Single-Photon Emission Computed Tomography/Computed Tomography Utilization for Extremity Melanomas at a High-Volume Center

INTRODUCTION

Planar lymphoscintigraphy (PL) is commonly used in mapping before sentinel lymph node biopsy (SLNB) for invasive cutaneous melanoma. Recently, single-photon emission computed tomography (SPECT)/ computed tomography (CT) has been utilized, in addition to PL, for detailed anatomic information and detection of sentinel lymph nodes (SLNs) outside of the primary nodal basin in truncal and head and neck melanoma. Following a protocol change due to COVID-19, our institution began routinely obtaining both PL and SPECT-CT imaging for all melanoma SLN mapping. We hypothesized that SPECT-CT is associated with higher instances of SLNBs from "nontraditional" nodal basins (NTNB) for extremity melanomas.

METHODS

Patients with extremity melanoma (2017-2022) who underwent SLNB were grouped into SPECT-CT with PL versus PL alone. Outcomes were total SLNs removed, + or-SLN status, total NTNB sampled, and postoperative complication rate. Poisson regression and logistic regression models were used to assess association of SPECT-CT with patient outcomes.

RESULTS

Of 380 patients with extremity melanoma, 42.11% had SPECT-CT. There were no differences between the groups with regards to age at diagnosis or sex. From 2020 to 2022, all patients underwent SPECT-CT. SPECT-CT was associated with increased odds of SLNB from an NTNB, (odds ratio = 2.39 [95% confidence interval: 1.25-4.67]). There was no difference in odds of number of SLNs sampled, SLN positivity rate, or postoperative complication rate with SPECT-CT.

CONCLUSIONS

Routine SPECT-CT was associated with higher incidence of SLNB in NTNB but did not increase number of SLNs removed or SLN positivity rate. The added value of routine SPECT-CT in cutaneous melanoma of the extremities remains to be defined.

Feasibility of personalized circulating tumor DNA detection in stage II and III melanoma

The objective of this study was to evaluate the feasibility of developing personalized, tumor-informed assays for patients with high-risk resectable melanoma and examine circulating tumor DNA (ctDNA) levels in relation to clinical status. Pilot prospective study of clinical stage IIB/C and resectable stage III melanoma patients. Tumor tissue was used to design bespoke somatic assays for interrogating ctDNA in patients' plasma using a multiplex PCR (mPCR) next-generation sequencing (NGS)-based approach. Plasma samples for ctDNA analysis were collected pre-/post-surgery and during surveillance. Out of 28 patients (mean 65 years, 50% male), 13 (46%) had detectable ctDNA prior to definitive surgery and 96% (27/28) tested ctDNA-negative within 4 weeks post-surgery. Pre-surgical detection of ctDNA was significantly associated with the later-stage (P = 0.02) and clinically evident stage III disease (P = 0.007). Twenty patients continue in surveillance with serial ctDNA testing every 3-6 months. With a median follow-up of 443 days, six out of 20 (30%) patients developed detectable ctDNA levels during surveillance. All six of these patients recurred with a mean time to recurrence of 280 days. Detection of ctDNA in surveillance preceded the diagnosis of clinical recurrence in three patients, was detected concurrent with clinical recurrence in two patients and followed clinical recurrence in one patient. One additional patient developed brain metastases without detection of ctDNA during surveillance but had positive pre-surgical ctDNA. Our results demonstrate the feasibility of obtaining a personalized, tumor-informed mPCR NGS-based ctDNA assay for patients with melanoma, particularly in resectable stage III disease.

Early Detection and Prognostic Assessment of Cutaneous Melanoma: Consensus on Optimal Practice and the Role of Gene Expression Profile Testing

Importance

Therapy for advanced melanoma has transformed during the past decade, but early detection and prognostic assessment of cutaneous melanoma (CM) remain paramount goals. Best practices for screening and use of pigmented lesion evaluation tools and gene expression profile (GEP) testing in CM remain to be defined.

Objective

To provide consensus recommendations on optimal screening practices and prebiopsy diagnostic, postbiopsy diagnostic, and prognostic assessment of CM.

Evidence Review

Case scenarios were interrogated using a modified Delphi consensus method. Melanoma panelists (n = 60) were invited to vote on hypothetical scenarios via an emailed survey (n = 42), which was followed by a consensus conference (n = 51) that reviewed the literature and the rationale for survey answers. Panelists participated in a follow-up survey for final recommendations on the scenarios (n = 45).

