Chemotherapy in the multidisciplinary approach to soft tissue sarcomas. EORTC Soft Tissue and Bone Sarcoma Group studies in perspective

Structure of the human cone photoreceptor cyclic nucleotide-gated channel

Cyclic nucleotide-gated (CNG) channels transduce light-induced chemical signals into electrical signals in retinal cone and rod photoreceptors. Structures of native CNG channels, which are heterotetramers formed by CNGA and CNGB subunits, have not been obtained. In the present study, we report a high-resolution cryo-electron microscopy structure of the human cone CNG channel in the apo closed state. The channel contains three CNGA3 and one CNGB3 subunits. Arg403 in the pore helix of CNGB3 projects into an asymmetric selectivity filter and forms hydrogen bonds with two pore-lining backbone carbonyl oxygens. Arg442 in S6 of CNGB3 protrudes into and occludes the pore below the hydrophobic cavity gate previously observed in homotetrameric CNGA channels. It is interesting that Arg403Gln is a disease mutation, and Arg442 is replaced by glutamine in some animal species with dichromatic or monochromatic vision. These and other unique structural features and the disease link conferred by CNGB3 indicate a critical role of CNGB3 in shaping cone photoresponses.

High-dose chemotherapy consolidation for chemosensitive advanced soft tissue sarcoma patients: an open-label, randomized controlled trial

BACKGROUND

Metastatic soft tissue sarcoma (STS) prognosis remains poor and few cytotoxic agents offer proven efficacy. This randomized open phase III study examines whether high-dose (HD) chemotherapy with peripheral blood stem cells (PBSCs) could improve overall survival (OS) of chemosensitive patients.

PATIENTS AND METHODS

Advanced STS patients aged 18-65 years received four courses of standard mesna, adryamycin, ifosfamide and dacarbazine (MAID) treatment. Chemotherapy-responding patients and patients with at least stable disease amenable to complete surgical resection were randomized to receive standard dose (SD) with two successive MAID cycles or HD treatments of one MAID then MICE intensification: mesna (3.6 g/m(2), day 1-5), ifosfamide (2.5 g/m(2), day 1-4), carboplatin [area under the curve (AUC) 5/day 2-4] and etoposide (300 mg/m(2), day 1-4) with PBSC reinjection at day 7.

RESULTS

From 2000 to 2008, 207 patients received four cycles of MAID and 87 assessable patients were randomly assigned to receive the following: 46 SD, 41 HD, with 45 and 38 maintained for analyses after secondary centralized histological review. Futility analyses led to study closure in November 2008. Three-year OS was 49.4% for the SD group versus 32.7% for HD arm, hazard ratio= 1.26, 95% confidence interval 0.70-2.29; progression-free survival was 32.4% and 14.0%, respectively. HD treatment led to higher grades 3-4 toxicity.

CONCLUSION

This study failed to show an OS advantage for advanced STS patients treated with dose-intensified chemotherapy with PBSC.

Pediatric soft tissue sarcomas

Soft tissue sarcomas in children are rare. Approximately 850 to 900 children and adolescents are diagnosed each year with rhabdomyosarcoma (RMS) or a non-RMS soft tissue sarcoma (NRSTS). RMS is more common in children 14 years old and younger and NRSTS in adolescents and young adults. Infants get NRSTS, but their tumors constitute a distinctive set of histologies. Surgery is a major therapeutic modality and radiation plays a role. RMS is treated with adjuvant chemotherapy, whereas chemotherapy is reserved for the NRSTS that are high grade or unresectable. This review discusses the etiology, biology, and treatment of pediatric soft tissue sarcomas.

Chemotherapeutic management of soft tissue sarcoma

Soft tissue sarcomas are a heterogeneous group of connective tissue tumors, with more than 50 different subtypes. Given the heterogeneity, and the relative small numbers of patients, performing large adequately powered clinical trials in which one can glean any overall broad treatment decisions based on outcome is difficult at best. There is controversy on which chemotherapeutic agents to use in the adjuvant and metastatic settings, or even if to use chemotherapy in the adjuvant setting. In the metastatic setting, doxorubicin and ifosfamide have remained the standards of care for more than 20 years. This review discusses the data on chemotherapy for treatment of metastatic sarcomas and the utility of chemotherapy in the adjuvant and neoadjuvant settings. In addition, the utility of newer biologic agents in the treatment for sarcomas is considered.

