Baseline serum NTx levels are prognostic in metastatic breast cancer patients with bone-only metastasis

BACKGROUND

There is significant heterogeneity in survival of patients with metastatic breast cancer who have bone-only metastasis. We studied the correlation of serum N-telopeptide (NTx), a marker of bone resorption, and its correlation with clinical outcomes in patients with metastatic breast cancer with bone-only or bone plus soft tissue metastasis.

PATIENTS AND METHODS

Serum was taken from 250 metastatic breast cancer patients with bone-only or bone plus soft tissue metastasis who participated in two similar randomized studies of second-line hormone therapy. An enzyme-linked immunosorbent assay specific for NTx of type I bone collagen was used to detect serum levels.

RESULTS

Sixty patients (24%) had elevated serum NTx levels, using the mean + 2 standard deviations (26 nanomoles Bone Collagen Equivalents per liter) of healthy women as a cut-off. The median duration of clinical benefit was significantly shorter in the group with elevated serum NTx levels compared with the group that had normal serum NTx levels (P=0.0004). Time to progression (TTP) was also significantly shorter in the patients with elevated serum NTx at 139 days compared with 220 days (P=0.0006). Median survival was also significantly shorter in patients with elevated baseline serum NTx levels at 663 days compared with 941 days (P<0.0001).

CONCLUSION

In this study, breast cancer patients with bone-only or bone plus soft tissue metastasis and elevated serum NTx levels have a shorter duration of clinical benefit, TTP and overall survival.

Treatment of advanced pancreatic cancer with opioid growth factor: phase I

Opioid growth factor (OGF) is an endogenous pentapeptide that inhibits growth of human pancreatic cancer cells in culture, as well as xenografts in nude mice. To establish the maximum tolerated dose (MTD), and determine safety and toxicity of OGF, a phase I trial was performed in patients with advanced unresectable pancreatic cancer. Patients with unresectable pancreatic adenocarcinoma were treated with escalating doses of OGF for 30 min i.v. to determine the MTD. The s.c. route of administration also was evaluated. Once the MTD was established, a group of patients was treated chronically, and monitored for safety and toxicity. Hypotension was the dose-limiting toxicity, resulting in a MTD of 250 microg/kg i.v. Due to limited solubility of OGF in small volumes, a maximum dose of 50 microg/kg twice daily was determined by the s.c. route of administration. No adverse events were reported for oxygen saturation, cardiac rhythm, laboratory values or neurological status in either the acute or chronic parts of the study with the i.v. or s.c. routes. During the chronic i.v. phase, two subjects had resolution of liver metastases and one showed regression of the pancreatic tumor. Mean survival from the time of diagnosis was 8.7 months (range 2-23 months) in the i.v. group and 9.5 months (range 1-18 months) in the s.c. group. We conclude that OGF can be safely administered to patients with advanced pancreatic cancer. Further studies are needed to determine the efficacy of OGF alone or in combination with present modes of therapy for the treatment of pancreatic cancer.

Metastatic breast cancer: overview of treatment

Patients with metastatic breast cancer have a median survival of 2 to 3 years. Twenty percent of the patients who present with bone-only metastasis will be alive at 5 years from diagnosis. Current therapies are aimed at improving the quality of life, symptom control, and prolongation of survival. Newer endocrine and chemotherapeutic drugs are available to the medical oncologist for care of patients with metastatic breast cancer. We will briefly review the new advances in the treatment of metastatic breast cancer.

Serum HER-2/neu and response to the aromatase inhibitor letrozole versus tamoxifen

PURPOSE

To determine the effect of elevated serum HER-2/neu on the response of metastatic breast cancer patients to an aromatase inhibitor versus an antiestrogen.

PATIENTS AND METHODS

Five hundred sixty-two estrogen receptor-positive metastatic breast cancer patients were randomized to first-line hormone therapy with either letrozole or tamoxifen. An automated enzyme-linked immunosorbent assay was used to detect serum HER-2/neu.

RESULTS

For patients with normal serum HER-2/neu (70.5%), objective response rate (ORR; 39% in letrozole-treated patients v 26% in tamoxifen-treated patients; P =.008), clinical benefit (CB; 57% v 45%; P =.016), time to progression (TTP; median, 12.2 v 8.5 months; P =.0019), and time to treatment failure (TTF; median, 11.6 v 6.2 months; P =.0066) were significantly better in patients treated with letrozole. In the elevated HER-2/neu group (29.5%), there was no significant difference in ORR (17% in letrozole-treated patients v 13% in tamoxifen-treated patients; P =.45) or CB (33% v 26%; P =.31), but there was a strong trend in favor of a longer TTP with letrozole (median, 6.1 v 3.3 months; P =.0596) and a significantly longer TTF with letrozole (median, 6.0 v 3.2 months; P =.0418). Multivariate analysis revealed that elevated serum HER-2/neu was a negative predictor for ORR and TTP.