Findings

The panelists reached consensus (≥70% agreement) in supporting a risk-stratified approach to melanoma screening in clinical settings and public screening events, screening personnel recommendations (self/partner, primary care provider, general dermatologist, and pigmented lesion expert), screening intervals, and acceptable appointment wait times. Participants also reached consensus that visual and dermoscopic examination are sufficient for evaluation and follow-up of melanocytic skin lesions deemed innocuous. The panelists reached consensus on interpreting reflectance confocal microscopy and some but not all results from epidermal tape stripping, but they did not reach consensus on use of certain pigmented lesion evaluation tools, such as electrical impedance spectroscopy. Regarding GEP scores, the panelists reached consensus that a low-risk prognostic GEP score should not outweigh concerning histologic features when selecting patients to undergo sentinel lymph node biopsy but did not reach consensus on imaging recommendations in the setting of a high-risk prognostic GEP score and low-risk histology and/or negative nodal status.

Conclusions and Relevance

For this consensus statement, panelists reached consensus on aspects of a risk-stratified approach to melanoma screening and follow-up as well as use of visual examination and dermoscopy. These findings support a practical approach to diagnosing and evaluating CM. Panelists did not reach consensus on a clearly defined role for GEP testing in clinical decision-making, citing the need for additional studies to establish the clinical use of existing GEP assays.

Therapeutic Value of Sentinel Lymph Node Biopsy in Patients With Melanoma: A Randomized Clinical Trial

Importance

Sentinel lymph node (SLN) biopsy is a standard staging procedure for cutaneous melanoma. Regional disease control is a clinically important therapeutic goal of surgical intervention, including nodal surgery.

Objective

To determine how frequently SLN biopsy without completion lymph node dissection (CLND) results in long-term regional nodal disease control in patients with SLN metastases.

Design, Setting, and Participants

The second Multicenter Selective Lymphadenectomy Trial (MSLT-II), a prospective multicenter randomized clinical trial, randomized participants with SLN metastases to either CLND or nodal observation. The current analysis examines observation patients with regard to regional nodal recurrence. Trial patients were aged 18 to 75 years with melanoma metastatic to SLN(s). Data were collected from December 2004 to April 2019, and data were analyzed from July 2020 to January 2022.

Interventions

Nodal observation with ultrasonography rather than CLND.

Main Outcomes and Measures

In-basin nodal recurrence.

Results

Of 823 included patients, 479 (58.2%) were male, and the mean (SD) age was 52.8 (13.8) years. Among 855 observed basins, at 10 years, 80.2% (actuarial; 95% CI, 77-83) of basins were free of nodal recurrence. By univariable analysis, freedom from regional nodal recurrence was associated with age younger than 50 years (hazard ratio [HR], 0.49; 95% CI, 0.34-0.70; P < .001), nonulcerated melanoma (HR, 0.36; 95% CI, 0.36-0.49; P < .001), thinner primary melanoma (less than 1.5 mm; HR, 0.46; 95% CI, 0.27-0.78; P = .004), axillary basin (HR, 0.61; 95% CI, 0.44-0.86; P = .005), fewer positive SLNs (1 vs 3 or more; HR, 0.32; 95% CI, 0.14-0.75; P = .008), and SLN tumor burden (measured by diameter less than 1 mm [HR, 0.39; 95% CI, 0.26-0.60; P = .001] or less than 5% area [HR, 0.36; 95% CI, 0.24-0.54; P < .001]). By multivariable analysis, younger age (HR, 0.57; 95% CI, 0.39-0.84; P = .004), thinner primary melanoma (HR, 0.40; 95% CI, 0.22-0.70; P = .002), axillary basin (HR, 0.55; 95% CI, 0.31-0.96; P = .03), SLN metastasis diameter less than 1 mm (HR, 0.52; 95% CI, 0.33-0.81; P = .007), and area less than 5% (HR, 0.58; 95% CI, 0.38-0.88; P = .01) were associated with basin control. When looking at the identified risk factors of age (50 years or older), ulceration, Breslow thickness greater than 3.5 mm, nonaxillary basin, and tumor burden of maximum diameter of 1 mm or greater and/or metastasis area of 5% or greater and excluding missing value cases, basin disease-free rates at 5 years were 96% (95% CI, 88-100) for patients with 0 risk factors, 89% (95% CI, 82-96) for 1 risk factor, 86% (95% CI, 80-93) for 2 risk factors, 80% (95% CI, 71-89) for 3 risk factors, 61% (95% CI, 48-74) for 4 risk factors, and 54% (95% CI, 36-72) for 5 or 6 risk factors.

Conclusions and Relevance

This randomized clinical trial was the largest prospective evaluation of long-term regional basin control in patients with melanoma who had nodal observation after removal of a positive SLN. SLN biopsy without CLND cleared disease in the affected nodal basin in most patients, even those with multiple risk factors for in-basin recurrence. In addition to its well-validated value in staging, SLN biopsy may also be regarded as therapeutic in some patients.

Trial Registration

ClinicalTrials.gov Identifier: NCT00297895.

