Case report: Diagnosis of NUT carcinoma of hepatic origin by next-generation sequencing

NUT carcinoma is a rare subcategory of squamous cell carcinoma. The latter is primarily characterized by the fusion of the coding sequence NUTM1 on chromosome 15q14 with BRD4 or BRD3, both of which are acetyl-histone binding bromodomains. This tumor is often misdiagnosed due to its rarity and its histological similarity with other squamous cell carcinomas. It typically presents as a poorly differentiated squamous cell carcinoma in the head, neck, and mediastinal region, and has no distinct clinical characteristics that set it apart from other malignancies. Although uncommon, other NUT carcinomas have been reported in the literature outside of the midline region. Through next-generation sequencing, we were able to correctly diagnose our patient with the first-documented case of NUT carcinoma of hepatic-only origin.

Prognostic indicators of KRAS G12X mutations in pancreatic cancer

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Background: We have studied the role of KRAS mutations in relation to the prognosis in patients with advanced pancreatic ductal adenocarcinoma (PDAC). KRAS is a well-described oncogenic driver in PDAC, with mutations identified in over 90% of cases, typically involving codon 12. The three predominant missense variants include G12D, G12V and G12R. PDAC has the highest rate of G12R mutations compared to other malignancies, comprising 15-20% of KRAS-mutated tumors. This study presents a new finding in the progression of advanced PDAC utilizing a large clinical and genomic database to further characterize the clinical features of pathogenic KRAS variants in PDAC with a focus on G12R. Methods: PDAC samples were tested using whole transcriptome sequencing (WTS; Illumina NovaSeq) and NextGen DNA sequencing (NextSeq, 592 Genes and NovaSEQ, WES) at Caris Life Sciences (Phoenix, AZ). Transcriptomic signatures including MPAS (MAPK activation score), T-cell inflamed score and tumor micro environment (TME) characterization were calculated on WTS data. Significance was determined by X2 and Fisher-Exact and p adjusted for multiple comparisons (q) was < 0.05 (Benjamini-Hochberg). Real-world overall survival (rwOS) was obtained from insurance claims data and calculated from tissue collection to last contact; time-on-treatment (TOT) was calculated from start to finish of specific treatments; comparison was done by Kaplan-Meier test. Results: A total of 5,555 patients with PDAC harboring either KRAS G12D (n = 2,671), G12V (n = 1,871) G12R (n = 904) or G12C (n = 109) variants were identified. The patients with KRAS G12R mutant tumors had significantly longer median real-world overall survival (mRWOS) compared to G12D (452 vs 358 days, HR 0.82, CI 0.74 – 0.9, p < 0.0001). This difference persisted regardless of treatment with FOLFIRINOX or gemcitabine plus nab-paclitaxel. There was no difference in outcomesbetween patients with KRAS G12R, G12V or G12C. PD-L1 expression was significantly lower in G12R than in G12C or G12D (13% vs 27% vs 19%,) while the prevalence of TMB-H and dMMR was comparable across isoforms. Conclusions: Patients with KRAS G12R variants has improved rwOS compared to G12D irrespective of the chemotherapy regimen administered. Immune profiling suggested that the immune contexture in G12R-driven tumors are distinct from G12D as reflected by reduced PDL1 staining, decreased levels of multiple checkpoint receptors. We aim to further explore the molecular basis for these differences with a focus on PI3K and MAPK pathways. Based on this data, survivorship studies in patients with advanced PDAC should consider reporting KRAS mutational status.

Cobimetinib Plus Gemcitabine: An Active Combination in KRAS G12R-Mutated Pancreatic Ductal Adenocarcinoma Patients in Previously Treated and Failed Multiple Chemotherapies

Purpose: The KRAS proto-oncogene is involved in the RAS/MAPK pathway. KRAS is present in the wild type or mutated forms. The oncogene KRAS is frequently mutated in various cancers. At the time that amino acid glycine is mutated, KRAS protein acquires oncogenic properties that result in the tumor cell growth, proliferation, and cancer progression. There has been limited understanding of the different mutations at codon 12. The consequences of such mutations is not fully understood. Various G12X mutations in pancreatic cancer patients have been examined, with the most common mutations being G12D (40%), G12V (30%), and G12R (15-20%). Now we are understanding that G12X mutations in the KRAS are not all equal. Methods: In a single-arm exploratory study, we accrued 13 KRAS-G12X-mutated pancreatic patients (KRAS G12D, G12V, and G12R). They were divided into two groups: group 1 consisted of seven patients with G12D and G12V and group 2 included six patients with the KRAS G12R mutation. All patients were treated with the combination of gemcitabine at 1250 mg/m² intravenous weekly for 3 weeks and oral cobimetinib 20 mg b.i.d. for 3 weeks. This was followed by a week of rest before the initiation of the next cycle. Results: In the first cohort, seven patients were on treatment, all of whom progressed and died within the 2 months of the study. In the second cohort, one of six patients achieved partial response, and five achieved stable disease. Median progression-free survival was 6 months (9% confidence interval 3.0-9.3 months) and overall survival has been reached at 8 months. Common adverse reactions included rash, fatigue, nausea, and vomiting (grades 2 and 3). Cancer antigen CA19-9 decreased by >50% in all group 2 patients. Conclusion: Our pancreatic cancer patients were heavily pretreated (all had received FOLFIRINOX and gemcitabine/nab-paclitaxel) before the entry into our trial. Upon entry into our trial, all patients were treated with the combination of gemcitabine and oral cobimetinib. Therefore, this constituted the second exposure of the patients to gemcitabine. This study illustrates a new discovery, which can potentially target 15-20% of pancreatic cancer patients and allow for a significant improvement in their prognosis. We will be conducting randomized phase II trials to substantiate our findings.

Pancreatic cancer presenting as bowel obstruction and role of next generation sequencing: A case report

Introduction and importance

Pancreatic adenocarcinoma is one of the leading causes of death. Presentation with colonic metastases is far less frequently reported in the literature and may be misdiagnosed as colonic adenocarcinoma. We report the case of a female patient with metastatic pancreatic adenocarcinoma that presented with a sigmoid obstruction.

Case presentation

A 66-year-old female presented with constipation and abdominal pain. She was found to have an obstructing sigmoid colon lesion, multiple metastatic lesions in the liver, and a pancreatic tail lesion. She underwent left hemicolectomy and ostomy placement. The gross pathology of the colon and needle biopsy of the liver was consistent of pancreatobiliary origin. Genomic screening performed, patient found to be KRAS G12R mutated. She was given one cycle of chemotherapy, thereafter was referred to hospice care.

Clinical discussion

Primary metastatic pancreatic cancer is now the 2nd most diagnosed cancer in the United States after lung cancer. The prognosis for the malignancy is poor, patients are usually diagnosed late at the time that the tumor has metastasized to other organs. Colonic metastasis is a rarely seen and far less frequently reported in the literature. Next-generation-sequencing was performed at baseline to further characterize her tumor for any actionable mutations.

Conclusion

Pancreatic adenocarcinoma is an aggressive malignancy with a poor prognosis. Next-generation-sequencing may offer targeted therapy if an actionable mutation is present such as our patient's, however due to late diagnosis, rapid clinical deterioration, and next-generation sequencing delay we were unable to alter the patient's outcome.

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Colonic obstruction is a rare presentation of metastatic pancreatic adenocarcinoma.

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Next-generation sequencing may offer therapies if patient has a targetable mutation.

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Pancreas cancer is limited in treatment, NGS may offer better outcome if targetable.

