Abstract 4294: C6 Ceramide potentiates paclitaxel and gemcitabine mediated antitumor effects against pancreatic cancer via inhibition of prosurvival PI3k/AKT/mTOR and ERK pathways

The 5% survival of pancreatic cancer emphasizes need for new treatment strategies. Our studies suggest potential value of C6Ceramide (C6Cer) as a chemotherapeutic adjunct. The current study demonstrates that combination chemotherapy of Paclitaxel with adjunct C6Cer significantly increased cell death (apoptosis) in pancreatic cancer cell lines (L3.6,PANC-1, MIA (PaCa-2) in vitro as well as in vivo - enhancing tumor regression in SCID mice bearing L3.6 transplants. A similar synergistic effect was observed with addition of C6Cer to cetuximab which is not effective in KRAS mutant Pancreatic or Colorectal cancer and thus is not used clinically. At the molecular level combining C6Cer with Gemcitabine or Paclitaxel resulted in significant decreased p-AKT and p-GSK-a/b(PI3K/AKT (survival)pathway in L3.6 cells.

Conclusion: C6Cer significantly inhibited key cancer survival pathways resulting in significant synergism with chemotherapeutics in therapy of Pan Ca and KRAS mutant CRC.

Citation Format: Harold J. Wanebo. C6 Ceramide potentiates paclitaxel and gemcitabine mediated antitumor effects against pancreatic cancer via inhibition of prosurvival PI3k/AKT/mTOR and ERK pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4294.

C6-ceramide's effect on KRAS-defined colorectal cancer cells treated with oxaliplatin, 5-fluoruracil with and without cetuximab

619

Background: Cetuximab (Cet) is beneficial for patients with metastatic KRAS Wild type (WT) colorectal cancer (mCRC) only. C6-Ceramide (C6-Cer) can act synergistically with chemotherapy to induce cancer cell death. The aim of this study was to compare growth inhibition percentage (GIP) of cytostatics 5-fluoruracil (5-FU), oxaliplatin (Ox) and Cet with or without C6-Cer in KRAS WT and KRAS mutant (KRAS Mut) CRC cell lines (SW48 and SW480, respectively). Methods: Both cell lines were incubated with IC50 concentrations of test drugs. Drug concentrations included 0.8µM for 5-FU, 0.04µM for Ox, 25 µg/mL for Cet, and C6-Cer concentrations ranged from 5 to 10 µM. Cell survival was assessed 72h after using 0.4% Trypan Blue. Results: With above mentioned concentrations, C6-Cer’s GIP was 78.3% for SW-480 (vs. 33.33% for SW-48). It was also noted that the addition of C6-Cer to a combination of steady concentrations of Ox, Cet and 5-FU increased GIP with an especially significant effect on SW-480. Addition of 5 and 7.5µM resulted in doubling of GIP (75% and 86.25%, respectively, vs 32.5% of 5-FU + Ox + Cet). The greatest effect was seen when 10µM of C6-Cer was added to the IC50 concentrations of chemotherapeutic agents (using the 25µg/mL concentration of Cet), where GIP increased from 32.5% to 92.5% in SW-480. Same concentration of drugs increased GIP for SW-48 to a similar 93.5%. Conclusions: C6-Cer appears to have direct inhibitory properties, especially on KRAS Mut cells. Additionally when added to Ox, 5-FU and Cet, C6-Cer reversed the apparent insensitivity of KRAS Mut to Cet. Also, the study showed C6-Cer can provide additional synergism to their cytostatic properties in KRAS WT CRC cell lines. The true mechanism of these observations is still undergoing analysis, however the effect of isolated C6-Cer on KRAS Mut raises possibility of a different pathway that could bypass EFGR pathway. We believe the results of this study provide a starting point for clinical studies with C6-Ceramide in patients with relapsing or metastatic KRAS Mut CRC in combination with standard chemotherapy plus molecular target agents hoping they will translate into clinical benefit for this difficult to treat patient population.

Effect of neoadjuvant pelvic perfusion on symptom control and resection of pelvic recurrent rectal cancer

723

Background: Isolated pelvic perfusion (IPP) may improve disease control and facilitate pelvic resection in selected high-risk patients with advanced recurrent rectal cancer by reducing painful tumor burden and lessening chances of recurrence. Methods: IPP was done in 42 patients with locally advanced previously irradiated rectal cancer, 26 as preoperative therapy and 16 for palliation. A comparative larger non-perfused group included 63 patients with pelvic resection only via abdominal sacral resection (ABSR) for recurrent rectal cancer. Isolated pelvic perfusion (IPP) with a pump oxygenator, (temp > 41ºc), delivered sequential (q 10 minutes) chemotherapy:– 5FU (5fluorouracil) 1,500 mg/m2, cisplatin/oxaliplatin 100/150 mg/m2, mitomycin 10mg/m2, for 60 minutes in 42 patients. Results: Palliative IPP in 16 advanced rectal cancer patients resulted in significant relief (1–4 months) of narcotic resistant pain (in 70%). Pre-operative IPP in 26 locally advanced rectal cancer patients achieved a clinical path (CR) in 2 patients, and significant regression in 11 patients rendering them resectable. Seven had RO pelvic resections. Of 6 other patients, 4 refused surgery, 2 were medically excluded. Median survival was 30 months in 7 resected patients (all had RO resections) and 2 were 5-year survivors. This is compared to outcome in 63 patients having pelvic resection alone for recurrence: 57 % had RO resection (median OS = 36 months), 28% had R1 resection (median OS = 15 months) and 15% had R2 resection (marrow invasion) (median OS = 21 months). Conclusions: Neoadjuvant IPP may facilitate resection of advanced or (borderline resectable) recurrent rectal cancer by reducing tumor bulk and identifying therapeutic responders likely to benefit from major pelvic resection while excluding non-responders mostly likely to benefit from non-surgical therapy. The potential to induce regression and facilitate RO resection merits further exploration

Induction cetuximab, paclitaxel, and carboplatin followed by chemoradiation with cetuximab, paclitaxel, and carboplatin for stage III/IV head and neck squamous cancer: a phase II ECOG-ACRIN trial (E2303)

BACKGROUND

E2303 evaluated cetuximab, paclitaxel, and carboplatin used as induction therapy and concomitant with radiation therapy in patients with stage III/IV head and neck squamous cell carcinoma (HNSCC) determining pathologic complete response (CR), event-free survival (EFS), and toxicity.

PATIENTS AND METHODS

Patients with resectable stage III/IV HNSCC underwent induction therapy with planned primary site restaging biopsies (at week 8 in clinical complete responders and at week 14 if disease persisted). Chemoradiation (CRT) began week 9. If week 14 biopsy was negative, patients completed CRT (68-72 Gy); otherwise, resection was carried out. p16 protein expression status was correlated with response/survival.