CONCLUSION

Patients with normal serum HER-2/neu receiving letrozole demonstrated a significantly greater ORR and CB and longer TTP and TTF than patients receiving tamoxifen. Although in patients with elevated serum HER-2/neu there was no significant difference between letrozole and tamoxifen in ORR or CB, there was a strong trend favoring longer TTP and significantly longer TTF with letrozole.

Relationship of Serum HER-2/neu and Serum CA 15-3 in Patients with Metastatic Breast Cancer

Background: Serum HER-2/neu antigen concentrations have been reported to correlate with increased tumor volume in patients with breast cancer. We measured serum CA 15-3, a surrogate marker of disease burden, and correlated serum CA 15-3 with serum HER-2/neu and analyzed the association of both markers with clinical outcomes.

Methods: Pretreatment serum samples from 566 patients were retrospectively analyzed from 2 phase III clinical trials of estrogen receptor-positive (ER+), ER−/progesterone receptor-positive, or ER status unknown metastatic breast cancer patients randomized in two similar studies to receive second-line hormone therapy with either megestrol acetate or an aromatase inhibitor (fadrozole). The extracellular domain of the HER-2/neu (c-erbB-2) oncogene and serum CA 15-3 were measured by ELISA on the Bayer Immuno 1.

Results: Serum HER-2/neu protein was increased in 168 patients (30%), and CA 15-3 was increased in 337 (60%) patients. Serum CA 15-3 and HER-2/neu were weakly correlated (r = 0.39; P &lt;0.0001). The clinical benefit (complete responses plus partial responses plus stable disease) of endocrine therapy was significantly lower in patients with increased serum HER-2/neu. When adjusted for serum HER-2/neu, serum CA 15-3 was not predictive of response rates. The median time to progression was shorter in patients with increased serum HER-2/neu (89 days) compared with patients with normal serum HER-2/neu (176 days). Survival was significantly shorter in patients with increased serum HER-2/neu (513 vs 869 days; P &lt;0.0001) or increased serum CA 15-3 (689 vs 939 days; P &lt;0.0001). This observation was confirmed by multivariate analysis.

Conclusions: Serum HER-2/neu is a significant independent predictive and prognostic factor in hormone receptor-positive metastatic breast cancer, even when adjusted for tumor burden as measured by CA 15-3. The combination of increased serum HER-2/neu and increased serum CA 15-3 predicts a worse prognosis than does increased CA 15-3 alone.

Relationship of serum HER-2/neu and serum CA 15-3 in patients with metastatic breast cancer

BACKGROUND

Serum HER-2/neu antigen concentrations have been reported to correlate with increased tumor volume in patients with breast cancer. We measured serum CA 15-3, a surrogate marker of disease burden, and correlated serum CA 15-3 with serum HER-2/neu and analyzed the association of both markers with clinical outcomes.

METHODS

Pretreatment serum samples from 566 patients were retrospectively analyzed from 2 phase III clinical trials of estrogen receptor-positive (ER(+)), ER(-)/progesterone receptor-positive, or ER status unknown metastatic breast cancer patients randomized in two similar studies to receive second-line hormone therapy with either megestrol acetate or an aromatase inhibitor (fadrozole). The extracellular domain of the HER-2/neu (c-erbB-2) oncogene and serum CA 15-3 were measured by ELISA on the Bayer Immuno 1.

RESULTS

Serum HER-2/neu protein was increased in 168 patients (30%), and CA 15-3 was increased in 337 (60%) patients. Serum CA 15-3 and HER-2/neu were weakly correlated (r = 0.39; P <0.0001). The clinical benefit (complete responses plus partial responses plus stable disease) of endocrine therapy was significantly lower in patients with increased serum HER-2/neu. When adjusted for serum HER-2/neu, serum CA 15-3 was not predictive of response rates. The median time to progression was shorter in patients with increased serum HER-2/neu (89 days) compared with patients with normal serum HER-2/neu (176 days). Survival was significantly shorter in patients with increased serum HER-2/neu (513 vs 869 days; P <0.0001) or increased serum CA 15-3 (689 vs 939 days; P <0.0001). This observation was confirmed by multivariate analysis.