Potential benefit of treatment with MEK inhibitors and chemotherapy in BRAF-mutated KRAS wild-type pancreatic ductal adenocarcinoma patients: a case report

This is the first case report of a 60-yr-old female who underwent therapy for metastatic pancreatic cancer with fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX). Upon the progression of her disease, she was switched to gemcitabine and nab-paclitaxel. Per genomic sequencing, her tumor was found to be a KRAS wild-type and BRAF V600E mutation, which then warranted treatment with the MEK1 and MEK2 inhibitor, cobimetinib. The patient has achieved a complete response (CR) to a combination of gemcitabine, nab-paclitaxel, and cobimetinib. It has been 16 mo since the start of the treatment, and the patient continues to demonstrate a complete durable response both serologically and radiologically.

Implementation of hepatic artery infusion (HAI) chemotherapy for unresectable colorectal liver metastases (CRLM): The University of Miami experience

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Background: In patients with unresectable liver-confined CRLM, regional chemotherapy via HAI in combination with modern systemic chemotherapy (CT) can achieve hepatic disease control and expand surgical resectability. We describe patient selection and early outcomes following implementation of a HAI program at our tertiary referral academic center. Methods: We analyzed demographics, previous systemic treatment, primary tumor location, molecular profiling, extent of hepatic/extrahepatic disease, perioperative HAI outcomes (toxicity, conversion to resection/ablation, radiographic response), and overall survival (OS) in CRLM patients selected for HAI treatment (01/2018—06/2020) after multidisciplinary review. Results: Of 35 patients with unresectable CRLM (primary: colon, n = 24; rectum, n = 11) selected for HAI, 57% were heavily pre-treated (with at least 2 lines of pre-HAI systemic chemotherapy), 71% had a Fong clinical risk score ≥3, 86% presented with synchronous disease, 80% had bilobar metastasis, and 86% had > 5 tumors. All tumors were microsatellite stable, with 20% harboring KRAS/NRAS mutations and none had class I/II BRAF mutations. HAI was initiated at a median 14 (IQR 3, 64) months after CRLM diagnosis, and administered for a median of 7 (range 2, 16) cycles; 91% of patients (31/34) received concurrent HAI and systemic chemotherapy. Although most (69%) patients experienced some degree of hepatic toxicity during HAI therapy resulting in FUDR dose reduction and steroid administration, biliary sclerosis requiring intervention was observed in only 3 (9%) of patients. The overall perioperative morbidity was 17%, and there were no surgical-related 90-day mortalities following HAI pump placement. Excluding patients who initiated HAI treatment within the last 3 months of the study period (n = 3), 13 of 32 patients (41%) were rendered disease-free in the liver following complete resection and/or ablation in combination with HAI/systemic chemotherapy; in the remaining 19 patients (59%), hepatic progression-free survival was 7.3 months (IQR 4, 12). At a median follow-up of 11.2 months, post-HAI median OS for the overall cohort was 12.3 (IQR 7, 20) months. Patients undergoing complete resection/ablation demonstrated improved survival compared with those with progressive disease (median 20 vs 12 months, respectively). Conclusions: Implementation of a HAI program for multimodality liver-directed management of unresectable CRLM is feasible and is associated with meaningful clinical outcomes unlikely to be achieved with systemic therapy alone in heavily pre-treated patients.

Cobimetinib plus gemcitabine is an active combination in KRAS G12R-mutated in previously chemotherapy-treated and failed pancreatic patients

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Background: he KRAS proto-oncogene is involved in the RAS/MAPK pathway. Various G12X mutations have been examined with the most common mutations being G12D (40%), G12V (30%), and G12R (15-20%) in pancreatic cancer patients. Throughout the course of studying the G12X mutations, we have observed that not all KRAS mutations are equal. Preclinical data shows G12R is impaired in pI3Kα signaling, as compared to KRAS G12V/D. This mechanism is important in PDAC as it allows tumor growth to be sustained. In preclinical studies, PDX derived tumors were transplanted in mice and were treated with a MEK inhibitor plus chemotherapy, which demonstrated a greater tumor regression than either agent alone. Therefore, we have decided to treat patients with Gemcitabine alongside a 2nd generation MEK inhibitor (Cobimetinib). Methods: In our single arm study, 13 KRAS mutated pancreatic patients (KRAS G12D, G12V, and G12R) received the combination of Cobimetinib 20mg BID weekly for three weeks alongside Gemcitabine at 1000mg/m2 weekly, followed by one week of rest. The above constitutes one cycle. Results: Patients were divided into two groups; Group 1 consists of seven patients that were KRAS G12D/G12V mutated, and Group 2 included six KRAS G12R mutated patients. In Group 1, seven patients on treatment progressed and died within two months on the study. In Group 2, one achieved PR and others stable disease. Median progression-free survival was 6.0 months (95% CI 3-9.3 months) and median OS has not been reached. All patients are alive at 8 months. Common adverse reactions include rash, fatigue, nausea, and vomiting. Cancer antigen 19-9 decreased in ≥ 50 of all patients in the latter group. We would like to report our positive study to the society. Moreover, we intend to confirm the study in a larger patient cohort. Conclusions: Pancreatic cancer patients that demonstrate KRAS G12R mutations are treatable with a new active combination chemotherapy.

Metastatic involvement of skeletal muscle from gastric adenocarcinoma

Gastric cancer represents the fifth most common cancer diagnosis worldwide and the third leading cause of cancer-related mortality. In the USA, the overall 5-year survival rate is 31%, with distant disease nearing 5%. The most common sites of metastasis are the liver and peritoneum. Skeletal muscle involvement has been rarely reported. Since clinical and imaging findings overlap with primary sarcomas, a confirmatory biopsy is required for diagnosis. Prognosis remains poor with treatment options including palliative chemotherapy, radiotherapy and surgical resection. We report the case of a 57-year-old female presenting with extensive involvement of skeletal muscle 10 years after achieving remission. In addition to illustrating the refractoriness and poor outcomes associated with muscle involvement, this case and comprehensive review of the literature highlights important characteristics of disease biology and tumor genomics that warrant detailed discussion and exposition to a wider audience.

Treatment of advanced colorectal cancer in a patient with cardiotoxic reactions to 5-fluorouracil and capecitabine using suboptimal doses

A 32-year-old female with stage IV colorectal cancer and metastasis to the liver experienced cardiotoxic reactions after treatment with 5-fluorouracil and its oral prodrug capecitabine even at two-thirds the recommended dose. After careful considerations, the decision was made to attempt capecitabine retrial at a further suboptimal dose with combination chemotherapy where she no longer experienced cardiac events. As a result, the liver tumour shrank and rectal mass stabilised, tumour markers dropped and she underwent surgical resection of both masses. Later there was local recurrence of disease near the previous liver tumour, so the suboptimal capecitabine therapy was restarted without complaint. The patient became a candidate for a NanoKnife procedure, offering a potentially curative therapy. This case report summarises a novel treatment strategy for those patients with advanced colorectal cancer who experience cardiotoxic reactions to fluoropyrimidines, the active agent of gold standard treatment.

Long-term survival based on pathologic response to neoadjuvant therapy in esophageal cancer

BACKGROUND

Neoadjuvant treatment is standard for locally advanced esophageal cancer. However, whether the addition of radiation to neoadjuvant regimen improves survival remains unclear. The aim of this study was to compare survival in locally advanced esophageal cancer treated with neoadjuvant chemotherapy versus chemoradiation.