RESULTS

Seventy-four patients were enrolled; 63 were eligible. Forty-four (70%) were free of surgery to the primary site, progression, and death 1-year post-treatment. Following induction, 41 (23 CR) underwent week 8 primary site biopsy and 24 (59%) had no tumor (pathologic CR). Week 14 biopsy during chemoradiation (50 Gy) in 34 (15 previously positive biopsy; 19 no prior biopsy) was negative in 33. Thus 90% of eligible patients completed CRT. Overall survival and EFS were 78% and 55% at 3 years, respectively. Disease progression in 23 patients (37%) was local only in 10 (16%), regional in 5 (8%), local and regional in 2 (3%), and distant in 5 patients (8%). There were no treatment-related deaths. Toxicity was primarily hematologic or radiation-related. p16 AQUA score was not associated with response/survival.

CONCLUSIONS

Induction cetuximab, paclitaxel, and carboplatin followed by the same drug CRT is safe and induces high primary site response and promising survival.

CLINICAL TRIALS NUMBER

NCT 00089297.

Prognostic biomarkers in phase II trial of cetuximab-containing induction and chemoradiation in resectable HNSCC: Eastern cooperative oncology group E2303

PURPOSE

We sought to evaluate the correlation between tissue biomarker expression (using standardized, quantitative immunofluorescence) and clinical outcome in the E2303 trial.

EXPERIMENTAL DESIGN

Sixty-three eligible patients with operable stage III/IV head and neck squamous cell cancer (HNSCC) participated in the Eastern Cooperative Oncology Group (ECOG) 2303 phase II trial of induction chemotherapy with weekly cetuximab, paclitaxel, and carboplatin followed by chemoradiation with the same regimen. A tissue microarray (TMA) was constructed and EGF receptor (EGFR), ERK1/2, Met, Akt, STAT3, β-catenin, E-cadherin, EGFR Variant III, insulin-like growth factor-1 receptor, NF-κB, p53, PI3Kp85, PI3Kp110a, PTEN, NRAS, and pRb protein expression levels were assessed using automated quantitative protein analysis (AQUA). For each dichotomized biomarker, overall survival (OS), progression-free survival (PFS), and event-free survival (EFS) were estimated by the Kaplan-Meier method and compared using log-rank tests. Multivariable Cox proportional hazards models were used to estimate HRs and test for significance.

RESULTS

Forty-two of 63 patients with TMA data on at least one biomarker were included in the biomarker analysis. Tumor extracellular signal-regulated kinase (ERK)1/2 levels were significantly associated with PFS [HR (low/high), 3.29; P = 0.026] and OS [HR (low/high), 4.34; P = 0.008]. On multivariable Cox regression analysis, ERK1/2 remained significantly associated with OS (P = 0.024) and PFS (P = 0.022) after controlling for primary site (oropharynx vs. non-oropharynx) and disease stage (III vs. IV), respectively. Clustering analysis revealed that clusters indicative of activated RAS/MAPK/ERK and/or PI3K/Akt pathways were associated with inferior OS and/or PFS and maintained significance in multivariable analysis.

CONCLUSIONS

These results implicate PI3K/Akt and RAS/MAPK/ERK pathways in resistance to cetuximab-containing chemoradiation in HNSCC. Large prospective studies are required to validate these results.

Abstract B104: Liposomal C6 Ceramide appears to potentiate chemotoxicity of paclitaxel, gemcitabine and cetuximab against aggressive pancreatic cancer

Introduction: Pancreatic adenocarcinoma a highly lethal malignancy (5 yr survival ∼ 5%) is poorly responsive to all chemotherapy, in part related to presence of chemo resistant pathways: prosurvival (AKT/PI3K/mTOR and mutant KRAS. We have previously demonstrated reversal of these resistant pathways by C6 Ceramide and now are pursuing optimum intracellular delivery using selected liposomal preparations ofC6Ceramide.

Methods: C6 Ceramide housed in 4 different liposomal vesicle formulations were tested against pancreatic cell lines L3.6, PANC1 and MIA, using combination therapy with chemotherapy agents Gemcitabine, Paclitaxel and Cetuximab with determination of the MTT anti tumor response. Liposomal preparations included : (#1)18:1 PC(1,2-dioleoyl-sn-glycero-3-phosphocholine; (#3),18:0 PC (1,2-distearoyl-sn-glycero-3-phosphocholine;(#5) DPGG (1,2-dipalmitoyl-sn-glycero-3-galloyl); and (#7) 18:0 PEG2 PE (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N [methoxy(polyethylene glycol)-2000. (#1)18:1 PC- has low transition temp and is fluid at bodyT*(# 3). 18:0 PC- has high transition Temperature(T*) is rigid at body T*;#5 DPGG- avoids RE System (is fluid at bodyT*, induces long circulations)#7. 18:0 PEG 2 PE - industry standard (also avoids RE system) Biologic effects of the 4 lipid formulations with/without C6 Ceramide were initially assessed invitro.

Results: Dose response MTT assay demonstrated no distinctive response of C6 combined liposomes vesicles # 1 & 3, but confirmed high activity in preparations #5 & 7.

Predictive biomarkers in a phase II trial of weekly carboplatin (CBDCA), paclitaxel (P), and cetuximab (C) induction and chemoradiation (CRT) in patients (pts) with resectable stage III/IVa,b head and neck squamous cell carcinoma (HNSCC): Eastern Cooperative Oncology Group E2303

6081

Background: We studied the addition of C to a sequential regimen of weekly CBDCA and P followed by CBDCA-P-radiation in pts with locally advanced resectable HNSCC. Tissue-based biomarkers may aid in pt selection for such approaches. Methods: Sixty-three eligible pts withoperablestage III/IV HNSCC participated in E2303, an Eastern Cooperative Oncology Group (ECOG) phase II trial of induction chemotherapy with weekly C, P and CBDCA x 6 followed by CRT with concurrent weekly C, paclitaxel, carboplatin. A tissue microarray was constructed and b-catenin, E-cadherin, Epidermal Growth Factor Receptor Variant III (EGFRVIII), insulin-like growth factor-1 receptor (IGF1R), NF-kappa b, p53, PI3Kp85, PI3Kp110a, PTEN, ΝRAS, and pRb protein expression levels were assessed using automated quantitative protein analysis (AQUA). For each marker, time-to-event distributions (OS, PFS, and EFS) were estimated by Kaplan-Meier estimates and compared using log-rank tests. Multivariable Cox proportional hazards models were used to estimate hazard ratios and test for significance, with primary site (oropharynx vs. non-oropharynx), disease stage (III vs. IV), and other important markers adjusted in the model. All p-values are two-sided. A level of p < 0.05 is considered statistically significant. Results: Based on the continuous scale, pRb tended to association with EFS (p=0.05). On multivariable analysis, low pRb level was a significant predictor for improved EFS (p=0.048). Our pRb data analysis was based on 32 pts with marker data available. Conclusions: pRb level is a potential predictive biomarker for response to cetuximab. HPV E7 oncoprotein binds and degrades pRb; therefore, low pRb protein level might be a surrogate marker for HPV association.Large prospective studies will be required to determine the association between pRb, HPV status and response to cetuximab in HNSCC.

