Retinoids as potential chemopreventive agents in squamous cell carcinoma of the head and neck

Although newer combined modality approaches, including neoadjuvant cytotoxic chemotherapy, for patients with squamous cell carcinoma (SCCA) of the head and neck have produced high initial complete response rates, they have not improved overall survival for patients with advanced disease. Vitamin A plays an essential role in the normal differentiation of epithelial tissues. Retinoids, analogs of vitamin A, are active in certain premalignant and malignant disorders including SCCA. Six studies, including one recently reported placebo-controlled randomized trial, have demonstrated the efficacy of retinoids in oral leukoplakia. Two studies (totalling 48 patients) have shown significant retinoid activity (67% overall complete response rate) in patients with aggressive, recurrent laryngeal papillomatosis. Two trials (including a randomized phase II trial) of isotretinoin in advanced, refractory SCCA of the head and neck have produced an objective response rate of 16%, which is comparable to that reported in single-agent studies with cytotoxic drugs. There is a need for further study of retinoids in head and neck cancer. The high initial response rates with current therapy and the high subsequent risks of local recurrence and of developing second primary tumors in head and neck cancer patients offer an excellent opportunity to investigate the use of retinoids as adjuvant therapy for this malignancy.

Barrett's esophagus: a model premalignant lesion for adenocarcinoma

Barrett's esophagus is a condition in which the lower esophagus is lined with metaplastic columnar epithelium rather than normal stratified squamous epithelium. It is associated with an increased risk of cancer. Cancers developing in Barrett's epithelium are adenocarcinomas rather than the usual squamous cell esophageal cancers. Barrett's is somewhat unique among premalignant lesions, since it represents an entirely different epithelium from the normal and can therefore be histologically identified with certainty. The abnormal mucosa can be safely accessed repeatedly and its extent quantitated by endoscopy, thereby allowing serial follow-up studies and intervention trials. We are studying Barrett's esophagus as a model premalignant lesion for adenocarcinoma. Ornithine decarboxylase activity was increased in this lesion especially when dysplastic changes were present. Interestingly there was no relationship between polyamine levels and the increased ODC activity. Flow cytometric abnormalities have been demonstrated in Barrett's mucosa. Their significance remains to be determined. Epithelial cells from this lesion have been cultured and characterized. Clonal cytogenetic abnormalities were detected in some specimens. The cultured cells were used to test the effect of drugs on their growth. The ornithine decarboxylase inhibitor, alpha-difluoromethylornithine, significantly inhibited growth even at low concentrations. A clinical intervention trial using 13-cis-retinoic acid has produced no change in the extent of the lesion in 11 evaluable patients. Nevertheless, the successful performance of this clinical study confirms that this lesion can be used for intervention trials aimed at reversing premalignant lesions.

Management of high-grade dysplasia in Barrett's esophagus

When Barrett's esophagus is complicated by adenocarcinoma, surgery is indicated in appropriate patients. Until now, high-grade dysplasia in Barrett's esophagus has been managed in a similar fashion. We explore this approach and review reported cases of high-grade dysplasia to suggest guidelines for collection of data to make future clinical decisions more rational.

Increase in ornithine decarboxylase activity associated with development of dysplasia in Barrett's esophagus

A case of Barrett's esophagus of the specialized columnar type is described in which mucosal ornithine decarboxylase levels were measured in endoscopic biopsies at two intervals over which severe dysplasia had developed. The Barrett's mucosa extended 5 cm above the gastroesophageal junction, was free of dysplasia, and had no detectable ornithine decarboxylase activity at initial evaluation. On follow-up endoscopy one year later, the Barrett's mucosa had become dysplastic with a markedly elevated ornithine decarboxylase activity of 1.56 units/mg protein. The patient underwent an esophagectomy because of persistent severe dysplasia and continues to do well postoperatively. Elevated ornithine decarboxylase activity has been described in other premalignant conditions, especially when dysplasia has been present. Further studies in Barrett's esophagus are warranted, since ODC activity might prove to be a useful biochemical marker for dysplasia and increased cancer risk.

Managing malignant pericardial effusion

The involvement of the pericardium by metastatic tumors is not uncommon, particularly in patients with lung cancer, breast cancer, lymphomas, leukemias, and melanomas. There are five therapeutic modalities for the treatment of malignant pericardial effusion, including pericardiocentesis, pericardial sclerosis, systemic chemotherapy, radiotherapy, and surgical treatment. The optimal treatment selection is dependent principally on a patient's life expectancy; responsiveness of the tumor to chemotherapy, irradiation, or both; and whether or not cardiac tamponade is present at diagnosis. The overall prognosis of patients with malignant pericardial effusion is primarily influenced by the extent and histologic features of the underlying cancer. Although this condition is usually incurable, a reasonable period of useful palliation can be obtained in most patients.

