A phase II study evaluating the safety and efficacy of an adenovirus-ΔLMP1-LMP2 transduced dendritic cell vaccine in patients with advanced metastatic nasopharyngeal carcinoma

BACKGROUND

Individuals with metastatic Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) continue to have poor outcomes. To evaluate the ability of a dendritic cell (DC) vaccine to target subdominant EBV antigens LMP1 and LMP2 expressed by NPC cells, we vaccinated patients using autologous DCs transduced with an adenovirus encoding a truncated LMP1 (ΔLMP1) and full-length LMP2 (Ad-ΔLMP1-LMP2).

MATERIALS AND METHODS

Sixteen subjects with metastatic NPC received Ad-ΔLMP1-LMP2 DC vaccines i.d. biweekly for up to five doses. Toxicity, immune responses and clinical responses were determined.

RESULTS

Most patients had extensive disease, with a median of three visceral sites of involvement (range 1-7). No significant toxicity was observed. Ad-ΔLMP1-LMP2 DCs induced delayed type hypersensitivity responses in 9 out of 12 patients, but although these DCs activated LMP1/2-specific T cells in vitro, no such increase in the frequency of peripheral LMP1/2-specific T cells was detected. Three patients had clinical responses including one with partial response (for 7½ months) and two with stable disease (for 6½ and 7½ months).

CONCLUSIONS

Ad-ΔLMP1-LMP2 transduced DCs can be successfully generated and safely administered to patients with advanced NPC. Since efficacy was limited, future studies should focus on DC vaccines with greater potency administered to subjects with less tumor burden.

Graft-vs-tumor effect in patients with advanced nasopharyngeal cancer treated with nonmyeloablative allogeneic PBSC transplantation

While nonmyeloablative peripheral blood stem cell transplantation (NST) has shown efficacy against several solid tumors, it is untested in nasopharyngeal cancer (NPC). In a phase II clinical trial, 21 patients with pretreated metastatic NPC underwent NST with sibling PBSC allografts, using CY conditioning, thymic irradiation and in vivo T-cell depletion with thymoglobulin. Stable lymphohematopoietic chimerism was achieved in most patients and prophylactic CYA was tapered at a median of day +30. Seven patients (33%) showed partial response and three (14%) achieved stable disease. Four patients were alive at 2 years and three showed prolonged disease control of 344, 525 and 550 days. With a median follow-up of 209 (4-1147) days, the median PFS was 100 days (95% confidence interval (CI), 66-128 days), and median OS was 209 days (95% CI, 128-236 days). Patients with chronic GVHD had better survival-median OS 426 days (95% CI, 194-NE days) vs 143 days (95% CI, 114-226 days) (P=0.010). Thus, NST may induce meaningful clinical responses in patients with advanced NPC.

A phase I pharmacokinetic study of a liposomal formulation of paclitaxel administered weekly to Asian patients with solid malignancies

2581

Background: Genexol-PM is a sterile, lyophilized polymeric micellar formulation of paclitaxel which is devoid of Cremophor EL and hence is more tolerable and less toxic. This phase 1 study sought to determine the maximum tolerated dose and the pharmacokinetic profile of Genexol-PM in Asian cancer patients with solid malignancies. Methods: Patients (N=35) refractory to previous chemotherapy were enrolled in a phase 1, open-label, dose-escalating study to assess safety, tolerability ad pharmacokinetics of Genexol-PM administered as a 1h infusion on a weekly basis for 3 weeks followed by a resting week. The starting dose was 80mg/m2. Cohorts of 1–6 patients were treated at 100, 120, 140, 160, 180 and the maximum administered dose was 200 mg/m2. Results: The median age was 56 years (range: 39 - 67 years) and two thirds of the enrolled patients were male (67%). Twenty-three patients (96%) had received prior chemotherapy, including eleven patients (46%) who had previously received taxane-based chemotherapy. The majority of patients had lung, nasopharyngeal and breast cancers. DLT was reached at 200 mg/m2. The MTD was 180 mg/m2. Grade 3 granulocytopenia was common in patients receiving Genexol-PM at doses of 120 mg/m2 or higher in the first cycle. The most common grade 3 non-haematologic adverse events in cycle 1 were fatigue, myalgia and neuropathy and occurred mainly at dose level 7 (200 mg/m2) in 4%, 4% and 8% of the patients. Five (21%) patients had partial response, 9 (38%) had stable disease and seven (29%) patients had disease progression. The pharmacokinetics of Genexol-PM displayed dose-proportionality, with both Cmax and AUC0-∞ values increasing by approximately 4- and 3-fold as the dose of Genexol-PM was increased from 80mg/m2 to 200mg/m2 with no significant change in clearance. The median total-body clearance of Genexol-PM for all patients was 43.9 L/hr. Conclusions: The weekly regimen of Genexol-PM was found to be well-tolerated and responses were observed in patients with refractory tumours, including patients who had failed taxane-based chemotherapy previously.

No significant financial relationships to disclose.

High incidence of symptomatic methemoglobinemia (metHb) in Asian patients (pts) treated with 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, triapine) and gemcitabine (GEM) in a second-line phase II trial of metastatic non-small cell lung cancer

18207

Background: Triapine (Vion Pharmaceuticals) is an inhibitor of ribonucleotide reductase that can enhance GEM uptake in GEM- resistant cell lines. Clinically significant metHb has been rarely reported with triapine & G6PD-deficient pts maybe more susceptible. This multicenter study evaluated the activity & safety of combined triapine-GEM in pts with metastatic NSCLC who had progressed despite prior response or disease stabilization to 1st line platinum-GEM regimen. Methods: Eligible pts were treated with triapine (105mg/m2) as 4-hr IV infusion, followed by GEM (1g/m2) over 30-min on days 1, 8 & 15, repeating every 28 days for 6 cycles. G6PD-deficient pts were excluded. Results: 6 males & 6 female Asian pts (median age: 65 yrs) received a median no. of 2 cycles (range 1–6 cycles). At a median follow-up of 4.6 mos, no response was seen. 4 pts had stable disease. Median time to progression was 3 mos (95% CI: 1.7–9.1 mos). Gr 3–4 toxicities included neutropenia (gr 3, 2 pts), hypoxia (gr 3, 3 pts) & dyspnea (gr 3, 1 pt). There were no treatment-related deaths & all pts remained alive at analysis. 4 pts developed symptomatic metHb during, or ≤ 4 hrs of stopping triapine. This was manifested as dyspnea &/or hypoxia, associated with an oxygen saturation of ≤90% at room air. Arterial metHb assay performed during the hypoxic episode showed a metHb level of up to 15% of total concentration of hemoglobin ([Hb]), which fell to < 5% of [Hb] within 4–6 hrs of stopping triapine. All pts recovered with conservative treatment & none required reversal with methylene blue. 3 out of the 4 pts were able to continue treatment after dose-reduction of triapine. Conclusions: The cause of the relatively high incidence of triapine-related symptomatic metHb was unclear in this Asian cohort. This study was terminated prematurely due to lack of response.

