancreatectomy (44.3%) followed by pancreatoduodenectomy (31.3%) and total pancreatectomy (8.1%). In patients clinically staged as node (N0) and distant metastasis (M0) negative, occult pathologic lymph node involvement was found in 0% (n = 28) of patients with stage cT1 and 0.5% (n = 185) of patients with cT2 disease. The risk of occult nodal metastasis significantly increased to 8.9% (n = 61) for patients with cT3 disease. The risk further increased to 50% (n = 2) in patients with cT4 disease. Herein, the specificity of excluding nodal involvement clinically is 99.5% in tumors ≤ 4 cm and 100% in tumors ≤ 2 cm. Therefore, there may be a role for close observation in patients with cT1N0 lesions to mitigate morbidity from major pancreatic resection.

Sentinel lymph node biopsy in Merkel cell carcinoma: Rates and predictors of compliance with the National Comprehensive Cancer Network guidelines

To the Editor: Primary Merkel cell carcinoma (MCC) has a 25% to 30% risk of occult nodal metastasis,1 and the National Comprehensive Cancer Network (NCCN) guidelines recommend sentinel lymph node biopsy (SLNB) in all patients without clinical nodal disease or known metastasis.2 SLNB status guides the prognosis and indications for adjuvant therapy.1 The rates of SLNB compliance have not been studied for MCC.

Semaphorin-3F/Neuropilin-2 Transcriptional Expression as a Predictive Biomarker of Occult Lymph Node Metastases in HNSCC

Simple SummaryThe presence of lymph neck node metastasis is the most important clinical prognostic factor in patients with head and neck squamous cell carcinoma. The expression of the semaphorin-3F and neuropilin-2 proteins is involved in the regulation of lymphangiogenesis. We analized the transcriptional expression of semaphorin-3F and neuropilin-2 in head and neck squamous cell carcinoma tumors of patients without clinical or radiology evidence of lymph node involvement treated with elective neck dissection. We found that patients with high semaphorin-3F and low neuropilin-2 had a lower risk of occult lymph node metastasis than the ones who had low semaphorin-3F or high semaphorin-3F and high neuropilin-2. If our results are validated, the expression of the SEMA3F-NRP2 axis could be used as a biomarker predicting the risk of occult lymph node metastasis, with elective neck dissections being indicated exclusively for patients at higher risk. The availability of a biomarker with the capacity to predict the presence of occult lymph node metastases would make it possible to avoid elective neck dissections in low-risk patients, with the consequent decrease in surgical time and morbidity of the treatment without impairing the oncologic outcome.The expression of the semaphorin-3F (SEMA3F) and neuropilin-2 (NRP2) is involved in the regulation of lymphangiogenesis. The present study analyzes the relationship between the transcriptional expression of the SEMA3F-NRP2 genes and the presence of occult lymph node metastases in patients with cN0 head and neck squamous cell carcinomas. We analyzed the transcriptional expression of SEMA3F and NRP2 in a cohort of 53 patients with cN0 squamous cell carcinoma treated with an elective neck dissection. Occult lymph node metastases were found in 37.7% of the patients. Patients with occult lymph node metastases (cN0/pN+) had significantly lower SEMA3F expression values than patients without lymph node involvement (cN0/pN0). Considering the expression of the SEMA3F-NRP2 genes, patients were classified into two groups according to the risk of occult nodal metastasis: Group 1 (n = 34), high SEMA3F/low NRP2 expression, with a low risk of occult nodal involvement (14.7% cN0/pN+); Group 2 (n = 19), low SEMA3F or high SEMA3F/high NRP2 expression, with a high risk of occult nodal involvement (78.9% cN0/pN+). Multivariate analysis showed that patients in Group 2 had a 26.2 higher risk of lymph node involvement than patients in Group 1. There was a significant relationship between the transcriptional expression values of the SEMA3F-NRP2 genes and the risk of occult nodal metastases.

Machine learning directed sentinel lymph node biopsy in cutaneous head and neck melanoma.

The specificity of sentinel lymph node biopsy (SLNB) for detecting lymph node metastasis in head and neck melanoma (HNM) is low under current National Comprehensive Cancer Network (NCCN) treatment guidelines. Multiple machine learning (ML) algorithms were developed to identify HNM patients at very low risk of occult nodal metastasis using National Cancer Database (NCDB) data from 8466 clinically node negative HNM patients who underwent SLNB. SLNB performance under NCCN guidelines and ML algorithm recommendations was compared on independent test data from the NCDB (n=2117) and an academic medical center (n=96). The top-performing ML algorithm (AUC=0.734) recommendations obtained significantly higher specificity compared to the NCCN guidelines in both internal (25.8% vs. 11.3%, p < 0.001) and external test populations (30.1% vs. 7.1%, p < 0.001), while achieving sensitivity >97%. Machine learning can identify clinically node negative HNM patients at very low risk of nodal metastasis, who may not benefit from SLNB.