Neoadjuvant pelvic perfusion may facilitate resection of pelvic recurrent rectal cancer

e14599

Background: Pelvic recurrence of rectal cancer is a persisting therapeutic challenge in spite of wide spread use of adjuvant/neoadjuvant chemo radiation and wide resection isolated pelvic perfusion (IPP) may facilitate pelvic resection in selected high-risk patients.IPP was done in 42 patients with locally advanced previously irradiated rectal cancer, 26 as a preoperative therapy and 16 for palliation. A comparative larger non-perfused group included 63 patients with pelvic resection only for recurrent rectal cancer. Methods: Isolated pelvic perfusion (60 min) utilized pump oxygenation (Temp>41°C)with chemo agents – 5 FU 1500mg/m2, Cisplatin/Oxaliplatin 100/ 150mg/m2, Mitomycin 10-20 mg/m2, which was done in 42 patients (26 as preoperative and 16 as palliative therapy). Results: Palliative IPP in 16 advanced rectal cancer patients (pts)resulted in significant relief (1-4 months) of narcotic resistant pain (in 70%). Preoperative IPP in 26 locally advanced rectal cancer pts achieved a clinical pathologic complete response (CR) in 2 patients, and significant regression in 11 patients rendering them resectable. Seven pts had R0 pelvic resections,(6 abdominal sacral resection (ABSR) and 1 extended APR).Of 8 other patients, 3 responders refused surgery, 5 were excluded.(medical or disease related ). Median survival was 22.5 months in 15 resectable and 32 mos in 7 resected pts (2 pts were 5 year survivors). This is compared to outcome in 63 patients amenable to having pelvic resection alone: 57% had R0 resection (median OS 36 mos), 28% had R1 resection (med OS = 15 mos) and 15% had R2 resection (med OS 21 mos). Conclusions: Neoadjuvant IPP may facilitate selection of recurrent rectal cancer by identifying therapeutic responders likely to benefit from major pelvic resection and excluding non-responders most likely to benefit from non-surgical therapy. The potential to induce regression and facilitate R0 resection merits further exploration.

Hepatic artery infusion for recurrentor chemoresistant hepatic malignancy

295

Background: Previously treated Hepatic Colorectal Metastases (CRC) and advanced hepato cellular cancer (HCC) are tumor challenges frequently unresponsive to systemic chemo therapy (CT). We reviewed survival outcome in chemo resistant / high risk patients following hepatic artery infusion (HAI) in 21 CRC pts, 10 HCC pts, and 6 miscellaneous metastatic cancers. Methods: Patient groups: 21 CRC pts (16M, 5 F), mean age 63: 16 had metachronous (DFI-17 mos), and 5 Synchronous CA; liver extent: 76% multiple (>5) mets or extensive bilateral; CEA (ng/m), >100, 8 pts > 50 (3 pts) ;< 5 (3 pts),UNK(7 pts). Previous CT:FU/LV (11pts), Oxaliplatin (OX) or Irinotecan (IR) (10 pts). Liver surgery: Partial Resection/RFA – 9 pts. HCC – (9 PTS), cholangioCA(1pt); M/F 5/5; av.age 63yr.. Previous RX Hepatic lobectomy 4 pts, RFA/TACE – 3 patients. Miscellaneous GP (therapy): Hepatic lobectomy + HAI were in metastatic lung (1), Breast (1), advanced gall bladder Ca (GBCA) (T 3-4) (2 pts); HAI alone was done in Br. CA (1) carcinoid (1) Treatment Protocols: CRC: HAI-FUDR 12/15mg/kg/d, dexamethasone 2mg.kg/d, leukovorin (20mg/M2/d) X14 d plus bolus (d1), oxaliplatin OX 130 mg/M2 cisplatin CIS, 100 mg/M2; Systemic RX: d20-30. OX I.V. 130mg/M2, capecitabine 750-1,000 mg/M2/d x 10 days (also used in Miscel. Grp.) HCC Protocol: HAI-14 d as in CRC Protocol. Bolus infusion d1-doxorubicin 75mg/M2or OX or CIS as in CRC schema. Results: CRC:OS-CRC post start HAI = med/16 mos., 2yr/5yr = 27%/6%. HCC OS = 9 mos.( Median); 3->41mos in 9 evaluable pts.; 1 HCC pt with recurrence 2 yr. post hepatectomy survived over 3.5 yrs. with HAI + RFA/TACE – (OS-67mo).Miscellaneous group included lung (11 mos) Br CA (23, 9 mos) adv. Carcinoid (3 mos), GBCA (2 pts > 60 mos), Major Complications; Pump malfunction (4 pts), misperfusion (2) pts, infected pocket (2) pt, duodenal fistula (1) pt. Conclusions: Hepatic artery infusion alternating with systemic chemo therapy has apparent survival benefit in selected patients with persistent or progressive chemo resistant malignancy from metastatic CRC, HCC, or selected miscellaneous cancers (breast, lung, liver, gall bladder cancer) and warrants further study.

Trojan-horse nanotube on-command intracellular drug delivery

A major challenge to nanomaterial-based medicine is the ability to release drugs on-command. Here, we describe an innovative drug delivery system based on carbon nanotubes (CNTs), in which compounds can be released inside cells from within the nanotube "on-command" by inductive heating with an external alternating current or pulsed magnetic field. Without inductive heating the drug remains safely inside the CNTs, showing no toxicity in cell viability tests. Similar to the "Trojan-Horse" in function, we demonstrate the delivery of a combination of chemotherapeutic agents with low aqueous solubility, paclitaxel (Taxol), and C6-ceramide, to multidrug resistant pancreatic cancer cells. Nanotube encapsulation permitted the drugs to be used at a 100-fold lower concentration compared to exogenous treatment yet achieve a comparable ~70% cancer kill rate.