CONCLUSIONS

Serum HER-2/neu is a significant independent predictive and prognostic factor in hormone receptor-positive metastatic breast cancer, even when adjusted for tumor burden as measured by CA 15-3. The combination of increased serum HER-2/neu and increased serum CA 15-3 predicts a worse prognosis than does increased CA 15-3 alone.

Elevated serum Her-2/neu level predicts decreased response to hormone therapy in metastatic breast cancer

PURPOSE

To determine the effect of elevation of serum HER-2/neu on response to hormone therapy.

PATIENTS AND METHODS

Seven hundred nineteen metastatic patients with estrogen receptor-positive (ER(+)), progesterone receptor-positive, or both or ER status unknown breast cancer were randomized in three independent clinical trials to receive second-line hormone therapy with either megestrol acetate or an aromatase inhibitor (fadrozole or letrozole). An automated enzyme-linked immunosorbent assay specific for the extracellular domain of the HER-2/neu (c-erbB-2) oncoprotein product was used to detect serum levels.

RESULTS

Two hundred nineteen patients (30%) had elevated serum HER-2/neu protein levels, using the mean + 2 SD (15 ng/mL) from the serum of healthy women as an upper limit. Response to treatment was available for 711 patients. The response rate (complete responses plus partial responses plus stable disease) to endocrine therapy was 45% in 494 patients with non-elevated and 23% in 217 patients with elevated serum HER-2/neu levels (P <.0001). Median duration of treatment response (using the time to progression [TTP] variable for patients who responded) was shorter in the group with elevated serum HER-2/neu levels (11.7 months) compared with the patient group with non-elevated levels (17.4 months). TTP, time to treatment failure, and median survival (17.2 months v 29.6 months) were also significantly shorter in the patients with elevated serum HER-2/neu levels (P <.0001).

CONCLUSION

Patients with ER(+) and serum HER-2/neu-positive metastatic breast cancer are less likely to respond to hormone treatment and have a shorter duration of response than ER(+) and serum HER-2/neu-negative patients. Their survival duration is also shorter.

Receptor-mediated endocytosis of Neisseria gonorrhoeae into primary human urethral epithelial cells: the role of the asialoglycoprotein receptor

Urethral epithelial cells are invaded by Neisseria gonorrhoeae during gonococcal infection in men. To understand further the mechanisms of gonococcal entry into host cells, we used the primary human urethral epithelial cells (PHUECs) tissue culture system recently developed by our laboratory. These studies showed that human asialoglycoprotein receptor (ASGP-R) and the terminal lactosamine of lacto-N-neotetraose-expressing gonococcal lipooligosaccharide (LOS) play an important role in invasion of PHUECs. Microscopy studies showed that ASGP-R traffics to the cell surface after gonococcal challenge. Co-localization of ASGP-R with gonococci was observed. As ASGP-R-mediated endocytosis is clathrin dependent, clathrin localization in PHUECs was examined after infection. Infected PHUECs showed increased clathrin recruitment and co-localization of clathrin and gonococci. Preincubating PHUECs in 0.3 M sucrose or monodansylcadaverine (MDC), which both inhibit clathrin-coated pit formation, resulted in decreased invasion. N. gonorrhoeae strain 1291 produces a single LOS glycoform that terminates with Gal(beta1-4)GlcNac(beta1-3)Gal(beta1-4)Glc (lacto-N-neotetraose). Invasion assays showed that strain 1291 invades significantly more than four isogenic mutants expressing truncated LOS. Sialylation of strain 1291 LOS inhibited invasion significantly. Preincubation of PHUECs in asialofetuin (ASF), an ASGP-R ligand, significantly reduced invasion. A dose-response reduction in invasion was observed in PHUECs preincubated with increasing concentrations of NaOH-deacylated 1291 LOS. These studies indicated that an interaction between lacto-N-neotetraose-terminal LOS and ASGP-R allows gonococcal entry into PHUECs.

The mimicry of human glycolipids and glycosphingolipids by the lipooligosaccharides of pathogenic neisseria and haemophilus

It has been known for many years that bacteria can induce autoimmune responses in humans resulting in serious disease. Recent work has shown that a number of bacteria that colonize human mucosal surfaces exclusively express antigens on their surfaces which are molecular mimics of glycosphingolipids found on human cells. These structures are important in the pathogenesis of Neisseria and Haemophilus species for both immune evasion and in the adherence and invasion of human cells. There is no evidence that colonization or infections by these bacterial species is associated with autoimmune disease.