Phase II trial of fenretinide [N-(4-hydroxyphenyl) retinamide] in myelodysplasia: possible retinoid-induced disease acceleration

To determine the activity of fenretinide in patients with myelodysplastic syndromes, 15 patients were treated (300 mg/d starting dose, escalated to 400 mg/d) for a 12-week course. No responses were observed in 14 evaluable patients. Exacerbation of thrombocytopenia occurred in one patient with chronic myelomonocytic leukemia, who succumbed to an intracerebral hemorrhage after 3 weeks of treatment. Two patients with long-standing stable sideroblastic anemia experienced interval leukemic progression. In one patient, clinical features of chronic myelomonocytic leukemia appeared, characterized by a striking rise in peripheral monocyte count (0.49 x 10(9)/l to 10.8 x 10(9)/l) and hepatosplenomegaly, which resolved promptly after cessation of treatment. The second patient experienced evolution into acute myelomonocytic leukemia with cytogenetic progression. The drug was well tolerated with no patient having to discontinue treatment because of toxicity. We conclude that fenretinide lacks clinical efficacy in the treatment of myelodysplasia and in some patients may enhance leukemic progression.

Effect of dipyridamole on fluorodeoxyuridine cytotoxicity in vitro and in cancer patients

Dipyridamole (DP) has previously been studied both in vitro and in vivo in combination with various anti-metabolites, including methotrexate and 5-fluorouracil (5FU). We evaluated in vitro and clinically the effects of adding DP to fluorodeoxyuridine (FUDR) in colorectal cancer. Using a human colony-forming assay, we observed that 0.05 microM DP increased the cytotoxicity of FUDR by a median of 33.5-fold vs 1.5-fold for 5FU against human colon-cancer cell lines. The mechanism of the DP-enhanced antitumor activity of FUDR is not completely understood but appears to be related to a profound inhibition by DP of thymidine accumulation in and FUDR efflux from colon-cancer cell lines. On the basis of these in vitro results, 28 patients with metastatic colon cancer were entered in a clinical trial of monthly courses of 0.1 mg/kg FUDR daily for 14 days and 75 mg oral DP 5 times daily for 14 days starting on the 3rd day of continuous i.v. FUDR infusion. The pharmacokinetics of DP was studied in three patients; the results showed that 98% of total serum DP was protein-bound and that free DP levels were significantly lower than the concentrations necessary for the expected in vitro DP/FUDR modulation. Treatment was well tolerated, with only 12 patients developing mild to moderate toxicity. Of 27 evaluable patients, 4 achieved a partial response that lasted 2, 3, 5, and 6+ months. This relatively low response rate (15%), which is similar to that achieved with FUDR alone, may be explained by the low steady-state plasma concentrations of free DP achieved in our patients. Other means of DP administration, such as i.v., i.a., and i.p. injection, may be required to achieve free DP concentrations necessary for successful biochemical modulation of FUDR in patients.

Mitomycin C in the chemotherapy of advanced breast cancer

Mitomycin C is a chemotherapeutic agent active against breast cancer. Because one of its potential toxicities is prolonged myelosuppression, it is not generally used in first-line chemotherapy regimens. However, several mitomycin C-containing combinations are effective in the salvage therapy of patients that have failed to respond to previous regimens. The choice of a salvage combination depends on the previous treatment received by an individual patient. Patients failing regimens based on CMF (cyclophosphamide, methotrexate, 5-fluorouracil [5-FU]) should be treated with combinations incorporating drugs not included in CMF. Active agents in this setting include mitomycin C, doxorubicin, and vinca alkaloids (usually vinblastine). Patients treated with combinations based on doxorubicin and cyclophosphamide (AC) are frequently administered a CMF-type regimen after a cumulative dose of doxorubicin has been reached. Therefore, they have often received doxorubicin, cyclophosphamide, methotrexate, and 5-FU. Salvage chemotherapy for failing patients in this setting is generally based on mitomycin C and/or vinblastine. Selection of a chemotherapeutic regimen for breast cancer must take into account the palliative nature of chemotherapy in this disease. Consequently, effective combinations that can be administered with minimal disruption of a patient's life-style are preferred.

