Monotherapy of Metastatic Breast Cancer: A Review of Newer Agents

Comprehensive studies on the biological activities of human metastatic (MDA-MB-231) and non-metastatic (MCF-7) breast cancer cell lines, directly or combinedly treated using non-thermal plasma-based approaches

Progressive incidence and a pessimistic survival rate of breast cancer in women worldwide remains one of the most concerning topics. Progressing research indicates a potentially high effectiveness of use cold atmospheric plasma (CAP) systems. The undoubted advantage seems its simplicity in combination with other anti-cancer modalities. Following observed trend of studies, one inventory CAP system was applied to directly treat human breast cancer cell lines and culturing in two different Plasma Activated Media (PAM) for combined utilization. Proposed CAP treatments on MCF-10 A, MCF-7, and MDA-MB-231 cell lines were studied in terms of impact on cell viability by MTT assay. Disturbances in cell motility following direct and combined CAP application were assessed by scratch test. Finally, the induction of apoptosis and necrosis was verified with annexin V and propidium iodide staining. Reactive species generated during CAP treatment were determined based on optical emission spectrometry analysis along with colorimetric methods to qualitatively assess the NO2-, NO3-, H2O2, and total ROS with free radicals concentration. The most effective approach for CAP utilization was combined treatment, leading to significant disruption in cell viability, motility and mostly apoptosis induction in breast cancer cell lines. Determined CAP dose allows for mild outcome, showing insignificant harm for the non-cancerous MCF-10 A cell line, while the highly aggressive MDA-MB-231 cell line shows the highest sensitivity on proposed CAP treatment. Direct CAP treatment seems to drive the cells into the sensitive state in which the effectiveness of PAM is boosted. Observed anti-cancer response of CAP treatment was mostly triggered by RNS (mostly NO2- ions) and ROS along with free radicals (such as H2O2, OH•, O2-•, 1O2, HO2•). The combined application of one CAP source represent a promising alternative in the development of new and effective modalities for breast cancer treatment.

Phase II study of DHP107 (oral paclitaxel) in the first-line treatment of HER2-negative recurrent or metastatic breast cancer (OPTIMAL study)

Background:

Standard intravenous (IV) paclitaxel is associated with hypersensitivity/toxicity. Alternative IV formulations have improved tolerability but still require frequent hospital visits and IV infusion. DHP107 is a novel oral formulation of paclitaxel that is approved in South Korea for the treatment of gastric cancer.

Methods:

This multicenter, phase II study using a Simon’s two-stage design investigated the efficacy and safety of DHP107 200 mg/m² administered orally twice daily on days 1, 8, and 15 every 4 weeks for the first-line treatment of recurrent or metastatic HER2-negative breast cancer.

Results:

Thirty-six patients were enrolled and 31 were assessable for efficacy. Patient median age was 57 years (range = 34–81) and 11 (31%) had triple-negative disease. A median of seven cycles (range = 1–28) of DHP107 was administered. Objective response rate was 55% (17 patients), all partial responses, according to the investigator’s decision and independent central review (ICR), and 44% (4/9 patients) in those with triple-negative disease. Disease control rate (partial response and stable disease) was 74% (23 patients) according to the investigator’s decision and ICR. In the intention-to-treat (ITT) population of all enrolled participants, the objective response rate was 50% (18/36 patients). Median progression-free survival was 8.9 months [95% confidence interval [CI]: 5.2–12.3) and median time to treatment failure was 8.0 months (95% CI: 4.2–10.0). DHP107 had an acceptable toxicity profile. All patients experienced treatment-emergent adverse events; the most common adverse events were decreased neutrophil count (81% all grades and 78% grade ⩾ 3) followed by peripheral sensory neuropathy (61% all grades and 8% grade 3). However, there was no febrile neutropenia or sepsis.

Conclusion:

DHP107 showed promising efficacy and acceptable tolerability in this phase II study and is currently being investigated in the OPTIMAL phase III study (NCT03315364).

Trial registration:

This trial was registered with ClinicalTrials.gov identifier: NCT03315364.

Combination Therapy of Navitoclax with Chemotherapeutic Agents in Solid Tumors and Blood Cancer: A Review of Current Evidence

Combination therapy emerges as a fundamental scheme in cancer. Many targeted therapeutic agents are developed to be used with chemotherapy or radiation therapy to enhance drug efficacy and reduce toxicity effects. ABT-263, known as navitoclax, mimics the BH3-only proteins of the BCL-2 family and has a high affinity towards pro-survival BCL-2 family proteins (i.e., BCL-XL, BCL-2, BCL-W) to induce cell apoptosis effectively. A single navitoclax action potently ameliorates several tumor progressions, including blood and bone marrow cancer, as well as small cell lung carcinoma. Not only that, but navitoclax alone also therapeutically affects fibrotic disease. Nevertheless, outcomes from the clinical trial of a single navitoclax agent in patients with advanced and relapsed small cell lung cancer demonstrated a limited anti-cancer activity. This brings accumulating evidence of navitoclax to be used concomitantly with other chemotherapeutic agents in several solid and non-solid tumors that are therapeutically benefiting from navitoclax treatment in preclinical studies. Initially, we justify the anti-cancer role of navitoclax in combination therapy. Then, we evaluate the current evidence of navitoclax in combination with the chemotherapeutic agents comprehensively to indicate the primary regulator of this combination strategy in order to produce a therapeutic effect.