Abstract LB180: Clinical biomarker studies with two fusion-enhanced versions of oncolytic HSV (RP1 and RP2) alone and in combination with nivolumab in cancer patients indicate potent immune activation

Introduction:RP1 and RP2 are novel, enhanced potency oncolytic versions of HSV1 engineered to express human GM-CSF and the gibbon ape leukemia virus membrane R- glycoprotein (GALV-GP R-), providing constitutive fusion activity and increased immunogenic cell death. RP2 further expresses an anti-CTLA-4 antibody-like molecule. Murine versions of RP1 and RP2 exhibited synergy in combination with anti-mouse-PD-1 leading to enhanced regression of both injected and un-injected tumors in mice (Thomas et al JITC 2019). RP1 and RP2 are currently being evaluated in clinical trials in a range of solid tumors alone and combined with anti-PD1 therapy, where deep and durable responses have been demonstrated (SITC 2020). Here we present biomarker data from the Phase 1/2 clinical trial of RP1 alone and combined with nivolumab (NCT03767348) and from the Phase 1 portion of the clinical trial with RP2 alone (NCT04336241).

Methods: In the Phase 1/2 studies tumor biopsies and peripheral blood mononuclear samples (PBMCs) were collected at screening and at D43 for biomarker analysis, after combination therapy with nivolumab for RP1 and following single agent treatment for RP2. Immunohistochemistry (IHC) was performed for CD8 (SP57 clone, Ventana) and for PD-L1 (28-8 clone, pharmDx assay). Gene expression was analysed using NanoString to assess effects on a range of genes. The tumor inflammation signature score (TIS) was also calculated.

Results:Preliminary Phase 1/2 biomarker data from paired tumor biopsies include the following: Immunohistochemistry for CD8 and PD-L1 (n=30) indicated robust and increased infiltration of CD8+ T cells and PD-L1 expression, both after combined treatment with RP1 and nivolumab and after single agent RP2 across different tumor types, and including reversal of T cell exclusion following prior combined treatment with ipilimumab and nivolumab in melanoma. Gene expression analysis (n=15) demonstrated a significant increase in the expression levels of genes associated with innate and adaptive immune activation and genes previously reported to be associated with responsiveness to anti-PD1 therapy, particularly CD8, CXCL9, CD27 and TIGIT, as well as consistently increased TIS.

Conclusion:Consistent with the pre-clinical data, preliminary clinical biomarker data indicate substantial increase in CD8 T cell infiltration and PD-L1 expression, as well as increased TIS score in the majority of patients treated with RP2 alone or RP1 and nivolumab combination. Particularly marked effects were seen in some patients with clinical responses which occurred independent of both baseline PD-L1 and prior anti-PD1 therapy status, which suggests potential broad utility of the RP1/2 treatment approach in igniting an anti-tumor immune response. Tumor mutation burden analysis and T cell receptor sequencing are currently underway and further updates of the dataset will be presented.

Citation Format: Kevin J. Harrington, Francesca Aroldi, Joseph J. Sacco, Mohammed M. Milhem, Brendan D. Curti, Ari M. Vanderwalde, Scott Baum, Adel Samson, Anna C. Pavlick, Jason A. Chesney, Jiaxin Niu, Terence D. Rhodes, Tawnya L. Bowles, Robert Conry, Anna Olsson-Brown, Douglas E. Laux, Pablo Nenclares, Lavita Menezes, Alex Deterding, Victoria Roulstone, Joan Kyula, Suzanne Thomas, Praveen K. Bommareddy, Selda Samakoglu, Andrea Pirzkall, Robert S. Coffin, Mark R. Middleton. Clinical biomarker studies with two fusion-enhanced versions of oncolytic HSV (RP1 and RP2) alone and in combination with nivolumab in cancer patients indicate potent immune activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB180.

Impact of rurality on melanoma diagnosis in Utah

Aim

To analyze trends in Utah melanoma diagnosis and study the impact of rurality.

Patients & methods

State-wide melanoma incidence was calculated using Surveillance, Epidemiology, and End Results data (2005-2013). A subset of 5199 patients treated in an integrated healthcare system was further stratified for urban or rural residence.

Results

Early-stage tumors accounted for most of the increase in melanoma incidence over time. Age-adjusted melanoma incidence rate was higher in rural counties (46.7 vs 39.4). Anatomic site and stage did not differ between rural and urban patients. Rural patients were more commonly diagnosed by a local primary care provider.

Conclusion

Rurality had an impact on melanoma diagnosis in the specialty and location of the diagnosing provider.

