A randomized, open-label, phase 2 study of everolimus in combination with pasireotide LAR or everolimus alone in advanced, well-differentiated, progressive pancreatic neuroendocrine tumors: COOPERATE-2 trial

Background

Several studies have demonstrated the antitumor activity of first-generation somatostatin analogs (SSAs), primarily targeting somatostatin receptor (sstr) subtypes 2 and 5, in neuroendocrine tumors (NET). Pasireotide, a second-generation SSA, targets multiple sstr subtypes. We compared the efficacy and safety of pasireotide plus everolimus to everolimus alone in patients with advanced, well-differentiated, progressive pancreatic NET.

Patients and methods

Patients were randomized 1 : 1 to receive a combination of everolimus (10 mg/day, orally) and pasireotide long-acting release (60 mg/28 days, intramuscularly) or everolimus alone (10 mg/day, orally); stratified by prior SSA use, and baseline serum chromogranin A and neuron-specific enolase. The primary end point was progression-free survival (PFS). Secondary end points included overall survival, objective response rate, disease control rate, and safety. Biomarker response was evaluated in an exploratory analysis.

Results

Of 160 patients enrolled, 79 were randomized to the combination arm and 81 to the everolimus arm. Baseline demographics and disease characteristics were similar between the treatment arms. No significant difference was observed in PFS: 16.8 months in combination arm versus 16.6 months in everolimus arm (hazard ratio, 0.99; 95% confidence interval, 0.64-1.54). Partial responses were observed in 20.3% versus 6.2% of patients in combination arm versus everolimus arm; however, overall disease control rate was similar (77.2% versus 82.7%, respectively). No significant improvement was observed in median overall survival. Adverse events were consistent with the known safety profile of both the drugs; grade 3 or 4 fasting hyperglycemia was seen in 37% versus 11% of patients, respectively.

Conclusions

The addition of pasireotide to everolimus was not associated with the improvement in PFS compared with everolimus alone in this study. Further studies to delineate mechanisms by which SSAs slow tumor growth in NET are warranted.

Circulating cytokines and monocyte subpopulations as biomarkers of outcome and biological activity in sunitinib-treated patients with advanced neuroendocrine tumours

BACKGROUND

Sunitinib is approved worldwide for treatment of advanced pancreatic neuroendocrine tumours (pNET), but no validated markers exist to predict response. This analysis explored biomarkers associated with sunitinib activity and clinical benefit in patients with pNET and carcinoid tumours in a phase II study.

METHODS

Plasma was assessed for vascular endothelial growth factor (VEGF)-A, soluble VEGF receptor (sVEGFR)-2, sVEGFR-3, interleukin (IL)-8 (n=105), and stromal cell-derived factor (SDF)-1α (n=28). Pre-treatment levels were compared between tumour types and correlated with response, progression-free (PFS), and overall survival (OS). Changes in circulating myelomonocytic and endothelial cells were also analysed.

RESULTS

Stromal cell-derived factor-1α and sVEGFR-2 levels were higher in pNET than in carcinoid (P=0.003 and 0.041, respectively). High (above-median) baseline SDF-1α was associated with worse PFS, OS, and response in pNET, and high sVEGFR-2 with longer OS (P⩽0.05). For carcinoid, high IL-8, sVEGFR-3, and SDF-1α were associated with shorter PFS and OS, and high IL-8 and SDF-1α with worse response (P⩽0.05). Among circulating cell types, monocytes showed the largest on-treatment decrease, particularly CD14+ monocytes co-expressing VEGFR-1 or CXCR4.

CONCLUSIONS

Interleukin-8, sVEGFR-3, and SDF-1α were identified as predictors of sunitinib clinical outcome. Putative pro-tumorigenic CXCR4+ and VEGFR-1+ monocytes represent novel candidate markers and biologically relevant targets explaining the activity of sunitinib.