Isolated chemotherapeutic perfusion as neoadjuvant therapy for advanced/unresectable plevic malignancy

e13561

Background: Isolated pelvic perfusion (IPP) may have value in therapy of recurrent pelvic malignancy following previous surgery and chemoradiation. We performed 113 IPP in 78 such pts (34 palliation, and 44 pre op) using a simplified balloon occlusion technique. Methods: Of 42 patients (pts) with recurrent rectal cancer (ca), 26 had preop and 16 had palliative IPP. Other pelvic cancers included anal canal (8 pts), pelvic sarcoma (5 pts), melanoma (M) (4 pts), endometrial ca (EC) 2 pts, ovarian ca (OC) 2 pts, and bladder ca (BC) 1 pt. Chemo agents included Paclitaxel, 5FU, cisplatinum, or Oxaliplatin and mitomycin for epithelial cancer and (Doxorubicin, Ifosamide, Phenyl Alanine Mustard (PAM) for remaining tumors. High dose IPP with PAM, Paclitaxel and Cisplatin was given in 6 pts, 3 with stem cell support. Results: Palliative IPP in advanced rectal cancer (AdRca) pts relieved narcotic resistant pain (2-4 mos) in 11/16 pts (69%). Preop IPP in 26 AdRca achieved path CR in 2 pts and partial regression in 11 pts; 7 had RO resection. Of 5 other pts, 3 refused resection, 2 were inoperable. Median survival was 17 mos in 12 resectable pts and 30 mos in 7 resected pts and 8 mos in 12 non resectable pts. It was 30 months in 8 pts with anorectal ca (1>90 mos), 20 mos in 4 endometrial/ovarian ca pts, (1 died NED >48 mos), 13 mos in 4 M pts and 5 (4-34) mos in 5 pelvic sarcoma pts. Overall 17 of 44 (39%) were resected and 24 were palliated with IPP. Conclusions: IPP has value in palliating or augmenting resectability and survival in advanced pelvic cancer patients not amenable to conventional chemoradiation and surgery.

Predictors for response to cetuximab in a prospective clinical trial (E2303) of patients with head and neck squamous cell carcinoma (HNSCC)

5576

Background: Theidentification of resistance mechanisms to Epidermal Growth Factor Receptor (EGFR) inhibitors remains critical lack in the management of HNSCC. We sought to determine predictors for response to cetuximab in a phase II clinical trial. Methods: 63 patients (pts) with operable stage III/IV HNSCC participated in E2303, an Eastern Cooperative Oncology Group (ECOG) phase II trial of induction chemotherapy with weekly cetuximab, paclitaxel and carboplatin x 6 followed by chemoradiotherapy with the same regimen. A tissue microarray was constructed and EGFR, ERK1/2, Met, pAkt and STAT protein expression levels were assessed using AQUA. The objectives of analysis were to determine association of biomarkers with E2303 efficacy outcomes (best objective response (OR), overall survival (OS), progression-free survival (PFS), and event-free survival (EFS)). The logistic regression model was used to examine relationship between marker measurements (on a continuous scale) and OR. The univariate and multivariate Cox proportional hazards models were used to evaluate the relationship between markers and event-time distributions. Fisher’s exact test was used to evaluate differences in response rate between groups (high vs. low AQUA scores). Event-time distributions were estimated by the Kaplan-Meier method and compared by the log-rank test. Results: Cytoplasmic ERK1/2 levels weresignificantly associated with PFS and OS (p=0.03 and 0.01, respectively). Nuclear ERK1/2 levels were significantly associated with OS (p=0.02) and tended towards significance for PFS (p=0.09). The multivariate Cox regression analysis shows that cytoplasmic and nuclear ERK1/2 are significantly associated with OS and PFS after controlling for primary site and disease stage, respectively There was no significant association between cytoplasmic or nuclear ERK1/2 status and OR (p-values 0.98 and 0.41, respectively).No association was found between expression of any of other biomarkers and outcome measures. Our data analysis was based on 35 pts with marker data available. Conclusions: Ras/MAPK/ERKpathway may be associated with resistance to cetuximab in HNSCC.

Factors predictive of the status of sentinel lymph nodes in melanoma patients from a large multicenter database

BACKGROUND

Numerous predictive factors for cutaneous melanoma metastases to sentinel lymph nodes have been identified; however, few have been found to be reproducibly significant. This study investigated the significance of factors for predicting regional nodal disease in cutaneous melanoma using a large multicenter database.

METHODS

Seventeen institutions submitted retrospective and prospective data on 3463 patients undergoing sentinel lymph node (SLN) biopsy for primary melanoma. Multiple demographic and tumor factors were analyzed for correlation with a positive SLN. Univariate and multivariate statistical analyses were performed.

RESULTS

Of 3445 analyzable patients, 561 (16.3%) had a positive SLN biopsy. In multivariate analysis of 1526 patients with complete records for 10 variables, increasing Breslow thickness, lymphovascular invasion, ulceration, younger age, the absence of regression, and tumor location on the trunk were statistically significant predictors of a positive SLN.

CONCLUSIONS

These results confirm the predictive significance of the well-established variables of Breslow thickness, ulceration, age, and location, as well as consistently reported but less well-established variables such as lymphovascular invasion. In addition, the presence of regression was associated with a lower likelihood of a positive SLN. Consideration of multiple tumor parameters should influence the decision for SLN biopsy and the estimation of nodal metastatic disease risk.

Abstract 4767: C6 ceramide sensitizes multiple aggressive pancreatic cancer cell lines to gemcitabine, paclitaxel and cetuximab mediated anti tumor effects in vivo and in vitro

Introduction: Pancreatic adenocarcinoma continues to be a highly lethal malignancy (5 yr survival 5%) poorly responsive to all chemo radiation therapies, with only modest improvement with Gemcitabine the current “main line” drug. We have previously demonstrated the C6 Ceramide chemo enhancement of Gemcitabine and other pancreatic chemo agents. The current study explores the mechanism of C6 Ceramide effects on pancreatic chemo resistance pathways – pro-survival and ras-signaling in pancreatic cancer cells. Methods: In vivo: 2-3 month SCID male mice with pancreatic (pan) tumor implants (2 × 106 L3.6 cells) received intraperitoneal (I.P.) injections (3x/wk) of Paclitaxel (Pax) (3.0mg/gm), Gemcitabine (Gem, 10mg/gm) with/without C6 ceramide (10mg/ml) and were observed 6 weeks and tumor response/survival recorded. In vitro: Drug dose Pax 3 ug/ml, Gem 3 ug/ml, C6 Ceramide 10 ug/ml. The MTT anti tumor response was measured in 3 pancreatic lines L3.6, PANC-1, and MIA (Kras mutated). Signaling activation by Western blot utilized antibodies: LY294002, and Wortmannin to block PI3K/AKT pathway, U0126 and PD 98059 to block ERK pathway and Rapamycin to block mTORC1 pathway. Results: Combined therapy with C6 Ceramide induced significant inhibition of exponential tumor growth and prolonged survival by Gem and Pax. Administration of Gem or Pax with C6 Ceramide induced a significant increase in cell death and apoptosis in pancreatic cancer cells (L3.6, PANC-1 and MIA PaCa-2) which were associated with inhibiting perturbations of cell signaling pathways including pro-survival PI3K/Akt/mTOR, and ERK/MAPK, Ras signaling pathways. Pharmacological inhibition with specific signaling pathway inhibitors enhanced cytotoxicity by Gem or Pax, suggesting that survival pathway inhibition might be the key mechanism contributing to C6 Ceramide synergism of Pax or Gem anti-tumor effects. We also showed C6 ceramide potentiation of Cetuximab anti tumor effects on Kras mutant MIA cells thus overcoming (EGFR mAb) resistance by inhibiting pro-survival PI3K/AKT/mTOR pathways and bypassing K-RAS mutant Ras-ERK pathways. Conclusion: C6 Ceramide an apoptosis signal potentiates the anti tumor effects of chemo agents Gemcitabine and Paclitaxel and the biologic EGFR Inhibitor Cetuximab against 3 aggressive pancreatic cancer cell lines by apparent inhibition of the pro-survival PI3K/AKT/mTOR pathways and the Kras mutated ERK/MAPK pathway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4767. doi:10.1158/1538-7445.AM2011-4767