Raltitrexed plus oxaliplatin-based transarterial chemoembolization in patients with unresectable hepatocellular carcinoma

Raltitrexed has shown efficacy and safety in many tumor types; however, the clinical data on the treatment of hepatocellular carcinoma is rare. In this report, we aim to assess the efficacy and safety of raltitrexed plus oxaliplatin (OXA)-based transarterial chemoembolization (TACE) in patients with unresectable hepatocellular carcinoma (uHCC). Patients with uHCC were recruited from multi-centers in China and assigned randomly to raltitrexed+OXA-based (n=76), fluorouracil+OXA-based (n=76), and doxorubicin+OXA-based (n=75) TACE treatment. The primary end point was overall survival (OS). Tumor response was assessed using response evaluation criteria in solid tumors (RECIST), modified response evaluation criteria in solid tumors (mRECIST), and European Association for the Study of the Liver criteria (EASL). Safety and toxicity were evaluated using the National Cancer Institute Common Toxicity Criteria. The raltitrexed group showed a better disease control rate evaluated using RECIST (raltitrexed vs. fluorouracil vs. doxorubicin: 96.1 vs. 84.2 vs. 86.7%, P=0.05) and a better overall response rate on the basis of mRECIST (67.1 vs. 47.4 vs. 50.7%, P=0.03) and EASL (67.1 vs. 47.4 vs. 49.3%, P=0.02). The median OS and median progression-free survival (PFS) were higher in the raltitrexed group (median OS: 13.4 vs. 9.6 vs. 8.5 months; median PFS: 6.7 vs 4.9 vs 4.6 months). The most common toxicities included elevated aspartate aminotransferase (78.9 vs. 86.8 vs. 81.3%) and abdominal nonspecific pain (68.4 vs. 81.6 vs. 78.7%). No significant differences were found in the overall number of patients who experienced any toxicity. Raltitrexed plus OXA-based TACE suggested a safe and efficacious regimen in uHCC patients. The results warrant further clinical investigation.

Kanglaite sensitizes colorectal cancer cells to Taxol via NF-κΒ inhibition and connexin 43 upregulation

Taxol, a first-line anti-tumour drug, has low effectiveness against colorectal cancer. Combination with other agents is an effective strategy to enhance Taxol cytotoxicity. Kanglaite injection is an extract from Coix lacryma-jobi seed and is usually combined with other agents to treat cancer. The aim of this study was to investigate the treatment effect of Taxol combined with Kanglaite on colorectal cancer cell lines. Kanglaite pretreatment followed by Taxol treatment was found to show the best synergism among all combination strategies. This combination also resulted in the smallest tumour volume in a Balb/c mice model. Kanglaite inhibited the expression of nuclear factor (NF)-κΒ and upregulated that of connexin 43, both of which sensitized cancer cells to Taxol. Moreover, Kanglaite increased many cellular variations caused by Taxol, including tubulin polymerization, caspase-3 cleavage, and upregulated expression of survivin and cyclin B1. These results suggest that Kanglaite pretreatment may increase the effect of Taxol on colorectal cancer.

Toward prediction of efficacy of chemotherapy: a proof of concept study in lung cancer patients using [¹¹C]docetaxel and positron emission tomography

PURPOSE

Pharmacokinetics of docetaxel can be measured in vivo using positron emission tomography (PET) and a microdose of radiolabeled docetaxel ([(11)C]docetaxel). The objective of this study was to investigate whether a [(11)C]docetaxel PET microdosing study could predict tumor uptake of therapeutic doses of docetaxel.

EXPERIMENTAL DESIGN

Docetaxel-naïve lung cancer patients underwent 2 [(11)C]docetaxel PET scans; one after bolus injection of [(11)C]docetaxel and another during combined infusion of [(11)C]docetaxel and a therapeutic dose of docetaxel (75 mg·m(-2)). Compartmental and spectral analyses were used to quantify [(11)C]docetaxel tumor kinetics. [(11)C]docetaxel PET measurements were used to estimate the area under the curve (AUC) of docetaxel in tumors. Tumor response was evaluated using computed tomography scans.

RESULTS

Net rates of influx (Ki) of [(11)C]docetaxel in tumors were comparable during microdosing and therapeutic scans. [(11)C]docetaxel AUCTumor during the therapeutic scan could be predicted reliably using an impulse response function derived from the microdosing scan together with the plasma curve of [(11)C]docetaxel during the therapeutic scan. At 90 minutes, the accumulated amount of docetaxel in tumors was less than 1% of the total infused dose of docetaxel. [(11)C]docetaxel Ki derived from the microdosing scan correlated with AUCTumor of docetaxel (Spearman ρ = 0.715; P = 0.004) during the therapeutic scan and with tumor response to docetaxel therapy (Spearman ρ = -0.800; P = 0.010).