Modulation of gonococcal piliation by regulatable transcription of pilE

The gonococcal pilus, a member of the type IV family of pili, is composed of numerous monomers of the pilin protein and plays an important role in the initiation of disease by providing the primary attachment of the bacterial cell to human mucosal tissues. Piliation also correlates with efficient DNA transformation. To investigate the relationships between these pilus-related functions, the piliation state, and the availability of pilin, we constructed a derivative of MS11-C9 (DeltapilE1) in which the lacIOP regulatory sequences control pilE transcription. In this strain, MS11-C9.10, the steady-state levels of pilin mRNA and protein directly correlate with the concentration of IPTG (isopropyl-beta-D-thiogalactopyranoside) in the growth medium and can reach near-wild-type levels of expression. Transmission electron microscopy (TEM) demonstrated that the number of pili per cell correlated with the steady-state expression levels: at a low level of transcription, single long pili were observed; at a moderate expression level, many singular and bundled pili were expressed; and upon full gene expression, increased lateral association between pili was observed. Analysis of pilus assembly by TEM and epithelial cell adherence over a time course of induction demonstrated that pili were expressed as early as 1 h postinduction. Analysis at different steady-state levels of transcription demonstrated that DNA transformation efficiency and adherence of MS11-C9.10 to transformed and primary epithelial cells also correlated with the level of piliation. These data show that modulation of the level of pilE transcription, without a change in pilE sequence, can alter the number of pili expressed per cell, pilus bundling, DNA transformation competence, and epithelial cell adherence of the gonococcus.

Gonococcal lipooligosaccharide is a ligand for the asialoglycoprotein receptor on human sperm

In the present study, we show that Neisseria gonorrhoeae lipooligosaccharide (LOS) can bind to the asialoglycoprotein receptor (ASGP-R) on human sperm. This work demonstrates the presence of ASGP-R on human sperm. Binding of purified ASGP-R ligand decreased in the presence of gonococci. Binding of purified iodinated gonococcal LOS identified a protein of molecular weight corresponding to that of human ASGP-R. The presence of excess unlabelled LOS blocked binding of iodinated gonococcal LOS. Binding of wild-type gonococcal LOS to sperm was higher than that of mutant LOS lacking the galactose ligand for ASGP-R. These data suggest that the ASGP-R on human sperm cells recognizes and binds wild-type gonococcal LOS. This interaction may contribute to the transmission of gonorrhea from infected males to their sexual partners.

Macropinocytosis as a mechanism of entry into primary human urethral epithelial cells by Neisseria gonorrhoeae

Gonococcal entry into primary human urethral epithelial cells (HUEC) can occur by macropinocytosis. Scanning and transmission electron microscopy revealed lamellipodia surrounding gonococci, and confocal laser scanning microscopy analysis showed organisms colocalized with M(r) 70,000 fluorescein isothiocyanate-labeled dextran within the cells. Phosphoinositide 3-kinase inhibitors and an actin polymerization inhibitor prevented macropinocytic entry of gonococci into HUEC.

Combined chemoradiotherapy for unresectable pancreatic cancer

This study was undertaken to evaluate the efficacy of a regimen of combined chemoradiotherapy in patients with unresectable adenocarcinoma of the pancreas. An analysis was undertaken on 27 patients from January 1992 to May 1996. Patients had a median age of 70 years (range, 40-78) and Eastern Cooperative Oncology Group Performance Status of 0-2. Eighteen patients had locoregional disease (T2-T3, N0-N1, M0), and nine had metastatic disease. Chemotherapy consisted of four cycles of 5-fluorouracil 1 gm/m2/day as a continuous infusion over 110 hours, streptozotocin 300 mg/m2/day over 30 minutes on days 2-4, and cisplatin 100 mg/m2 over 2 hours on day 4 only, followed by a maintenance regimen of 5-fluorouracil and leucovorin every 2 weeks. The radiotherapy was administered as a split course concurrently with chemotherapy to a total dose of 6000 cGy. Toxicity was frequent, but there were no treatment-related deaths. Grade III and IV toxicity was primarily limited to myelosuppression, stomatitis, and gastrointestinal side effects. Fifteen patients (56%) were able to complete either three or four cycles of chemoradiotherapy. All patients were evaluable for toxicity, response, and survival. Nine patients (33%) had an objective response (four complete response 5 partial response), two remained stable, and 16 (59%) had disease progression. Median survival for the entire group was 19 weeks (2-139), and the median survival for overall responders was 56 weeks (15-139). No patient with localized disease underwent subsequent surgical resection. The authors conclude that those patients who are able to tolerate the entire treatment regimen may achieve a useful prolongation of time to tumor progression.