Ornithine decarboxylase and polyamine levels in columnar upper gastrointestinal mucosae in patients with Barrett's esophagus

Ornithine decarboxylase (ODC) activity was elevated in the premalignant metaplastic columnar epithelium (mean activity, 0.13 unit/mg protein, N = 18 individual samples from 18 patients), compared to either adjacent gastric (mean activity, 0.02 unit/mg protein, N = 9) or small intestinal (mean activity, 0.02 unit/mg protein, N = 9) epithelium in patients with Barrett's esophagus. Enzyme activity ranged from 0 (less than detectable) to more than 0.5 unit/mg protein in the metaplastic tissue. However, neither putrescine, spermidine, spermine (as individual parameters), nor total polyamine contents were related to ODC activity in the individual patient biopsies. Spermidine/spermine ratios ranged from 0.38 to 2.18 and were also not related to enzyme activity in any apparent manner. Nevertheless, cell strains derived from the metaplastic tissue were growth inhibited by alpha-difluoromethylornithine, an enzyme-activated, suicide inhibitor of ODC. In two different cell strains derived from Barrett's epithelium, growth was affected with drug concentrations as low as 0.05 mM. While the mechanism responsible for the elevation in enzyme activity is unknown, the regulation of polyamine metabolism appears to be altered in this premalignant tissue. The growth inhibition of Barrett's epithelium-derived cell lines by ODC inhibitors suggests a potential role for these compounds in the treatment of this disease.

Squamous mucosa overlying columnar epithelium in Barrett's esophagus in the absence of anti-reflux surgery

Seven of 45 patients with Barrett's esophagus prospectively followed with yearly endoscopy had histological evidence of squamous mucosa overlying Barrett's epithelium. This histological finding has previously been identified as a rare sequela of anti-reflux surgery. All seven patients had specialized columnar epithelium. No evidence of the overlying mucosa was recognized at endoscopy. Only one patient had previous anti-reflux surgery. During the observation interval, three patients had a decrease, and four had no change in the length of Barrett's epithelium. Squamous mucosa overlying columnar epithelium in Barrett's esophagus is not infrequent, and prior anti-reflux surgery is not a necessary precondition.

Ornithine decarboxylase activity in Barrett's esophagus: a potential marker for dysplasia

Ornithine decarboxylase activity is known to be increased in certain premalignant conditions. We determined the activity of this enzyme in mucosal biopsy specimens from 15 patients with Barrett's esophagus. Ornithine decarboxylase was greater in Barrett's mucosa than in squamous esophageal or gastric mucosa. In Barrett's mucosa from 4 patients with dysplasia, the enzyme activity was greater than in 11 patients without dysplasia (1.6 +/- 0.35 vs. 0.19 +/- 0.08 U/mg protein; p less than 0.005). Increased ornithine decarboxylase activity in biopsy specimens of Barrett's mucosa may represent a marker for dysplasia.

Effects of bone marrow fibroblastic cells and fibroblastic conditioned medium on HL-60 and KG-1

The in-vitro effects of bone marrow fibroblastic cells (FC) and fibroblastic conditioned medium (FCM) on the proliferation and differentiation of two human leukemic cell lines, HL-60 and KG-1 were studied. When FC were seeded onto only one-half of the culture dish an increase in colony size of HL-60 and KG-1 was observed directly above the FC. FCM had a greater effect, resulting in approximately a four-fold increase in the size of HL-60 and KG-1 colonies. In regards to colony number, FCM from normals inhibited HL-60, but FCM from other sources had no effect. FCM from both normals and ANLL in CR inhibited KG-1 colony number in contrast to the lack of effect with FCM from ANLL at diagnosis and RAEB. Neither FC nor FCM had any effect on the differentiation of either cell line. Our results indicate that FC modulate the proliferation of both HL-60 and KG-1. Furthermore, in ANLL the effects of FC are dependent upon the stage of the disease.

Danazol in the treatment of myelodysplastic syndromes

20 patients with myelodysplastic syndromes (MDS) were treated with danazol, 800 mg daily in 4 divided doses. 18 patients were evaluable for response. 3 patients (17%), whose principal problem was anemia, responded to treatment, but only with an increase in platelet count. Responses were short-lived and lacked clinical significance. No patients with anemia or leukopenia responded to treatment and none of the 7 patients with a platelet count less than 30 x 10(9)/l responded. Danazol appears to have limited clinical utility in the treatment of MDS. However, occasional patients with thrombocytopenia may benefit.