The neoadjuvant therapy of colorectal hepatic metastases and the role of biologic sensitizing and resistance factors

Liver metastasis represents a common systemic complication of colorectal cancers (CRCs). Partial liver resection has been demonstrated to result in long-term survival in certain well-selected patients with otherwise well-controlled systemic disease. Neoadjuvant therapy has been demonstrated to result in improved resectability and potentially longer survival in patients with liver metastases from CRC. The addition of biologic agents to chemotherapy has been shown to improve response rates and overall survival in patients with metastatic CRC. Here, we are discussing the role of biologic agents in the treatment of patients with liver metastases from CRC. We also discuss the role of biomarkers for response and resistance to such novel therapies.

Concurrent chemoradiotherapy with weekly paclitaxel and carboplatin for locally advanced head and neck cancer: Long-term follow-up of a Brown University Oncology Group Phase II Study (HN-53)

BACKGROUND

A phase II study was conducted using concurrent paclitaxel, carboplatin, and external beam radiotherapy (RT) in patients with advanced head and neck cancer.

METHODS

Forty-three patients (stage III, n = 12; stage IV, n = 31) were treated with 8 cycles of weekly paclitaxel (60 mg/m(2)), carboplatin (area under the curve [AUC] = 1), and RT (1.8 Gy daily; total dose, 66-72 Gy). Patients with initially palpable lymph nodes underwent neck dissection.

RESULTS

The overall clinical response rate was 91% (65% complete, 26% partial). Severe mucositis occurred in 37 (90%) patients, necessitating hospitalization in 13 (31%) patients. With a median follow-up of 49 months, the locoregional and distant failure rates were 26% and 21%, respectively.

CONCLUSIONS

Concurrent paclitaxel, carboplatin, and RT for advanced head and neck cancer results in high complete response rates. Long-term follow-up has revealed the curative potential of this regimen, though the doses used resulted in unacceptable toxicity.

Targeting growth factors and angiogenesis; using small molecules in malignancy

Targeted biologic therapy for cancer has evolved from the laboratory to active clinical protocols and applied clinical practice in selected patients. Major targets include epidermal growth factor, and vascular endothelial growth factor receptors which are commonly expressed in gastro-intestinal cancers head & neck and lung cancers, and to some degree breast and gynecologic malignancy. Down stream signal transduction pathway inhibition of B-raf and N-ras mutations are examined in melanoma. New approaches involving re-packaging of chemotherapeutic agents are being exemplified in the nanoparticle formulation of paclitaxel which provides increased access to endothelial and tumor cells with potential enhanced therapeutic efficacy compared to the conventional version solubilized in a cremophor.

Changing gastric cancer treatment in the United States and the pursuit of quality

The low incidence of gastric cancer in the US presents various quality challenges. For most US practitioners, individual experience is inadequate. Accrual to clinical trials testing new treatments can be daunting. However, through the use of nationally available clinical trials sponsored by many trial groups working in concert, and the use of national registries for treatment and outcome surveillance, a path to increased gastric cancer survival has been charted. Moreover, systems for continuous quality improvement at the institutional level are in place. Quality assurance is an increasing concern of both private and governmental groups. In this article, we summarize recent national US clinical trial findings concerning gastric cancer treatment, highlight national assessment systems for cancer outcomes, and describe what these systems tell us about the current status of gastric cancer care in the US, highlighting challenges and areas for potential improvement.

Isolated pelvic perfusion: plasma pharmacokinetics depend primarily on drug dosage and not the type of drug

PURPOSE

Comparison of the pharmacokinetics of four drugs with the isolated pelvic perfusion protocol showed linear relationships between drug dosage and two isolated pelvic plasma parameters, mean AUC (pelvic exposure, microM min) and the mean maximum pelvic drug level (microM). It appears that the pharmacokinetics are sufficiently defined as to predict plasma distribution curves for an additional drug with this protocol. Recent FDA approval of oxaliplatin allowed an evaluation of this premise.

METHODS

Linearity of drug dosage with maximum drug levels and exposure (AUC) in the isolated pelvic plasma yields initial estimates of these parameters for additional drugs. Use of an empirical, four-compartment pharmacokinetic model (Wanebo and Belliveau in Cancer Chemother. Pharmacol. 43:427, 1999) allowed the generation of predictive plasma distribution curves. These curves were established by optimizing the initial estimates of maximum drug levels and exposure along with estimates of two additional parameters (half-life of pelvic clearance and pelvic to systemic exposure ratio) from experimental data of the four drugs pharmacokinetically characterized.

RESULTS

Calculated plasma distribution curves for oxaliplatin matched the experimental curves from the first three patients receiving oxaliplatin therapy, given the experimental ranges of pharmacokinetic parameters seen with the initial four drugs.

CONCLUSION

These results give an overall picture for the plasma pharmacokinetics during the isolation period for the isolated pelvic perfusion protocol. Enough experimental data have been accumulated for five drugs to establish a simple pharmacokinetic model (Wanebo and Belliveau in Cancer Chemother Pharmacol 43:427, 1999) and interdrug relationships (i.e., this report) which can be used to predict reasonable plasma distribution curves for additional drugs with this protocol.

Laparoscopic cholecystectomy: its effect on the prognosis of patients with gallbladder cancer

Numerous reports suggest more recurrences and a worse prognosis after laparoscopic cholecystectomy (LC) than after open cholecystectomy (OC). The objective of this study was to compare the survival rate of patients undergoing a laparoscopic procedure versus those undergoing an open operation. A series of 24 patients with gallbladder cancer detected after LC were compared with 40 consecutive patients with gallbladder cancer detected after OC. Patients were matched by wall invasion, age, and whether they underwent a reoperation or only cholecystectomy. The series included 2 patients with in situ tumors, 2 with mucosal tumors, 1 with muscular invasion, 13 with subserosal invasion, and 6 with serosal invasion. Recurrences were observed in 4 of the 10 patients with subserosal compromise who underwent reoperation. In contrast, in the OC group of 26 patients with subserosal invasion, 20 of whom were reoperated, only 2 had a recurrence. Of the six patients with serosal infiltration, three in the LC underwent reoperation, all of whom had recurrences that precluded resection. Of the 12 patients in the OC group who presented with serosal invasion, 6 were reoperated and 4 had a recurrence. Overall survival curves did not show differences when patients were compared according to the type of procedure performed. Similarly, the analysis of patients according to the level of wall invasion indicated that there was no significant difference in survival. Although multiple reports have shown a worse prognosis for patients with gallbladder cancer undergoing LC, this study did not show a significant survival difference between the two methods. Although there is a higher but insignificant recurrence rate among the patients who underwent LC, this is not translated into survival.