MATERIALS AND METHODS

A prospectively maintained database of esophagectomies (1999-2012) was analyzed. We identified 297 patients with locally advanced esophageal cancer that underwent either neoadjuvant chemotherapy (n = 231) or chemoradiation (n = 66) followed by esophagectomy. Pretreatment and pathologic staging were compared to assess response. Overall survival was recorded.

RESULTS

Most patients in the chemotherapy and chemoradiation groups had pretreatment stage III disease (66.7% versus 65.2%; P = 0.44). Median follow-up was 79.3 and 64.9 mo for chemotherapy and chemoradiation cohorts, respectively. Complete response rate was higher in chemoradiation than chemotherapy groups (30.3% versus 13.8%; P < 0.001). Overall survival was similar between complete responders in both groups (median not reached versus 121.1 mo; chemotherapy versus chemoradiation). However, partial responders in the chemotherapy cohort had improved median survival (147.2 mo) versus those in the chemoradiation cohort (83.7 mo, P < 0.03). Within the chemotherapy-only group, partial responders had improved survival compared with nonresponders (P = 0.041); however, there was no difference in survival between partial and complete responders (P = 0.36).

CONCLUSIONS

In patients undergoing esophagectomy for locally advanced esophageal cancer, neoadjuvant chemotherapy was associated with an equivalent overall survival, when compared with neoadjuvant chemoradiotherapy. Adding neoadjuvant radiation may enhance complete response rates but does not appear to be associated with improved survival.

Arsenic Attenuates GLI Signaling, Increasing or Decreasing its Transcriptional Program in a Context-Dependent Manner

The metalloid arsenic is a worldwide environmental toxicant, exposure to which is associated with many adverse outcomes. Arsenic is also an effective therapeutic agent in certain disease settings. Arsenic was recently shown to regulate the activity of the Hedgehog (HH) signal transduction pathway, and this regulation of HH signaling was proposed to be responsible for a subset of arsenic's biologic effects. Surprisingly, these separate reports proposed contradictory activities for arsenic, as either an agonist or antagonist of HH signaling. Here we provide in vitro and in vivo evidence that arsenic acts as a modulator of the activity of the HH effector protein glioma-associated oncogene family zinc finger (GLI), activating or inhibiting GLI activity in a context-dependent manner. This arsenic-induced modulation of HH signaling is observed in cultured cells, patients with colorectal cancer who have received arsenic-based therapy, and a mouse colorectal cancer xenograft model. Our results show that arsenic activates GLI signaling when the intrinsic GLI activity is low but inhibits signaling in the presence of high-level GLI activity. Furthermore, we show that this modulation occurs downstream of primary cilia, evidenced by experiments in suppressor of fused homolog (SUFU) deficient cells. Combining our findings with previous reports, we present an inclusive model in which arsenic plays dual roles in GLI signaling modulation: when GLIs are primarily in their repressor form, arsenic antagonizes their repression capacity, leading to low-level GLI activation, but when GLIs are primarily in their activator form, arsenic attenuates their activity.

Neoadjuvant and adjuvant, floxuridine, leucovorin, oxaliplatin, and docetaxel (FLOD) in patients with locally advanced operable gastroesophageal adenocarcinoma: A phase II study with pathologic responses and long term follow-up

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Background: A complete pathological response to neoadjuvant chemotherapy without the use of radiation has infrequently been reported in operable chemo-naïve stage III gastro esophageal adenocarcinoma patients. Methods: Twenty-nine patients were enrolled in this study. Neoadjuvant therapy consisted of Floxuridine, Leucovorin, Oxaliplatin, and Docetaxel and was administered in 2, four week cycles. Chemotherapy consisted on day one and day fifteen; Oxaliplatin, Docetaxel, FUDR, and Leucovorin. The latter two drugs were given concurrently over twenty four hours. On day eight, chemotherapy consisted of Docetaxel, FUDR, and Leucovorin. Following therapy, patients underwent surgical resection. Those patients having residual disease were offered adjuvant chemotherapy. Patients having a complete pathological response were not offered any further therapy. Results: Twenty-four out of twenty-nine patients completed neoadjuvant therapy and underwent esophagectomy. Two were declared inoperable after treatment. Three patients died prior to surgery. The median follow-up of all patients is now sixty months. The median overall survival has not been reached at sixty months. Five yr actual OS is 51%. Clinical response to neoadjuvant therapy was seen in (72.4%) patients. Complete pathological response to neoadjuvant therapy was seen in (16.7%) who are disease free at sixty month follow-ups. Seven out of twenty-four patients achieved partial pathological response (29.1%) and received adjuvant chemotherapy. They are all alive (100%). Eight patients achieved less than partial pathological response and received adjuvant chemotherapy, four out of eight are alive at sixty months (50%). Grade three and four toxicities were seen in sixteen out of twenty nine patients during neoadjuvant therapy. Grade three and four toxicities were seen in six out of fourteen patients during adjuvant therapy. Conclusions: Our chemotherapy regimen of Floxuridine, Leucovorin, Oxaliplatin and Docetaxel (FLOD) has resulted in long term survival in patients with adenocarcinoma of the esophagus. Clinical trial information: NCT00448760.

In the war against solid tumors arsenic trioxide needs partners

In the past decade, the therapeutic potential of arsenic trioxide (ATO) in the treatment of acute promyelocytic leukemia (APL) was recognized. This encouraged other investigators to test the efficacy of ATO in the management of other hematological and solid tumor malignancies. Notably, as a single agent, arsenic trioxide did not benefit patients diagnosed with solid tumors. However, when it was combined with other agents, treatment benefit emerged. In this article, we have summarized the outcome of clinical trials that used arsenic trioxide as a single agent as well as in combination settings in patients diagnosed with solid tumors. We have also reviewed possible additional mechanisms by which ATO may be useful as a chemosensitizer in combination therapy. We hope that our review will encourage clinical investigators to rationally combine ATO with additional chemotherapeutic agents in treating patients diagnosed with solid tumors.

Depth of injury caused by liquid nitrogen cryospray: study of human patients undergoing planned esophagectomy

BACKGROUND

Cryotherapy using liquid nitrogen delivered endoscopically has been used for mucosal ablation of esophageal neoplasia. There are no data for the human esophagus on the depth of injury and effects of this technique.

AIM

Prospective study to examine the effect of treatment and depth of injury to the human esophagus of liquid nitrogen spray cryotherapy for subjects with esophageal neoplasia before planned esophagectomy.

METHODS

Liquid nitrogen spray cryoablation was performed seven days before scheduled esophagectomy for seven males with esophageal carcinoma. Subjects were assigned to either treatment of four cycles of 10 s each (group 1) or two cycles of 20 s each (group 2) applied to a 2-cm segment of healthy esophagus above the tumor area. Main outcomes measured were: mean depth of injury (mm); surface displaying mucosal ablation, and adverse events.

RESULTS

Mucosal destruction was similar for both groups (group 1, 95%; group 2, 93%; p = NS). Deeper injury was observed for group 2; mean depth was 5.4 mm compared with 4.0 mm for group 1. Cryonecrosis reached the submucosa for 60% (12/20) of subjects in group 1 versus 93% (14/15) of subjects in group 2 (p = 0.04, two-tailed Fisher's exact test). No serious adverse events occurred. No perforation was seen in the resected esophagus.

CONCLUSION

Mucosal ablation with liquid nitrogen spray cryotherapy was highly effective in inducing mucosal necrosis; the doses assessed had similar effects. Ablation reached the submucosa more often with longer spray time despite fewer treatment cycles.