No significant financial relationships to disclose.

Phase II Trial of Gemcitabine and Cisplatin Sequentially Administered in Asian Patients With Unresectable or Metastatic Non-small Cell Lung Cancer

Introduction: The aim of this study was to assess toxicity and response in the sequential administration of gemcitabine followed by cisplatin in unresectable or metastatic non-small cell lung cancer. Materials and Methods: Twenty-three patients were enrolled in this study. Gemcitabine was given at 1250 mg/m2 on days 1 and 8, for four 21-day cycles, followed by cisplatin 40 mg/m2 on days 1, 8 and 15, for three further 28-day cycles. Results: There were 4 patients with partial responses, 5 patients with stable disease and 10 patients with progressive disease, giving a response rate of 21%. The median time to disease progression was 3.3 months. The median overall survival was 14.6 months. Toxicities graded 3 or 4 included anaemia (13.0%), neutropaenia (13.0%), supraventricular tachycardia (4.3%), and nausea and vomiting (4.3%). Conclusion: Although these results show similar efficacy to single-agent treatment regimens, the low toxicity profile and promising survival outcome with this regimen are important points for consideration. Key words: Anaemia, Neutropaenia, Supraventricular tachycardia

Phase II trial of gemcitabine and cisplatin sequentially administered in Asian patients with unresectable or metastatic non-small cell lung cancer

INTRODUCTION

The aim of this study was to assess toxicity and response in the sequential administration of gemcitabine followed by cisplatin in unresectable or metastatic non-small cell lung cancer.

MATERIALS AND METHODS

Twenty-three patients were enrolled in this study. Gemcitabine was given at 1,250 mg/m2 on days 1 and 8, for four 21-day cycles.

RESULTS

There were 4 patients with partial responses. 5 patients with stable disease and 10 patients with progressive disease, giving a response rate of 21%. The median time to disease progression was 3.3 months. The median overall survival was 14.6 months. Toxicities graded 3 or 4 included anaemia (13.0%), neutropaenia (13.0%), supraventricular tachycardia (4.3%), and nausea and vomiting (4.3%).

CONCLUSION

Although these results show similar efficacy to single-agent treatment regimens, the low toxicity profile and promising survival outcome with this regimen are important points for consideration.

Concurrent chemoradiotherapy followed by surgery in locally advanced squamous cell carcinoma of the oesophagus: a single centre experience

INTRODUCTION

Data on combined modality treatment for locally advanced squamous cell carcinoma of the oesophagus involving Asian patients are limited.

MATERIALS AND METHODS

A retrospective study of 56 consecutive patients with this condition treated with concurrent chemoradiotherapy followed by surgery in a single tertiary institution in Singapore was performed.

RESULTS

The median overall survival of the entire cohort was 14.1 months [95% confidence interval (CI); range, 8.6 to 19.6 months]. In patients who underwent successful oesophagectomy after chemoradiotherapy (n = 17), the median survival was 27.8 months compared to 9.8 months for those who did not have surgery (n = 39) (P = 0.046, log-rank test). The median time to first relapse for the entire cohort was 16.1 months (95% CI, 7.7 to 24.5 months). The time to first relapse was 23.9 months in the subgroup of patients with successful surgery and 12.1 months in the group which did not (P = 0.147, log-rank test). The high proportion of patients who were medically unfit for surgery or declined surgery may have conferred a selection bias.

CONCLUSION

Concurrent chemoradiotherapy followed by surgery is feasible in selected patients. The benefit of adding of surgery to chemoradiotherapy is still controversial and we await the results of randomised controlled trials comparing chemoradiotherapy with surgery versus chemoradiotherapy alone.

Antivirion effects of streptovaricin complex against Friend virus

The in vitro antivirion activities of five different streptovaricin complex lots against the polycythemic strain of the Friend virus were evaluated. The assay system was based on the inhibition of the Friend virus-induced spleen foci. The virus inactivation process was shown to be susceptible to variation in temperature, pH, and time. The antivirion activity and the acute toxicity for mice, as well as the optical properties of these streptovaricin complexes, do not co-vary; this suggests that their biological activities are not associated with a single molecular structure. In addition, the antivirion activity of the five preparations of streptovaricin complex differs about 30-fold, indicating that this activity does not reside in a major component of the complex.

A case of metastatic squamous cell carcinoma of the hypopharynx manifesting as acute abdomen

INTRODUCTION

Squamous cell head and neck cancers are usually confined to local and regional sites but occasionally, patients may present with rare manifestations of distant metastases.

CLINICAL PICTURE

A 23-year-old female was treated with concurrent chemo-radiotherapy for stage IVA post-cricoid squamous cell carcinoma. A month later, she presented with acute abdomen and was found to have extensive peritoneal nodules at laparotomy. Intestinal obstruction soon followed.

TREATMENT

She was managed conservatively for the intestinal obstruction and given weekly paclitaxel.

OUTCOME

She continued to deteriorate and succumbed shortly after the diagnosis of carcinomatosis peritoneii.

CONCLUSION

This rare and aggressive presentation reminds us to be cognizant of relapsed head and neck cancers manifesting atypically, and the need for more aggressive search of distant disease in at least some subgroups of head and neck cancer.