Trends in the management of anorectal melanoma: A multi-institutional retrospective study and review of the world literature

BACKGROUND

Anorectal melanoma (ARM) is a rare disease with a poor prognosis. Evidence on optimal treatment is limited and surgical management varies widely. We hypothesized that the frequency of abdominoperineal resection used as primary treatment of ARM has decreased over the past several decades.

AIM

To update our understanding of outcomes for patients with ARM and analyze management trends around the world.

METHODS

This is a multi-institutional, retrospective study of patients treated for ARM at 7 hospitals. Hospitals included both large, academic, tertiary care centers and smaller, general community hospitals. Using prospectively maintained institutional tumor registries, we identified 24 patients diagnosed with ARM between January 2000 and May 2019. We analyzed factors prognostic for recurrence and survival. We then used Cox regression to measure overall survival (OS) and melanoma-specific survival. We also performed a literature review to assess trends in surgical management and outcomes.

RESULTS

Of the 24 patients diagnosed with ARM, 12 (50.0%) had local, 8 (33.3%) regional, and 4 (16.7%) distant disease at diagnosis. Median time to recurrence was 10.4 mo [interquartile range (IQR) 7.5-17.2] with only 2 patients (9.3%) not developing recurrence following surgical resection. Median OS was 18.8 mo (IQR 13.5-33.9). One patient is still alive without recurrence at 21.4 mo from diagnosis; no other patient survived 5 years. Primary surgical management with abdominoperineal resection (APR) vs wide excision (WE) did not lead to differences in OS [hazard ratio = 1.4 (95%CI: 0.3-6.8)]. Review of the literature revealed geographic differences in surgical management of ARM, with increased use of WE in the United States and Europe over time and more frequent use of APR in Asia and India. There was no significant improvement in survival over time.

CONCLUSION

There is wide variation in the management of ARM and survival outcomes remain poor regardless of approach. Surgical management should aim to minimize morbidity.

Recurrence patterns in patients with Stage II melanoma: The evolving role of routine imaging for surveillance

BACKGROUND AND OBJECTIVES

The relatively recent availability of effective systemic therapies for metastatic melanoma necessitates reconsideration of current surveillance patterns. Evidence supporting surveillance guidelines for resected Stage II melanoma is lacking. Prior reports note routine imaging detects only 21% of recurrent disease. This study aims to define recurrence patterns for Stage II melanoma to inform future surveillance guidelines.

METHODS

This is a retrospective study of patients with Stage II melanoma. We analyzed risk factors for recurrence and methods of recurrence detection. We also assessed survival. Yearly hazards of recurrence were visualized.

RESULTS

With a median follow-up of 4.9 years, 158 per 580 patients (27.2%) recurred. Overall, most recurrences were patient-detected (60.7%) or imaging-detected (27.3%). Routine imaging was important in detecting recurrence in patients with distant recurrences (adjusted rate 43.1% vs. 9.4% for local/in-transit; p = .04) and with Stage IIC melanoma (42.5% vs. 18.5% for IIA; p = .01). Male patients also self-detected recurrent disease less than females (52.1% vs. 76.8%; p < .01).

CONCLUSIONS

Routine imaging surveillance played a larger role in detecting recurrent disease for select groups in this cohort than noted in prior studies. In an era of effective systemic therapy, routine imaging should be considered for detection of asymptomatic relapse for select, high-risk patient groups.

Oncologic outcomes of patients with Merkel Cell Carcinoma (MCC): A multi-institutional cohort study

BACKGROUND

Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine tumor that primarily affects elderly patients. Despite aggressive treatment, overall survival (OS) remains low.

METHODS

This study is a multi-institutional, retrospective review of 102 patients with MCC. We evaluated OS, disease-specific survival (DSS), and risk factors for recurrence.

RESULTS

Median age of patients was 71.46% of patients recurred. Patients with stage I disease had median 5-year OS of 59.3%, compared to 68.1% DSS. For stage III, median 5-year OS was 46.0% vs 58.2% DSS. Disease stage and advanced age were risk factors for recurrence and decreased OS. Immunocompromised status and disease stage were the strongest predictors of DSS.

CONCLUSIONS

DSS is significantly better than OS for patients with MCC. Many elderly patients with newly diagnosed MCC have low remaining life expectancy, regardless of their MCC diagnosis. Patient age and overall health status should be considered to personalize care plans for patients with MCC.