Use of aromatase inhibitors in breast carcinoma

Aromatase, a cytochrome P-450 enzyme that catalyzes the conversion of androgens to estrogens, is the major mechanism of estrogen synthesis in the post-menopausal woman. We review some of the recent scientific advances which shed light on the biologic significance, physiology, expression and regulation of aromatase in breast tissue. Inhibition of aromatase, the terminal step in estrogen biosynthesis, provides a way of treating hormone-dependent breast cancer in older patients. Aminoglutethimide was the first widely used aromatase inhibitor but had several clinical drawbacks. Newer agents are considerably more selective, more potent, less toxic and easier to use in the clinical setting. This article reviews the clinical data supporting the use of the potent, oral competitive aromatase inhibitors anastrozole, letrozole and vorozole and the irreversible inhibitors 4-OH androstenedione and exemestane. The more potent compounds inhibit both peripheral and intra-tumoral aromatase. We discuss the evidence supporting the notion that aromatase inhibitors lack cross-resistance with antiestrogens and suggest that the newer, more potent compounds may have a particular application in breast cancer treatment in a setting of adaptive hypersensitivity to estrogens. Currently available aromatase inhibitors are safe and effective in the management of hormone-dependent breast cancer in post-menopausal women failing antiestrogen therapy and should now be used before progestational agents. There is abundant evidence to support testing these compounds as first-line hormonal therapy for metastatic breast cancer as well as part of adjuvant regimens in older patients and quite possibly in chemoprevention trials of breast cancer.

Effect of the potent aromatase inhibitor fadrozole hydrochloride (CGS 16949A) in postmenopausal women with breast carcinoma

BACKGROUND

Fadrozole hydrochloride (CGS 16949A) is a highly potent, nonsteroidal aromatase inhibitor that significantly lowers estrogen levels in postmenopausal women and can be effective therapy for patients with advanced hormone-dependent breast carcinoma. Circulating estradiol, estrone, and estrone sulfate are reduced to undetectable levels within weeks of the initiation of therapy. Before this study, it was not known whether this decrease in serum estrogen levels results in altered parameters associated with cardiovascular disease. The authors examined the levels of several critical blood parameters that are important to cardiovascular risk for heart disease and thromboembolic disorders in patients treated with fadrozole.

METHODS

Cholesterol, triglyceride, low density lipoprotein (LDL), high density lipoprotein (HDL), very low density lipoprotein (VLDL), antithrombin III, protein C, protein S, and fibrinogen were serially measured in 21 postmenopausal women with advanced breast carcinoma treated with various doses of fadrozole (1.8 mg/day, n=3; 2.0 mg/day, n=13; 4.0 mg/day, n=5) over 3-24 months (mean, 15.8 months). A repeated measure analysis of variance was applied to each cardiovascular variable to assess changes in the response over time. Analyses were performed separately for each dose group and were also pooled over the dose groups.

RESULTS

There was no statistically significant change over time in lipid parameters, namely, total cholesterol (P=0.57), triglyceride (P=0.27), LDL (P=0.99), HDL (P=0.30), and VLDL (P=0.43), over the 24 months of therapy. There were also no significant changes in coagulation factors, namely, antithrombin III (P=0.41), protein C (P=0.49), or protein S (P=0.31), over the 24 months. However, an increase in fibrinogen that occurred over time did reach statistical significance (P=0.011).

CONCLUSIONS

With the exception of acute phase reactant fibrinogen, this study did not identify an increase in parameters associated with cardiovascular disease in women treated with fadrozole, a potent aromatase inhibitor.