A multi-institutional, phase II open-label study of ganitumab (AMG 479) in advanced carcinoid and pancreatic neuroendocrine tumors

The IGF pathway has been implicated in the regulation of neuroendocrine tumor (NET) growth, and preliminary studies suggested that ganitumab (AMG 479), a human MAB against IGF1R, may have antitumor activity in this setting. We performed a two-cohort phase II study of ganitumab in patients with metastatic progressive carcinoid or pancreatic NETs (pNETs). This open-label study enrolled patients (≥18 years) with metastatic low- and intermediate-grade carcinoid or pNETs. Inclusion criteria included evidence of progressive disease (by Response Evaluation Criteria in Solid Tumors (RECIST)) within 12 months of enrollment, ECOG PS 0-2, and fasting blood sugar <160  mg/dl. Prior treatments were allowed and concurrent somatostatin analog therapy was permitted. The primary endpoint was objective response. Secondary endpoints included overall survival (OS), progression-free survival (PFS), and safety. Sixty patients (30 carcinoid and 30 pNETs) were treated with ganitumab 18  mg/kg every 3 weeks, among whom 54 patients were evaluable for survival and 53 patients for response. There were no objective responders by RECIST. The median PFS duration was 6.3 months (95% CI, 4.2-12.6) for the entire cohort; 10.5 months for carcinoid patients, and 4.2 months for pNET patients. The OS rate at 12 months was 66% (95% CI, 52-77%) for the entire cohort. The median OS has not been reached. Grade 3/4 AEs were rare and consisted of hyperglycemia (4%), neutropenia (4%), thrombocytopenia (4%), and infusion reaction (1%). Although well tolerated, treatment with single-agent ganitumab failed to result in significant tumor responses among patients with metastatic well-differentiated carcinoid or pNET.

Weekly docetaxel, cisplatin, and irinotecan (TPC): results of a multicenter phase II trial in patients with metastatic esophagogastric cancer

BACKGROUND

Recent studies have examined the addition of docetaxel to fluorouracil and cisplatin in advanced esophagogastric cancer.

PATIENTS AND METHODS

We carried out a phase I dose-escalation study of weekly docetaxel, cisplatin, and irinotecan (TPC), given on days 1 and 8 every 3 weeks, in patients with chemonaive solid tumors. Subsequently, we completed a multiinstitutional phase II study of TPC in patients with previously untreated, metastatic esophagogastric cancer.

RESULTS

Thirty-nine patients were enrolled in the phase I trial; a weekly schedule of TPC was well tolerated. On that basis, docetaxel 30 mg/m(2), cisplatin 25 mg/m(2), and irinotecan 65 mg/m(2) were selected for the phase II trial, where in the first 18 patients irinotecan 65 mg/m(2) caused too much diarrhea and was reduced to 50 mg/m(2). Among 56 eligible patients with previously untreated, metastatic esophagogastric cancer enrolled in the phase II trial, three complete and 27 partial responses were observed (overall response rate=54%), and 15 patients (30%) had stable disease. Median progression-free survival was 7.1 months, and median survival was 11.9 months. At the final irinotecan dose of 50 mg/m(2), grade 3 or higher toxicity included diarrhea (26%), neutropenia (21%), nausea (18%), fatigue (16%), anorexia (13%), and thrombosis/embolism (13%).

CONCLUSIONS

Weekly TPC is an active and well-tolerated regimen for patients with esophagogastric cancer.

Prediction of response to temozolomide (TMZ)-based therapy by loss of MGMT expression in patients with advanced neuroendocrine tumors (NET)