CONCLUSIONS

Microdosing data of [(11)C]docetaxel PET can be used to predict tumor uptake of docetaxel during chemotherapy. The present study provides a framework for investigating the PET microdosing concept for radiolabeled anticancer drugs in patients.

An open-labeled phase II trial of docetaxel in combination with cisplatin as first-line cytotoxic therapy for anthracycline-naive patients with metastatic breast cancer

The combination of docetaxel and cisplatin has shown promising results in anthracycline-pretreated patients with advanced breast cancer, but with substantial toxicity. The efficacy and safety in anthracycline-naive patients has not been evaluated. Between October 2003 and January 2006, we enrolled 39 patients. None had undergone chemotherapy for metastatic disease or been exposure to adjuvant anthracycline-based regimens earlier. Eligibility criteria included: histologically proven metastatic cancer; WHO performance status (PS) 0-2; and adequate hematological, hepatic and renal function. Docetaxel (70 mg/m) and cisplatin (50 mg/m) were administered every 3 weeks until the patient either refused to continue, or progression, or even unacceptable toxicity occurred. Tumor response was assessed every three cycles. One patient was withdrawn from response analysis because of toxicity. Thirty-eight patients had a complete tumor assessment. Median age was 50 years (range, 28-63); 5.1% had a WHO of PS of 0; 87% a PS of 1; 7.7% a PS of 2; in 69%, two or more organs were involved. A total of 291 cycles (range, 1-9) were administered. Three complete responses and 27 partial responses (intent-to-treat response rate 30/39=76.9%) resulted; disease remained stable in six patients and two had disease progression. Grade III/IV toxicities included diarrhea in 10.2%, asthenia/fatigue in 2.5%, mucositis in 5.1% and neutropenia in 87.3% of patients. Seven patients developed febrile neutropenia (17.9%). The median time to progression was 11.2 months; the timespan was not sufficient to track the median survival. Docetaxel/cisplatin is an active regimen with acceptable toxicity in the first-line treatment of metastatic breast cancer, but it is not sufficiently promising as a standard. Further randomized study is warranted.

Antimitotic activity of methoxyconidiol, a meroterpene isolated from an ascidian

Methoxyconidiol is a meroterpene previously extracted from the ascidian Aplidium aff. densum [A. Simon-Levert, A. Arrault, N. Bontemps-Subielos, C. Canal, B. Banaigs. Meroterpenes from the ascidian Aplidium aff. densum, J. Nat. Prod. 68 (2005) 1412-1415]. In the present work we investigated its antimitotic effect on eukaryotic cells by using a bioassay based on the sea urchin early embryo. This bioassay has been successfully used to evaluate the efficacy of antiproliferative agents and to rapidly determine the affected cell cycle phase. We demonstrated that methoxyconidiol inhibits the cleavages of sea urchin Sphaerechinus granularis and Paracentrotus lividus fertilized eggs. This meroterpene disrupts M-phase progression and completely blocks cytokinesis without having any effect on DNA replication. The treatment severely disturbs the establishment of a mitotic spindle, most likely by affecting microtubule dynamics. Moreover, while the cell cycle regulatory kinase cyclin B/CDK1 is activated, cyclin B proteolysis is inhibited, impeding the output of M-phase. This characteristic cell cycle arrest induced by methoxyconidiol in sea urchin eggs emphasizes the interest for this drug as a putative antiproliferative agent for tumor cells.

Activity and tolerability of a combined palliative chemotherapy with mitomycin C, folinate, and 5-Fluorouracil in patients with advanced breast cancer after intensive pretreatment: a retrospective analysis

OBJECTIVES

The aim of this retrospective study was to evaluate the activity and toxicity of a combined chemotherapy containing mitomycin, folinate, and 5-fluorouracil (MiFoFU) in patients with advanced metastatic breast cancer and reduced performance status, ie, elderly patients or heavily pretreated patients.

METHODS

We studied the charts of 76 patients with progressive metastatic breast cancer who received MiFoFU chemotherapy at our institution between 1997 and 2003. Primary end points were response and time-to-progression (TTP); secondary end points were overall survival (OAS) and tolerability.

RESULTS

Median age was 57 years. Seventeen patients had > or =2 palliative cytostatic treatments before; 19 patients were older 65 years. Patients received a median of 6 cycles. Clinical benefit rate was 58%. After MiFoFU, median TTP and OAS were 8 months and 14 months, respectively. Main nonhematologic toxicity was stomatitis (grade I/II, 21%) and diarrhea (grade I/II, 37%). Grade III/IV hematotoxicity was seen in 18 patients (24%).

CONCLUSIONS

A combined MiFoFU chemotherapy is a well-tolerated treatment option in the palliative therapy for patients with metastatic breast cancer. In particular, the favorable efficacy/toxicity ratio in intensively pretreated or elderly patients makes this combination a reasonable alternative within these settings.

Multidisciplinary Therapy of Locally Far‐Advanced or Inflammatory Breast Cancer with Fixed Perioperative Sequence of Epirubicin, Vinorelbine, and Fluorouracil Chemotherapy, Surgery, and Radiotherapy: Long‐Term Results

BACKGROUND

Based on phase II data in advanced breast cancer (BC), the fluorouracil, epirubicin, and vinorelbine (FEN) combination was assessed as perioperative chemotherapy, integrated in a multidisciplinary treatment for locally advanced BC.