Emerging role of aromatase inhibitors in the treatment of breast cancer

The new generation of potent steroidal and nonsteroidal inhibitors of the enzyme aromatase act by decreasing estrogen production throughout the body in postmenopausal women. The most potent of these agents may also inhibit estrogen synthesis within metastatic breast cancer tissue. The newly developed, orally administered, nonsteroidal competitive inhibitors, such as anastrozole (Arimidex), letrozole (Femara), and vorozole (Rizivor), are a thousand times more potent inhibitors of aromatase than is aminoglutethimide. Furthermore, these agents are highly selective. In several large randomized trials, the new inhibitors produced similar response rates as megestrol acetate (160 mg/d) in postmenopausal women with hormone-dependent breast cancer, but showed a trend toward improved response duration and survival. They also produced less weight gain and fewer cardiovascular and thromboembolic side effects. In addition, letrozole proved superior to aminoglutethimide in another randomized trial. Both anastrozole (1.0 mg/d) and letrozole (2.5 mg/d) have now been approved as second-line treatment for hormone-dependent breast cancer in postmenopausal women in whom disease has progressed following tamoxifen treatment. Either drug should replace the routine use of megestrol acetate in this setting. Ongoing clinical studies are comparing anastrozole and letrozole to antiestrogens as first-line endocrine therapy for metastatic breast cancer. Other trials will study the possible roles of these compounds as adjuvant therapy and chemoprevention for breast cancer.

Issues concerning the role of chemotherapy and hormonal therapy of bone metastases from breast carcinoma

A significant percentage (50-70%) of patients with metastatic breast carcinoma (MBC) will have disease involving the bony skeleton. Clonal selection mediated by parathyroid hormone-related protein and other factors may explain the high incidence of osseous metastases in MBC. The presence of specific growth factors and cytokines in the microenvironment of bone may contribute to the successful establishment and growth of metastatic lesions and also might determine response or resistance of these lesions to chemotherapy or hormonal therapy. Osteolytic bone lesions in MBC frequently give rise to serious clinical problems including bone pain, pathologic fracture, hypercalcemia, and neurologic complications. MBC often is treated with systemic chemotherapy or hormonal therapy. The purpose of this article was to review the recent published literature describing the impact of systemic chemotherapy and hormonal therapy of MBC on the response of bone lesions and their clinical course and complications. Evaluating the response of bone lesions can be problematic and may be complicated by the phenomenon of "tumor flare" that may be observed with either chemotherapy or hormonal therapy. Use of the International Union Against Cancer criteria for the response of bone lesions is recommended. Several studies report objective responses (20-60%) of lytic bone metastases to standard combination chemotherapy regimens such as cyclophosphamide, methotrexate, and 5-fluorouracil and cyclophosphamide, doxorubicin, and 5-fluorouracil, mitoxantrone and 5-FU, newer combinations, and single agents including paclitaxel and docitaxel but responses to vinorelbine may be less frequent. Complete responses of bone lesions to chemotherapy are rare but partial responses and disease stabilization can lead to long term patient benefit. A series from the M. D. Anderson Cancer Center of patients with bone metastases treated with 5-FU, doxorubicin, and cyclophosphamide chemotherapy reported a median duration of response of 14 months. In a recent multicenter study of 195 patients with lytic lesions from MBC treated with chemotherapy, the objective response rate (complete response + partial response) in bone was 18% and 65% of the patients developed at least 1 morbid skeletal event with a median onset of 7.0 months from the start of chemotherapy. Hormone-dependent breast carcinoma has a proclivity to metastasize to bone. In earlier studies comparing aminoglutethimide or medroxyprogesterone acetate with tamoxifen, a higher response rate of bone metastases was observed for the first two agents. However, in more recent studies comparing newer aromatase inhibitors, such as anastrozole, fadrozole, and letrozole, with megestrol acetate, there were no significant differences in rates of response in bone. Patients with MBC with bony lesions respond to both chemotherapy and hormonal therapy and can have a prolonged survival. Therefore such patients are in a more favorable position to benefit from adjunctive supportive therapy such as bisphosphonates intended to reduce skeletal morbidity.

Phase I study combining tumor necrosis factor with interferon-alpha and interleukin-2