Rate of Occult Neck Nodal Metastasis in Parotid Cancer: A Meta-Analysis.

The risk for occult neck nodal metastasis in carcinoma of the parotid gland is inconclusive. Therefore, addressing a negative neck prophylactically and the extent to do so remain controversial. This systematic review aimed to determine the rate of occult nodal metastasis for each neck level, and consequently, to elucidate the proper extent of elective neck dissection (END). A meta-analysis of all studies that included patients with a diagnosis of parotid malignancies who underwent an END was performed. The risk for occult nodal metastasis was calculated for each neck level separately. The search strategy identified 124 papers from January 1980 to December 2019 in the various databases. Nine retrospective studies (n =548) met the inclusion criteria. The risk for occult neck nodal metastasis ranged from 0.0 to 9.43% with a random-effect model of 2.2% for level 1 (n =459), from 3.4 to 28.38% with a random-effect model of 16.51% for level 2 (n =548), from 0.0 to 21.63% with a random-effect model of 4.23% for level 3 (n =518), from 0.0 to 17.02% with a fixed-effect model of 0.39% for level 4 (n =310), and from 0.0 to 11.63% with a fixed-effect model of 1.7% for level 5 (n =417). The rate of occult neck nodal metastasis in parotid malignancies is low, with neck level 2 the most commonly involved. The results of this meta-analysis prevented the authors from substantiating the appropriate extent of an END in parotid cancer.

The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Rectal Cancer.

The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Rectal Cancer.

Occult Nodal Metastases in Patients Down-Staged to Nonmuscle Invasive Disease Following Neoadjuvant Chemotherapy

To evaluate the risk of occult nodal metastasis in patients with muscle invasive bladder cancer who exhibit a complete or partial clinical response to neoadjuvant chemotherapy (NAC) and assess a potential role for "bladder sparing" management given that the gold standard treatment, radical cystectomy (RC), is associated with high morbidity. We queried the National Cancer Database for bladder cancer from 2004 to 2013 including patients with cT2-4aN0M0 bladder cancer who underwent multiagent NAC followed by RC and pelvic lymphadenectomy and excluding patients with nonurothelial predominant histology and those undergoing partial cystectomy. Student's t test was used to evaluate patients' demographics, presence of co-morbid conditions, and pathologic findings, notably the presence of lymphovascular invasion and variant histology. We identified 17,917 patients who underwent RC. Of these, 14.9% (n=2673) received NAC before RC. About 13.1% and 14.5% of patients had complete (ypT0) and partial (ypTa, Tis, and T1) pathologic response, respectively. These 14.7% of cT2, 9.0% of cT3, and 6.9% of cT4 patients exhibited pT0 status on final pathology. And 4.9% of complete and 5.4% of partial responders demonstrated occult nodal metastases. Age, sex, ethnicity, the presence of co-morbidities, LVI, and variant histology were not significantly associated with occult nodal metastasis. While bladder preservation may be a viable option in patients who are carefully selected and closely followed after NAC, patients undergoing NAC may be at risk of occult disease outside of the bladder despite an otherwise clinical complete response diagnosed with cross-sectional imaging, cystoscopy, TURBT, and cytology.

Predictors of occult lymph node metastasis in cutaneous head and neck melanoma.