PATIENTS AND METHODS

Patients with newly diagnosed inoperable (stage IIIB or inflammatory) BC. Multimodality treatment protocol consisted of four preoperative courses of fluorouracil (600 mg/m(2) day 1), epirubicin (75 mg/m(2) day 1), and vinorelbine (25 mg/m(2) day1 and day 8), all i.v. every 21 days, followed by radical or conservative surgery according to clinical response and four postoperative identical chemotherapy courses aimed to eradicate micrometastatic disease. Locoregional radiotherapy was offered to all patients after the completion of chemotherapy followed by hormonotherapy according to hormone receptor status. The primary end points of the study were: (a) clinical and pathological response, (b) downstaging and conversion to operable disease, and (c) recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Forty-eight women, one stage IIIA, 27 (56.2%) stage IIIB, two stage IIIC (4.1%), and 12 (25%) with inflammatory BC, aged 34-75 years (median, 52), were accrued. Thirty-eight and 34 patients completed the planned pre- and postoperative chemotherapy, respectively. Totals of 175 and 135 cycles were administered pre- and postoperatively, respectively. Toxicity of both phases, mainly hematologic, was in general acceptable without treatment-related death. Venous reactions were a frequent problem. All but three tumors were converted to operable, 31.3% with breast conservation. The clinical response rate (RR) was 77.7% (22.2% complete) and pathological RR was 73.3% (complete, 20% in both primary and axilla). After a median follow-up of 72 months, 62.5% and 16.7% of patients remain relapse free at 3 and 5 years, respectively, while 83% and 58.3% were alive 3 and 5 years, respectively, after the start of chemotherapy. Median RFS and OS have not yet been reached, and are currently 37+ and 62+ months, respectively.

CONCLUSION

This fixed number of FEN perioperative courses schedule followed by radiotherapy is safe and highly active in inducing both local and distant control of locally far-advanced BC. This strategy is at least not inferior to other established regimens or strategies for locally far-advanced BC, while the integration of taxanes or new targeted agents may help show its true value for this challenging clinical entity.

New trends in the medical management of glioblastoma multiforme: the role of temozolomide chemotherapy

Standard care for newly diagnosed glioblastoma multiforme (GBM) previously consisted of resection to the greatest extent feasible, followed by radiotherapy. The role of chemotherapy was controversial and its efficacy was marginal at best. Five years ago temozolomide (TMZ) was approved specifically for the treatment of recurrent malignant glioma. The role of TMZ chemotherapy administered alone or as an adjuvant therapy for newly diagnosed GBM has been evaluated in a large randomized trial whose results suggested a significant prolongation of survival following treatment. Findings of correlative molecular studies have indicated that methylguanine methyltransferase promoter methylation may be used as a predictive factor in selecting patients most likely to benefit from such treatment. In this short review the authors summarize the current role of TMZ chemotherapy in the management of GBM, with an emphasis on approved indications and practical aspects.

Clinical experience with docetaxel for Chinese breast cancer patients: Hematological toxicity profiles

BACKGROUND

Asians are generally regarded to tolerate cytotoxic drugs less well than their Caucasian counterpart. A substantial proportion of patients receive suboptimal doses of chemotherapy for fear of severe toxicity. This retrospective study aims to evaluate the adverse events, especially hematological, of docetaxel in Chinese patients with breast cancer.

PATIENTS AND METHODS

Fifty-nine patients, age ranged from 33 to 70 (median=47) years, were assigned to receive 3 to 6 (median=4) cycles of Docetaxel 100 mg/m2 every 21 days as neoadjuvant (n=3), adjuvant (n=26), neoadjuvant plus adjuvant (n=3), or active therapy for metastatic or relapsed breast cancer (n=27).

RESULTS

A total of 56 (95%) patients completed the assigned whole regimen and only 3 (5%) patients discontinued due to either poor tolerance to the drug's side effects or worsening of disease leading to death. On average, the received dose intensity (RDI) was 0.86 for docetaxel 100 mg/m2 in this study. Among all the clinical adverse events, hematological toxicities were not excessively higher. Of the total 59 patients, major adverse events of all grades were leukopenia (22%), neutropenia (20%), fever (19%), and febrile neutropenia (14%). Only 12% and 14% of patients experienced grade 3 or 4 leukopenia and neutropenia, respectively.

CONCLUSION

In view of the increasing breast cancer incidence and the acceptable toxicity profile of docetaxel among Chinese patients, a dosage of 100 mg/m2 can be recommended for use among Asians.