We evaluated the effects of the addition of escalating doses of tumor necrosis factor (TNF) to two fixed doses and schedules of a combination of interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) to determine the maximum tolerated dose of this three-cytokine combination and its feasibility as an outpatient regimen. Eighteen patients with metastatic cancer were enrolled. Each course consisted of 3 consecutive weeks of treatment with IFN-alpha 9 x 10(6) IU/m2/day intramuscularly (i.m.) or subcutaneously (s.c.) days 1, 3, and 5 each week for 3 weeks plus IL-2 continuous infusion 1 x 10(6) IU/m2/day (group A) or 3 x 10(6) IU/m2/day (group B) days 1-5 each week for 3 weeks. TNF was administered only during the first week of each course intravenously (i.v.) for 2 h on days 1-5. The dose of TNF was escalated (40, 80, 120 micrograms/m2) in cohorts of 3 patients. The most common side effects were fever, chills, and fatigue in all patients. Grade 3-4 toxicity included anemia (3 patients), thrombocytopenia (1 patients), arrhythmia (2 patients), pulmonary edema (3 patients),- and weight loss (1 patient). Five patients withdrew from study due to toxicity. The combination of the three cytokines is feasible as an outpatient regimen in one of the following combinations: (a) TNF 80 micrograms/m2/day as 2-h infusion on days 1-5 + IL-2 1 x 10(6) IU/m2/day continuous infusion on days 1-5 for 3 weeks + IFN-alpha 9 x 10(6) IU/m2/day s.c. or i.m. on days 1, 3, and 5 for 3 weeks, or (b) TNF 40 micrograms/m2/day as a 2-h infusion on days 1-5 + IL-2 3 x 10(6) IU/m2/day continuous infusion on days 1-5 for 3 weeks + IFN-alpha 9 x 10(6) IU/m2/day s.c. or i.m. on days 1, 3, and 5 for 3 weeks.

Ultrastructural analysis of primary human urethral epithelial cell cultures infected with Neisseria gonorrhoeae

In men with gonococcal urethritis, the urethral epithelial cell is a site of infection. To study the pathogenesis of gonorrhea in this cell type, we have developed a method to culture primary human urethral epithelial cells obtained at the time of urologic surgery. Fluorescent analysis demonstrated that 100% of the cells stained for keratin. Microscopic analyses indicated that these epithelial cells arrayed in a pattern similar to that seen in urethral epithelium. Using immunoelectron and confocal microscopy, we compared the infection process seen in primary cells with events occurring during natural infection of the same cell type in men with gonococcal urethritis. Immunoelectron microscopy studies of cells infected with Neisseria gonorrhoeae 1291 Opa+ P+ showed adherence of organisms to the epithelial cell membrane, pedestal formation with evidence of intimate association between the gonococcal and the epithelial cell membranes, and intracellular gonococci present in vacuoles. Confocal studies of primary urethral epithelial cells showed actin polymerization upon infection. Polyclonal antibodies to the asialoglycoprotein receptor (ASGP-R) demonstrated the presence of this receptor on infected cells in the primary urethral cell culture. In situ hybridization using a fluorescent-labeled probe specific to the ASGP-R mRNA demonstrated this message in uninfected and infected cells. These features were identical to those seen in urethral epithelial cells in exudates from males with gonorrhea. Infection of primary urethral cells in culture mimics events seen in natural infection and will allow detailed molecular analysis of gonococcal pathogenesis in a human epithelial cell which is commonly infected.

The impact of 2D versus 3D quantitation of tumor bulk determination on current methods of assessing response to treatment

PURPOSE

Measurements from sequential axial "2D" data in cancer patients are commonly used to assess treatment response or disease progression. This study compares the volume of tumor bulk calculated with 3D reconstructions with that calculated by conventional methods to determine if it might change patient classification.

METHOD

All medical, gynecologic, and pediatric oncology patients under treatment who were evaluated with serial CT scans between January 1, 1992, and July 31, 1994, for whom the digital data were available were included in this study. For each tumor site, the maximum diameter and its perpendicular were measured and multiplied together to yield an area. The sum of areas of the measured lesions was used as an approximation of overall 2D tumor volume. In addition, the 2D area of each site was multiplied by its height, yielding a 2D volume. Last, the digital data were loaded into a 3D computer system and total 3D tumor volumes determined. All medical and gynecologic oncology patients were treated based upon the 2D area of tumor. The pediatric oncology patients were treated based upon the 2D volume of tumor measured as per standard practice. The members of each treating oncologic service assessed their patients as to how the other two methods would have changed their classification of the patients' response category.

RESULTS

Four hundred thirty-three CT scans were performed in 139 patients, which included 204 baseline and 294 follow-up CT examinations. Seventy patients had new tumor foci and would have been classified as failure by all three methods of tumor bulk measurement. The 3D volume versus the 2D area method of tumor bulk assessment would have changed response categories in 52 of the 294 follow-up CT examinations (p < 0.0001). Thirty-five patients were recategorized from either "no response" to "failure" (21 patients) or "no response" to "response" (14 patients) categories. If only those follow-up studies without new metastatic foci are considered, the 3D volume versus the 2D area methods of tumor assessment would have changed the treatment response category in 23.2%. The use of the 2D volume method of calculating tumor volume of bulk tended to overestimate the overall tumor size by an average of 244 cm3 (p = 0.001).