Design of a prognostic index score for metastatic nasopharyngeal carcinoma

The survival outcome of patients with systemic cancer differs significantly between individuals even within the same tumour type. We set out to illustrate this by analysing the factors determining survival in patients with metastatic disease from nasopharyngeal carcinoma (NPC) and to design a scoring system based on these prognostic factors. Patients referred between January 1994 and December 1999 were retrospectively analysed. Factors analysed included patient (age group, gender, performance status (BS) at diagnosis of metastases), disease (number of metastatic sites, specific metastatic sites, disease-free interval (DFI), metastases at presentation, presence of locoregional recurrence), and laboratory factors (leucocyte count, haemoglobin level, albumin level). Univariate and multivariable analyses were performed using the Cox proportion hazards model. A numerical score was derived from the regression coefficients of each independent prognostic variable. The prognostic index score (PIS) of each patient was calculated by totalling up the scores of each independent variable. Independently significant, negative prognostic factors were liver metastasis, lung metastasis, anaemia, poor PS, distant metastasis at initial diagnosis, and a DFI of <6 months. Three prognostic groups based on the PIS were obtained: (i) good risk (PIS=0-6); (ii) intermediate risk (7-10); (iii) poor risk (>or=11). The median survivals for these groups were 19.5, 10, and 5.8, months, respectively, (log rank test: P<0.0001). The variable prognosis of patients with disseminated NPC can be assessed by using easily available clinical information (patient, disease and laboratory factors). The PIS system will need to be validated on prospectively collected data of another cohort of patients.

A multicenter phase II study of the efficacy and safety of docetaxel plus cisplatin in Asian chemonaïve patients with metastatic or locally advanced non-small cell lung cancer

AIMS

To evaluate the efficacy and safety of docetaxel-cisplatin in patients with metastatic or locally advanced non-small cell lung cancer (NSCLC).

METHODS

Chemotherapy-naïve patients with histologically confirmed TNM stage III or IV NSCLC were recruited from 12 Asian trial centers. Patients received docetaxel (75 mg/m2) and cisplatin (75 mg/m2) every 3 weeks for 6 cycles.

RESULTS

130 of 146 patients were evaluable for efficacy (60% stage IV). Three complete and 58 partial responses were observed (overall response rate: 46.9%; 95% CI: 38.3-55.5%). Median time to progression was 6.9 months and median survival was 14.0 months; 1-year survival was 59.5%. Grade 3/4 neutropenia, thrombocytopenia and anemia occurred in 69.2%, 6.2% and 18.5% of patients, respectively. Grade 3/4 vomiting was observed in 13.7% and grade 3/4 neurosensory effects were observed in 2.7% of patients. There was one case of treatment-related death due to sepsis.

CONCLUSION

Docetaxel-cisplatin is an effective and well-tolerated treatment in Asian patients with NSCLC.

Gemcitabine in metastatic nasopharyngeal carcinoma of the undifferentiated type

BACKGROUND

We conducted two parallel phase II trials in chemonaïve and previously treated patients with metastatic nasopharyngeal carcinoma (NPC) to evaluate the tumour response, progression-free and overall survival, and toxicity of gemcitabine.

PATIENTS AND METHODS

Gemcitabine 1250 mg/m2 was given on days 1 and 8 of a 21-day cycle. Patients with an Eastern Cooperative Oncology Group performance status <2, adequate renal, hepatic and bone marrow function, and radiologically measurable NPC were eligible.

RESULTS

Twenty-five chemonaïve and 27 previously treated patients were enrolled. The overall response rate was 28% [95% confidence interval (CI) 14% to 48%] for the chemonaïve and 48% (95% CI 31% to 66%) for previously treated patients. Toxicities greater than or equal to grade 3 occurred in 15 (60%) chemonaïve and 13 (48%) previously treated patients. Neutropenia was uncommon in chemonaïve patients, but occurred in 37% of previously treated patients. The median time to progression was 3.6 months (range 0.9-7.9) for chemonaïve and 5.1 months (0.9-13.1) for previously treated patients. Median overall survival time was 7.2 months (1.4-15.6) and 10.5 months (2.4-15.0) for chemonaïve and previously treated patients, respectively.

CONCLUSIONS

Gemcitabine has moderate activity in NPC with minimal toxicity, and is also an effective salvage agent for patients who have failed or progressed after treatment with other agents.

Primary intrathoracic malignant effusion: a descriptive study

BACKGROUND

Patients who present with malignant pleural/malignant effusion without a definite primary site are not well described in the medical literature. In the course of our clinical practice, we have observed certain traits that are peculiar to patients with such a presentation. We have applied the term primary intrathoracic malignant effusion (PIME) to describe this condition.

STUDY OBJECTIVES

Patients must fulfill the following criteria before a diagnosis of PIME can be made: clinical presentation dominated by pleural/pericardial effusion; histologic proof of malignancy obtained from the pleura and/or pericardium; no definite primary site in the lungs or elsewhere from CT scan of the chest, chest radiograph, or physical and endoscopic examination; no history of malignancy; and no history of asbestos exposure. Exposure to environmental tobacco smoke (ETS) among the nonsmokers was examined in a case-control setting.

METHODS

We conducted a retrospective search of our database of patients who were referred to the Department of Medical Oncology with a diagnosis of pleural/pericardial effusion from January 1993 to January 2000.

RESULTS

Seventy-one of 200 patients from our database met the criteria. A significant majority of the patients were women (65%) and nonsmokers (72%). All patients had adenocarcinoma shown on biopsy. The majority of patients (63%) had disease localized to the intrathoracic serosal surfaces; the rest had distant metastases involving the lung (50%), bone (27%), liver (19%), brain (8%), and skin (4%). Six patients had two or more sites of distant metastases. There was a significant association with ETS exposure when compared to a control group comprised of patients with colonic cancer, matched for sex and age. The median survival was 10 months for patients with disease localized to the pleura/pericardium and 7 months for those with distant metastases. Thirty-eight patients (54%) received chemotherapy. All had platinum-based chemotherapy, except for three patients. The median survival for patients treated or not treated with chemotherapy was 12 months and 5 months, respectively. This difference in survival was statistically significant (p = 0.003).

CONCLUSIONS

PIME should be viewed as a distinct entity. Its etiology remains largely unknown, although exposure to environmental tobacco smoke may play a part. Platinum-based chemotherapy may have a positive biological effect on this disease. More studies are required to elucidate the epidemiology, possible etiologic factors, and treatment options for this group of patients.

Recurrent nasopharyngeal carcinoma presenting as diffuse dermal lymphatic infiltration in the neck: three case reports

BACKGROUND

Any malignancy has the propensity to metastasize to skin. The frequency of skin metastases vary in different tumors and occur in about 0.7% to 10% of all patients diagnosed with cancer. It is rare in nasopharyngeal carcinoma.