Chemoprevention agents for melanoma: A path forward into phase 3 clinical trials

Recent progress in the treatment of advanced melanoma has led to unprecedented improvements in overall survival and, as these new melanoma treatments have been developed and deployed in the clinic, much has been learned about the natural history of the disease. Now is the time to apply that knowledge toward the design and clinical evaluation of new chemoprevention agents. Melanoma chemoprevention has the potential to reduce dramatically both the morbidity and the high costs associated with treating patients who have metastatic disease. In this work, scientific and clinical melanoma experts from the national Melanoma Prevention Working Group, composed of National Cancer Trials Network investigators, discuss research aimed at discovering and developing (or repurposing) drugs and natural products for the prevention of melanoma and propose an updated pipeline for translating the most promising agents into the clinic. The mechanism of action, preclinical data, epidemiological evidence, and results from available clinical trials are discussed for each class of compounds. Selected keratinocyte carcinoma chemoprevention studies also are considered, and a rationale for their inclusion is presented. These data are summarized in a table that lists the type and level of evidence available for each class of agents. Also included in the discussion is an assessment of additional research necessary and the likelihood that a given compound may be a suitable candidate for a phase 3 clinical trial within the next 5 years.

Similar survival of patients with multiple versus single primary melanomas based on Utah Surveillance, Epidemiology, and End Results data (1973-2011)

BACKGROUND

Survival data are mixed comparing patients with multiple primary melanomas (MPM) to those with single primary melanomas (SPM).

OBJECTIVES

We compared MPM versus SPM patient survival using a matching method that avoids potential biases associated with other analytic approaches.

METHODS

Records of 14,138 individuals obtained from the Surveillance, Epidemiology, and End Results registry of all melanomas diagnosed or treated in Utah between 1973 and 2011 were reviewed. A single matched control patient was selected randomly from the SPM cohort for each MPM patient, with the restriction that they survived at least as long as the interval between the first and second diagnoses for the matched MPM patient.

RESULTS

Survival curves (n = 887 for both MPM and SPM groups) without covariates showed a significant survival disadvantage for MPM patients (chi-squared 39.29, P < .001). However, a multivariate Cox proportional hazards model showed no significant survival difference (hazard ratio 1.07, P = .55). Restricting the multivariate analysis to invasive melanomas also showed no significant survival difference (hazard ratio 0.99, P = .96).

LIMITATIONS

Breslow depth, ulceration status, and specific cause of death were not available for all patients.

CONCLUSIONS

Patients with MPM had similar survival times as patients with SPM.

A phase I study of intratumoral ipilimumab and interleukin-2 in patients with advanced melanoma

Purpose

Intratumoral interleukin-2 (IL-2) is effective but does not generate systemic immunity. Intravenous ipilimumab produces durable clinical response in a minority of patients, with potentially severe toxicities. Circulating anti-tumor T cells activated by ipilimumab may differ greatly from tumor-infiltrating lymphocytes activated by intratumoral ipilimumab in phenotypes and functionality. The objective of this study was to primarily assess the safety of intratumoral ipilimumab/IL-2 combination and to obtain data on clinical efficacy.

Results

There was no dose limiting toxicity. While local response of injected lesions was observed in 67% patients (95% CI, 40%-93%), an abscopal response was seen in 89% (95% CI, 68%-100%). The overall response rate and clinical benefit rate by immune-related response criteria (irRC) was 40% (95% CI, 10%-70%) and 50% (95% CI, 19%-81%), respectively. Enhanced systemic immune response was observed in most patients and correlated with clinical responses.

Experimental Design

Twelve patients with unresectable stages III/IV melanoma were enrolled. A standard 3+3 design was employed to assess highest tolerable intratumoral dose of ipilimumab and IL-2 based on toxicity during the first three weeks. Escalated doses of ipilimumab was injected into only one lesion weekly for eight weeks in cohorts of three patients. A fixed dose of IL-2 was injected three times a week into the same lesion for two weeks, followed by two times a week for six weeks.

Conclusions

Intratumoral injection with the combination of ipilimumab/IL-2 is well tolerated and generates responses in both injected and non-injected lesions in the majority of patients.

Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma

BACKGROUND

Sentinel-lymph-node biopsy is associated with increased melanoma-specific survival (i.e., survival until death from melanoma) among patients with node-positive intermediate-thickness melanomas (1.2 to 3.5 mm). The value of completion lymph-node dissection for patients with sentinel-node metastases is not clear.

METHODS

In an international trial, we randomly assigned patients with sentinel-node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph-node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma-specific survival. Secondary end points included disease-free survival and the cumulative rate of nonsentinel-node metastasis.

RESULTS

Immediate completion lymph-node dissection was not associated with increased melanoma-specific survival among 1934 patients with data that could be evaluated in an intention-to-treat analysis or among 1755 patients in the per-protocol analysis. In the per-protocol analysis, the mean (±SE) 3-year rate of melanoma-specific survival was similar in the dissection group and the observation group (86±1.3% and 86±1.2%, respectively; P=0.42 by the log-rank test) at a median follow-up of 43 months. The rate of disease-free survival was slightly higher in the dissection group than in the observation group (68±1.7% and 63±1.7%, respectively; P=0.05 by the log-rank test) at 3 years, based on an increased rate of disease control in the regional nodes at 3 years (92±1.0% vs. 77±1.5%; P<0.001 by the log-rank test); these results must be interpreted with caution. Nonsentinel-node metastases, identified in 11.5% of the patients in the dissection group, were a strong, independent prognostic factor for recurrence (hazard ratio, 1.78; P=0.005). Lymphedema was observed in 24.1% of the patients in the dissection group and in 6.3% of those in the observation group.