4505

Background: TMZ, an oral alkylating agent, has recently been shown to be active in a subset of patients with NETs. In other tumor types, methyl-guanine methyl transferase (MGMT) expression is associated with TMZ resistance through its ability to remove methyl/alkyl groups from the O6 -position of guanine, thereby preventing TMZ-induced DNA damage. Methods: To better define NET pts who benefit from TMZ, we performed a retrospective analysis of 76 NET pts treated with TMZ-based regimens at 3 institutions, identified using IRB-approved observational and clinical trial databases. Immunohistochemical MGMT expression was measured in a subset of pts with available paraffin-embedded archival tissue specimens in a blinded fashion, utilizing mouse monoclonal antibodies to MGMT. Nuclear MGMT expression was scored as either present or absent in tumor cells and correlated with tumor type and treatment outcome. Results: Of 76 pts, 30 received TMZ/thalidomide and 46 received TMZ/bevacizumab. Both regimens incorporate oral TMZ, administered at a dose of 150 mg/m2 qd for 7d, every other week. 63 pts were enrolled on phase II studies, and 13 pts were treated outside a formal study protocol. Pt characteristics were: M:F=42:34; median age 57.5 (20–75); tumor type carcinoid (38), pancreatic NET (35), paraganglioma/pheochromocytoma (3). PR or CR (as measured by RECIST) was observed in 11/35 (31%) pancreatic NETs and 0/38 carcinoid pts (P<0.001), as well as 1/3 pts with paraganglioma/pheo. In 21 pts with available specimens, complete absence of MGMT expression was observed in 5/8 pancreatic NET and 0/13 carcinoid tumors (P<0.01). In this pt subset, absence of MGMT expression was associated with response to TMZ ( Table 1 ). Conclusions: Treatment with TMZ is associated with radiologic response in approximately one third of pts with pancreatic NET, but not in pts with carcinoid tumors. Absence of MGMT expression appears to define pts with pancreatic NET who achieve significant benefit from TMZ.

[Table: see text]

No significant financial relationships to disclose.

Prognostic significance of nuclear excision (NER) and base excision (BER) DNA repair gene polymorphisms in esophageal cancer

2511

Background: DNA repair pathways are involved in cisplatin-induced damage (NER pathway) & radiation damage (BER pathway). Some single nucleotide polymorphisms (SNPs) of DNA repair genes are associated with DNA repair capacity, cancer risk & outcomes. We investigated the prognostic significance of 7 NER/BER SNPs on disease free (DFS) & overall survival (OS) in esophageal cancer. Methods: 150 patients with esophageal cancer treated with cisplatin-based chemoradiation & surgery were genotyped for BER (XRCC1 Arg399Gln; APE1 Asp148Glu; hOGG1 Ser326Cys) & NER (ERCC1 8092C/A; ERCC1 codon 118 C/T; XPD Asp312Asn; XPD Lys751Gln) SNPs. Analysis involved Kaplan-Meier curves, log-rank tests, and Cox proportional hazards models. Results: Median age: 63 years (range 28–80); 91% male; 100% ECOG performance status (PS) 0–1; adenocarcinoma 79%; stages IIA 22%, IIB 30%, III 33%, and IVA 15%. No SNPs were associated with stage or PS. Multiple NER SNP was independently prognostic for OS and DFS (see Table ). When compared to individuals who were wildtype in all four studied NER SNPs, individuals with variants in all four NER SNPs were associated with substantial improvement in OS (Adjusted Hazard Ratio (AHR) = 0.40, 95% confidence interval (CI) = 0.2–0.7) and DFS (AHR = 0.44, 95%CI = 0.2–0.8). Furthermore, increasing numbers of variant genotypes were associated with a progressive increase in OS & DFS when all seven NER/BER pathway SNPs were analysed together ( Table ). There was a 3.8- fold increase in OS (75 vs. 20 months) and five-fold increase in DFS (51 vs. 10 months) when comparing individuals with 6–7 SNPs with variant alleles to individuals with 0–1 SNPs with variant alleles. Conclusions: The ERCC1 8092 C/A, XPD Asp312Asn & XPD Lys751Gln SNPs in the NER pathway are associated individually with prognosis in esophageal cancer patients treated with cisplatin-based trimodality regimens. In addition, as the number of NER and BER SNPs carrying variant alleles increased, OS and DFS improved dramatically.

[Table: see text]

No significant financial relationships to disclose.