Brostallicin, an agent with potential activity in metastatic soft tissue sarcoma: a phase II study from the European Organisation for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group

The study aimed to assess the efficacy and safety of brostallicin, a new DNA minor groove binder, at a dose of 10mg/m2, intravenous (i.v.) every three weeks, in patients with advanced or inoperable soft tissue sarcoma (STS) and gastrointestinal stromal tumour (GIST) failing first line therapy. Two groups were recruited: (1) GIST following treatment with imatinib; (2) other STS following treatment with single agent doxorubicin or ifosfamide or a single line of combination therapy. The primary end-point was overall response rate (ORR) as defined by response evaluation criteria in solid tumours (RECIST). Progression free survival (PFS) was a secondary end-point. In the GIST group, a Simon two step design was planned: first step 18 patients, total 32 patients (p1=20% p0=5% alpha=beta=0.1). In the non-GIST group, planned sample size was 40 in a standard Fleming one-step design (p0=10%, p1=25%, alpha=beta=0.1). Forty-three patients with non-GIST and 21 patients with GIST were recruited. In general, the drug was well tolerated. Common Toxicity Criteria (CTC) grade 3 or grade 4 toxicity was granulocytopenia: 70% of patients, 50% of cycles; fatigue: 25% of patients, 8% of cycles; febrile neutropenia: 14% of patients, 4% of cycles. There was one confirmed toxic death due to neutropenic septicaemia. Three patients had clinically significant allergic reactions in 249 cycles delivered. In the GIST group, no patients had a confirmed response and recruitment was discontinued at the first step. In the non-GIST group, there were two confirmed partial responses. The 3 month PFS was 46% in the non-GIST group and 33% in the GIST group. In the non-GIST group, this PFS is in the range of other agents considered active in STS, and may predict for more substantial first line activity. Further investigation in STS other than GIST appears warranted.

Sequential dose-dense doxorubicin and ifosfamide for advanced soft tissue sarcomas

BACKGROUND

Combinations of high-dose ifosfamide (IF; 10-12 g/m2) plus doxorubicin (DX; 50-90 mg/m2) have been administered to patients with advanced soft tissue sarcoma (ASTS) in an attempt to improve therapeutic efficacy. Although these combination regimens appear to yield higher response rates than do standard-dose regimens, they also are associated with significant hematologic toxicity, despite the administration of hematopoietic growth factor support. As a potentially less toxic alternative, the authors designed a sequential, dose-dense schedule of DX and IF and explored its feasibility and toxicity, as well as patient compliance with the schedule, in a Phase II trial.

METHODS

Chemotherapy-naive patients with unresectable locally advanced or metastatic ASTS were to receive DX at 30 mg/m2 per day for 3 consecutive days once every 2 weeks for 3 cycles followed by IF at 12.5 g/m2 delivered by continuous infusion over 5 days once every 3 weeks for 3 cycles. Granulocyte-colony-stimulating factor was administered subcutaneously for 7 days beginning 24 hours after the completion of each DX or IF cycle. Additional IF cycles were allowed if an objective response was achieved.

RESULTS

Sixty patients were enrolled in the trial. Three were ineligible, 9 had locally advanced disease, and 48 had metastatic disease. At the completion of therapy, the mean dose intensities for DX and IF were 40 mg/m2 per week and 3.87 g/m2 per week, respectively. Sixty-six percent of patients completed the regimen projected by the protocol. Grade 3 or 4 granulocytopenia, febrile neutropenia, and stomatitis occurred in 46%, 24%, and 27% of patients, respectively. Twenty of 53 assessable patients (38%; 95% confidence interval [CI], 25-51%) achieved objective responses, with a median time to progression of 24 weeks (95% CI, 18-30 weeks).

CONCLUSIONS

Sequential administration of dose-dense DX and high-dose IF is feasible and exhibits an acceptable hematologic toxicity profile and a level of activity that is within the range described for schedules that combine high-dose IF with an anthracycline.