Intracellular adenosine triphosphate as a measure of human tumor cell viability and drug modulated growth

Adenosine triphosphate is the primary energy unit for cells, and levels of this compound offer a potential marker for cell viability and growth. The availability of a bioluminescence assay allows for a rapid, sensitive, and reproducible measurement of ATP. A method is described for the quantification of intracellular ATP levels in human cancer cells. ATP levels were linearly related to the number of viable cells and increased with time in human cancer cell line cultures correlating with growth kinetics. The effect of 5-fluorouracil, doxorubicin, methotrexate, cytosine arabinoside, nitrogen mustard, melphalan, vinblastine, and cisplatin on the growth of human cancer cell lines was studied utilizing ATP levels. ATP levels and colony formation in agar of drug-exposed cells were compared. Overall there was a significant correlation between drug effects on colony formation and ATP levels. The ATP assay is rapid, simple, reproducible, and a relatively inexpensive method of quantifying drug effects on malignant cells. This makes it a potentially useful method for screening new anticancer drugs in human cancer cell lines.

Acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a subtype of acute myelogenous leukemia frequently associated with disseminated intravascular coagulation (DIC). Data on 11 patients with APL treated at our institution were analyzed and compared with those of 147 published cases. Most had a bleeding diathesis at presentation and evidence of DIC eventually developed in all. Seven patients (64%) showed the t(15;17)(q22;q21) karyotype or a similar translocation. Using a chemotherapy induction regimen containing an anthracycline, complete remission, requiring a total of 14 courses of treatment, was achieved in six patients (55%). The median duration of response and median survival for complete responders were 10 and 15 months, respectively. Three patients (27%) died of bleeding complications during induction therapy. The tritiated-thymidine labeling index of leukemia cells predicted which patients would achieve a complete remission. Review of six studies of 147 patients with APL from the past 12 years supports the use of a chemotherapy induction regimen containing anthracycline or amsacrine and heparin for the treatment of DIC.

Efficacy of danazol in pure red cell aplasia

Twenty-one unselected patients with refractory chronic anemias of various etiologies were treated with danazol, a synthetic attenuated androgen. All had previously failed treatment with hematinics, androgens, corticosteroids, high-dose intravenous immunoglobulin, antithymocyte globulin, cytotoxic immunosuppressive agents, and/or plasmapheresis. Three patients with pure red cell aplasia and one with aplastic anemia responded. No responses were observed in 11 patients with myelodysplastic syndromes, two patients with myelofibrosis, and two with paroxysmal nocturnal hemoglobinuria. Remission in pure red cell aplasia was maintained with danazol alone in one patient and required combined low-dose prednisone in two. Objective responses occurred in 2 to 3 weeks and therapy generally was well tolerated. To date, one patient with pure red cell aplasia remains in complete remission at 9 months on low-dose danazol alone. We conclude that danazol alone or combined with prednisone may induce and maintain remission in severe refractory pure red cell aplasia and possibly other chronic cytopenias characterized by immunologic marrow suppression. Further trials of danazol in treating these disorders are indicated.

ATP assay: ability to distinguish cytostatic from cytocidal anticancer drug effects

A bioluminescence assay for ATP was adapted to human cancer cell lines and used to study the effect of anticancer drugs on malignant cell growth by following serial ATP measurements. Eleven drugs were tested against a colon cancer cell line (WiDR). Excellent correlation was observed between simultaneously performed soft-agar colony-forming assays and the ATP assay. In addition, cytostatic (growth inhibitory) drug effects could be distinguished from cytocidal (lethal) effects by using the ATP assay. Cytocidal drugs resulted in a reduction of ATP level below baseline levels, whereas cytostatic drugs merely yielded a reduction in the rate of increase in ATP level, i.e., slower growth. Such characterizations are not possible in colony-forming assays. Changes in ATP were correlated with the number of viable cells present. Drug concentration and duration of exposure both were important. Some drugs became cytocidal only when exposures longer than the customary 1 hour were used. The ATP assay has excellent potential as a simple, inexpensive, and rapid technique for new drug screening in cell lines, with classification of drug effects as cytostatic or cytocidal.

Cranial metastases from prostate cancer simulating meningioma: report of two cases and review of the literature

Two cases of prostatic carcinoma metastatic to the cranium that presented with clinical and radiographic features simulating meningioma are described. The literature was reviewed, and 13 similar cases were identified. From the data gathered, we conclude that metastatic prostate cancer should be considered in the differential diagnosis of elderly males who present with characteristic clinical and radiological features of meningioma and that the classical description of meningioma is not specific.