Impact of Hispanic ethnicity on the clinical presentation and survival of esophageal and gastric cancer in south Florida

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Background: Race and ethnicity are associated with differences in survival among patients with esophageal and gastric cancer (EGC); outcomes are better in Asian patients but worse for African-Americans compared to Caucasians and Asians. Limited data exist for Hispanics (Hisp) compared to non-Hispanic whites (NHW) or African-Americans (AA). Because of the large Hisp population in South Florida, we compared the clinical presentation and survival of patients with EGC by race and ethnicity. Methods: Using a cross-sectional study design, this IRB-approved analysis of the Florida Cancer Data System database identified all patients diagnosed at the University of Miami and Jackson Memorial Hospital between January 2000 and December 2012 with squamous cell carcinoma (SCC) or adenocarcinoma (AC) of the esophagus, and adenocarcinomas of the gastro-esophageal junction (GEJ) or stomach (STO). Demographic, treatment and survival data were extracted from the registry. Survival was analyzed using the Kaplan-Meier method and variables associated with survival were analyzed using a Cox proportional hazards model. Results: Data from 2,170 patients were available; 44% were Hisp, 19% AA and 38% NHW. Compared to NHW's and AA's, Hisp's were more likely to have the following features: male gender, advanced age at cancer diagnosis, esophageal site of malignancy, adenocarcinoma histology, earlier stage at presentation, history of smoking and alcohol use, private insurance, surgical resection and receipt of chemotherapy (p < 0.001 in each case). Hisp were less likely to have STO (p<0.001). In a multivariate model, race and ethnicity were not independently associated with survival but age, stage, surgical resection and chemotherapy administration were all independently associated with survival (p < 0.01 in each case). Country of birth did not influence results among Hispanic patients. Conclusions: Race and ethnicity were not independently associated with survival in this large registry study. However, significant differences in the tumor location, histology and stage of presentation exist, and further studies to elucidate the biological or environmental reasons for these disparities are warranted.

Abstract 4019: Regulatory role of Gli motifs in thymidylate synthase expression

Fluoropyrimidine analogue 5-Flurorouracil (5-FU) is the mainstay of CRC treatment. It was designed as a competitive inhibitor of the enzyme thymidylate synthase [TS; TYMS]. All the new agents (Irinotecan, CPT-11, Avastin etc) are effective only in combination with 5-FU. The enzyme thymidylate synthase is pivotal for DNA replication. It controls cell survival and proliferation. Increases in TS level that follows 5-FU administration renders the treatment ineffective. Considerable efforts have been made to reverse 5-FU resistance by down-regulating TS expression. In this context, we demonstrated that arsenic trioxide (ATO) sensitized 5-FU resistant colorectal cancer cells by inhibiting TS mRNA expression both in vitro and in clinic. However, the precise mechanism of TS reduction by arsenic trioxide is not known.

Many investigators, including ourselves, have shown a direct correlation between Glioma associated oncogene homolog (Gli) and TS expression in cultured cells as well in patient samples, who received arsenic trioxide and 5-FU combination therapy. However, the link between ATO, Gli and TS is not known.

Gli is an important molecule in hedgehog (hh) signaling. It plays a vital role in development and cancer. As a transcription factor, Gli binds the sequence 5’ GACCACCCA 3’ a conserved 9 bp DNA motif. We hypothesized that TS promoter may harbor one or more of the 9 bp Gli motifs.

We queried for Gli motifs in the TS gene regulatory region. Position specific base frequencies for the TF consensus sequence for Gli1-3, Ci, cECF, TGM were prepared using the data from Hallikas et al. (2006). We used FIMO (Find Individual Motif Occurrences) tool in the Meme Suite (http://meme.nbcr.net) to search for Gli motifs in the query sequence. Anti-Gli antibodies and non-specific IgG were used to precipitate chromatin immuno complex. The immuno precipitates were probed with TS specific primer.

This search yielded 35 possible Gli motifs in TS promoter. From among the 35 motifs with significant homology (p≤0.001), only top eight matches had passed FDR threshold (q≤0.05). However, these eight matches represented three distinct binding sites on TS promoter. Thus we computationally determined that TS promoter has three unique Gli motifs viz BS1, BS2 and BS3. BS-2 in TS promoter is identical to BS-3 on the Jun and BS1 is identical to the BS 1 of Fgf15 which had been experimentally confirmed to be regulated by Gli1. The binding site was subsequently confirmed by ChIP assays.

It appears that the inhibition of Gli1 by ATO down regulates TS expression. This cascade of reactions initiated by ATO reverts refractory tumors, once again sensitive to 5-FU. Taken together the results strongly indicate a direct role of Gli in TS transcription.

Citation Format: Subbarayan R. Pochi, Nikesh Doshi, Xiaoqing Han, Zhiqiang Wang, Anthony Capobianco, David Robbins, Bach Ardalan. Regulatory role of Gli motifs in thymidylate synthase expression . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4019. doi:10.1158/1538-7445.AM2013-4019

Achyranthes aspera (Apamarg) leaf extract inhibits human pancreatic tumor growth in athymic mice by apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Achyranthes aspera (Family Amaranthacea) is used for cancer therapy by ayurvedic medical practitioners in India. However, due to the non formal nature of its use, there are no systematic studies validating its medicinal properties. Thus, it's utility as an anti cancer agent remains anecdotal. Earlier, we demonstrated A. aspera to exhibit time and dose-dependent preferential cytotoxicity to cultured human pancreatic cancer cells. In this report we validate in vivo anti tumor properties of A. aspera.

MATERIALS AND METHODS

The in vivo anti tumor activity of leaf extract (LE) was tested by intraperitoneal (IP) injections into athymic mice harboring human pancreatic tumor subcutaneous xenograft. Toxicity was monitored by recording changes in behavioral, histological, hematological and body weight parameters.

RESULTS

Dosing LE to athymic mice by I.P. injection for 32 days showed no adverse reactions in treated mice. Compared to the control set, IP administration of LE to tumor bearing mice significantly reduced both tumor weight and volume. Gene expression analysis using Real time PCR methods revealed that LE significantly induced caspase-3 mRNA (p<0.001) and suppressed expression of the pro survival kinase Akt-1 (p<0.05). TUNEL assay and immunohistochemistry confirmed apoptosis induction by activation of caspase-3 and inhibiting Akt phosphorylation in treated sets. These results are in agreement with RT PCR data.

CONCLUSION

Taken together, these data suggest A. aspera to have potent anti cancer property.

The presence of three repeats in the 5' UTR region of thymidylate synthase (TS) is associated with increased TS mRNA expression in cultured human cancer cell lines in vitro

Thymidylate synthase (TS) gene contains 28-bp polymorphic sequence and 6-bp insert at the 5'- and 3'-untranslated region, respectively. We investigated the role of these two polymorphic traits on TS mRNA expression in nine different cultured human cancer cell lines in vitro. Three cell lines each were 2R/2R, 2R/3R and 3R/3R genotypes. Six of the nine cell lines tested homozygous for the presence of 6-bp insert (+6/+6) and the rest three lacked this insert (-6/-6). TS expression analyses associated homozygous three repeats (3R/3R) to higher TS expression.

A phase II study of neoadjuvant and adjuvant chemotherapy with 5-fluorodeoxyuridine, leucovorin, oxaliplatin and docetaxel in the treatment of previously untreated advanced esophageal adenocarcinoma

OBJECTIVE

A complete pathologic response to neoadjuvant chemotherapy, without the use of radiation, has infrequently been reported in operable chemo-naïve stage III esophageal adenocarcinoma patients.