CONCLUSIONS

Immediate completion lymph-node dissection increased the rate of regional disease control and provided prognostic information but did not increase melanoma-specific survival among patients with melanoma and sentinel-node metastases. (Funded by the National Cancer Institute and others; MSLT-II ClinicalTrials.gov number, NCT00297895 .).

Patterns of failure and predictors of outcome in cutaneous malignant melanoma of the scalp

BACKGROUND

Patients with melanoma of the scalp may have higher failure (recurrence) rates than melanoma of other body sites.

OBJECTIVE

We sought to characterize survival and patterns of failure for patients with scalp melanoma.

METHODS

Between 1998 and 2010, 250 nonmetastatic patients underwent wide local excision of a primary scalp melanoma. Kaplan-Meier analyses were performed to evaluate overall survival, scalp control, regional neck control, distant metastases-free survival, and disease-free survival.

RESULTS

Five-year overall survival was 86%, 57%, and 45% for stages I, II, and III, respectively, and 5-year scalp control rates were 92%, 75%, and 63%, respectively. Five-year distant metastases-free survival for these stages were 92%, 65%, and 45%, respectively. Of the 74 patients who recurred, the site of first recurrence included distant disease in 47%, although 31% recurred in the scalp alone.

LIMITATIONS

This is a retrospective review.

CONCLUSION

Distant metastases-free survival and overall survival for stage II and III patients with scalp melanoma are poor, and stage III patients experience relatively high rates of scalp failure suggesting that these patients may benefit from additional adjuvant systemic and local therapy. Further research is needed to characterize the environmental, microenvironmental, and genetic causes of the increased aggressiveness of scalp melanoma and to identify more effective treatment and surveillance methods.

The role of Akt activation in the response to chemotherapy in pancreatic cancer

The PI3K/Akt signaling pathway is constitutively activated in some pancreatic cancers; when activated, it inhibits chemotherapy-mediated apoptosis. We examined whether Akt activity correlates with apoptotic resistance to chemotherapy in pancreatic cancer.

MATERIALS AND METHODS

A panel of human pancreatic cancer cells was evaluated for basal Akt activity as well as response to three chemotherapies. Chemotherapy-induced cell death was evaluated following either up- or down-regulation of Akt activity. Evaluation of phosphorylation of p21Cip/Waf1, a downstream target of Akt, was also evaluated.

RESULTS

There was a broad distribution among pancreatic cancer cell lines by Akt activity, as well as sensitivity to the three chemotherapeutic agents with no apparent correlation. Phosphorylation of p21Cip/Waf1, but not change in total levels, correlated with the chemosensitizing effect of Akt inhibition to paclitaxel.

CONCLUSIONS

Basal Akt activity does not appear to be a useful predictor for selection of pancreatic cancers in targeting Akt to broadly induce chemosensitivity.

Conditional survival estimates improve over 5 years for melanoma survivors with node-positive disease

BACKGROUND

Conditional survival estimates provide useful prognostic information for cancer survivors. The objective of this study was to determine conditional survival estimates for melanoma patients with substages of stage III disease.

MATERIALS AND METHODS

A retrospective analysis of 760 patients who underwent lymphadenectomy for node-positive melanoma was conducted, and patients were stratified into substages: IIIA, IIIB, and IIIC. The 5-year conditional disease-free survival (DFS) and disease-specific survival (DSS) were calculated following lymphadenectomy using the methods of Kaplan and Meier and were reassessed for survivors on an annual basis. Multivariate Cox regression models were used to calculate adjusted conditional DFS and DSS accounting for age, gender, tumor histology, and extracapsular extension.

RESULTS

For patients with IIIA, IIIB, and IIIC disease, 5-year conditional DSS from treatment to year 5 improved from 78% to 90%, 54% to 79%, and 39% to 78%, respectively. For 5-year conditional DFS over the same period, the estimates increased from 65% to 79%, 37% to 81%, and 26% to 92%, respectively. Male patients experienced decreased 5-year conditional DSS and DFS across all substages, with the most pronounced effect on DSS in stage IIIC. Multivariate analysis demonstrated that survival differences among stage IIIC patients based on histologic subtype and extracapsular extension decreased over time.