ObjectiveTo use the Surveillance, Epidemiology, and End Results (SEER) database to verify the findings of a recent National Cancer Database (NCDB) study that identified factors predicting occult nodal involvement in cutaneous head and neck melanoma (CHNM) while identifying additional predictors of occult nodal metastasis and comparing two distinct cancer databases.MethodsCases of CHNM in the SEER database diagnosed between 2004 and 2014 were identified. Demographic information and oncologic data were obtained. Univariate and multivariate analysis were performed to identify factors associated with pathologic nodal positivity.ResultsThere were 34002 patients with CHNM identified. Within this population, 16232 were clinically node-negative, 1090 of which were found to be pathologically node-positive. On multivariate analysis, factors associated with an increased risk of occult nodal metastasis included increasing depth of invasion (stepwise increase in adjusted odds ratio [OR]), nodular histology (aOR: 1.47 [95% CI: 1.21–1.80]), ulceration (aOR: 1.74 [95% CI: 1.48–2.05]), and mitoses (aOR: 1.86 [95% CI: 1.36–2.54]). Factors associated with a decreased risk of occult nodal metastasis included female sex (aOR: 0.80 [0.67–0.94]) and desmoplastic histology (aOR: 0.37 [95% CI: 0.24–0.59]). Between the SEER database and the NCDB, factors associated with occult nodal involvement were similar except for nodular histology and female sex, which did not demonstrate significance in the NCDB.ConclusionRegarding clinically node-negative CHNM, the SEER database and the NCDB have similarities in demographic information but differences in baseline population sizes and tumor characteristics that should be considered when comparing findings between the two databases.Level of evidence4.

2651 Secrets of the Ampulla: A Rare Neuroendocrine Tumor

INTRODUCTION: Neuroendocrine tumors (NETs) of the ampulla of Vater represent less than 0.3% of gastrointestinal NETs and less than 2% of all periampullary malignancies. There are approximately 139 cases in literature, making this rare condition a diagnostic challenge. Jaundice is the predominant symptom followed by abdominal pain. Acute pancreatitis as the initial presentation has seldom been reported. Herein we report a case of a patient who presented with acute pancreatitis and biliary obstruction secondary to an ampullary NET. CASE DESCRIPTION/METHODS: Case of a 74-year-old male with hypertension who reported burning epigastric pain. Denied fever, vomits, weight loss, diarrhea, flushing or dyspnea. Physical examination with epigastric tenderness. Laboratories showed elevated alkaline phosphatase 398 U/L, total bilirubin 3.4 mg/L, lipase 594 U/L and amylase 216 U/L. Contrast abdominopelvic CT showed a duodenal periampullary mass with common bile duct measuring 1.1 cm and intrahepatic and extrahepatic dilatation. Endoscopic retrograde cholangiopancreatography (ERCP) revealed an irregular, ulcerated ampullary mass. Biopsy showed poorly differentiated carcinoma. Immunostains were positive for chromogranin, synaptophysin, CK7, weakly positive for CDX-2. Negative for TTF-1 and CK20. Octreotide scintigraphy with no uptake. Somatostatin, chromogranin, and 5-hydroxy-in-dole acetic acid were normal. Patient underwent surgical treatment with pancreaticoduodenectomy. DISCUSSION: The rarity of ampullary NETs and its proliferation under an intact mucosa makes it difficult to detect in biopsy. Most of the time the diagnosis is based on histology and preoperative diagnosis may be challenging since they clinically present like adenocarcinoma. The usual presentation of jaundice and abdominal pain places this diagnosis low on the differential. In our case, the unusual morphologic appearance likely facilitated obtaining an assertive pre-operative diagnosis. Our patient presented with obstructive jaundice and acute pancreatitis, which occurs in less than 6% of cases. The clinical picture of ampullary NETs is easily confounded given the associated symptoms and biopsy challenges. A high index of suspicion is paramount to ensure this rare diagnosed is not missed. Pancreaticoduodenectomy has been advocated as the treatment of choice regardless of size due to high risk of occult nodal metastases. Considering this diagnosis within the differential is important given the drastically different outcomes for patients if caught early.

Which patients benefit most from stereotactic body radiotherapy or surgery in medically operable non-small cell lung cancer? An in-depth look at patient characteristics on both sides of the debate.

The role of stereotactic body radiotherapy (SBRT) in early stage medically operable non‐small cell lung cancer is currently under debate. SBRT's advantage is its ability to provide high radiotherapy doses to a tumor in a short timeframe, without the risk of postoperative complications and mortality. Currently, in part due to limited prospective data comparing both treatments, international guidelines continue to recommend surgical resection as the gold standard for medically operable patients. However, not all patients possess uniform characteristics, and there is some evidence that certain subgroups of patients would benefit more from one form of treatment ‐ SBRT or surgery ‐ than the other. The aim of this review is to provide a brief summary of the evidence comparing SBRT to surgery, followed by a deeper discussion of the subgroups of patients who would benefit most from surgery: those with large tumors, centrally located tumors, increased risk of occult nodal metastases, increased risk of toxicity from radiotherapy and radioresistant histological tumor subtypes. Meanwhile, patients who could benefit most from SBRT might include elderly patients, those with reduced lung function or cardiac comorbidities, those with synchronous lung nodules, and those with specific tumor mutational status. We hope that this review will aid in the clinical decision‐making process regarding patient selection for either treatment.