METHODS

Twenty-nine eligible patients were enrolled in the study. Neoadjuvant therapy consisted of 5-fluorodeoxyuridine, leucovorin, oxaliplatin and docetaxel and was administered in two 4-week cycles. Following therapy, patients underwent surgical resection. Those patients having residual disease were offered adjuvant chemotherapy. Patients having a complete pathologic response were not offered any further chemotherapy.

RESULTS

Twenty-four out of 29 patients finished neoadjuvant therapy and underwent curative esophagectomy. Two patients were declared inoperable after treatment, and three patients died prior to surgery. The median follow-up on all patients was 20.2 months. Median progression-free survival and median overall survival were 13.6 and 21.4 months, respectively. Clinical response to neoadjuvant chemotherapy was seen in 21 out of 29 patients (72.4%). Complete pathologic response with neoadjuvant chemotherapy was seen in 4 out of 24 patients (16.7%). Those four patients have been alive and progression-free for 20-37 months. Grade 3-4 toxicities occurred in 16 of the 29 patients during neoadjuvant therapy. Grade 3-4 toxicities were seen in 6 out of 14 patients during adjuvant therapy. (18)F-fluorodeoxyglucose-positron emission tomography standardized uptake values of ≥8 correlated with better progression-free survival.

CONCLUSION

5-Fluorodeoxyuridine, leucovorin, oxaliplatin and docetaxel regimen is active in patients with esophageal adenocarcinoma. Toxicity profiles are manageable. Neoadjuvant chemotherapy allowed achievement of complete pathologic response without radiation. (18)F-fluorodeoxyglucose-positron emission tomography standardized uptake values might be prognostic.

Anti-proliferative and anti-cancer properties of Achyranthes aspera: specific inhibitory activity against pancreatic cancer cells

AIMS OF THE STUDY

Achyranthes aspera (Family: Amaranthacea) is a medicinal plant used as an anti-cancer agent in ayurveda, a traditional system of medicine practiced in subcontinental India. The aim of the study was to systematically investigate the anti-proliferative properties of Achyranthes aspera leaves extracted in methanol (LE) on human cancer cells in vitro.

MATERIALS AND METHODS

We tested time, dose dependent and specific anti-proliferative activity of LE by clonogenic cell survival assay on human cancer and normal epithelial cell lines in vitro. We further investigated its effect on the expression of metastatic and angiogenic genes by real time polymerase chain reaction. On silica gel column, we carried out initial fractionation analysis.

RESULTS

LE exhibited time and dose dependent cytotoxicity on several tumor cells. Compared to cancer cells of colon, breast, lung and prostate origin, pancreatic cancer cells were significantly more sensitive to LE. Preliminary mechanistic studies suggested that LE selectively suppressed the transcription of metalloproteases (MMP-1 and -2), inhibitors of MMPs (TIMP-2) and angiogenic factors (VEGF-A and VEGF-B). Fractionation of LE on methanol equilibrated silica gel column resolved into three fractions of which fraction (F 3) was found to be enriched with anti-proliferative activity.

CONCLUSION

Methanolic extract of Achyranthes aspera contains potent anti-proliferative compound with specific activity against pancreatic cancer. Further studies are needed to confirm the in vivo anti-tumorigenicity and subsequent chemical characterization of the active molecule(s).

Arsenic trioxide suppresses thymidylate synthase in 5-FU-resistant colorectal cancer cell line HT29 In Vitro re-sensitizing cells to 5-FU

Identification of new agents with antitumor activity in chemoresistant tumors is urgently needed for the treatment of colorectal cancer. Arsenic trioxide (As(2)O(3)), a Food and Drug Administration (FDA) approved drug is successfully being used to treat acute promyelocytic leukemia (APL). Several clinical trials also suggest its ineffectiveness on solid tumors. We proposed that arsenic trioxide may be used as chemosensitizer, especially to 5-fluorouracil (5-FU). The effect of arsenic trioxide on cell proliferation of 5-FU-sensitive and -resistant HT29 colorectal cancer cells in vitro was tested by trypan blue dye exclusion assay, 2, 3-bis(2-methoxy-4-nitro-5-sulfophenyl)-S-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) cell proliferation assay and cell cycle analysis using flow cytometry. Gene expression was analyzed using real-time polymerase chain reaction (PCR) and Western blot methods. There was a dose-dependent increase in cell detachment and proliferation in HT29 and HT29FU cells. As a single agent, arsenic trioxide also down-regulated thymidylate synthase (TS) expression without affecting the expression of some other genes analyzed in the above cell lines. Combination of arsenic trioxide and 5-FU increased cytotoxicity. In vitro data show that as a single agent, arsenic trioxide down-regulated TS expression in HT29 cells. Addition of 5-FU to these sensitized cells increased cytotoxicity. These findings open up a possibility to use arsenic trioxide as a chemosensitizer in combination therapy.

Chronic exposure of colorectal cancer cells in culture to fluoropyrimidine analogs induces thymidylate synthase and suppresses p53. A molecular explanation for the mechanism of 5-FU resistance

Resistance to chemotherapy is a major issue in treating malignant diseases. 5-Fluorouracil (5-FU) is the drug of choice in managing colorectal cancer (CRC) patients. However, 5-FU resistance leads to eventual treatment failure. Therefore, delaying or reversing the onset of 5-FU resistance will benefit these terminally ill patient populations. A metabolite of 5-FU irreversibly binds thymidylate synthase (TS) thus inhibiting its activity. Many studies demonstrated that these resistant patients had an increased intratumoral TS level. We used TS-siRNA to reduce TS and resensitize HT29FU CRC cells back to this uracil analogue. We exposed the CRC cell line HT29 to an increasing concentration of 5-FU or 5-fluorouridine (FUR) and established a derivative cell line (HT29FU and HT29FUR). Using real-time polymerase chain reaction (PCR) and Western immunodetection assays, we analyzed the expression of TS and p53 mRNA and protein in control and experimental groups. Cytotoxicity to 5-FU was determined by reduction of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT assay) or trypan blue dye exclusion assay. The HT29FU and HT29FUR cells have a distinct morphology: they are generally asteroid shaped. The half maximal inhibitory concentration (IC(50)) values for the resistant cell line for 5-FU is over 148 microM compared to 5 microM for the sensitive parental cell line. The resistant cell lines expressed more of TS and less of p53. TS-siRNA suppressed TS only. Other pathways were not significantly altered. It also marginally (20%) re-sensitized resistant cells to 5-FU. Restoration of partial sensitivity to 5-FU by TS-siRNA reiterates the primacy of the DNA synthesis pathway in 5-FU mode of action. We speculate that the short half-life of the transiently transfected siRNA may contribute to the marginal restoration of sensitivity. By integrating TS-siRNA expression vector into the genome and regulating its expression, we may be able to reverse 5-FU resistance and make the cells as sensitive as the parental cell line.