METHOD

Three cases of relapsed nasopharyngeal carcinoma with diffuse dermal involvement were described. Their clinical presentation, results of investigations, and response to treatment were reviewed. Literature review of similar forms of presentation was done by means of a MEDLINE search.

RESULTS

At the time of dermal relapse, all three patients had a uniform clinical picture of facial, periorbital, and lip swelling associated with stridor and dysphagia. Histologic findings showed dermal infiltrates of malignant cells, and CT scan showed diffuse infiltration of the subcutaneous tissue. Despite chemotherapy, the clinical course was relentless.

CONCLUSION

This report describes a presentation of disease that is underdiagnosed and heightens awareness of oncologists to this form of recurrence in nasopharyngeal carcinoma.

Induction chemotherapy followed by concurrent chemoradiotherapy in stage III unresectable non-small cell lung cancer

The favourable experience with the combination regimen of vinorelbine, ifosfamide and cisplatin (NIP) in patients with metastatic non-small cell lung cancer (NSCLC) has led to a protocol assessing this regimen as an induction treatment in patients with stage III unresectable NSCLC, followed by thoracic radiotherapy with concurrent daily cisplatin as a radiosensitizer. Two cycles of NIP were administered 21 days apart; each cycle comprised i.v. vinorelbine 25 mg/m2 on days 1 and 8, i.v. ifosfamide 3 g/m2 on day 1 with MESNA as uroprotection, and i.v. cisplatin 50 mg/m2 on day 1. Radical thoracic radiotherapy commenced on day 43 to a total dose of 64 Gy and i.v. cisplatin 6 mg/m2 was given concurrently prior to each fraction of radiation as a sensitiser. Two more cycles of NIP were given to patients who responded favourably to the induction treatment about 2 weeks after completion of radiation. Between July 1995 and July 1997, 44 patients were treated with this protocol. This treatment schedule was generally well tolerated. Grade 3-4 neutropenia occurred in 50% of the patients and neutropenic sepsis was seen in 8. Grade 3-4 oesophagitis was uncommon. Most of the patients were able to complete the induction and concurrent chemoradiotherapy phase. Major response occurred in 75% of the patients with 2 (4.5%) complete responses (CR). A total of 6 patients achieved CR after chemoradiotherapy. At a median follow-up of 35 months, the median overall survival for all patients was 15 months with a 3-year survival rate of 24%. The median overall survival for stage IIIA patients was 19 months with a 3-year survival rate of 39% in contrast to 13 months' median overall survival and only 15% 3-year survival rate for stage IIIB. The NIP regimen results in a high response rate in NSCLC and this treatment programme seems to benefit selected patients with stage III disease.

Single-agent gemcitabine and gemcitabine/irinotecan combination (irimogem) in non-small cell lung cancer

Gemcitabine is a fluoridated pyrimidine related to cytosine arabinoside that has significant activity in solid tumor models. Irinotecan is a camptothecin analog with an active metabolite, SN-38, which inhibits topoisomerase I activity by stabilizing the topoisomerase I-DNA cleavable complex. Gemcitabine studies in non-small cell lung cancer conducted in the United States, as well as an international collaboration and clinical trials from Europe and Japan, found overall response rates of 20% to 26%, a median duration of response between 5 to 9 months, and a median duration of survival ranging from 7 to 12.3 months. Gemcitabine also has been shown to be more effective than best supportive care in non-small cell lung cancer. In a phase I trial of irinotecan (50, 75, 100, and 115 mg/m2) in combination with 1,000 mg/m2 gemcitabine, three patients had documented partial responses: one with pancreas cancer at irinotecan 100 mg/m2, one with pancreas cancer, and one with metastatic carcinoma of unknown primary at irinotecan 115 mg/m2. Three of five non-small cell lung cancer patients had stable disease for four or more cycles at irinotecan doses of 50, 75, and 100 mg/m2; no non-small cell lung cancer patients were treated at irinotecan 115 mg/m2. We recommend that a combination of gemcitabine 1,000 mg/m2 and irinotecan 100 mg/m2 given on days 1 and 8 every 3 weeks be used as the starting dose in future phase II studies. Furthermore, based on the absence of severe nonhematologic toxicity or grade IV hematologic toxicity in the majority of patients treated at the highest dose, escalation of irinotecan to 115 mg/m2 may be considered for subsequent cycles in patients who do not experience > or =grade I hematologic or non-hematologic toxicity during the first cycle of gemcitabine/irinotecan combination chemotherapy.

Concurrent chemoradiotherapy followed by adjuvant chemotherapy in Asian patients with nasopharyngeal carcinoma: toxicities and preliminary results

PURPOSE

Nasopharyngeal carcinoma (NPC) is endemic in Singapore. Nearly 60% of the patients diagnosed with NPC will present with locally advanced disease. The North American Intergroup study 0099 reported improved survival outcome in patients with locally advanced NPC who received combined chemoradiotherapy when compared to radiotherapy alone. Hence we explored the feasibility and efficacy of a similar protocol in our patients.

METHODS AND MATERIALS

Between June 1996 and December 1997, 57 patients were treated with the following schedule as described. Radical radiotherapy (RT) of 66-70 Gy to the primary and neck with cisplatin (CDDP) 25 mg/m2 on days 1-4 given by infusion over 6-8 hours daily on weeks 1, 4, and 7 of the RT. This is followed by a further 3 cycles of adjuvant chemotherapy starting from week 11 from the first dose of radiation (CDDP 20 mg/m2/d and 5-fluorouracil [5-FU] 1 gm/m2/d on days 1-4 every 28 days).

RESULTS

The majority of patients (68%) had Stage IV disease. About 54% of patients received all the intended treatment; 75% received all 3 cycles of CDDP during the RT phase and 63% received all three cycles of adjuvant chemotherapy. The received dose intensity of CDDP and 5-FU of greater than 0.8 was achieved in 58% and 60% of the patients respectively. Two treatment-related deaths due to reactivation of hepatitis B and neutropenic sepsis respectively, were encountered. At median follow-up of 16 months, 14 patients had relapsed, 12 systemically and 2 loco-regionally.

CONCLUSION

Due to the acceptable tolerability of such a protocol in our cohort of patients, we have embarked on a Phase III study to confirm the results of the 0099 Intergroup study in the Asian context.