Paclitaxel induces the phosphorylation of the eukaryotic translation initiation factor 4E-binding protein 1 through a Cdk1-dependent mechanism

Initial chemotherapeutic treatment triggers a stress-related response, which can lead to an increase in the expression of survival proteins. In this study we examine whether paclitaxel (PTX) alters the expression and/or phosphorylation of the translation initiation proteins, eukaryotic initiation factor 4E (eIF-4E) and 4E-binding protein (4E-BP1), a suppressor of eIF-4E in the dephosphorylated state. We found that PTX induced the hyperphosphorylation of 4E-BP1 in the breast cancer cell line, MDA MB 231, which reduced its association with eIF-4E, but did not alter the expression and phosphorylation of eIF-4E. The hyperphosphorylation of 4E-BP1 correlated with G2/M accumulation and with an increase in the phosphorylation of cdk1 substrates. Cotreatment with a histone deacetylase inhibitor (an indirect inhibitor of cdk activity), purvalanol A and roscovitine (direct cdk inhibitors), and the reduction of cyclin B expression using RNA interference decreased the hyperphosphorylation of 4E-BP1 in PTX treated cells. The hyperphosphorylation of 4E-BP1 by PTX increased the association of eIF-4E with eIF-4G, whereas cotreatment with purvalanol A inhibited the association of eIF-4E with eIF-4G in PTX treated cells. Taken together, our data suggest that PTX-increases the functional level of eIF-4E by promoting the hyperphosphorylation and release of 4E-BP1 through a cdk1-dependent mechanism.

Effect of Particle Size of Nanospheres and Microspheres on the Cellular-Association and Cytotoxicity of Paclitaxel in 4T1 Cells

PURPOSE

To compare the effect of size of delivery systems on the cell-association and in vitro cytotoxicity of paclitaxel.

METHODS

Four sizes of PLGA-paclitaxel particles were prepared to study the effect of particle size on the cell-association of paclitaxel in 4T1 monolayer in the presence, and absence, of BCRP inhibitor, endocytic inhibitor, and P-glycoprotein (P-gp) inhibitor. Paclitaxel cell-association studies were repeated in Caco-2, Cor-L23/R, and bovine brain microvessel endothelial cells (BBMECs), as well as the association of etoposide in 4T1 cells. Cytotoxicity of paclitaxel to 4T1 cells delivered in nanospheres was compared to microspheres.

RESULTS

The concentration of paclitaxel and etoposide associated with 4T1 cells was 4.8 and 29 times greater, respectively, as the size increased from 310 to 2077 nm. Paclitaxel association consistently increased in Caco-2 and Cor-L23/R as the size of the delivery system increased. The endocytic inhibitor, 2-deoxyglucose, significantly decreased the cellular paclitaxel association when delivered by nanospheres but not microspheres. Consistent with the cell-association results, paclitaxel was thrice more cytotoxic to 4T1 cells when delivered in microspheres.

CONCLUSIONS

Cell-association of paclitaxel increased in 4T1, Caco-2, and Cor-L23/R as particle size increased. Paclitaxel delivered from 1-mum microspheres was thrice more cytotoxic to 4T1 cells compared to the drug delivered from nanospheres or solution.

Radiopharmaceuticals for targeted radiotherapy

This work intends to find specific radiopharmaceuticals for cancer therapy based on beta (153Sm and 166Ho) or Auger (99Tc(m)) emitter radionuclides, using cyclic and acyclic polyamines as bifunctional chelators. These chelators are designed to allow the binding of a tumour seeking biomolecule and/or a DNA intercalator. The cyclic amines, such as 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid and 1,4,7,10-tetraazacyclotridecane-1,4,7,10-tetraacetic acid, were radiolabelled with 153Sm and 166Ho. The radiochemical and biological behaviour of the resulting complexes were evaluated in order to assess their potential as building blocks for the attachment of selected biomolecules, with the aim of further applying them for the development of specific therapeutic radiopharmaceuticals. Novel pyrazolyldiamines, bearing a DNA intercalating anthracenyl fragment, were also explored to synthesize radioactive complexes with the fac-[99Tc(m)(CO)]3]+ moiety. The identity of these 99Tc(m) tricarbonyl complexes was confirmed by high-performance liquid chromatography comparison with rhenium congeners fully characterized. By including a DNA intercalator into the chelator framework, we expect to induce more efficient and selective damage to the DNA of cancer cells by the action of the short-range Auger electrons emitted by 99Tc(m).

The role of the liposomal anthracyclines and other systemic therapies in the management of advanced breast cancer