Phase II study of bevacizumab (B), camptosar (I), high-dose 24-hour continuous intravenous infusion of floxuridine (F) and leucovorin (L) in patients with previously untreated metastatic colon cancer. (B-IFL)

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Background: In a previous study, IFL was used in patients (pt) with untreated metastatic colon cancer and a median overall survival (MOS) of 31 months (m). In the current study we added B to IFL to determine toxicity profiles (TP) and the response rate (RR) to the B-IFL regimen. The primary end-point is MOS Methods: Each cycle involved 6 weeks (wks) of treatment. The treatment cycle consisted of a 90 minute infusion of I (110 mg/m2), followed by a 24 hour infusion of F (120mg/kg) and L (500 mg/m2) on wks 1, 2, 4, 5. Pt received B (7.5mg/kg) over 90 minutes on wks 1 and 4 prior to IFL. No therapy was given on wks 3 and 6. Eligible pt received 2 cycles of B-IFL followed by CT scan. Quality of life data and thymidylate synthase expression in peripheral blood mononuclear cells was monitored Results: 22 pt with a median age of 57 (38–82), 11 males and 11 females were enrolled. Median KPS was 90% (50–100). 8 pt (36%) had bilobar liver disease and involvement of 1 other organ, 6 pt (27%) had bilobar liver disease with involvement of ≥ 2 other organs; 5 pt (23.5%) had bilobar liver disease; 2 pt (9%) had abdominal carcinomatosis; 1 pt (4.5 %) had involvement in one liver lobe. Grade (Gr) 4 toxicity: pulmonary embolus 1 pt (5%) incidental CT finding. Gr 3 occurred in 11 pt (50%); DVT, diarrhea (Drh) 3 pt (14%); fatigue (Ftg), infection, port site thrombosis (Pst), small bowel obstruction 2 pt (9%); wound dehiscence 1pt (5%); Gr 2 and 1: constipation; Drh; Ftg; nausea; neutropenia; Pst; alopecia; anorexia; mucositis. 17 pt remain alive with median follow up of 15 m (2–28). 5 pt have died due to progression of disease. The estimated median time to progression was 13 m with corresponding lower 95% confidence bound of 8.4 m. Kaplan-Meier estimate at 2 yr survival is 61% (95% CI 27–83%). RR in 21 pt was 67% (95% CI: 43–85%). Conclusions: B-IFL regimen has a manageable TP. RR and progression free interval were promising. Pt accrual is ongoing. Supported by Pfizer.

No significant financial relationships to disclose.

Arsenic trioxide/ascorbic acid therapy in patients with refractory metastatic colorectal carcinoma: a clinical experience

Arsenic trioxide (As2O3) has demonstrated effectiveness in treating acute promyelocytic leukemia (APL). Therefore the FDA has approved it to treat APL. In patients with refractory metastatic colorectal carcinoma (CRC), we assessed the efficacy and toxicity of As2O3/AA (ascorbic acid) as the outcome of this trial. Five patients with refractory metastatic CRC who failed all previous standard chemotherapy were enrolled in this study. They were treated with 0.25 mg/kg body weight/day As2O3 and 1000 mg/day of ascorbic acid for 5 days a week for 5 weeks. Each treatment cycle extended for 7 weeks with 5 weeks of treatment and 2 weeks of rest. All the patients developed moderate to severe toxic side effects to arsenic trioxide/AA therapy and therefore the study was discontinued. No CR (complete remission) or PR (partial remission) was observed. CT scans demonstrated stable or progressive disease. Three of the five patients died within 2 to 5 months after cessation of the therapy. None of the deaths could be related to this clinical trial. Two years of follow-up study showed that two patients were alive with stable disease. Under the current treatment regimen all patients developed moderate to severe side effects with no clinically measurable activity. As an alternate, efforts may be made to reduce the dose and arsenic trioxide may be combined with other standard regimen in reversing the chemo resistance.

A phase II study of irinotecan, high-dose 24-h continuous intravenous infusion of floxuridine and leucovorin (IFLUX) for advanced, previously untreated colorectal cancer

Our objectives were to determine response rate, time to progression, overall survival and tolerability of novel combination chemotherapy, consisting of irinotecan, high-dose 24-h continuous intravenous infusion of floxuridine and leucovorin in advanced previously untreated colorectal cancer. Thirty-eight patients with advanced colorectal cancer were treated at Sylvester Comprehensive Cancer Center, University of Miami, from 2000 to 2004, and received weekly intravenous infusion of irinotecan at 110 mg/m with a combination of 120 mg/kg floxuridine and 500 mg/m leucovorin administered as a 24-h continuous intravenous infusion. The treatment cycle consisted of 4 weeks of consecutive therapy followed by 2 weeks of rest. Five (13%) patients achieved complete response, 10 (26%) patients achieved partial response, 17 (45%) patients attained stable disease and six (16%) patients progressed. The overall response rate was 39% in this study. This chemotherapy regiment was well tolerated; the most common grade 3 toxicities were neutropenia (16%), anemia (16%), vomiting (24%), diarrhea (16%), and hand-and-foot syndrome (26%). The median time to progression was 11.5 months (347.5 days) with 95% confidence intervals of 6.8-12.9 months (206-389 days). The time to progression ranged from 1.8 to 34 months. The median survival of the patients in this trial was 31.28 months (952 days) with a confidence interval of 20.9-38.0 months (629-1141 days). Intravenous infusion of floxuridine and leucovorin is beneficial as first-line therapy in advanced colorectal cancer, demonstrating a prolonged time to progression and overall survival with acceptable tolerability and manageable toxicity profile.

Neoadjuvant, surgery and adjuvant chemotherapy without radiation for esophageal cancer

BACKGROUND

A phase II trial to evaluate neoadjuvant (NAD), surgery and adjuvant (AD) combination chemotherapy without radiation therapy (RT) for patients with esophageal adenocarcinoma staged with endoscopic ultrasound and CT as T3N1 was carried out.

METHODS

Thirty-three eligible patients were enrolled. NAD therapy was administered in two 49-day cycles and included cisplatin, floxuridine, paclitaxel and leucovorin. Esophageal resection was performed followed by AD therapy.

RESULTS

Thirty-three patients initiated NAD therapy; 10 experienced grade 3 and 4 toxicities, which included leucopenia, fatigue, nausea, diarrhea and stomatitis. Additionally, 16 patients experienced grade 1 and 2 hematologic and non-hematologic toxicities. Fifteen patients were down-staged, of whom five were T2, seven were T1, and three had nodal disease with no evidence of residual cancer in the esophageal bed. Fifteen patients remained T3, and two showed progressive disease. Thirty-two patients proceeded to surgery and 30 were resected. Although all resected patients were eligible for AD therapy, 15 did not receive it either because of patient refusal or surgeon recommendation. Fifteen patients received AD therapy: nine who had remained T3 and six who had down-staged. Three patients experienced grade 3 and 4 toxicities similar to those in NAD therapy. Six patients had grade 1 and 2 toxicities. Kaplan-Meier estimates of overall survival at 1, 3 and 5 years were 73% (95% CI: 58-88%), 52% (95% CI: 34-69%) and 29% (95% CI: 13-45%), respectively. Median survival was 42 months.

CONCLUSION

Deletion of RT may safely allow for more aggressive chemotherapy and increase chances of survival. The results need to be confirmed in a randomized phase II or larger phase III trial.