MMP1 1G/2G promoter polymorphism and risk of esophageal adenocarcinoma

10555

Background: The 2G allele of the MMP1 -1607 1G/2G promoter polymorphism creates an Ets binding site that leads to increased transcriptional and enzyme activity, particularly in the presence of growth factors and cytokines. This polymorphism has been associated with greater risk of cancer (e.g., renal cell, lung and oral cancers, glioblastomas) and cancer invasiveness (e.g., melanoma, cervical, lung and colorectal cancer). The aim of the current study was to evaluate the role of this MMP 1G/2G polymorphism in the risk of esophageal adenocarcinoma (EA). Methods: We evaluated 323 histologically confirmed EA cases and 464 healthy controls frequency-matched for age and gender. Genotyping of the MMP1 1G/2G promoter polymorphism involved a Taqman approach. All EAs had endoscopic evidence showing that the center of the tumors were located at or above the gastroesophageal junction. Odds Ratios (OR) were calculated using multivariate logistic regression, adjusted for age, gender, smoking status, and body-mass index (BMI) at the age of 18 years (to represent a healthy adult BMI). Results: Genotype frequencies were: 33% (1G/1G), 47% (1G/2G) & 20% (2G/2G) in controls; in cases, 26% (1G/1G), 50% (1G/2G) & 24% (2G/2G). 88% of cases were male. The MMP1 2G/2G and 1G/2G genotypes conferred a greater risk of EA, with adjusted ORs of 1.50 (95%CI=1.0–2.3) and 1.34 (95%CI=0.9–1.9), respectively, when compared with the wildtype 1G/1G genotype. The 2G allele (2G/2G + 1G/2G) conferred an adjusted OR of 1.38 (95%CI=1.0–1.9). By stage, the adjusted ORs for the 2G allele were 1.26 (95%CI=0.8–2.1), 1.45 (95%CI=0.9–2.3), & 1.54 (95%CI=0.9–2.7) for node negative, node-positive, and metastatic disease, respectively. Conclusions: The 2G allele of the MMP1 -1607 1G/2G polymorphism was associated with an increased risk of EA in this analysis. In addition, there was a non-significant trend towards conferring greater risk in the more advanced stages of EA, suggesting a possible role of this polymorphism in the invasiveness of this cancer.

No significant financial relationships to disclose.

A phase II study of docetaxel in combination with ZD1839 (gefitinib) in previously treated patients with metastatic pancreatic cancer

15080

Background: The reported activity of docetaxel in pancreatic cancer and high level of EGFR expression in pancreatic carcinomas led us to examine the efficacy of combination docetaxel and gefitinib in patients with metastatic pancreatic cancer. Methods: Eligibility criteria included PS = 1, failed prior adjuvant ot metastatic gemcitabine-containing regimen, = 1 prior regimen for metastatic disease, no prior taxane or EGFR inhibitor, and adequate organ function. Patients received docetaxel 40 mg/m2 intravenously weekly for 2 of every 3 weeks and daily oral gefitinib 250 mg. The primary endpoint was CA19–9 response (>50% decrease in tumor marker CA19–9 levels). Additional endpoints included radiologic response, toxicity, and survival. Results: Fifteen patients received docetaxel and gefitinib between 11/2/04 and 11/26/05. The median age of patients was 60 (46–76), and included 7 women and 8 men. The regimen was generally well tolerated, and there were no unanticipated toxicities. Grade 3 or 4 toxicities included lymphopenia (6 pts), hyperglycemia (3 pts), leucopenia (3 pts), infection (2 pts), fatigue (2 pts), elevated transaminases (2 pts), neutropenia (2 pts), pleural effusion (2 pts), irregular menses (1 pt), anorexia (1 pt), dysphagia/esophagitis (1 pt), diarrhea (1 pt), alkaline phosphatase (1 pt), and sensory neuropathy (1 pt). No treatment-related deaths occurred. No patient experienced a biochemical (CA 19–9) response to treatment. All 15 patients were evaluable for radiologic response, of which 9 experienced stable disease and 6 progressive disease as their best response to therapy. The trial was stopped due to lack of efficacy, in accordance with an early stopping rule incorporated into the trial design. Conclusions: In the doses and schedule used in this trial, the combination of docetaxel and gefitinib does not appear to be active in patients with pancreatic cancer who have failed prior gemcitabine-based chemotherapy.

No significant financial relationships to disclose.