For patients whose breast cancers are not responsive to endocrine therapy, there are a large number of cytotoxic drugs that will induce a response. In spite of the introduction of new, very active drugs such as the taxanes, vinorelbine, capecitabine, gemcitabine, and trastuzumab, the anthracyclines are still as active as any--and more active than most--drugs used to treat breast cancer. Their inclusion in combinations to treat early and advanced disease prolongs survival. However, they cause nausea, vomiting, alopecia, myelosuppression, mucositis, and cardiomyopathies. There is no evidence that increasing the dose of conventional anthracyclines or any other of the cytotoxics beyond standard doses will improve outcomes. Schedule may be more important than dose in determining the benefit of cytotoxics used to treat breast cancer. Weekly schedules and continuous infusions of 5-fluorouracil and doxorubicin may have some advantages over more intermittent schedules. Liposomal formations of doxorubicin reduce toxicity, including cardiotoxicity; theoretically they should also be more effective because of better targeting of tumor over normal tissues. Both pegylated liposomal doxorubicin (Doxil/Caelyx [PLD]) and liposomal doxorubicin (Myocet [NPLD]) appeared to be as effective as conventional doxorubicin and much less toxic in multiple phase II and phase III studies. PLD has been evaluated in combinations with cyclophosphamide, the taxanes, vinorelbine, gemcitabine, and trastuzumab, and NPLD has been evaluated in combination with cyclophosphamide and trastuzumab. Both liposomal anthracyclines are less cardiotoxic than conventional doxorubicin. The optimal dose of PLD is lower than that of conventional doxorubicin or NPLD. Patients treated with PLD have almost no alopecia, nausea, or vomiting, but its use is associated with stomatitis and hand-foot syndrome, which can be avoided or minimized with the use of proper dose-schedules. In contrast, the optimal dose-schedule of NPLD is nearly identical to that of conventional doxorubicin. The toxicity profile of NPLD is similar to that of conventional doxorubicin, but toxicities are less severe and NPLD is better tolerated than conventional doxorubicin at higher doses.

Dose-dense vinorelbine and paclitaxel with granulocyte colony-stimulating factor in metastatic breast cancer patients: anti-tumor activity and peripheral blood progenitor cell mobilization capability

We studied the safety, activity and peripheral blood progenitor cell mobilizing capability of a dose-dense combination of vinorelbine (VNB) and paclitaxel (PTX) as first-line chemotherapy for patients with metastatic breast cancer (MBC). Forty-three MBC patients were submitted to four cycles of VNB 30 mg/m2 and PTX 175 mg/m2 intravenously, every 2 weeks, as the first induction step of a tandem high-dose chemotherapy program. Granulocyte colony-stimulating factor (G-CSF) 5 microg/kg was administered daily from day +5 to +10 in order to accelerate hematopoietic recovery, or 48h after the last VNB-PTX when a leukapheresis was planned (after the third or fourth cycle). A total of 172 cycles were administered. The mean delivered dose-intensity of VNB and PTX was 14.7 and 86 mg/m2/week, respectively (98% of the planned dose-intensity). The main per-patient toxicities were: peripheral neurotoxicity (G1/2 60%, G3 5%), constipation (G1/2 10%), oral mucositis (G1/2 20%), and asthenia (G1/2 35%). Hematological toxicity was unremarkable, except for anemia with hemoglobin (Hb) values < 10 g/dl (28%), and lymphopenia with lymphocyte counts < 1000/mm3 (28%). Two complete (5.1%) and 24 partial (61.5%) responses were observed in 39 assessable patients, for an overall response rate of 66.6% (95% CI 51.6-80.9). A median of one apheretic procedure (range 1-3) was required to achieve the target number of 6 x 10(6)/kg CD34+ cells. The median number of CD34+ harvested per patient was 15 x 10(6)/kg (range 6.4-36.5). Four cycles of dose dense VNB and PTX showed a favorable toxicity profile, a relevant anti-tumor activity and a high peripheral blood progenitor cell mobilizing activity.

Clinical experience with trastuzumab (herceptin)

Trastuzumab is a humanized monoclonal antibody against the epidermal growth factor family oncogene, Her-2/neu. It has revolutionized therapy for the 15-20% of patients with metastatic breast cancer whose tumors have gene amplification for Her-2/neu. Results of clinical trials with single agent trastuzumab and in combination with paclitaxel, docetaxel, vinorelbine, gemcitabine and platinum salts have been encouraging. Durable remissions in excess of 5 years have occasionally been reported. Subjectively the side effect profile of this novel, targeted therapy, has been mild. Cardiac toxicity, while reported in combination regimens with anthracyclines tend to be easily manageable and not absolute contradictions to continuation of trastuzumab. Outside of clinical trials, however, anthracycline/trastuzumab combinations should be avoided. Preliminary results of trials with various combinations of chemotherapeutic agents have been promising while combinations with hormonal and other biologic therapy are ongoing. Trastuzumab is an exciting new monoclonal antibody with interesting anti-tumor activity in patients with Her-2/neu gene amplified breast cancer. We look forward to ongoing clinical trials combining trastuzumab with a broad array of other chemotherapeutic, hormonal and biological agents.

Platinum-based chemotherapy in metastatic breast cancer: current status

Cisplatin and carboplatin are active in previously untreated patients with metastatic breast cancer (MBC) with mean response rates (RRs) of 50 and 32%, respectively. In pretreated patients the RR to cisplatin/carboplatin monotherapy declines markedly to <10%. Cisplatin and carboplatin have been combined with many other cytotoxics. In first-line setting high activity has been observed in combination with taxanes or vinorelbine (RRs consistently approximately 60%). It appears that these newer combinations are superior to older regimens with etoposide (RRs 30 to 50%) or 5-fluorouracil (RRs 40 to 60%). Cisplatin-/carboplatin-based regimens with infusional 5-FU and epirubicin/paclitaxel/vinorelbine achieve high RRs of around 60 to 80%. However these regimens are difficult to administer in all patients because they require central venous access for continuous 5-FU infusion. In pretreated MBC the combinations of cisplatin-taxane/vinorelbine/gemcitabine or carboplatin-docetaxel/vinorelbine yield RRs of 40 to 50%, which are higher than those achieved with platinum-etoposide/5-FU. In locally advanced disease cisplatin-based regimens achieve very high RRs (>80%). This would suggest that in chemotherapy-naïve patients platinum-based therapy might have an important role to play. Additionally the synergy demonstrated between platinum compounds, taxanes and herceptin, in preclinical and clinical studies is of immense importance and the results of the two ongoing Breast Cancer International Research Group randomized phase III studies are eagerly awaited. These studies may help clarify the role of platinum compounds in the treatment of metastatic and possibly early breast cancer.