Randomised phase II trial of pegylated liposomal doxorubicin (DOXIL/CAELYX) versus doxorubicin in the treatment of advanced or metastatic soft tissue sarcoma: a study by the EORTC Soft Tissue and Bone Sarcoma Group

CAELYX/DOXIL, pegylated liposomal doxorubicin, has shown antitumour activity and reduced toxicity compared with standard doxorubicin in other tumour types. In this prospective randomised trial, 94 eligible patients with advanced soft-tissue sarcoma (STS) were treated, 50 with CAELYX (50 mg/m(2) by a 1 h intravenous (i.v.) infusion every 4 weeks) and 44 with doxorubicin (75 mg/m(2) by an i.v. bolus every 3 weeks). Histological subtypes were evenly matched, 33% were leiomyosarcoma (CAELYX: 18; doxorubicin: 13). Primary disease sites were well matched. CAELYX was significantly less myelosuppressive, only 3 (6%) patients had grade 3 and 4 neutropenia, versus 33 (77%) on doxorubicin; febrile neutropenia occurred in 7 (16%) patients given doxorubicin, but only 1 (2%) given CAELYX. 37 (86%) patients on doxorubicin had grade 2-3 alopecia, but only 3 (6%) on CAELYX, and the major toxicity with CAELYX was to the skin. Palmar-plantar erythrodysesthesia with CAELYX was grade 1: 4 (8%) patients, grade 2: 11 (22%) patients, grade 3: 9 (18%) patients and grade 4: 1 (2%) patient. Other non-haematological grade 3 and 4 toxicities were rare. Confirmed responses were observed with both agents: CAELYX: complete response (CR) 1 (uterine), partial response (PR) 4 (response rate (RR) 10%); and doxorubicin: CR 1, PR 3 (RR of 9%); with the best response being stable disease (NC) in 16 and 18 patients, respectively. The reason for the low response rate is unknown, but it may be due partly to a high proportion of gastrointestinal stromal tumours. In conclusion, CAELYX has equivalent activity to doxorubicin in STS with an improved toxicity profile and should be considered for further investigation in combination with other agents such as ifosfamide.

Phase II trial of first-line high-dose ifosfamide in advanced soft tissue sarcomas of the adult: a study of the Spanish Group for Research on Sarcomas (GEIS)

BACKGROUND

The agent Ifosfamide (IFOS) is active against soft tissue sarcomas (STS), and patients who progress to IFOS at doses < or = 10 g/m2 show remissions when exposed to high-dose ifosfamide (HDI) (i.e., doses > 10 g/m2), which supports a dose-response relationship for this drug. Because of a lack of first-line studies in adult STS patients, we decided to test the activity and toxicity of HDI in a phase II trial.

PATIENTS AND METHODS

Forty-eight patients were enrolled in the study. IFOS was administered at a dose of 14 g/m2 by continuous infusion over six days every four weeks. Granulocyte-macrophage colony-stimulating factor (GM-CSF) at 5 micrograms/kg/day for 10 consecutive days was systematically administered after an episode of neutropenic fever or a delay in hematologic recovery. Patients were treated until progression or the occurrence of severe toxicity, and surgical rescue was attempted when possible.

RESULTS

Six pathology-established complete remissions and 11 partial remissions were observed in 45 assessable patients with a response rate of 37.7% (95% CI: 25.5%-50%). Grade 3-4 toxicity (% of cycles) was noted by hemoglobin (17%), leukocyte (75%), granulocyte (75%) and platelet (13%) counts in 158 evaluable cycles. GM-CSF was administered to 28 patients, and 25 suffered one or more episodes of neutropenic fever. Renal toxicity was mild and reversible with some degree of tubular and glomerular dysfunction detected in up to 60% of patients. Grade 3 CNS toxicity was observed in 32% of patients but only one required interruption of therapy. Sixty-four per cent of the patients had asthenia grade 2-3 and 20% were excluded from the study due to excessive toxicity. There was one treatment-related death.

CONCLUSIONS

HDI is an active drug in first-line therapy against adult STS. Different administration schedules should be evaluated in an attempt to improve its therapeutic index.

Phase II studies of docetaxel in the treatment of various solid tumours. EORTC Early Clinical Trials Group and the EORTC Soft Tissue and Bone Sarcoma Group

Docetaxel has been evaluated in six tumour types in a total of 189 patients entered into phase II studies. Treatment consisted of a 1 h intravenous infusion of docetaxel 100 mg/m2 repeated every 3 weeks. No premedication was administered for possible hypersensitivity reactions. Docetaxel was found to be effective as first-line chemotherapy for head and neck cancer (response rate 44%) gastric cancer (23%) and melanoma (14%) and as second-line chemotherapy for soft tissue sarcomas (21%; 95% confidence interval: 7.5%-43.7%). The results in colorectal and renal cancer were disappointing, with response rates of less than 10%. The most frequent adverse effects were alopecia (81%), grade III-IV leukocytopenia of short duration (66%) and skin reactions (52%). Hypersensitivity reactions were mild and occurred in 26% of patients. Docetaxel is an important new drug in the treatment of solid tumours.