An effective in vitro antitumor response against human pancreatic carcinoma with paclitaxel and daunorubicin by induction of both necrosis and apoptosis

The highly metastatic human pancreatic cell line L3.6 was used to study mechanisms for antitumor activity with various chemotherapeutic drug combinations. The most effective drugs were daunorubicin (IC50 0.4 microM), doxorubicin (IC50 22 microM), paclitaxel (IC50 5.3 microM) and 5-fluorouracil (IC50 5.4 microM). The most effective drug combination was equitoxic concentrations of paclitaxel and daunorubicin. Kinetic analysis demonstrated that both paclitaxel and daunorubicin had to be added simultaneously for maximum cytotoxicity. Daunorubicin treatment alone demonstrated ROS (reactive oxygen species) induction and cellular morphological changes more consistent with chemical damage in a total of 93% of the cells and apoptotic changes in 20% of the cell population. The apoptosis induced by daunorubicin does not appear to be caspase-dependent, as demonstrated by the lack of conversion of the procaspases 8 and 3. Within 24 h of treatment with paclitaxel, Bcl-2 formed a doublet at 26 kilodaltons and the expression was abrogated with daunorubicin and the combination of the two drugs as determined by Western blots. These data suggest that the human pancreatic cell line L3.6 is more effectively killed following treatment with chemotherapeutic agents that cause death through at least two pathways, a caspase-dependent and caspase-independent apoptosis and necrosis.

Phase II study of external irradiation and weekly paclitaxel for nonmetastatic, unresectable pancreatic cancer: RTOG-98-12

Unresectable cancer of the pancreas was treated with the combination of weekly paclitaxel and external beam irradiation in an effort to improve palliation and extend life expectancy. One hundred twenty-two patients were entered in a multicentered protocol. Thirteen patients were either ineligible, cancelled, or had delinquent data, thus providing 109 for analysis. Unresectable cancer was based on imaging studies (computed tomography or magnetic resonance imaging), all had histologic proof of adenocarcinoma, and none had evidence of metastatic disease or peritoneal seeding. Image-guided radiotherapy treatment consisted of 50.4 Gy in 28 fractions over 5.5 weeks with coplanar anterior/posterior and lateral ports. An initial dose of 45 Gy was given to fields covering the primary tumor plus the regional peripancreatic, celiac, and porta hepatis lymph nodes. A cone down field was used for the last three fractions to encompass the gross tumor volume with a 1- to 1.5-cm margin. Paclitaxel was administered weekly with irradiation in a dosage of 50 mg/m2 as a 3-hour infusion. The median age was 63 and 53% were female. The Karnofsky performance status was greater than or equal to 80 in 81%. Eighty percent were classified T3 or 4; 20% had N1 disease. The primary tumor was located in the pancreatic head in 65%. Eighty-five percent received all six cycles of paclitaxel per protocol, whereas 93% received irradiation with acceptable protocol variation. Field placement, total dose, fractionation, and overall treatment time were given per protocol in greater than or equal to 90%. Acute toxicity (worst per patient) occurred in 39% with grade III (35% of these were asymptomatic neutropenia), 5% with grade IV, and one patient died of infection during the fourth cycle of chemotherapy (grade V). The median follow-up time for alive patients is 20.6 months (range 5-30). The median survival is 11.2 months (95% CI 10.1, 12.3) with estimated 1- and 2-year survivals of 43% and 13%, respectively. External irradiation plus concurrent weekly paclitaxel is well tolerated when given with large-field radiotherapy. The median survival is better than historical results achieved with irradiation and fluoropyrimidines. These data provide the basis for a new Radiation Therapy Oncology Group trial using paclitaxel and irradiation combined with a second radiation sensitizer, gemcitabine, now under way.

Isolated chemotherapeutic perfusion of the pelvis for advanced rectal cancer

OBJECTIVE

Isolated pelvic perfusion exposes tissue to high doses of drug without the toxicity of high-dose systemic therapy and may benefit patients with advanced malignancy.

PATIENTS AND METHODS

There were 32 patients with locally advanced, previously irradiated cancer of the rectum and 5 patients with anal canal cancer. These patients underwent a total of 65 isolated pelvic perfusions using 5-Fu (1500 mg/m2) for 60 min; cisplatinum (100 mg/m2) and mitomycin (10-20 mg/m2) were added to some perfusions. Hospital stay averaged 3-5 days.

RESULTS

Palliative perfusion in 15 patients with advanced rectal cancer resulted in symptomatic relief from 1 to 4 months in 11 of 14 with pelvic pain and limited benefit in 6 patients with mass, but no pain. Pre-operative perfusion in 16 rectal cancer patients achieved a complete response (no tumour in pelvis) in 1 patient and significant tumour regression in 8 patients rendering them potentially resectable. Five were resected with clear margins. Three patients with recurrent epidermoid cancer had significant tumour regression and were resected with clear margins.

CONCLUSION

Isolated chemotherapeutic perfusion of the pelvis provides excellent palliation for patients with advanced or pelvic recurrence of rectal cancer or epidermoid cancer of anorectum and may potentiate resection in selected patients.

Mucosal melanomas

Cutaneous malignant melanoma is a common malignancy and has been increasing at an alarming rate in the United States. Sun exposure is a well-known risk factor related to this disease and much is understood regarding the etiology and epidemiology of cutaneous melanomas. In contrast, primary mucosal melanomas represent an extremely rare malignancy and do not have the same risk factors or behavior patterns. They occur in areas that have no sun exposure and solid predisposing risk factors have not been identified, making this disease very difficult to diagnose or screen for. It is usually diagnosed at a later stage and carries a poor prognosis. Identifying the differences between a primary lesion and a metastatic melanoma is often challenging, because of the lack of definitive criteria, both pathologically and clinically. The rich vascular and lymphatic network surrounding these lesions may be responsible for their aggressive behavior and poor prognosis. In addition, the obscure locations where mucosal melanomas occur are an obvious reason why these lesions often go unnoticed until symptoms develop. Recent literature has raised significant questions regarding recommended treatment strategies. Earlier reports advocated radical surgery as the mainstay of therapy; however, local recurrence and survival were unchanged whether radical surgery or local excision was performed, and the most recent data are favoring the conservative approach when appropriate. Unfortunately, a multitude of adjuvant therapies have been tried without any success. Adjuvant radiotherapy plays a role when combined with surgery, particularly in the head and neck region and female genitalia, but this is reserved for nodal and locoregionally advanced disease and has had no effect when used as a prophylactic method. It is difficult to make significant advances in treatment strategies because of the rarity of the disease. As an example, one in 75 persons born in the year 2000 will develop cutaneous melanoma in his lifetime, compared with four cases per ten million people diagnosed with mucosal melanoma per year in the United States. Possible new therapies based on new biologic and immunologic findings may have future promise on being able to impact this disease. Until then, this aggressive tumor continues to have a poor prognosis, and surgical resection continues to be the mainstay of primary therapy.