A phase II study of pemetrexed in patients (pts) with advanced neuroendocrine tumors (NETs)

15149

Background: Traditional antifolates such as 5-florouracil have been associated with only modest activity in NETs. Pemetrexed is a multitargeted antifolate active in diseases not known to be responsive to other antifolates. We performed a prospective phase II study of pemetrexed in pts with advanced NETs to assess response, toxicity, and survival. Methods: Pts were treated with Pemetrexed administered intravenously at a dose of 500 mg/m2 every 21 days. To reduce toxicity, folic acid and vitamin B12 supplementation were mandatory. Pts were also treated with oral dexamethasone 4 mg twice daily the day prior to, day of, and day after pemetrexed administration. The study utilized a two-step design, with an initial accrual phase of 17. Pts were required to have metastatic neuroendocrine tumors (excluding small cell carcinoma), and preserved hematologic, renal, and hepatic function. Treatment with prior chemotherapy was allowed; pts receiving octreotide remained on octreotide at a stable dose level during study therapy. Results: 17 pts were enrolled with the following characteristics: M: F=4:13. median age 56 (range 38 to 72); ECOG Performance Status 0/1/2=4/12/1. Tumor types included carcinoid n=12(71%) and islet cell n=5(29%). 17 pts received treatment for a median of three, 21-day cycles; the median time on study was 10 weeks. Grade 3–4 toxicities included: fatigue n=8(47%), leukopenia n=7 (41%), neutropenia n=6 (35%), elevated alkaline phosphatase n=4 (23%), thrombocytopenia n=3 (17%), lymphopenia n=3 (17%), pneumonitis n=2 (11%), hyponatremia n=2 (11%), dyspnea n=1 (5%), hyperbilirubinemia n=1 (5%), weight loss n=1 (5%), diarrhea n=1 (5%), elevated ALT/SGPT n=1 (5%), edema n=1 (5%), weakness n=1 (5%), grade 4 proteinuria n=1 (5%). 15 pts were evaluable for response; the best treatment response was stable disease (n=9;), the remaining 6 pts experienced progressive disease as their best response to therapy. Accrual to the study was halted due to lack of observed antitumor activity. Conclusions: Pemetrexed does not have significant antitumor activity in pts with advanced NET.

No significant financial relationships to disclose.

A phase II study of temozolomide and bevacizumab in patients with advanced neuroendocrine tumors

4044

Background: Inhibitors of the VEGF pathway have been shown to have activity in neuroendocrine tumors (NETs). Temozolomide (TMZ), an oral analog of dacarbazine is also active in this setting. We performed a prospective, phase II study to assess the safety and efficacy of TMZ, administered in combination with bevacizuamb, in patients (pts) with advanced NETs. Methods: Pts received TMZ, 150 mg/m2/day po for 7 days every other week, and bevacizumab, 5 mg/kg IV every other week. Due to anticipated lymphopenia, pts received prophylaxis with trimethoprim/sulfamethoxazole (1 DS tablet q MWF) and acyclovir (400 mg po TID). Pts were followed for toxicity, response, and survival. Results: Enrolled patients (n=34) had the following characteristics: M:F = 19:15; median age 61 (range 37–75); ECOG PS 0/1/2 = 12/20/2; carcinoid/pancreatic NET = 16/18. Prior treatments included chemoembolization (n=7) chemotherapy (n=12); and octreotide (n=17); pts on octreotide remained on octreotide at stable doses for the duration of the study. Pts had either well-differentiated tumors (n=27) or moderately/poorly-differentiated NETs (n=7); pts with small cell carcinoma were not eligible for the study. Pts have received treatment for a median of 22 weeks. Grade 3–4 toxicities included: lymphopenia (n=21, 62%), leukopenia (n=2, 6%), thrombocytopenia (n=7, 21%), neutropenia (n=2, 6%), hyponatremia (n=1, 3%), vomiting (n=3, 9%), nausea (n=2, 6%), dehydration (n=1, 3%), fatigue (n=2, 6%), constipation (n=1, 3%), and hypertension (n=1, 3%). 20 pts had elevated CGA levels (>36.4 ng/ml) at baseline; 0/9 (0%) carcinoid and 4/11 (36%) pancreatic NET experienced CGA decreases of >50% from baseline on two consecutive assessments. 29 pts are currently evaluable for radiologic response ( Table ). Conclusions: The combination of TMZ and bevacizumab can be safely administered and shows promising activity in pts with advanced pancreatic NETs. Additional studies with this combination are warranted.