Management of myelodysplastic syndromes

The treatment of myelodysplastic syndromes is reviewed, with emphasis on recently published clinical trials. Pyridoxine is rarely effective, but a trial in patients with refractory anemia with ringed sideroblasts is justifiable. Corticosteroids do not appear indicated unless in vitro data suggest response. Androgens are generally not beneficial, although danazol merits further evaluation. Both 13-cis-retinoic acid and low-dose cytosine arabinoside have considerable toxicity and yield short-lived partial responses that may not have a significant impact on survival. Combination chemotherapy may be considered in selected patients with refractory anemia with excess of blasts, refractory anemia with excess of blasts in transformation, and chronic myelomonocytic leukemia; however, in general, its toxicity outweighs potential benefit. For unusual patients under 30 years old, bone marrow transplantation should be considered as first-line therapy. Until more effective and less toxic agents are available, supportive care may still be the most appropriate therapy for many of these generally elderly patients.

Phase II trial of 4'-deoxydoxorubicin (esorubicin) in hormone resistant prostate cancer

Fifteen patients with hormone resistant advanced prostate cancer were treated with anthracycline analog 4'-deoxydoxorubicin (Esorubicin). No patient had objective evidence of tumor regression. Six patients (40%) were classified using the National Prostatic Cancer Project criteria as having stable disease after two courses of therapy. Treatment was associated with significant hematologic toxicity with 50% of patients experiencing grade III or IV neutropenia. Clinical cardiac toxicity was not observed. Further trials of 4'-deoxydoxorubicin do not appear to be warranted in advanced prostate cancer.

Phase II trial of esorubicin (4' deoxydoxorubicin) in cancers of the breast, colon, kidney, lung and melanoma

A phase II trial of esorubicin (4' deoxydoxorubicin) was performed in patients with cancers of the breast, colon, kidney, lung and melanoma. Two partial responses were observed out of 16 patients with breast cancer treated with esorubicin. No objective responses (complete or partial) were seen in patients with colon cancer (18 patients), lung cancer (12 patients), renal cell cancer (12 patients) and melanoma (18 patients). Myelo-suppression was the most significant toxicity encountered with granulocytopenia (neutrophils less than 1,000) observed in 38% of patients. As discussed, we feel that further investigation of esorubicin in anthracycline-sensitive tumors is warranted.

Metoclopramide in vincristine-induced ileus

Three cases of vincristine-induced gastrointestinal toxicity were treated with metoclopramide. Two patients had severe abdominal pain and adynamic ileus, while the third had severe constipation and abdominal bloating. Rapid resolution of symptoms occurred in all three patients. Metoclopramide may, therefore, prove useful in the treatment of these not infrequent toxic effects of vinca alkaloids.

Anti-fibrinolytic therapy with aminocaproic acid for the control of bleeding in thrombocytopenic patients

11 courses of EACA were given to 9 acutely ill, severely thrombocytopenic patients (platelet count less than 20 X 10(9)/l). 6 patients were being treated for acute leukaemia while 1 each had cyclical amegakaryocytic thrombocytopenia, dysmyelopoietic syndrome and advanced chronic lymphocytic leukaemia. 8 were refractory to HLA-matched platelets and 1 refused blood product transfusion. All had simultaneous major medical complications such as infection and granulocytopenia. The highest dose of EACA used was 24 mg/d. Improvement in haemostasis was noted in all patients with successful control of epistaxis in 1, control of gastrointestinal bleeding in 3 and lack of significant bleeding for 4-29 d in the remaining 5 patients. The only toxicity was dose-related nausea. Since this patient group was at extremely high risk for haemorrhage, we conclude that EACA is safe and useful in the management of thrombocytopenia including that occurring during leukaemic induction.

Danazol-induced factor VIII and IX bypassing activity in hemophiliacs

Danazol, a synthetic androgen reported to increase factor VIII and IX activity levels, was given to 6 hemophiliacs. With danazol therapy (600 mg/da) the APTTs shortened by 30-45% of pre-treatment times. However, the activity levels of the deficient factors did not increase significantly nor consistently with the APTT change. The prothrombin times and activity levels of factors XI and XII also did not change during the study period. Addition of plasma from danazol-treated patients to plasma with a known factor VIII inhibitor and to plasma from an untreated severe hemophilia A patient caused a similar shortening of the respective APTTs. Absorption of the danazol plasma with precipitating antibody against factor VIII and IX did not remove the APTT correcting principal. The data suggest that danazol may cause the de novo appearance of an intrinsic coagulation pathway activator having factor VIII and IX bypassing activity.