Extremity rhabdomyosarcoma: biological principles, staging, and treatment

Rhabdomyosarcoma is the most common soft tissue sarcoma in childhood and adolescence with 20% of the primary tumors anatomically located on extremities. It is a complicated entity that requires careful planning and coordination between the surgical oncologist and other members of the therapeutic team for successful treatment. Even with the most effective regimens more than 50% of patients will die from progressive, usually distant disease. Further progress may require new therapeutic agents or techniques. The surgical oncologist is a necessary and often prominent member of the team. Elements of the biological behavior, histopathology, clinical staging, and treatment of extremity rhabdomyosarcomas occurring in children are discussed. In particular, the importance of the alveolar subtype in determination of prognostic risk as well as new findings regarding the molecular biologic determinants of phenotypic behavior are mentioned. Finally, innovative methods of local control like regional arterial perfusion and rapid intraoperative brachytherapy are addressed.

Epirubicin and ifosfamide in advanced soft tissue sarcomas

BACKGROUND

To evaluate the feasibility, toxicity and efficacy of the combination of (IFO) ifosfamide and epirubicin (EPI) given at conventional doses for monochemotherapy, we started a phase II study in advanced/metastatic soft tissue sarcoma patients.

PATIENTS AND METHODS

Treatment consisted of: epirubicin 75 mg/m2 i.v. day 1; IFO 1.8 g/m2 days 1 to 5; MESNA 20% of the IFO dose at 4-hour intervals three times a day during IFO administration. Cycles were given every 3-4 weeks for at least three cycles.

RESULTS

The overall response rate for non-visceral sarcomas (51 pts) was 31% (95% confidence limits +/- 13%). Among the 13 visceral sarcomas no response was seen for the leiomyosarcomas of the gastrointestinal tract, whereas one complete and one partial remission were observed for the uterine sarcomas. The duration of response was 10 months (range 5-34+) for complete responses and 9 (range 4-42+) for partial responses. The median survival for responders is 18 months (range 2-60+) and for non-responders 10 months (range 1-33) (p < 0.004).

CONCLUSIONS

This combination proved to be feasible and tolerable. The overall response rate does not appear to be superior to those with other standard treatments, but it should be pointed out that our patient population was totally unselected.

Effects of verapamil on the pharmacokinetics and metabolism of epirubicin

Experimental data suggest that multidrug resistance in cancer may be overcome by using an increased dose of anticancer agent(s) in combination with a resistance-modifying agent (RMA). We studied the pharmacokinetics and metabolism of both epirubicin (EPI) and verapamil (VPL) to explore the possible pharmacokinetic interactions between these two drugs. Ten patients with advanced breast cancer were given EPI (40 mg/m2 in a daily i.v. bolus for 3 consecutive days), and five of them also received VPL (4 x 120 mg/daily p.o. for 4 consecutive days). The data indicated a significant interaction between these two drugs that affected their metabolism. The areas under the concentration-time curves (AUC) obtained for epirubicin glucuronide, epirubicinol glucuronide, and both of the 7-deoxy-aglycones were higher in the EPI + VPL group as compared with the EPI group. The AUC, terminal half-life, mean residence time, volume of distribution at steady state, and plasma clearance of EPI alone as compared with EPI + VPL did not differ significantly. These results suggest either an induction of enzymes necessary for drug metabolism or an increase in the liver blood flow, resulting in an enhanced generation of metabolites with time or in an inhibition of excretion processes. Comparisons of the AUC values obtained for EPI and its metabolites after the first, second, and third injections of EPI revealed a cumulative effect for the metabolites that was more pronounced in the EPI + VPL group, being significant (P < 0.05) for epirubicin glucuronide in both treatment groups and for epirubicinol glucuronide in the EPI + VPL group. Maximal concentrations of VPL and nor-VPL reached 705 +/- 473 and 308 +/- 122 ng/ml, respectively, with the steady-state concentrations being 265 +/- 42 ng/ml for VPL and 180 +/- 12 ng/ml for nor-VPL.