[Table: see text]

[Table: see text]

Analysis of circulating biomarkers of sunitinib malate in patients with unresectable neuroendocrine tumors (NET): VEGF, IL-8, and soluble VEGF receptors 2 and 3

4045

Background: Sunitinib malate (SU11248) is a multitargeted tyrosine kinase inhibitor with antitumor and antiangiogenic activity that specifically inhibits VEGFR, PDGFR, KIT, RET, and FLT3. In a phase II trial of 109 patients with metastatic neuroendocrine tumors (NET), sunitinib treatment was associated with ORR and high rates of SD in patients with carcinoid and pancreatic islet cell tumors (Kulke et al, ASCO 2005). To characterize potential biomarkers of biological response to sunitinib, we analyzed plasma levels of a panel of soluble proteins from patients in this trial. Methods: Patients received sunitinib in 6-week cycles comprised of 50 mg/day for 4 weeks followed by 2 weeks off treatment. Pre-dose plasma samples from 106 patients were obtained on days 1 and 28 of multiple cycles. Plasma levels of VEGF, soluble VEGF receptor 2 (sVEGFR-2), interleukin-8 (IL-8), and a novel biomarker, sVEGFR-3, were measured via ELISA analysis. Results: Plasma levels of each protein were frequently modulated during the course of treatment. At the end of cycle 1, VEGF levels were increased more than 3-fold over baseline in ∼50% of all patients. Average baseline VEGF levels were higher in the islet cell group (62 vs. 40 pg/ml, P = 0.06). In cycle 1, sVEGFR-2 and sVEGFR-3 levels were significantly decreased by ≥30% in ∼60% and 70% of all patients, respectively (P < 0.0001). Levels tended to return to near-baseline after 2 weeks off treatment. The reduction in sVEGFR-3 levels in cycle 1 was, on average, greater in the subset of patients with PR (n=11) compared to others (45% vs. 38%). Overall, there was a 2.2-fold average increase in IL-8 levels by the end of cycle 1, and a larger proportional increase in IL-8 levels in patients exhibiting decreases in tumor size, patients who also tended to have lower baseline IL-8 levels. Further analysis of correlations with pharmacokinetic and clinical parameters is ongoing. Conclusions: Our results suggest that this panel of circulating proteins may be of utility as pharmacodynamic biomarkers of sunitinib activity in patients with advanced NET. sVEGFR-3 may be a novel biomarker of the biological activity of sunitinib in NET, and IL-8 may be of particular interest as a potential predictor of response.

[Table: see text]

Malignant transformation of the esophageal mucosa is enhanced in p27 knockout mice

OBJECTIVE

In a previous study, we showed that experimentally induced gastroduodenal-esophageal reflux in mice treated with a carcinogen can result in Barrett esophagus and Barrett-associated adenocarcinoma. Since we have shown that most Barrett-associated adenocarcinomas in human beings have lost the tumor suppressor gene p27, we sought to determine whether cancer would be more likely to develop in p27 knockout mice than in p27 heterozygous or p27 wild type mice.

METHODS

Three groups of mice were treated by esophagojejunostomy resulting in gastroduodenal-esophageal reflux and by a carcinogen (N -methyl-N -benzylnitrosamine): group I (50 wild type), group II (45 p27 heterozygous), and group III (50 p27 knockout). The mice were killed 18 to 20 weeks after operation and studied macroscopically and histopathologically.

RESULTS

Barrett esophagus developed in 7 (14%) mice in group I, 4 (8.9%) mice in group II, and 13 (26%) mice in group III. Cancers developed in 30 (60%) mice in group I, 31 (68%) mice in group II, and 43 (86%) mice in group III. Ten percent of the cancers in group I were adenocarcinomas, as were 16.1% in group II, and 23.3% in group III. The difference between rates of Barrett esophagus in groups I and II compared with group III was statistically significant (P =.035), as was true of the cancer rates (P =.006). The percentage of cancers that were adenocarcinomas was highest in group III, but not significantly different from groups I and II.