CONCLUSION

The 3D method of tumor volume measurement differs significantly from conventional 2D methods of tumor volume determination. Large prospective studies analyzing the usefulness of 3D tumor volume measurements and assessing possible changes in patient response categories would be required for full utilization of this more accurate method of following disease bulk.

Aromatase inhibitors in clinical practice: current status and a look to the future

Aromatase inhibitors are a new class of agents that are of considerable interest for potential use as palliative therapy for hormone-dependent metastatic breast cancer in postmenopausal women. In the postmenopausal or castrate female, the process of aromatization accounts for the majority of circulating, biologically active estrogens. This report presents a clinical perspective on some of the most recent information concerning the biology and pharmacology of the aromatase enzyme and highlights the development of newer aromatase inhibitors with important therapeutic potential. Clinical questions addressed include the selection of aromatase inhibitors, the selection of the most appropriate patients for therapy with these new agents, and the positioning of these new agents with respect to other forms of endocrine therapy for breast cancer. Finally, we shall consider areas for future investigation of possible new indications for these agents in clinical medicine.

The role of bisphosphonates in the treatment of bone metastases--the U.S. experience

Frequent complications of bone metastases include pain, pathologic fracture, hypercalcemia and spinal cord compression. Lytic bone metastases result from excessive activation of osteoclasts by tumor-produced cytokines. Aredia (pamidronate) is a potent bisphosphonate that inhibits osteoclast activation. In two dose-seeking phase I trials in patients with breast cancer and prostate cancer, repeated intravenous infusion of Aredia was shown to be safe and effective in reducing bone resorption and pain. In a randomized phase III trial of 377 patients with multiple myeloma, Aredia was administered in a dosage of 90 mg i.v. every 4 weeks. Compared with placebo, treatment with Aredia was associated with a significant decrease in bone pain and in the incidence and time to development of all skeleton-related events. Data from two phase III breast cancer trials each involving 300 patients are now being analyzed. The newer bisphosphonates can safely be used together with standard anticancer therapy to provide effective palliation of symptoms caused by lytic bone metastases.

Phase I trial of recombinant platelet factor 4 (rPF4) in patients with advanced colorectal carcinoma

BACKGROUND

Recombinant platelet factor 4 (rPF4) is a naturally occurring protein found in platelet alpha granules that can inhibit angiogenesis.

METHODS

In this Phase I trial, 9 patients with metastatic colorectal cancer who had failed 5-FU treatment received rPF4 at doses ranging from 0.3 to 3.0 mg/kg via 30-minute infusion. Three additional patients were treated with the 3 mg/kg dose over a 6-hour period of infusion.

RESULTS

The only toxicity encountered was mild leg twitching in 2/3 patients treated with the 6-hour infusion. One patient with a history of phlebitis developed a lower extremity deep venous thrombosis after the first dose of rPF4. A mild rise in fibrinogen level was noted in several patients. Of the 11 evaluable patients, there were no clinical responses to treatment.

CONCLUSIONS

rPF4 is well tolerated at the doses and schedules tested. No clinical responses were observed. Prolonged infusion schedules should be investigated.

Growth inhibition of breast cancer cell lines by combinations of anti-P185HER2 monoclonal antibody and cytokines

The p185HER2 oncogene is associated with poor prognosis in patients with breast cancer. Both anti-p185HER2 MAb and cytokines have been shown to downregulate p185HER2 expression. We investigated the effect of combinations of humanized 4D5, and anti-p185HER2 MAB, and the cytokines IFN-alpha, IFN-gamma or TNF-alpha on the growth of three p185HER2 positive human abreast carcinoma cell lines, SK-BR-3, BT-474, and MDA-MB-453. All three cell lines were treated with IFN-alpha (1000 U/ml) or IFN-gamma (1000 U/ml) or TNF-alpha (100 U/ml) with or without huMAb 4D5 (100 microM), and cell growth was determined on days 3-7. While IFN-alpha, IFN-gamma, TNF-alpha, and huMAb 4D5 all inhibited growth, an apparently additive inhibitory effect occurred using combinations of huMAb 4D5 plus cytokine, with huMAb 4D5 plus TNF-alpha causing the greatest growth inhibition. These results demonstrate the potentiation of growth inhibition of breast cancer cell lines by the combination of anti p185HER2 MAb and cytokines, and suggest that combinations of anti-growth factor receptor MAb and cytokines may be useful in the treatment of breast cancer.