Neoadjuvant and adjuvant chemotherapy without radiation for esophageal cancer

4054

Background: A Phase II trial to evaluate neoadjuvant (NAD) and adjuvant (AD) combination chemotherapy (CT) without radiation therapy (RT), for Stage III esophageal adenocarcinoma. Methods: Stage III disease by CAT scan or EUS and ECOG performance status 0–1. The CT cycles included Cisplatin, Taxol, FUDR and Leucovorin. The chemotherapy was given for 16 weeks prior to surgery, followed by adjuvant chemotherapy for patients whose pathology at the time of surgery demonstrated microscopic disease. Survival was estimated via Kaplan Meier. Results: 33 patients were enrolled: 28 completed NAD, 15 received AD. Of 33 pts given NAD, 16 had grade I/II toxicity and 14 had grade III/IV. In addition, 6 of 15 pts receiving AD had grade I/II toxicity and 3 had grade III/IV during that phase of treatment. Thirty-two (32) patients went to surgery, 30 patients were resected: 24 transhiatial and 6 transthoracic. Of the 28 patients who completed NAD, 19 (68%) demonstrated improvement in dysphagia; 11 (41%) gained weight, and 7 (26%) had no weight change. Pathologic response to NAD: 30 patients had partial response and 2 patients had progressive disease, one died prior to surgery, post carotid endarterectomy. Ten (10) patients showed no gross disease. Twenty-three (23) patients have expired, 17 disease related with distant metastasis, 1 with local recurrence and distant metastasis, 3 non-disease related and 2 unresectable cases. Kaplan-Meier estimates of overall survival at 1, 3, and 5 years were 73% (95% CI: 58 to 88%), 52% (95%CI: 34 to 69%), and 29% (95% CI: 13 to 45%), respectively. Median survival was 42 months (95% CI: 14 to 52 months). Ten (10) patients are alive after a median follow up of 73 months (range 45 to 89). Seven (70%) of the surviving patients received both NAD (2 cycles) and AD (1 to 2 cycles) and all had no evidence of disease as of last clinical and radiological evaluation. Conclusions: This regimen of combination CT for locally advanced esophageal adenocarcinoma is safe and comparable with those regimens that contain RT. There has been 1 local recurrence; 17 patients have recurred distantly. Omission of RT may allow for a more aggressive CT and reduction in the local complications post-surgery. This study needs to be confirmed in a larger phase II or in randomized phase III trial.

No significant financial relationships to disclose.

Phase II trial of DJ-927, an oral tubulin depolymerization inhibitor, in the treatment of metastatic colorectal cancer

3591

Background: DJ-927, a novel oral tubulin depolymerization inhibitor, causes apoptosis and DNA cell division arrest. It is not a substrate for the MDR and has excellent activity in preclinical colorectal cancer models. Methods: We are conducting a two-stage, multi-center, phase II trial to assess the efficacy of DJ-927 administered initially as second-line therapy following failure of irinotecan or oxaliplatin based therapy (n= 39). DJ-927 is given as a single oral dose on day 1 of a 21-day cycle at a dose range of 27 - 35 mg/m2. Results: Thirty-nine patients were enrolled, including 14 with prior irinotecan based therapy and 25 who had received prior oxaliplatin therapy. The median age was 56 years (range: 30–87) and the median ECOG PS at baseline was 1 (range: 0–2). A total of 155 courses (range: 1–24) have been administered with a median of 2 courses. Nine patients required dose reduction due to toxicity. Thirty-seven patients were evaluable for efficacy. There were 2 CRs and 2 PRs (10.3%) reported that were confirmed as per RECIST criteria. Fourteen patients (35.9%) had SD, including 6 patients (15.4%) with SD >12 weeks. The most common Grade 3 or 4 AEs were neutropenia (48.7%), fatigue (10.3%), neuropathy (7.8%), and nausea (5.0%).Six patients experienced febrile neutropenia, all requiring hospitalization but tolerated treatment with subsequent dose reduction. There were 13 episodes (33.3%) of peripheral neuropathy reported; however, only 3 (7.8%) were grade 3 or 4. Six patients withdrew due to adverse events. Conclusions: The results of this study indicate activity of DJ-927 as second line therapy in patients with metastatic colorectal cancer. Severe toxicity was generally limited to reversible neutropenia and peripheral neuropathy. This novel oral agent is well tolerated and warrants further evaluation in combination with other active agents.

[Table: see text]

Endoscopic ultrasound restaging after neoadjuvant chemotherapy in esophageal cancer

BACKGROUND

The role of endoscopic ultrasound (EUS) to evaluate treatment response postneoadjuvant therapy for restaging esophageal cancer prior to surgical resection is uncertain. Accuracy of EUS is lower but potential to predict response to chemoradiation indicates that EUS may be helpful prior to surgery.

OBJECTIVE

To determine staging accuracy of EUS after neoadjuvant chemotherapy, predictors of tumor response, and survival in locally advanced esophageal cancer.

METHODS

Single-center retrospective evaluation of patients with locally advanced esophageal cancer on a prospective chemotherapy study. Patients who underwent EUS without FNA pre- and postchemotherapy were included.

RESULTS

A total of 49 patients (43 men and 6 women) were evaluated with EUS pre- and postneoadjuvant chemotherapy. Forty-seven patients had tumor localized at the GE junction and two had mid-esophageal lesions. The median survival time was 53 months. Tumor and nodal staging accuracy postchemotherapy were 60% (27 of 45). T-stage accuracy postchemotherapy was superior in patients without a response to chemotherapy (95.7%vs 26.1%, p<0.0001). More than 50% in reduction of tumor thickness postchemotherapy was associated with tumor downstage and better survival. N0 disease on final pathology was the best predictor of improved survival.

CONCLUSION

Accuracy of EUS postchemotherapy is lower than initial staging accuracy; therefore the ability to predict downstaging based on EUS is marginal. Pathology N1 disease postchemotherapy is the best predictor of survival. EUS staging postneoadjuvant chemotherapy should focus on improving nodal staging accuracy with FNA.

Esophageal Carcinoma: Current Controversial Topics

Worldwide, esophageal carcinoma is a common gastrointestinal cancer with a high mortality. The incidence of adenocarcinoma of the esophagus is increasing in the western world, but squamous cell carcinoma remains dominant in the underdeveloped parts of the world. Both types of esophageal carcinoma remain equally virulent. Currently, there are no optimal preventative screening programs available and most patients present with advanced or metastatic disease. Although many options are available for improving diagnostic accuracy, a single method has not displayed significant advantages over the others. In addition, selecting a superior treatment regimen has not surfaced. Preferred resection techniques exist, but one method has not illustrated improvements in survival over the others. A lack of improved survival rates with single modality therapies has led to a multi modality approach. However, developments in neoadjuvant and adjuvant therapies have led to mixed conclusions. Collectively, past studies have not shown an optimal neoadjuvant or adjuvant regimen in terms of survival benefit. This review highlights existing staging modalities and treatment regimens for esophageal carcinoma, in an effort to illustrate the controversial nature surrounding its management.

A phase II pilot study of high-dose 24-hour continuous infusion of 5-FU and leucovorin and low-dose PALA for patients with colorectal cancer: A Southwest Oncology Group study

PURPOSE

The purpose of this phase II multi-institutional study was to define the efficacy and toxicity of infusional 5-FU in combination with PALA and leucovorin in patients with advanced colorectal cancer.

PATIENTS AND METHODS

Patients were required to have histologically confirmed colorectal cancer with distant metastases. The treatment regimen consisted of 5-FU 2600 mg/m(2) as a 24-hours continuous infusion given once a week, concurrently with leucovorin (LV) at 500 mg/m(2) as a 24-hour continuous infusion. PALA was administered 24 hours prior to 5-FU/LV at a dose of 250 mg/m(2) iv over 15 minutes weekly. Patients were continued on the assigned treatment regimen until progression of disease, unacceptable toxicity, or the patient declined further therapy.

RESULTS

This study accrued 28 patients and all were eligible and evaluable for toxicity. Four patients had inadequate assessment of response and are considered non-responders. There was one complete response and five partial responses for an overall response rate of 6/28 or 21% (95% confidence interval 8-41%). Estimated median survival was 17.4 months (95% confidence interval 13.3-20.5 months). One patient died of a treatment related infection. This patient also had grade 4 diarrhea and vomiting.