CONCLUSIONS

This experimental mouse model of Barrett esophagus and Barrett- associated adenocarcinoma is similar to what occurs in human beings and may be useful in developing methods to inhibit malignant transformation of Barrett esophagus.

Microsatellite instability and hMLH1/hMSH2 expression in Barrett esophagus-associated adenocarcinoma

BACKGROUND

Microsatellite instability (MSI) has been documented in malignancies associated with hereditary nonpolyposis colon carcinoma and in sporadic malignancies of the colon, stomach, and endometrium. In these malignancies, MSI is associated with defects in the DNA mismatch repair enzymes hMSH2 and hMLH1. Defects in these enzymes result in a phenotype characterized by instability of multiple microsatellite repeat sequences throughout the genome. This study sought to determine the prevalence of MSI in 80 primary Barrett esophagus-associated adenocarcinomas (BEAd) and to examine the relation of MSI with the clinical and pathologic features of the tumors.

METHODS

Eighty BEAd were evaluated for the presence of MSI by using the microsatellite markers BAT25, BAT26, D10S219, D10S541, and D10S551. These tumors also were evaluated for immunohistochemical expression of hMSH2 and hMLH1.

RESULTS

High levels of MSI were not found in any of the tumors examined. Furthermore, immunohistochemical expression of hMSH2 and hMLH1 was retained in all cases evaluated. Evidence of low level MSI was found in 16% of tumors. In none of these tumors, however, was MSI present in more than two of five loci. The presence of MSI did not correlate with patient age, tumor stage, degree of differentiation, or with patient survival.

CONCLUSIONS

High level MSI and loss of hMLH1/hMSH2 expression is uncommon in BEAd. A subset of BEAd demonstrate low level MSI. The presence of low level MSI was not associated with the clinicopathologic features of the tumors examined.

Microsatellite instability and hMLH1/hMSH2 expression in Barrett esophagus-associated adenocarcinoma

BACKGROUND

Microsatellite instability (MSI) has been documented in malignancies associated with hereditary nonpolyposis colon carcinoma and in sporadic malignancies of the colon, stomach, and endometrium. In these malignancies, MSI is associated with defects in the DNA mismatch repair enzymes hMSH2 and hMLH1. Defects in these enzymes result in a phenotype characterized by instability of multiple microsatellite repeat sequences throughout the genome. This study sought to determine the prevalence of MSI in 80 primary Barrett esophagus-associated adenocarcinomas (BEAd) and to examine the relation of MSI with the clinical and pathologic features of the tumors.

METHODS

Eighty BEAd were evaluated for the presence of MSI by using the microsatellite markers BAT25, BAT26, D10S219, D10S541, and D10S551. These tumors also were evaluated for immunohistochemical expression of hMSH2 and hMLH1.

RESULTS

High levels of MSI were not found in any of the tumors examined. Furthermore, immunohistochemical expression of hMSH2 and hMLH1 was retained in all cases evaluated. Evidence of low level MSI was found in 16% of tumors. In none of these tumors, however, was MSI present in more than two of five loci. The presence of MSI did not correlate with patient age, tumor stage, degree of differentiation, or with patient survival.

CONCLUSIONS

High level MSI and loss of hMLH1/hMSH2 expression is uncommon in BEAd. A subset of BEAd demonstrate low level MSI. The presence of low level MSI was not associated with the clinicopathologic features of the tumors examined.

Microsatellite instability and hMLH1/hMSH2 expression in Barrett esophagus-associated adenocarcinoma

BACKGROUND

Microsatellite instability (MSI) has been documented in malignancies associated with hereditary nonpolyposis colon carcinoma and in sporadic malignancies of the colon, stomach, and endometrium. In these malignancies, MSI is associated with defects in the DNA mismatch repair enzymes hMSH2 and hMLH1. Defects in these enzymes result in a phenotype characterized by instability of multiple microsatellite repeat sequences throughout the genome. This study sought to determine the prevalence of MSI in 80 primary Barrett esophagus-associated adenocarcinomas (BEAd) and to examine the relation of MSI with the clinical and pathologic features of the tumors.