Synergistic effect of interleukin-2 and a vaccine of irradiated melanoma cells transfected to secrete staphylococcal enterotoxin A

We have previously reported that immunization of mice with melanoma cells transfected to secrete the superantigen, Staphylococcal enterotoxin A (SEA), increased the production of antibodies to the B700 melanoma antigen, stimulated the production of endogenous interleukin 2 (IL-2), activated the expression of CD4, CD8 and CD25 T cell markers and enhanced NK cell activity. Now we show that immunization of mice with a vaccine of irradiated sea-transfected melanoma cells coupled with IL-2 therapy was even more effective in inhibiting the growth of primary melanoma tumors and the development of lung metastases than was the irradiated melanoma cell vaccine alone or IL-2 alone. The morphological and immunological effectiveness of the therapy was dose-dependent on IL-2.

Capacity of murine IL-12 to inhibit the development of primary melanoma tumors and to prevent lung metastases in the melanoma-challenged mice

Interleukin-12 (IL-12) has the capacity to activate cytotoxic lymphocytes, stimulate natural killer cells, induce the production of INF-gamma, and be synergistic with IL-2. We have evaluated this cytokine in an experimental model for metastatic melanoma that approximates the major clinical stages of metastatic dissemination. To develop primary melanoma tumors, mice were injected subcutaneously with 5 x 10(5) cells in a volume of 25 microliters into the middle of the tail (11). In a month, mice were started to be treated for 4 weeks with recombinant murine IL-12 (R mIL-12) at the following doses: 0, 0.5, 2.5, 5.0, 15.0, and 50 micrograms/kg. Diameters of the primary melanoma tumors were measured at weekly intervals. At the end of 13 weeks (9 weeks from the start of treatment with R mIL-12), all surviving mice were sacrificed. Pathological examination of lung metastases (macroscopy) was done with all dead or sacrificed mice. Treatment of mice bearing melanoma at a dose of 300 ng/mouse (15 micrograms/kg) inhibited development of primary tumors in 40% of mice. The primary tumor diameters were significantly lower in the group treated with 300 ng/mouse (15 micrograms/kg) in comparison to controls. At the end of the observation period, groups treated with 0.5, 2.5, 15.0, and 50 micrograms/kg had mean primary tumor diameters smaller than the control group. Evaluation of IL-12 therapy on primary tumor growth, mean diameters of primary tumors, survival rate, and development of lung metastases showed that the best results were observed using 300 ng/mouse (15 micrograms/kg) R mIL-12.

Changing patterns of failure of head and neck cancer

BACKGROUND

With the increased use of neoadjuvant therapy for advanced stage squamous cell carcinoma of the head and neck, we have observed an apparent change in the pattern of failure from predominantly locoregional sites to distant metastases. We reviewed the patterns of failure in cancers of the oral cavity, oropharynx, and larynx at our institution during the last decade.

OBJECTIVE

To determine whether there has been a significant change in the patterns of recurrence from the historical locoregional failure to distant sites, and whether this change is associated with the increased use of multimodality therapy.

METHODS

We reviewed cancer registry data on patients with squamous cell carcinoma of the head and neck diagnosed between January 1, 1988, and December 31, 1999. Sites included the oral cavity and oropharynx (including the tongue, floor of mouth, retromolar trigone, gingiva, tonsil, and lip) and larynx.

RESULTS

Among 432 patients with squamous cell carcinoma of the head and neck, 280 (65%) had oral cavity and oropharyngeal cancers, and 152 (35%) had laryngeal cancers. Overall, 19% developed locoregional recurrence, and 8% developed distant failure. Although locoregional failure for oral cavity and oropharyngeal squamous cell carcinoma decreased from 26% to 16% from 1988-1993 to 1994-1999, distant failure increased significantly from 3% to 8%. During these periods, multimodality therapy was used in 62% of oral cavity and oropharyngeal cancers, and this rate remained essentially unchanged. For laryngeal cancer, locoregional and distant failure remained stable at 18% and 9%, respectively. In these laryngeal cancers, the use of multimodality therapy decreased from 60% to 46%, but this difference was not statistically significant (P =.43).

CONCLUSIONS

Although locoregional control in oral cavity and oropharyngeal cancers has improved significantly with the use of multimodality therapy, the incidence of distant failure has doubled. In laryngeal squamous cell carcinoma, the patterns of failure have not changed significantly.

Paclitaxel, cisplatin, and concurrent radiation for esophageal cancer

Paclitaxel is an active agent for adenocarcinomas and squamous cell carcinomas of the esophagus and is a radiation sensitizer. We sought to investigate the toxicity and complete response rate of paclitaxel, cisplatin, and concurrent radiation for esophageal cancer. Forty-one patients with esophageal cancer were studied, 29 with adenocarcinomas and 12 with squamous cell cancers. Twelve patients had tumor extension into the proximal stomach and/or abdominal adenopathy. Patients received paclitaxel 60 mg/m2 by 3-hour intravenous (i.v.) infusion, and cisplatin 25 mg/m2 weekly on days 1, 8, 15, and 22. Radiation was administered concurrently to a total dose of 39.60 Gy, in 1.80 Gy fractions, for 22 treatments. Patients with medical or surgical contraindications to esophagectomy received 2 additional weeks of paclitaxel with a radiation boost to 50.4 Gy. Neutropenia was the most common grade 3/4 toxicity occurring in 10 patients (24%). Only 2 patients (5%) had grade 4 esophagitis requiring parenteral nutrition. Twelve patients (29%) obtained a complete response. The 2-year progression-free and overall survival rates were 40% and 42%, respectively. Esophagitis was less severe than expected and prophylactic enteral feeding tubes were not necessary. Additional effective systemic treatments are needed to reduce the development of distant metastases.

Long-term results of a prospective surgical trial comparing 2 cm vs. 4 cm excision margins for 740 patients with 1-4 mm melanomas

BACKGROUND

The Intergroup Melanoma Surgical Trial began in 1983 to examine the optimal surgical margins of excision for primary melanomas of intermediate thickness (i.e., 1-4 mm). There is now a median 10-year follow-up.