Impact of invasive regional lymph node examination (IRLNE) and time to radiation on overall survival for patients with stage I NSCLC treated with SBRT- a NCDB analysis.

e20041 Background: SBRT is the standard of care for patients (pts) with early stage NSCLC who are not surgical candidates due to co-morbidities. Current NCCN guidelines state that IRLNE prior to definitive treatment for stage IA NSCLC is optional. Performing SBRT without IRLNE may increase the risk for occult nodal metastasis that could lead to regional recurrences and impact survival, however small retrospective studies have failed to demonstrate any benefit of IRLNE. Prior studies have also shown that delay in time to surgery impacts survival in stage 1 NSCLC pts, and due to co-morbidities SBRT pts are more likely to have a delayed time to radiation. However, the impact of time to radiation on OS in such pts is not well defined. Methods: We queried the NCDB for pts with stage 1 NSCLC treated with SBRT diagnosed from 2004 to 2014. We identified whether regional lymph nodes were examined for these pts. In addition, we obtained data regarding other clinicopathologic and treatment associated variables. Kaplan Meier method was used for survival analysis. Cox proportional hazards model was used to assess the impact of the co-variates on OS. Results: We identified 15,338 pts with stage 1 NSCLC treated with SBRT. Of these, 943 pts had IRLNE. Median age was 75 years (range 26-90) and Charlson-Deyo score was ≥ 1 in 6,427 pts. Median OS was 35.4 months (95% CI 34.6-36.2 months). The median time to radiation from diagnosis was 57 days. In a multivariate analysis, there was no impact of IRLNE on OS. Other clinicopathologic variables that impacted OS are listed in the table. A delay in initiation of radiation was associated with significantly worse OS. Conclusions: Invasive staging prior to SBRT for stage I NSCLC does not impact OS. A delay in initiating definitive radiation adversely affects survival in this population and the risk is incremental per week delay. [Table: see text]

Management of neck metastases in head and neck cancer: United Kingdom National Multidisciplinary Guidelines.

This is the official guideline endorsed by the specialty associations involved in the care of head and neck cancer patients in the UK. A rational plan to manage the neck is necessary for all head and neck primaries. With the emergence of new level 1 evidence across several domains of neck metastases, this guideline will identify the evidence-based recommendations for management. Recommendations • Computed tomographic or magnetic resonance imaging is mandatory for staging neck disease, with choice of modality dependant on imaging modality used for the primary site, local availability and expertise. (R) • Patients with a clinically N0 neck, with more than 15-20 per cent risk of occult nodal metastases, should be offered prophylactic treatment of the neck. (R) • The treatment choice of for the N0 and N+ neck should be guided by the treatment to the primary site. (G) • If observation is planned for the N0 neck, this should be supplemented by regular ultrasonograms to ensure early detection. (R) • All patients with T1 and T2 oral cavity cancer and N0 neck should receive prophylactic neck treatment. (R) • Selective neck dissection (SND) is as effective as modified radical neck dissection for controlling regional disease in N0 necks for all primary sites. (R) • SND alone is adequate treatment for pN1 neck disease without adverse histological features. (R) • Post-operative radiation for adverse histologic features following SND confers control rates comparable with more extensive procedures. (R) • Adjuvant radiation following surgery for patients with adverse histological features improves regional control rates. (R) • Post-operative chemoradiation improves regional control in patients with extracapsular spread and/or microscopically involved surgical margins. (R) • Following chemoradiation therapy, complete responders who do not show evidence of active disease on co-registered positron emission tomography-computed tomography (PET-CT) scans performed at 10-12 weeks, do not need salvage neck dissection. (R) • Salvage surgery should be considered for those with incomplete or equivocal response of nodal disease on PET-CT. (R).