Vinorelbine, ifosfamide and cisplatin in advanced non-small cell lung cancer

Between September 1994 and July 1997, 78 patients with advanced/metastatic, non-small cell lung cancer (NSCLC) were selected for the NIP (vinorelbine, ifosfamide, and cisplatin) protocol. The study group included 43 males; age range 34-74 years; median age 56 years; median follow-up for all patients was 14 months and for surviving patients, 30 months. Histological distribution included 55 adenocarcinomas (70.5%), 8 squamous cell carcinomas, and 9 large cell carcinomas. Stage distribution was 14 stage IIIB (malignant effusions) and 64 stage IV or recurrent metastatic; sites of metastasis were lungs, -26; liver-19; bones-27; brain-7; adrenals-3; distant nodes-2; skin-2. The NIP regimen was well tolerated by most of the patients but nausea/vomiting was noted in 55% of the cycles administered, most of them of grade 1-2 severity. Fifteen neutropenic episodes (5%) were encountered. Response to NIP was: 44 partial responses (56%); 1 complete response (1%); overall response, 58%. For stage IIIB, overall response was 36%, while for stage IV/metastatic, overall response was 63%. The median time to progression was 7 months for stage IIIB and 8 months for stage IV/metastatic disease and the overall median survival achieved was 14 months, with 60% of patients alive after one year. No significant difference in survival outcome was noted between patients with metastatic disease and those with stage IIIB (malignant effusion) disease. The NIP regimen has produced encouraging results in advanced NSCLC, as well as a favourable toxicity profile. The efficacy of NIP as a palliative tool should be assessed. A randomized trial to compare NIP with a two-drug combination of vinorelbine and cisplatin has been initiated.

The 1997 International Staging System for non-small cell lung cancer: have all the issues been addressed?

The International Staging System for Lung Cancer has been revised recently. Important changes have been made to allow better correlation of prognoses and direction of management. The classification of synchronous pulmonary nodules in the same lobe as the primary tumor as T4 stage IIIB may imply a poorer outcome than is warranted, while the designation of a similar stage for malignant pleural effusion may not be reflective of the very poor prognosis associated with this extent of disease.

Use of ondansetron in the control of emesis in autologous peripheral blood stem cell transplant (APBSCT) for solid tumours

AIM

The use of autologous peripheral blood stem cell transplant (APBSCT) for solid tumours have increased exponentially in the last 5 years. While the use of 5-hydroxytryptamine 3 (5HT3) receptor antagonists has been shown to improve control of emesis in patients receiving conventional dose chemotherapy, similar literature in APBSCT is more limited. We report our experience in the use of ondansetron in APBSCT.

METHOD

Twenty-three patients with solid tumours receiving high-dose chemotherapy with APBSCT were studied. All were started on intravenous ondansetron at 24 mg/day before commencement of the conditioning regimen and continued till vomiting had ceased for 24 hours. The conditioning regimen used was dependent on the tumour type and the duration ranged from 4 to 6 days. Control of emesis was assessed by the number of vomiting episodes in each 24-hour period, monitored throughout conditioning till discharge from hospital.

RESULTS

Complete or major protection from vomiting was achieved in 83% of patients on day 1. During the entire conditioning period, 52% of patients achieved complete or major response to ondansetron. After the conditioning period (delayed emesis), 44% of patients achieved complete or major response.

CONCLUSIONS

The control of emesis for patients undergoing high-dose chemotherapy with APBSCT is fair with ondansetron. Research on more effective combinations to further improve emetic control in this selected group of patients is needed.

Splenic abscesses from 1987 to 1995

BACKGROUND

Isolated splenic abscesses is an uncommon clinical entity that is being increasingly recognized as a cause of intraabdominal sepsis in a wide variety of clinical situations, and involving a wide range of organisms. The increasing incidence of immunosuppressed states in this decade due to the use of chemotherapy for oncology, immunosuppression therapy for transplantation, and acquired immune deficiency syndrome, has changed the disease pattern of splenic abscesses.

METHOD

Data from 287 cases reported in the English literature between 1987 and 1995 were collected, analyzed, and compared with two previous reviews of cases reported before 1987.

RESULTS

Staphylococcus, Salmonella, and Escherichia coli are the most common organisms cultured. Immunosuppressed states were present in 33.5% of cases, with intravenous drug abuse and acquired immune deficiency syndrome accounting for half these cases. Computerized tomography and ultrasonography are diagnostic, with a sensitivity of 92.2% and 87.2%, respectively. Nonoperative management has a success rate of less than 65%, but salvage splenectomy does not increase mortality compared with splenectomy as initial therapy.

CONCLUSIONS

Splenic abscesses are increasingly recognized with immunosuppressed states. Percutaneous radiologically guided drainage may be suitable in some cases, but splenectomy with appropriate antibiotics is the definitive treatment.

Usefulness of bacteriologic cultures in choice of antibiotics in patients with chemotherapy-induced neutropenic sepsis

Neutropenic sepsis is a potential problem in cancer patients undergoing cytotoxic chemotherapy. Septic work-up including cultures from various sites is routinely done for these patients. To assess the usefulness of these cultures, a retrospective review of all patients admitted for neutropenic sepsis in the period from June 1994 to August 1995 was conducted. All patients included in the study had solid tumours which were being treated at our institution during the study period. All had fever and documented neutrophil count of < 1 x 10(9)/l on at least one occasion. There was a total of 41 patients with 52 episodes of neutropenic sepsis. Of the 52 episodes, there were positive cultures in 14 (27%) episodes, including 7 from blood, 2 from urine and 5 from skin. In the bacteriologic cultures, gram-negative bacteria were isolated in 11 episodes and gram-positive bacteria in 5 episodes (2 episodes had both gram-negative and gram-positive bacteria isolated, and 1 episode had two gram-negative bacteria). Majority of the patients (96%) were treated with a third generation cephalosporin with/without an aminoglycoside. This empirical treatment was effective with resolution of fever in 39 (75%). Thirteen (25%) had change of antibiotics because of deteriorating clinical state or drug resistance. Nine patients with unabated sepsis had bacteriological cultures which grew organisms resistant to the empirical antibiotics. Eight responded to the change of antibiotics. One patient with pseudomonas bacteraemia failed to respond to empirical treatment with ceftriaxone and died before antibiotics could be changed. Of the patients with positive cultures, the results of drug sensitivity made a difference to treatment. None of the patients with negative cultures died from sepsis. It appears that even though the rate of positive culture is low (27%), it is still useful as a guide when change of antibiotics is required.