METHODS

There were two cohorts entered into a prospective multi-institutional trial: (1) 468 patients with melanomas on the trunk or proximal extremity who randomly received a 2 cm or 4 cm radial excision margin and (2) 272 patients with melanomas on the head, neck, or distal extremities who received a 2 cm radial excision margin.

RESULTS

A local recurrence (LR) was associated with a high mortality rate, with a 5-year survival rate of only 9% (as a first relapse) or 11% (anytime) compared with an 86% survival for those patients who did not have a LR (P < .0001). The 10-year survival for all patients with a LR was 5%. The 10-year survival rates were not significantly different when comparing 2 cm vs. 4 cm margins of excision (70% vs. 77%) or comparing the management of the regional lymph nodes (observation vs. elective node dissection). The incidences of LR were the same for patients having a 2 cm vs. 4 cm excision margin regardless of whether the comparisons were made as first relapse (0.4% vs. 0.9%) or at anytime (2.1% vs. 2.6%). When analyzed by anatomic site, the LR rates were 1.1% for melanomas arising on the proximal extremity, 3.1% for the trunk, 5.3% for the distal extremities, and 9.4% for the head and neck. The most profound influence on LR rates was the presence or absence of ulceration; it was 6.6% vs. 1.1% in the randomized group involving the trunk and proximal extremity and was 16.2% vs. 2.1% in the non-randomized group involving the distal extremity and head and neck (P < .001). A multivariate (Cox) regression analysis showed that ulceration was an adverse and independent factor (P = .0001) as was head and neck melanoma site (P = .01), while the remaining factors were not significant (all with P > .12).

CONCLUSION

For this group of melanoma patients, a local recurrence is associated with a high mortality rate, a 2-cm margin of excision is safe and ulceration of the primary melanoma is the most significant prognostic factor heralding an increased risk for a local recurrence.

Thin < or = 1 mm level III and IV melanomas are higher risk lesions for regional failure and warrant sentinel lymph node biopsy

BACKGROUND

Thin melanomas have become increasingly prevalent, and lesions 1 mm or less in thickness are frequently diagnosed. They are considered highly curable when treated with wide local excision alone with reported 5-year disease free survivals of 95% to 98%. However, thin Clark level III and IV melanomas may have an increased potential for metastasizing and late recurrence because of dermal lymphatics located at the interface of the papillary and reticular dermis. We have addressed this controversial area by reviewing the outcomes of patients with invasive thin (< or = 1.0 mm thick) melanomas.

METHODS

We reviewed 415 invasive melanomas from 1983-1995 in the Rhode Island tumor registries which kept records of both tumor thickness and Clark levels. Sixty-eight (16.4%) of the 415 invasive melanomas were thin (< or = 1.0 mm in thickness) and were treated by wide local excision only. In situ lesions were excluded. Thirty-eight (56%) of the 68 thin melanomas were either Clark level III or IV.

RESULTS

Seven (18.4%) of the 38 level III and IV thin melanomas had a recurrence at a minimum follow-up of 36 months. Median time to recurrence was 52 months, and the average measured depth of tumor thickness was 0.84 mm. Only one (3.3%) of 30 level II melanomas recurred (P < .05).

CONCLUSIONS

Thin level III and IV melanomas are at increased risk for late recurrence when compared with all thin melanomas. Because there is effective adjuvant therapy with alpha interferon for patients with stage III melanoma to treat regional and systemic disease, and because sentinel lymph node biopsy (SLNB) offers minimal morbidity, we suggest using SLNB to accurately stage and treat all patients with thin melanoma that are high Clark levels that are at increased risk for metastases.

Long-term results of a multi-institutional randomized trial comparing prognostic factors and surgical results for intermediate thickness melanomas (1.0 to 4.0 mm). Intergroup Melanoma Surgical Trial

BACKGROUND

Ten- to 15-year survival results were analyzed from a prospective multi-institutional randomized surgical trial that involved 740 stages I and II melanoma patients with intermediate thickness melanomas (1.0 to 4.0 mm) and compared elective (immediate) lymph node dissection (ELND) with clinical observation of the lymph nodes as well as prognostic factors that independently predict outcomes.

METHODS

Eligible patients were stratified according to tumor thickness, anatomical site, and ulceration, and then prerandomized to either ELND or nodal observation. By using Cox stepwise multivariate regression analysis, the independent predictors of outcome were tumor thickness (P < .001), the presence of tumor ulceration (P < .001), trunk site (P = .003), and patient age more than 60 years (P = .01).

RESULTS

Overall 10-year survival was not significantly different for patients who received ELND or nodal observation (77% vs. 73%; P = .12). Among the prospectively stratified subgroups of patients, 10-year survival rates favored those patients with ELND, with a 30% reduction in mortality rate for the 543 patients with nonulcerated melanomas (84% vs. 77%; P = .03), a 30% reduction in mortality rate for the 446 patients with tumor thickness of 1.0 to 2.0 mm (86% vs. 80%; P = .03), and a 27% reduction in mortality rate for 385 patients with limb melanomas (84% vs. 78%; P = .05). Of these subgroups, the presence or absence of ulceration should be the key factor for making treatment recommendations with regard to ELND for patients with intermediate thickness melanomas.

CONCLUSIONS

These long-term survival rates from patients treated at 77 institutions demonstrate that ulceration and tumor thickness are dominant predictive factors that should be used in the staging of stages I and II melanomas, and confer a survival advantage for these subgroups of prospectively defined melanoma patients.

Paclitaxel and concurrent radiation for gastric cancer

PURPOSE

To determine the activity and toxicity of paclitaxel and concurrent radiation for gastric cancer.

METHODS AND MATERIALS

Twenty-seven patients were studied. Twenty-five had proximal gastric cancers, two had distal cancers. Eight had esophageal extension, 6 had celiac adenopathy, and 7 had retroperitoneal adenopathy. Patients received paclitaxel, 50 mg/m(2) by 3-hour intravenous (IV) infusion, weekly, on days 1, 8, 15, 22, and 29. Radiation was administered concurrently to a total dose of 45.0 Gy, in 1.80 Gy fractions, for 25 treatments. Patients who were medically or surgically inoperable received a sixth week of paclitaxel with a radiation boost to 50.4 Gy.

RESULTS

Esophagitis and gastritis were the most important toxicities, Grade 3 in four patients (15%), and Grade 4 in three patients (11%). Five patients (19%) had Grade 3 nausea. The overall response rate was 56%, including three patients (11%) with a complete response. The 2-year progression-free and overall survival rates were 29% and 31%, respectively.

CONCLUSION

Concurrent paclitaxel and radiation demonstrates substantial local-regional activity in gastric cancer. Future investigations combining paclitaxel and radiation with other local-regional and systemic treatments are warranted.