CONCLUSION

The combination of 5-FU, leucovorin, and PALA in the doses and schedule used here, produces a response rate similar to other modulated schedules of 5-FU with similar survival and toxicity profiles.

A phase II study of high-dose 24 hour continuous infusion 5-FU and leucovorin and low-dose PALA for patients with advanced pancreatic adenocarcinoma: A Southwest Oncology Group Study

PURPOSE

The purpose of this phase II multi-institutional study was to define the efficacy and toxicity of infusional 5-FU in combination with PALA and leucovorin in patients with advanced pancreatic cancer.

PATIENTS AND METHODS

Patients were required to have histologically confirmed pancreatic cancer that was locally advanced, unresectable or disseminated. The treatment regimen consisted of weekly 5-FU 2600 mg/m(2) given concurrently with leucovorin at 500 mg/m(2). Both drugs were administered by 24-hour continuous infusion. PALA was administered 24 hours prior to the administration of 5-FU/LV at a dose of 250 mg/m(2) IV over 15 minutes weekly. Patients were continued on the assigned treatment regimen until progression of disease, unacceptable toxicity, or the patient declined further therapy.

RESULTS

This study accrued 30 patients. Four of these patients were ineligible. All 26 eligible patients were evaluated for toxicity. One patient had inadequate assessment of response and was considered a non-responder. Three of the twenty-six eligible patients had partial responses, for a response rate of 12% (95% confidence interval 2% to 30%). All 26 eligible patients have died and the median overall survival was 7 months (95% confidence interval: 5.2 to 9 months). Four patients experienced grade 4 toxicities, including bilirubin increase (2 patients), vomiting (1 patient) and non-local skin ulceration (1). Two patients discontinued therapy due to toxicity.

CONCLUSION

The dual modulation of 5-FU with PALA and leucovorin in the dose and schedule used here, has a response rate similar to other single agents in pancreatic cancer and can result in some long term survival while having relatively mild toxicity.

A phase II trial of FUdR in patients with advanced pancreatic cancer

PURPOSE

This phase II study was conducted to assess the efficacy of fluorodeoxyuridine (FUdR) in patients with metastatic, advanced pancreatic cancer who had no previous chemotherapy.

PATIENTS AND METHODS

Twenty patients were enrolled in this single institution trial. The primary endpoint of this study was the assessment of overall survivorship. The secondary endpoints were to estimate the time to tumor progression and the assessment of toxicity in this cohort of patients. Treatment consisted of FUdR 150 mg/kg dissolved in 500 cc normal saline intravenous infusion over 24 h. Eight weeks of treatment constituted one course of chemotherapy. Tumor measurements were conducted at 8-weekly intervals.

RESULTS

Four patients achieved partial response and 16 patients had stable disease. Median survival of patients treated with FUdR was 11.6 months with a range of 3-16 months. Median progression-free survival was 6 months. Overall, chemotherapy was well tolerated with low incidence of grade 3 or 4 toxicity.

CONCLUSIONS

Systemic chemotherapy with high dose FUdR administered on a weekly schedule has led to encouraging survival outcomes and improved quality of life as compared to previous phase II single agent chemotherapeutic trials.

Effects of oxaliplatin and CPT-11 on cytotoxicity and nucleic acid incorporation of the fluoropyrimidines

PURPOSE

The addition of oxaliplatin or CPT-11 to 5-FU has become common practice in the treatment of colorectal cancer. It is not known, however, which fluoropyrimidine drug (5-FU, FUdR, or FUR) will produce superior cytotoxicity when combined with either oxaliplatin or CPT-11. The purpose of the study was to determine the effects of oxaliplatin and CPT-11 on cytotoxicity and nucleic acid incorporation of all three fluoropyrimidines.

METHODS

HT-29 cells were exposed for 2 h to IC(10), IC(30), and IC(70) of oxaliplatin and CPT-11. Subsequently, cells were exposed for 24 h to IC(10), IC(30), and IC(70) of 5-FU, FUdR, and FUR. Cytotoxicity was measured by the MTT assay. Nucleic acid incorporation of [(3)H]fluoropyrimidine was then compared in the presence and absence of oxaliplatin or CPT-11 pretreatment.

RESULTS

Synergistic cytotoxicity was displayed when IC(30) of oxaliplatin or CPT-11 was combined with IC(10) and IC(30) of the fluoropyrimidines. One fluoropyrimidine did not achieve superior cytotoxicity over the others. After pretreatment with oxaliplatin or CPT-11, cytotoxic antagonism was observed as the concentration of a fluoropyrimidine increased up to IC(70). The increasing cytotoxic antagonism correlated with decreases in fluoropyrimidine nucleic acid incorporation. The most significant incorporation difference existed within the 5-FU treated group.

CONCLUSIONS

No single fluoropyrimidine is more cytotoxically effective over the others when combined with oxaliplatin or CPT-11. Correlation of cytotoxic antagonism to the inhibition of fluoropyrimidine nucleic acid incorporation implies difficulties in drug transport and/or metabolism only after oxaliplatin or CPT-11 pretreatment.

Cytotoxic effects and mechanisms of an alteration in the dose and duration of 5-fluorouracil

5-Fluorouracil (5-FU) is the most routinely administered drug in the treatment of colon cancer. The main mechanism of the drug is not completely understood and its method of administration has been strongly disputed. A 24-hour infusion of 5-FU has clinically yielded better response rates and lower toxicities in comparison to bolus administration, but an exploration into possible mechanisms needs to be performed. Experiments were conducted with two 5-FU resistant cell lines where cytotoxicity, thymidylate synthase (T.S.) activity, thymidine kinase (T.K.) activity, DNA and RNA incorporation, and T.S. expression were contrasted between a 10 microM/24 hour administration of 5-FU (simulating continuous exposure) and a 100 microM/1 hour schedule (simulating bolus administration). After 6 days from the initial exposure, the 10 microM/24 hour schedule (schedule A) inhibited more cell growth than the 100 microM/1 hour regimen (schedule B) by more than 38% and 17% in the two cell lines. After the 6-day observation, schedule A inhibited twice as much T.S. activity as schedule B. Incorporation of [14C]-5-FU into DNA and total RNA was higher in cells exposed to schedule A in comparison to schedule B over the 6 days. T.S. expression and T.K. activity patterns were variable over time. Thus, the exposure of 10 microM/24 hour 5-FU results in superior cytotoxicity when compared to a 100 microM/1 hour regimen and its effectiveness may be explained mechanistically by T.S. activity and DNA and RNA incorporation.

Recombinant leukocyte interferon, doxorubicin, and 5FUDR in patients with hepatocellular carcinoma-A phase II trial

PURPOSE

To study the combination of 5FUDR, recombinant leukocyte interferon (IFN), and doxorubicin in patients with unresectable hepatocellular carcinoma.

METHODS

IFN was administered at a dose of 6 miu/m(2) subcutaneously followed in 2 h by doxorubicin 20 mg/m(2) intravenously. After doxorubicin, 5FUDR was given as a 24-h infusion at a starting dose of 80 mg/kg. The dose of IFN was escalated to three times a week if tolerated. Both doxorubicin and 5FUDR were administered once weekly.

RESULTS

There were 30 patients entered into the study. Among the 30 patients, there were two partial responses (7%) and one patient had stable disease. Toxicity was generally tolerable with fever, and chills, fatigue, and myelosuppression as the most common side effects.

CONCLUSIONS

This chemotherapy combination was generally well tolerated, but has limited activity in unresectable, advanced hepatocellular carcinoma.