Ulcerative and plaque-like tracheobronchitis due to infection with Aspergillus in patients with AIDS

Tracheobronchitis is an uncommon manifestation of infection due to Aspergillus species, occurring in < 7% of cases of pulmonary aspergillosis. At least 58 cases of invasive aspergillus tracheobronchitis have been described since 1962. We describe four patients with AIDS, all of whom were severely immunocompromised, who had ulcerative tracheobronchitis due to Aspergillus species demonstrated histologically. Three patients had received corticosteroids or were neutropenic at presentation. At bronchoscopy, three patients had some degree of diffuse tracheobronchitis, multiple ulcerative or "plaque-like" inflammatory lesions, and occasionally nodules involving the mainstem and segmental bronchi. The remaining patient had a single deep ulceration of the proximal trachea. Aspergillus was isolated from biopsy specimens from all four patients. There were varied degrees of invasion of the mucosa, submucosa, and cartilage on histological examination in three patients, one of whom had evidence of disseminated aspergillosis. Two patients subsequently developed pulmonary parenchymal disease due to Aspergillus. A review of aspergillus tracheobronchitis, including a discussion of airway disease in patients infected with human immunodeficiency virus, is presented.

Abdominal visceral peliosis associated with bacillary angiomatosis. Ultrastructural evidence of endothelial destruction by bacilli

Peliosis involving solid internal organs is a rare entity, and it has been reported in association with chronic debilitating diseases. Bacillary angiomatosis (BA), on the other hand, is a recently identified lesion found virtually only in individuals infected by the human immunodeficiency virus. We describe herein two cases of visceral BA and peliosis in human immunodeficiency virus-infected patients. Based on light and electron microscopic findings, we conclude that (1) BA bacilli present in the hepatic sinusoidal endothelial cells, in a suitable host milieu, may be the causative agents of peliosis hepatis; (2) BA bacilli can be found both intracellularly and extracellularly; and (3) peliosis is also identified in association with BA in abdominal lymph nodes.

Demonstration of Chromogranin A in human neuroendocrine cell lines by immunohistology and immunoassay

We have used immunohistology and radioimmunoassay procedures to study Chromogranin A (CgA) in human neuroendocrine tumor cell lines, especially small cell lung cancers (SCLC). By immunohistology, CgA could be detected in 11 of 18 classical SCLC cell lines, in a medullary thyroid carcinoma (MTC) cell line, and in only one of 13 variant- or non-SCLC cell lines. By radioimmunoassay, CgA could be detected in the cells and culture media of all of the classical SCLC cell lines tested. Many of the classical SCLC cell lines also produced calcitonin (CT). These studies demonstrate that CgA production is a common feature of SCLC cell lines, especially those with neuroendocrine characteristics.

Atypical stromal smooth muscle hyperplasia of prostate

A prostatic lesion was resected but recurred six years later with the same atypical smooth muscle hyperplasia in the stroma and without glandular atypia. Ultrastructural study confirms the smooth muscle origin and its atypicality. Review of previous reports of leiomyosarcoma of the prostate show that the minimum criteria for malignancy are gross evidence of capsular invasion and one to two mitotic figures per ten high-power field. Cellular pleomorphism and cellularity by themselves are insufficient to diagnose sarcoma.

Acetylcholine and affective disorder

We reviewed the evidence for involvement of central cholinergic neurons in affective disorder. Cholinomimetics inhibit speech, thought, and activity in most subjects, decrease manic symptoms and, in some affective disorder patients, produce depressive symptoms. Cholinomimetics also cause ACTH and cortisol secretion and decrease latency to REM sleep. It is unclear whether cholinomimetics are specifically "antimanic" or "depressogenic" or whether their fundamental effect is nonspecific behavioral inhibition; whether the observed effects of cholinomimetics are mediated largely through cholinergic pathways, are secondary to changes in other neurotransmitters or are part of a nonspecific stress response. The suggestion that anticholinergic agents have mood elevating properties has not yet been subjected to controlled investigation. Although the proposal that affective disorders involve cholinergic neurons has received some support from clinical investigation further research is required to substantiate the intriguing observations to date and to clarify the physiologic and psychologic processes mediating them.

Potential therapeutic effect of adriamycin-monoclonal anti-prostatic acid phosphatase antibody conjugate on human prostate tumor

Adriamycin was conjugated to an IgG1 monoclonal antibody specific for human prostatic acid phosphatase via a dextran bridge. The adriamycin-monoclonal antibody conjugate retained substantially the original immunological activity of the antibody. Antitumor effect of the conjugate in vitro was studied by its inhibition on RNA synthesis in human prostate tumor cells (LNCaP), which exhibited a higher inhibition than that by an identically prepared adriamycin-normal mouse IgG conjugate but was less than that by free adriamycin. The loss in pharmacological activity of the conjugate in vitro was proportional to the extent of dextran oxidation. Antitumor effect in vivo demonstrated that adriamycin-monoclonal antibody conjugate greatly inhibited the growth of xenografted prostate tumor, as compared with control groups, only in the early phase of experiment. These results suggested that although adriamycin conjugated to monoclonal anti-PAP antibody via a dextran bridge may be a potential reagent for experimental immunochemotherapy of prostate tumor, caution must be exercised at this stage of development.

Preferential inhibition by cytarabine of CFU-GM from patients with chronic granulocytic leukemia

Granulocyte-macrophage colony-forming (CFU-GM) cells from peripheral blood of normal subjects and patients with chronic granulocytic leukemia (CGL) were cultured in soft agar. Drugs under study were added in a liquid overlay 2 days after initiation of cultures, providing prolonged exposure to these agents thereafter. Dose-dependent inhibition of colony growth was recorded with each of eleven agents examined, and at the higher concentrations tested, colony formation was often completely suppressed. Cytarabine showed selectivity against CFU-GM from patients in the chronic stage of CGL (P = 0.006); the median 50% inhibitory concentration for 12 such patients was 3.4 ng/ml versus 11.8 ng/ml for 15 healthy subjects. Such selectivity was not found with busulfan, hydroxyurea, mercaptopurine, thioguanine, daunorubicin, vincristine, vinblastine, methotrexate, desacetylmethylcolchicine, and trimethylcolchicinic acid. One other group has also reported a preferential effect of cytarabine against colony-forming cells from patients with CGL, and this appears to be the only drug for which such selective activity has been recorded to date.