CONCLUSIONS

Conditional survival estimates are more optimistic and realistic for cancer survivors than traditional survival estimates over time. For node-positive melanoma survivors, 5-year conditional DFS and DSS improve significantly over time. These estimates are critical to treatment decisions and non-treatment-related planning for both clinicians and patients.

Abstract 4847: Arginine deprivation by PEG-ADI induces autophagic cell death and enhances the tumor suppression effect of gemcitabine in pancreatic cancer

Metabolic stress has been recently recognized to induce autophagic cell death; we have recently shown that nearly 80% of pancreatic adenocarcinoma tumor specimens are auxotrophic for the semi-essential amino acid arginine due to transcriptional suppression of argininosuccinate synthase (ASS). We hypothesized that selective arginine deprivation would induce autophagy and furthermore, by targeting alternative death pathways would increase the cytotoxic response to the chemotherapy gemcitabine.

Methods: The human pancreatic cell line MIA-PaCa-2 was shown to be deficient in ASS by western blot. Arginine deprivation was achieved by treatment of cells and xenografts with PEG-ADI, which shuttles arginine to citrulline. Cells were treated with either PEG-ADI, gemcitabine or both. Cell death was measured by MTT and FACS. Western blot was used to measure autophagy by LC3 processing and apoptosis by caspase-3 cleavage. RRM2 expression was measured by western blot in cells treated with PEG-ADI. ASS expression was measured by western blot in cells treated with gemcitabine. To test the in vivo effect arginine deprivation a mice xenograft model was created by subcutaneously injecting Mia-PaCa2 cells into the flanks of 28 mice (two tumors per mice). Tumors were allowed to mature at which time the mice were assigned to one of four treatment groups: PBS control (once weekly), ADI-PEG20 (5 IU once weekly), Gemcitabine (125mg/kg twice weekly), or Gemcitabine and ADI-PEG20. All treatments were administered via intraperitoneal injection and tumors were measured twice a week.

Results: 1. MIA-PaCa-2 lacks ASS and is auxotrophic for arginine. 2. PEG-ADI induces autophagy and cell death 3. Gemcitabine has little in vitro cytotoxicity 4. The combination of gemcitabine and PEG-ADI is at least additive in vitro and in vivo. 5. PEG-ADI does not regulate RRM2 expression and gemcitabine does not regulate ASS expression.

Conclusions: Therapy targeting autophagy may provide increased efficacy for traditional genotoxic chemotherapies in pancreatic cancer. PEG-ADI in combination with gemcitabine is a novel combination to be pursued in clinical trials

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4847.

Arginine deiminase as a novel therapy for prostate cancer induces autophagy and caspase-independent apoptosis

Arginine deprivation as an anticancer therapy has historically been met with limited success. The development of pegylated arginine deiminase (ADI-PEG20) has renewed interest in arginine deprivation for the treatment of some cancers. The efficacy of ADI-PEG20 is directly correlated with argininosuccinate synthetase (ASS) deficiency. CWR22Rv1 prostate cancer cells do not express ASS, the rate-limiting enzyme in arginine synthesis, and are susceptible to ADI-PEG20 in vitro. Interestingly, apoptosis by 0.3 microg/mL ADI-PEG20 occurs 96 hours posttreatment and is caspase independent. The effect of ADI-PEG20 in vivo reveals reduced tumor activity by micropositron emission tomography as well as reduced tumor growth as a monotherapy and in combination with docetaxel against CWR22Rv1 mouse xenografts. In addition, we show autophagy is induced by single amino acid depletion by ADI-PEG20. Here, autophagy is an early event that is detected within 1 to 4 hours of 0.3 microg/mL ADI-PEG20 treatment and is an initial protective response to ADI-PEG20 in CWR22Rv1 cells. Significantly, the inhibition of autophagy by chloroquine and Beclin1 siRNA knockdown enhances and accelerates ADI-PEG20-induced cell death. PC3 cells, which express reduced ASS, also undergo autophagy and are responsive to autophagy inhibition and ADI-PEG20 treatment. In contrast, LNCaP cells highly express ASS and are therefore resistant to both ADI-PEG20 and autophagic inhibition. These data point to an interrelationship among ASS deficiency, autophagy, and cell death by ADI-PEG20. Finally, a tissue microarray of 88 prostate tumor samples lacked expression of ASS, indicating ADI-PEG20 is a potential novel therapy for the treatment of prostate cancer

Pancreatic cancer cell lines deficient in argininosuccinate synthetase are sensitive to arginine deprivation by arginine deiminase