Current Status of Liposomal Anthracycline Therapy in Metastatic Breast Cancer

Doxorubicin is a mainstay for the treatment of metastatic breast cancer (MBC); however, its use is limited by toxicity, particularly cardiotoxicity. Novel drug delivery systems using liposomes have been developed to maintain the clinical utility of conventional doxorubicin while minimizing cardiotoxicity. Three liposomal anthracyclines have been developed: liposomal daunorubicin, nonpegylated liposomal doxorubicin, and pegylated liposomal doxorubicin. Liposomal daunorubicin, currently approved in the United States for the treatment of AIDS-related Kaposi sarcoma, has shown preliminary activity in MBC in a phase I trial; further investigation is ongoing. Nonpegylated liposomal doxorubicin, which is not available in the United States, has demonstrated activity similar to that of conventional doxorubicin (both as a single agent and in combinations). Pegylated liposomal doxorubicin has demonstrated activity in phase II and III trials when used alone or in combination with other chemotherapeutic agents in patients with MBC. It is currently approved in the United States and Europe for AIDS-related Kaposi sarcoma and platinum/paclitaxel-refractory ovarian carcinoma; in Europe and Canada, it is also approved as monotherapy for MBC. In addition, accumulating evidence suggests that the combination of liposomal anthracyclines (pegylated and nonpegylated) and trastuzumab is active, with acceptable toxicity. Based on these encouraging experiences, randomized clinical trials are ongoing or planned to further assess the therapeutic potential of pegylated liposomal doxorubicin as a single agent and in combination with other chemotherapeutic agents and targeted agents, such as trastuzumab, for MBC.

Trastuzumab in the treatment of advanced breast cancer: single-center experience

A significant number of women with advanced breast cancer fail to respond to standard-dose chemotherapy. From the beginning of 1999, 17 women with HER2 positive advanced breast cancer received Herceptin as monotherapy or in combination with paclitaxel or other non-anthracyclines. Eight (47%) women previously received high-dose chemotherapy followed by haematopoiesis stem cell rescue. Three women received Herceptin alone, eleven Herceptin plus paclitaxel and three Herceptin and some of the other non-anthracyclines (CCNU, cisplatin and gemcitabine). In the group of patients who received Herceptin monotherapy, one has partial response (PR), one stable disease (SD) and in the third patient the disease progressed. Out of three patients who received Herceptin in combination with other non-anthracyclines, two have SD and one progressed. In the group of 11 women who received Herceptin + Taxol, 7 (64%) patients achieved PR, 2 (18%) SD, and 2 (18%) had disease progression. Grade 3-4 neutropenia has been observed in four (23%) women. Febrile neutropenia was observed in two cases and resolved completely when antibiotics were introduced. Other grade 3 toxicity that has been noted is peripheral neuropathy in three (18%) patients, diarrhoea in four (23%) and onycholysis in one (6%). Serial heart ultrasound showed no significant decline in left ventricular ejection fraction. According to our preliminary experience, Herceptin therapy showed promising results in women with metastatic breast cancer.

Breast cancer

Several interesting aspects of breast cancer were covered at this year's American Society of Clinical Oncology meeting. Sentinel lymph node (SN) mapping is now in widespread use, in concert with the general trend toward trying to decrease the morbidity of breast cancer surgery. With every advance, however, comes new challenges, and there was a timely presentation from Giuliano's group addressing the controversial issue of how to interpret the presence of cells in the SN seen only with keratin stains but not by routine hematoxylin and eosin stains. Two abstracts addressed the issue of whether for certain women with invasive breast cancer radiation therapy could be omitted after lumpectomy. Another interesting topic related to hormonal issues in the adjuvant treatment of premenopausal women. An analysis from the ZIPP-TRIAL reported on bone marrow density studies in young women given two years of ovarian suppression in the adjuvant setting: it seems that the loss of bone density may be reversible and, more interestingly, may be prevented with concurrent tamoxifen. Two other presentations looked at the prognostic significance of drug-induced amenorrhea in young women treated with adjuvant chemotherapy and at the efficacy of ovarian suppression during chemotherapy in preserving fertility. In an unpublicized presentation, Mary-Claire King presented very interesting results from the National Surgical Adjuvant Breast and Bowel Project Breast Cancer Prevention Trial suggesting that tamoxifen may be an effective chemopreventive drug for women with BRCA2, but not BRCA1, mutations. Two important presentations re-analyzed the outcome of the pivotal trials using Herceptin to treat metastatic breast cancer and nicely show that FISH analysis of HER-2 overexpression is a more accurate indicator of response to Herceptin than immunohistochemical staining. Finally, there were two interesting presentations related to tamoxifen resistance which may be relevant clinically, pertaining to subsequent raloxifene use and the interaction of the estrogen receptor and EGF receptor pathways, respectively.