Status of the Regional Nodal Basin Remains Highly Prognostic in Melanoma Patients with In-Transit Disease

The role of SLNB for in-transit (IT) melanoma is controversial. The objective of this study was to determine the rate and prognostic significance of occult nodal disease in patients undergoing surgical nodal staging for IT disease. We conducted a retrospective review of patients with IT melanoma from May 2005 through September 2014. Analysis was limited to patients with a first-time IT event who underwent surgical excision. Associations between clinicopathologic characteristics, patterns of recurrence, and survival were analyzed. A total of 261 patients treated at our center were identified and 157 met inclusion criteria, of which 135 (86%) presented with no evidence of nodal disease. At the time of surgical excision of the IT lesion, 80 (58%) clinically node-negative patients underwent observation of the nodal basin and 55 (41%) surgical nodal staging. Twenty (36%) clinically node-negative but surgically staged patients were found to have nodal disease. Distant metastasis-free survival was 70.8 months for surgically staged node-negative patients, 19.2 months for surgically staged node-positive patients, 22.8 months for those staged node-negative by clinical examination only and 4.8 months for those with clinical nodal disease (p= 0.01). The regional nodal basin was the first site of failure in 14 of 66 (21%) clinically staged patients, 5 of 50 (10%) for those surgically staged, and 6 of 16 (38%) for those with clinical nodal disease. Patients with IT disease are at high risk for occult nodal metastasis. Because clinical staging is unreliable, SLNB should be considered. For patients with IT recurrence, the status of the regional basin is strongly prognostic and stratifies patients into low-, intermediate-, and high-risk groups.

Sentinel lymph node biopsy in cN0 squamous cell carcinoma of the lip: A retrospective study.

The purpose of this study was to assess the use of sentinel lymph node biopsy (SLNB) in clinically lymph node-negative (cN0) squamous cell carcinoma (SCC) of the lip deemed high risk for occult nodal metastasis. Twenty-six patients with cT1 to T2 cN0 with SCC of the lip underwent SLNB at a tertiary referral center between January 2001 and March 2012. Initial staging methods were clinical examination only (65.4%), ultrasound (23.1%), or CT (11.5%). Operations were performed with the patients under local anesthesia with sedation (50%) or general anesthesia (50%). The mean follow-up time was 53 months. Three patients (11.5%) had a positive sentinel node and were upstaged. One SLNB-related complication was observed. Regional recurrence occurred in 2 patients (7.7%). The relationship between regional status and both tumor diameter and tumor thickness was statistically significant (p < .05). SLNB can be a viable staging technique in SCC of the lip. Tumor diameter of ≥ 20 mm and increasing tumor thickness seem to delineate higher risk for regional disease in our study. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1375-E1380, 2016.

Utility of mediastinoscopy in clinical stage I lung cancers at risk for occult mediastinal nodal metastases

The prevalence of mediastinal lymph node metastases is unknown for patients with clinical N0 lung cancer who are thought to be at high risk for occult nodal metastases. Further, the utility of mediastinoscopy in these patients is unknown. We performed a prospective trial to evaluate the utility of routine cervical mediastinoscopy for patients who may be at high risk of occult nodal metastases. From January 1, 2008, July 31, 2013, 90 patients with lung cancer with clinical stage T2N0 or T1N0 with standardized uptake value greater than 10 by positron emission tomography/computed tomography underwent routine cervical mediastinoscopy before lung resection. Biopsy of a minimum of 3 nodal stations at mediastinoscopy and a minimum of 4 nodal stations with lung resection was advised. The prevalence of nodal metastases at mediastinoscopy and lung resection was recorded. Some 64% of patients with lung cancer were male with a mean age of 67.3 years. A total of 81 patients had clinical T2N0 and 9 patients had T1N0 with standardized uptake value greater than 10. Mean tumor size was 4.3 ± 1.7 cm, and mean standardized uptake value was 13.5 ± 6.8. One patient (1.1%) had occult metastases detected at mediastinoscopy. A total of 86 patients underwent surgical resection; 4 patients (4.6%) were upstaged to pN2, and 18 patients (21%) were upstaged to pN1. Of 90 patients with clinically staged N0 lung cancer by positron emission tomography/computed tomography, 5.6% (5) were upstaged to pN2 and 20% (18) were upstaged to pN1 (total nodal upstaging=25.6%). Mediastinoscopy seems to have limited utility in these patients with T1 and T2 clinically staged N0 by positron emission tomography/computed tomography. Selective use of mediastinoscopy is recommended, along with thorough mediastinal lymph node evaluation in all patients at the time of lung cancer resection.

Who Should Be Offered a Sentinel Node Biopsy for Melanoma Less Than 1 mm in Thickness?

Who Should Be Offered a Sentinel Node Biopsy for Melanoma Less Than 1 mm in Thickness?