The regulation of somatostatin production in human medullary thyroid carcinoma cells by dexamethasone

There have been few studies of physiological importance on the regulation of somatostatin by hormones. We have studied the effect of the synthetic glucocorticoid dexamethasone on somatostatin production in the human medullary thyroid carcinoma TT cell line, a model for somatostatin production by the parafollicular cell. Dexamethasone inhibited somatostatin production in a dose-related manner with a maximal effect at a concentration of 10(-6) M. TT cells treated with dexamethasone (10(-6) M) showed an almost complete inhibition of somatostatin peptide production by 48 h of treatment. Molecular sizing chromatography demonstrated a decrease in both the probable somatostatin precursor (13,000 dalton) and the fully processed peptide. Analysis of mRNA content by hybridization revealed that dexamethasone also caused a decrease in detectable somatostatin mRNA. The hybridizable somatostatin mRNA decreased to approximately 50% of basal levels within 12 h of treatment. Northern blot hybridization showed a decrease in a single RNA species representing mature somatostatin mRNA. Dose-response experiments revealed inhibition of both peptide and mRNA at concentrations from 1 X 10(-8) to 1 X 10(-5) M dexamethasone. Four days after withdrawal from dexamethasone treatment, peptide and mRNA levels were higher than dexamethasone-treated controls. The sex steroid estradiol had no inhibitory effect on somatostatin production. These results suggest a potential regulator of somatostatin production and provide a system for the study of somatostatin gene regulation.

Effect of methotrexate-monoclonal anti-prostatic acid phosphatase antibody conjugate on human prostate tumor

Methotrexate (MTX) was conjugated to an immunoglobulin G1 (IgG1) monoclonal antibody specific for human prostatic acid phosphatase (PAP) by the active ester method. The molar ratio of MTX to IgG was 14. MTX-monoclonal antibody conjugate retained substantially the original PAP-binding inhibition activity of the monoclonal antibody. Both MTX-monoclonal antibody conjugate and an identically prepared MTX-normal mouse IgG conjugate preserved 90% of the original dihydrofolate reductase inhibitory activity of MTX. [3H]MTX conjugated to monoclonal anti-PAP antibody was significantly accumulated more in PAP-producing human prostate tumor LNCaP cells than its normal mouse IgG counterpart. No statistical difference was found between the uptake of [3H]MTX conjugated to monoclonal antibody and that of [3H]MTX conjugated to normal mouse IgG by control PAP nonproducing thyroid tumor cells (TT). The antitumor effect of the conjugate was evaluated in vitro by its inhibition on deoxy[6-3H]uridine incorporation into LNCaP cells. The inhibition by MTX-monoclonal antibody conjugate was significantly higher than that by MTX-normal mouse IgG conjugate at 8 micrograms of drug per ml, although it was significantly less than that by free MTX. However, an in vivo tumor and tissue distribution study of [3H]MTX and its conjugates revealed that, 5 days after i.v. administration, [3H]MTX conjugated to monoclonal antibody was preferentially accumulated in LNCaP prostate tumor. Tumor:blood ratios for [3H]MTX, [3H]MTX-monoclonal antibody conjugate, and [3H]MTX-normal mouse IgG conjugate were 1.47, 5.06, and 1.26, respectively. Preliminary results obtained from a pilot study with a small number of animals demonstrated that multiply injected MTX-monoclonal antibody conjugate retarded the growth of xenografted prostate tumor (LNCaP) as compared with the control groups, including free MTX which showed a shorter period of therapeutic effectiveness. This study suggests that MTX conjugated to monoclonal anti-PAP antibody could be a potential reagent for experimental immunochemotherapy of prostate tumor, should the initial in vivo data be extended and confirmed.

Somatostatin production by a human medullary thyroid carcinoma cell line

Somatostatin (SRIF, SRIF-14) is a known product of the normal and malignant parafollicular cell of the thyroid. In this report we characterize SRIF production by the TT cells, a line of transformed calcitonin-producing cells derived from a human medullary thyroid carcinoma. The cells were found to contain (5-12 ng/10(6) cells) and secrete (3-10 ng/10(6) cells X 48 h) immunoreactive SRIF. Molecular sieve chromatography of cell extracts under denaturing conditions showed a major peak with a mol wt slightly larger than 12,700, probably representing pro-SRIF and a second peak which coeluted with SRIF; in one gel chromatogram a very small peak was also noted which coeluted with SRIF-28, but represented less than 0.4% of the total immunoreactive SRIF. Short term secretion of calcitonin and SRIF was stimulated by calcium in vitro (0.5-4 mM) in a dose-related manner. mRNA isolated from the TT cells hybridized to a specific bovine fetal pancreatic SRIF DNA (BFPS-2); there was no hybridization to identical amounts of mRNA from the atT-20/D16, 3T3, or RINC5F cell lines. In vitro translation of the TT cell mRNA followed by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the product revealed a single protein band of approximately 13,000 daltons. It was completely abolished when the immunoprecipitation was performed in the presence of excess unlabeled SRIF. Northern transfer of TT cell cytoplasmic RNA and hybridization with FBPS-2 cDNA showed a single hybridizing band with an apparent size of approximately 750 nucleotides. Our observations demonstrate the production of SRIF by a continuous line of human medullary thyroid carcinoma cells and provide a model for studying the biosynthesis and secretion of SRIF in the parafollicular cell.

Phorbol esters increase calcitonin gene transcription and decrease c-myc mRNA levels in cultured human medullary thyroid carcinoma

Medullary thyroid carcinoma is a tumor of the calcitonin-secreting thyroid C-cell, with a variable malignant potential. Virulent tumors are characterized by decreased calcitonin production, suggesting the emergence of a less differentiated medullary thyroid carcinoma cell. In order to further delineate relationships between tumor progression and status of differentiation of medullary thyroid carcinoma cells, we have sought to chemically manipulate the TT cell line, an established culture of human medullary thyroid carcinoma, derived from a patient with aggressive disease. We found that the phorbol esters, 12-O-tetradecanoyl phorbol 13-acetate and phorbol 12,13-dibutyrate 1) altered the morphology of the TT cells towards that of high-calcitonin-containing cells; 2) enhanced calcitonin secretion 7-fold; 3) increased calcitonin production at the transcriptional level by 2-fold; 4) inhibited cellular proliferation; and 5) decreased, by 80%, the levels of the c-myc gene mRNA. These data suggest that phorbol esters induce, in human medullary thyroid carcinoma cells in culture, a programmed pattern of events resulting in differentiation of these cells.