A review of vinorelbine in the treatment of breast cancer

As combinations and sequences of anthracyclines and taxanes increasingly become standard adjuvant treatment for early breast cancer, a major need for new treatment options for metastatic breast cancer will arise. Vinorelbine is highly active in the treatment of metastatic breast cancer, both as a single agent and in combination regimens. Furthermore, it is well tolerated, with a low incidence of subjective toxicities. It is anticipated, therefore, that vinorelbine will become increasingly utilized for treating metastatic breast cancer due to its favorable safety profile, good tolerability, and promising results in combination with other chemotherapy agents. Combinations with trastuzumab and newer molecular targeting agents are being explored. Doublets or triplets of vinorelbine with drugs other than anthracyclines and taxanes could be considered in the next generation of adjuvant and neoadjuvant trials, where it is anticipated that anthracycline/taxane combinations are likely to replace anthracycline/cyclophosphamide combinations as the mainstay of adjuvant treatment.

The ex vivo effect of high concentrations of doxorubicin on recurrent ovarian carcinoma

The cardiotoxicity of anthracyclines has largely prevented dose intensification, but the use of liposomal preparations (e.g. Caelyx/Doxil) allows much higher intra-tumoral concentrations to be achieved without cardiotoxicity. However, it is uncertain how much this will improve response rates over standard anthracycline therapy. The ATP-based chemosensitivity assay (ATP-TCA) has been used to develop new regimens for several tumor types, to investigate the molecular basis of chemosensitivity and shows considerable promise as a clinical method for individualizing chemotherapy. In this study, we have used the ATP-TCA to determine the concentration responsiveness of tumor-derived cells to concentrations of doxorubicin. The 22 tumor samples included were obtained from 20 heavily pretreated patients with recurrent ovarian cancer. Eight had previous anthracycline exposure, four as part of the CAP regimen. The results show more than 95% inhibition at clinically achievable concentrations in 11 of 22 tumors tested. Of the rest, seven showed a plateau effect between 80 and 95% inhibition, suggesting that there might be a subset of resistant cells present that is not inhibited by high concentrations of doxorubicin. Two tumors showed complete resistance and neither of these had previously received anthracycline therapy. As it has been suggested that gemcitabine might enhance anthracycline sensitivity in combination and we have had good results with gemcitabine modulation of alkylating agents in the assay, we have tested the combination of doxorubicin+gemcitabine under assay conditions in 11 tumors with little indication of improvement. In conclusion, doxorubicin at concentrations achievable with liposomal preparations shows strong ex vivo activity against pretreated recurrent ovarian cancer in just over half of the cases tested.

Cellular immune profile of patients with advanced cancer before and after taxane treatment

The purpose of this study is to determine immune recovery and function after treatment with docetaxel or paclitaxel. Peripheral blood mononuclear cells were harvested before chemotherapy and at weekly times afterwards for cycle 1. Leukocyte subsets ICD45hiCD14lo polymorphonuclear neutrophils, CD45hiCD14hi monocytes, CD45hiCD14- lymphocytes, CD3+CD4/CD8+ T cells, CD3-CD19+ B cells, CD3-CD16/CD56+ natural killer (NK) cells], and circulating cytokine levels [tumor necrosis factor-alpha, gamma-interferon (gamma-IFN), and interleukins (IL-2, IL-10, IL-12)] were followed. In addition, T-cell mitogenic function, NK function, and lymphokine activated killer (LAK) function was assessed. Ten patients were entered in the trial. T-cell frequency, B-cell frequency, and CD4/CD8 ratio did not change. IL-10 serum levels significantly decreased in paclitaxel-treated patients (4.4+/-1.3 pg/ml at week 4 versus 7.8+/-2.1 pg/ml at baseline; p < 0.05). IL-2, IL-12, and gamma-IFN levels were not detectable. NK cytotoxic activity decreased in docetaxel-treated patients. LAK cell activity was not altered. Four patients achieved a partial or complete response. They demonstrated higher than normal CD4:CD8 T-cell ratios and an improved phytohemagglutinin stimulation index (SI = 2.5). In conclusion, our findings suggest that immune function was affected more significantly after docetaxel treatment. Investigational approaches, which enhance cellular immunity, may be of greater relevance after treatment with docetaxel. Additional studies monitoring NK function after chemotherapy are recommended.

Mechanism-based target identification and drug discovery in cancer research

Cancer as a disease in the human population is becoming a larger health problem, and the medicines used as treatments have clear limitations. In the past 20 years, there has been a tremendous increase in our knowledge of the molecular mechanisms and pathophysiology of human cancer. Many of these mechanisms have been exploited as new targets for drug development in the hope that they will have greater antitumor activity with less toxicity to the patient than is seen with currently used medicines. The fruition of these efforts in the clinic is just now being realized with a few encouraging results.