Negative Predictive Value of Positron Emission Tomography and Computed Tomography for Stage T1-2N0 Non–Small-Cell Lung Cancer: A Meta-Analysis

BackgroundNodal staging of non–small-cell lung cancer (NSCLC) is crucial in evaluation of prognosis and determination of therapeutic strategy. This study aimed to determine the negative predictive value (NPV) of combined positron emission tomography and computed tomography (PET-CT) in patients with stage I (T1-2N0) NSCLC and to investigate the possible risk factors for occult nodal disease. MethodsStudies investigating the performance of PET in conjunction with CT in the nodal staging of stage I NSCLC were identified in the MEDLINE database. The initiative of standards for reporting of diagnostic accuracy (STARD) was used to ensure study quality. Pathologic assessments through mediastinoscopy or thoracotomy were required as the reference standard for evaluation of PET-CT accuracy. Stata-based meta-analysis was applied to calculate the individual and pooled NPVs. ResultsTen studies with a total of 1122 patients with stage I (T1-2N0) NSCLC were eligible for analysis. The NPVs of combined PET and CT for mediastinal metastases were 0.94 in T1 disease and 0.89 in T2 disease. Including both T1 disease and T2 disease, the NPVs were 0.93 for mediastinal metastases and 0.87 for overall nodal metastases. Adenocarcinoma histology type (risk ratio [RR], 2.72) and high fluorine-18 (18F) fluorodeoxyglucose (FDG) uptake in the primary lesion were associated with greater risk of occult nodal metastases. ConclusionsAlthough overall occult nodal metastases in clinical stage T1-2N0 NSCLC is not infrequent, combined PET and CT provide a favorable NPV for mediastinal metastases in T1N0 NSCLC, suggesting a low yield from routine invasive staging procedures for this subgroup of patients.

32. Sentinel lymph node biopsy in patients with thin melanoma

Background Most new cases of melanoma are thin (≤1 mm) tumours. A small but significant proportion of patients with thin melanoma suffer disease progression and melanoma-related death. We sought to determine clinico-pathological factors predictive poor clinical outcomes in patients with thin melanoma who underwent sentinel lymph node (SLN) biopsy. Methods Patients diagnosed with a single primary thin cutaneous melanoma who underwent SLN biopsy between 1992 and 2009 were identified from the database of the Melanoma Institute Australia. Thin melanomas were defined as having a Breslow thickness ≤1.00 mm. Clinico-pathological factors associated with SLN positivity, regional lymph node recurrence and survival were analysed. Results There were 432 patients (226 male, 206 female, median age 49.5 years). SLNs were positive in 29 (6.7%) patients. No SLN positivity was detected in 37 patients with tumour thickness ≤0.50 mm. Breslow thickness (OR = 52.0, 95%CI 1.4-1948.7) and presence of lymphovascular invasion (OR = 8.5, 95%CI 1.8-41.4) were the only independent predictors of SLN positivity. Anatomic location in head/neck region (OR = 8.5, 95%CI 1.8-40.2; compared to location in the limbs) was the only independent predictor of regional lymph node recurrence. Mitotic rate was the only independent predictor of melanoma-specific survival (HR=1.2, 95% CI 1.1-1.3). SLN positivity in Clark level III tumours (HR=8.0, 95%CI 1.8-36.0) and anatomic location in head/neck region in Clark level IV tumours (HR = 23.7, 95% CI 2.0-277, compared to limbs) were the only independent predictors of poorer disease-free survival. Conclusions Patients with thicker tumours (>0.5 mm) and other adverse prognostic factors (e.g., ulceration, elevated mitotic rate, lymphovascular invasion) have a greater risk of occult nodal metastasis and are more likely to benefit from SLN biopsy.

The European approach to in-transit melanoma lesions

The biological behavior of melanoma is unpredictable. Three to five per cent of melanoma patients will develop in-transit lesions and the median time to recurrence ranges between 13–16 months. At the time of recurrence the risk of occult nodal metastasis, with clinically negative regional lymph nodes, is as high as 50%. The risk of in-transit lesions depends on the tumor biology and not on the surgical approach to the regional lymph nodes. The high incidence of in-transit lesions at the lower limb may be caused by the gravity and delayed lymphatic drainage. The treatment of limited disease is local excision, laser ablation, cryosurgery, while multiple in-transit lesions or bulky disease located in a limb can be successfully treated with regional chemotherapy, a therapeutic isolated limb perfusion or infusion with melphalan or a combination of melphalan and tumor necrosis factor (TNF) alpha. If local regional treatment or systemic dacarbazine based systemic treatment fails, novel systemic treatment strategies with vaccines, antibodies and gene therapy are currently investigated.