Potentiation of the cell growth inhibitory effect of beta interferon by mopidamole

It was suggested that the antitumor effect of the interferons is based in part on their ability to stimulate increased cAMP production. We have explored the interaction of human fibroblastic beta interferon (HFIF) with a cAMP decomposition inhibitory pyrimido-pyrimidine derivative, Mopidamole (RA-233) in cultures of neoplastic and normal cell lines. Mopidamole potentiated the growth inhibitory effect of HFIF in cultures of ES-1 malignant melanoma cells, LNCaP prostatic carcinoma cells, RT-4 transitional carcinoma cells, HT-29 colon adenocarcinoma cells and in diploid fibroblast cells.

Structure and expression of a gene encoding human calcitonin and calcitonin gene related peptide

Messenger RNAs for calcitonin (CT) and calcitonin gene related peptide (CGRP) have been detected in a human medullary thyroid carcinoma cell line. DNA sequences of their cloned cDNAs, and genomic restriction mapping, indicate that both mRNAs probably originate from a single gene; the separate mRNAs are derived by alternative processing. The calcitonin gene is expressed in 10 of 10 examined culture lines of human lung cancer; most of these lines express a higher ratio of CGRP to CT specific mRNA than does the medullary thyroid carcinoma cell line.

Human medullary thyroid carcinoma in culture provides a model relating growth dynamics, endocrine cell differentiation, and tumor progression

We used an unique model, human medullary thyroid carcinoma (MTC) in culture (the TT line), to study features of neuroendocrine-related biochemistry in relationship to growth, differentiation, and tumor progression. Tumor tissues from patients with virulent MTC contain a very heterogeneous distribution of cells staining for calcitonin (CT) and have a high ratio of intracellular L-dopa decarboxylase activity (DDC) to CT. We found, in a culture line of MTC derived from a patient with virulent disease, that the degree of the inverse relationship between DDC and CT and the heterogeneous cellular distribution of CT probably relate to the rate of cellular growth and the biochemical set of individual cell clones. During exponential growth of the parent TT cell line, intracellular DDC and CT varied. DDC increased by 70% and CT decreased by 40%. Single time-point measurements in 54 cell clones or highly enriched cell populations revealed a more dramatic variability for CT (15-fold) than for DDC (5-fold). During growth of the clones having the highest and lowest CT measurements, respectively, inverse dynamics between DDC and CT were again found. However, each clone maintained a distinct range of CT during the entire growth curve, with a 2- to 4-fold difference in CT between the two clones throughout. In the low producing CT clone, ratios between DDC and CT rose to greater than 1.0 during growth, a very high value found before this study only in MTC tissues from patients with virulent disease. Immunohistochemical staining for CT of parent cells and clones grown on embryonic chick skin revealed increased cellular heterogeneity for CT distribution during growth. The TT line provides a powerful tool to study neuroendocrine related biochemical events in relationship to growth, differentiation, and tumor progression in MTC. Our in vitro findings in the TT line well explain observations made previously in patients. We conclude that: (1) DDC, a neural property of MTC, is an early differentiation marker as compared to CT and that the differentiation status of MTC cells varies inversely with cell growth rate; and (2) in patients with MTC, the virulence of the tumor probably varies inversely with differentiation status. The inverse ratio of DDC to CT is probably determined in MTC by the proportion of rapidly growing cells and numbers of cell clones which have a poor ability for maturation.

Antineoplastic effect of the pyrimido-pyrimidine derivative: RA 233

A number of normal and neoplastic human cell lines in culture were studied by cell count and 3H thymidine incorporation for growth inhibitory effect by the pyrimido-pyrimidine derivative RA-233 (mopidamole). There was more inhibition when the drug was added to the culture in the lag phase than in the logarithmic growth phase. There was more inhibition (particularly at low doses) of the neoplastic cell lines than of the non-neoplastic cell lines.

LNCaP model of human prostatic carcinoma

The LNCaP cell line was established from a metastatic lesion of human prostatic adenocarcinoma. The LNCaP cells grow readily in vitro (up to 8 x 10(5) cells/sq cm; doubling time, 60 hr), form clones in semisolid media, are highly resistant to human fibroblast interferon, and show an aneuploid (modal number, 76 to 91) human male karyotype with several marker chromosomes. The malignant properties of LNCaP cells are maintained. Athymic nude mice develop tumors at the injection site (volume-doubling time, 86 hr). Functional differentiation is preserved; both cultures and tumor produce acid phosphatase. High-affinity specific androgen receptors are present in the cytosol and nuclear fractions of cells in culture and in tumors. Estrogen receptors are demonstrable in the cytosol. The model is hormonally responsive. In vitro, 5 alpha-dihydrotestosterone modulates cell growth and stimulates acid phosphatase production. In vivo, the frequency of tumor development and the mean time of tumor appearance are significantly different for either sex. Male mice develop tumors earlier and at a greater frequency than do females. Hormonal manipulations show that, regardless of sex, the frequency of tumor development correlates with serum androgen levels. The rate of the tumor growth, however, is independent of the gender of hormonal status of the host.

Human pancreatic adenocarcinoma: in vitro and in vivo morphology of a new tumor line established from ascites

A human pancreatic tumor cell line has been established from the ascites of a patient with histopathologically confirmed adenocarcinoma of the head of the pancreas and maintained for more than 12 months in the laboratory. Epithelioid tumor cell colonies, which resulted from primary tissue cultures of the ascitic cell component, were mechanically isolated by needle micromanipulation. Tumorigenicity was proven in athymic nude mice. Morphologically the pancreatic tumor epithelial cells grew to confluency with moderately tight adhesion to the culture plastic surface and with free-floating cells in the medium. Upon re-establishment of the tumoral xenograft in tissue culture, the epithelial cells retained their original morphology. Histologically the tumor grown in nude mice exhibited prototypic characteristics of the primary adenocarcinoma in the patient, producing abundant mucin and displaying a broad spectrum of glandular differentiation, which ranged from well to poorly differentiated adenocarcinomas with occasionally localized lymphocytic infiltrations. Furthermore, the tumor expressed carcinoembryonic antigen and human pancreas cancer associated antigen. This tumor line, designated AsPC-1, has been cultured for at least 10 passages in vitro and 3 in vivo. It represents a new model for human pancreatic cancer.