METHODS

Eighty BEAd were evaluated for the presence of MSI by using the microsatellite markers BAT25, BAT26, D10S219, D10S541, and D10S551. These tumors also were evaluated for immunohistochemical expression of hMSH2 and hMLH1.

RESULTS

High levels of MSI were not found in any of the tumors examined. Furthermore, immunohistochemical expression of hMSH2 and hMLH1 was retained in all cases evaluated. Evidence of low level MSI was found in 16% of tumors. In none of these tumors, however, was MSI present in more than two of five loci. The presence of MSI did not correlate with patient age, tumor stage, degree of differentiation, or with patient survival.

CONCLUSIONS

High level MSI and loss of hMLH1/hMSH2 expression is uncommon in BEAd. A subset of BEAd demonstrate low level MSI. The presence of low level MSI was not associated with the clinicopathologic features of the tumors examined.

Allelic loss of 10q23, the PTEN tumour suppressor gene locus, in Barrett's oesophagus-associated adenocarcinoma

PTEN is a putative tumour suppressor gene located on chromosome band 10q23. Mutations in PTEN have been identified in numerous human malignancies, including cancers of the brain, endometrium, ovary, and prostate. In this study, we screened 80 Barrett's oesophagus-associated adenocarcinomas (BOAd) for loss of heterozygosity (LOH) at 10q23, using the microsatellite markers D10S541, D10S219, and D10S551. Tumours demonstrating LOH were then screened for the presence or absence of PTEN mutations. LOH at one or more loci was identified in 17/80 (21%) cases. In none of these cases did we detect mutations in PTEN. The presence of LOH did not correlate with patient age, tumour stage, degree of differentiation, presence of perineural or vascular invasion, or overall survival. We conclude that LOH at chromosome 10q23 is uncommon in BOAd, is not associated with mutations in the PTEN tumour suppressor gene, and does not correlate with the clinical or pathologic features of these tumours. It is possible that PTEN is inactivated through other mechanisms in BOAd.

Malignant epithelioid angiomyolipoma ('sarcoma ex angiomyolipoma') of the kidney: a case report and review of the literature

Malignant epithelioid angiomyolipoma is a recently described rare tumor of the kidney. Its existence has been questioned, however, on the basis of incomplete evidence of malignant behavior, the absence of an associated classic angiomyolipoma component, or the absence of immunoreactivity for HMB-45 in some cases. We describe a case that was HMB-45-positive and arose in association with a classic angiomyolipoma. The patient was treated with a partial nephrectomy. Three years later, she developed rapidly enlarging liver nodules. A fine-needle aspiration of the liver confirmed the presence of pleomorphic epithelioid cells morphologically and immunohistochemically identical to those comprising the primary renal tumor. After two cycles of treatment with doxorubicin, there was a 50% reduction in the size of the tumors with marked improvement in performance status. We believe this case confirms the existence of a malignant epithelioid angiomyolipoma.

Pneumocystis carinii pneumonia in patients receiving chemotherapy for breast cancer

Pneumocystis carinii pneumonia (PCP) is uncommon in patients undergoing chemotherapy for breast cancer. Most previously described patients with breast cancer and PCP received treatment with corticosteroids, a known risk factor for PCP. We describe two patients with metastatic breast cancer who developed PCP after receiving therapy with high doses of cyclophosphamide with peripheral blood stem cell support. Both patients developed fevers of unclear etiology in the setting of recovery of the neutrophil count. Only one patient had pulmonary symptoms. P. carinii infection was documented in both cases by bronchoscopy. One patient died after prolonged ventilatory support for PCP. Steroid exposure did not appear to be a risk factor for the development of PCP in either patient. Patients receiving sequential high doses of chemotherapy with stem cell support may be at increased risk for PCP. The role of prophylaxis for PCP in this setting should be continually redefined as the type and intensity of chemotherapy, as well as methods of procurement of autologous stem cells, continue to change.