Eukaryotic cells can synthesize the non-essential amino acid arginine from aspartate and citrulline using the enzyme argininosuccinate synthetase (ASS). It has been observed that ASS is underexpressed in various types of cancers ASS, for which arginine become auxotrophic. Arginine deiminase (ADI) is a prokaryotic enzyme that metabolizes arginine to citrulline and has been found to inhibit melanoma and hepatoma cancer cells deficient of ASS. We tested the hypothesis that pancreatic cancers have low ASS expression and therefore arginine deprivation by ADI will inhibit cell growth. ASS expression was examined in 47 malignant and 20 non-neoplastic pancreatic tissues as well as a panel of human pancreatic cancer cell lines. Arginine deprivation was achieved by treatment with a recombinant form of ADI formulated with polyethylene glycol (PEG-ADI). Effects on caspase activation, cell growth and cell death were examined. Furthermore, the effect of PEG-ADI on the in vivo growth of pancreatic xenografts was examined. Eighty-seven percent of the tumors lacked ASS expression; 5 of 7 cell lines similarly lacked ASS expression. PEG-ADI specifically inhibited growth of those cell lines lacking ASS. PEG-ADI treatment induced caspase activation and induction of apoptosis. PEG-ADI was well tolerated in mice despite complete elimination of plasma arginine; tumor growth was inhibited by approximately 50%. Reduced expression of ASS occurs in pancreatic cancer and predicts sensitivity to arginine deprivation achieved by PEG-ADI treatment. Therefore, these findings suggest that arginine deprivation by ADI could provide a beneficial strategy for the treatment of pancreatic cancer, a malignancy in which new therapy is desperately needed.

ERK/BCL-2 pathway in the resistance of pancreatic cancer to anoikis

BACKGROUND

Anoikis is a special type of programmed cell death after loss of cell-cell and cell-extracellular matrix interactions. Resistance to anoikis is likely involved in the process of metastasis, specifically during the tumor cell migration through lymph or vascular channels. We have previously shown that BCL-2 confers resistance to other forms of programmed cell death (i.e., apoptosis); furthermore, the extracellular signaling-regulated kinase (ERK) signaling pathway regulates BCL-2 expression. We therefore tested the hypothesis that pancreatic cancer cell lines are resistant to anoikis and this resistance is due to activation of ERK1/2 and subsequent overexpression of BCL-2.

MATERIALS AND METHODS

Pancreatic cancer cell lines (MIA-PaCa-2 and BxPC-3) were examined for cell death following loss of adherence to extracellular matrix. Subclones of the MIA-PaCa-2 cell line (either selected in vivo for increased metastatic potential [MIA-LM2] or overexpressing BCL-2 [MIA-BCL2]) were also examined for induction of anoikis following loss of extracellular matrix adherence. Finally, the effect of the ERK inhibitor (PD98059) on BCL-2 expression and induction of anoikis was examined.

RESULTS

Under conditions of loss of cell-extracellular matrix interaction, pancreatic cancer cells undergo varying amounts of anoikis. Basal levels of activated ERK and BCL-2 paralleled the sensitivity to induction of anoikis. The highly metastatic cell line, MIA-LM2, was more resistant to anoikis than the parental cell line. Inhibition of ERK down-regulated BCL-2 and was associated with restoration of sensitivity to anoikis.

CONCLUSIONS

Activation of a signaling pathway from ERK to overexpression of BCL-2 may confer resistance to anoikis, a critical step in the development of metastasis. Targeting the ERK/BCL-2 pathway may lead to sensitization of pancreatic cancer to anoikis, thereby decreasing the ability of these cells to metastasize.

Experience and Attitudes of Surgeons Toward Palliation in Cancer

BACKGROUND

Surgery can effectively palliate symptoms in patients with advanced malignancy and thereby maintain quality of life. However, the goal of surgical palliation should be balanced with the associated risks, and the decision to operate can be challenging for even the most experienced surgeon.

HYPOTHESIS

There are significant deficiencies in training during residency and in continuing medical education in palliative surgical care leading to a lack of agreement for treatment recommendations.

DESIGN AND SETTING

A survey of general surgeons involving 4 clinical vignettes of patients with advanced malignancies and varying degrees of symptoms. Respondents were asked to select the best treatment option for each patient from a list of 6 alternatives. Furthermore, respondents identified the clinical factors that most influenced the decision, as well as the major goal of the palliative intervention.

SUBJECTS

Surgeons in a midsized urban setting and its surrounding region.

RESULTS

Of 124 surveys sent out, 70 (56%) were completed. Significant deficiencies in education were identified; 59 (84%) of the respondents did not receive any education in palliative surgical care during residency and 28 (44%) lacked continuing medical education. A consensus treatment recommendation was not selected in 3 of the 4 clinical vignettes, but the respondents used similar clinical factors and goals of treatment for selection of the specific recommendation.

CONCLUSIONS

Palliative care is a major deficiency of postgraduate surgical training. A more focused effort in training surgeons in palliative care may allow for the more uniform and standard provision of palliative surgical care to patients with advanced cancer.