Judith R. Kroep

Chemotherapeutic adjuvant treatment for osteosarcoma: Where do we stand?

AIM Since the introduction of chemotherapy, survival in localised high-grade osteosarcoma has improved considerably. However, there is still no worldwide consensus on a standard chemotherapy approach. In this systematic review evidence for effectiveness of each single drug and the role of response guided salvage treatment of adjuvant chemotherapy are addressed, whereas in a meta-analysis the number of drugs in current protocols is considered. METHODS A systematic literature search for clinical studies in localised high-grade osteosarcoma was undertaken, including both randomised and non-randomised trials. Historical clinical studies from the pre-chemotherapy era were included for comparison purposes. RESULTS Nine historical studies showed a long-term survival of 16% after only local treatment. Fifty single agent phase II studies showed high response rates for adriamycin (A, 43%), ifosfamide (Ifo, 33%), methotrexate (M, 32%), cisplatin (P, 26%) but only 4% for etposide (E). In 19 neo-adjuvant studies the mean 5-year event free survival (EFS) was 48% for 2-drug regimens and 58% for ⩾3 drug regimens, with a 5-year overall survival (OAS) of 62% and 70%, respectively. Meta-analysis showed that ⩾3 drug regimens including methotrexate plus adriamycin plus cisplatin (plus ifosfamide) (MAP(Ifo)) had significant better outcome (EFS: HR=0.701 (95% confidence interval [95% CI]: 0.615-0.799); OAS: HR=0.792 (95% CI: 0.677-0.926) than 2-drug regimens, but there was no significant difference between MAP and MAPIfo (or plus etoposide). Salvage of poor responders by changing drugs, or intensifying treatment postoperatively has not proven to be useful in this analysis. CONCLUSION Meta-analysis in patients with localised high-grade osteosarcoma shows that 3-drug regimens, for example MAP are the most efficacious drug regimens.

Efficacy of imatinib mesylate for the treatment of locally advanced and/or metastatic tenosynovial giant cell tumor/pigmented villonodular synovitis

Pigmented villonodular synovitis (PVNS) (also known as diffuse‐type giant cell tumor) and tenosynovial giant cell tumors (TGCT) are rare, usually benign neoplasms that affect the synovium and tendon sheaths in young adults. These tumors are driven by the overexpression of colony stimulating factor‐1 (CSF1). CSF1 is expressed by a minority of tumor cells, which, in turn attract non‐neoplastic inflammatory cells that express CSF1 receptor (CSF1R) through a paracrine effect.

Chemotherapy Alters Monocyte Differentiation to Favor Generation of Cancer-Supporting M2 Macrophages in the Tumor Microenvironment

Current therapy of gynecologic malignancies consists of platinum-containing chemotherapy. Resistance to therapy is associated with increased levels of interleukin (IL)-6 and prostaglandin E2 (PGE(2)), 2 inflammatory mediators known to skew differentiation of monocytes to tumor-promoting M2 macrophages. We investigated the impact of cisplatin and carboplatin on 10 different cervical and ovarian cancer cell lines as well as on the ability of the tumor cells to affect the differentiation and function of cocultured monocytes in vitro. Treatment with cisplatin or carboplatin increased the potency of tumor cell lines to induce IL-10-producing M2 macrophages, which displayed increased levels of activated STAT3 due to tumor-produced IL-6 as well as decreased levels of activated STAT1 and STAT6 related to the PGE(2) production of tumor cells. Blockade of canonical NF-κB signaling showed that the effect of the chemotherapy was abrogated, preventing the subsequent increased production of PGE(2) and/or IL-6 by the tumor cell lines. Treatment with the COX-inhibitor indomethacin and/or the clinical monoclonal antibody against interleukin-6 receptor (IL-6R), tocilizumab, prevented M2-differentiation. Importantly, no correlation existed between the production of PGE(2) or IL-6 by cancer cells and their resistance to chemotherapy-induced cell death, indicating that other mechanisms underlie the reported chemoresistance of tumors producing these factors. Our data suggest that a chemotherapy-mediated increase in tumor-promoting M2 macrophages may form an indirect mechanism for chemoresistance. Hence, concomitant therapy with COX inhibitors and/or IL-6R antibodies might increase the clinical effect of platinum-based chemotherapy in otherwise resistant tumors.

Discordances in ER, PR and HER2 receptors after neoadjuvant chemotherapy in breast cancer

Neoadjuvant chemotherapy (NAC) for breast cancer is evolving and subsequent adjuvant systemic treatment is mainly based on the presence of the Estrogen (ER) receptor, Progesterone (PR) receptor and Human Epidermal growth factor Receptor 2 (HER2) status on the core needle biopsy prior to treatment. It is not well known whether these biomarkers change after NAC, requiring a change in further adjuvant systemic treatment. A review of the literature (PubMed search) revealed 32 relevant studies that investigated the concordance of the hormone receptors (ER and/or PR) and HER2 after NAC with or without trastuzumab. Discordance of the hormone receptor status was reported in four out of eight studies in 8-33% of the patients. About half of the studies that tested the ER and PR receptor status separately reported discordances of 2.5-17% and 5.9-51.7% respectively. Studies that concluded that ER and/or PR receptor remained stable after NAC were performed with evidently lower number of patients compared to studies that reported a change. Good concordance of the HER2 amplification tested with FISH was reported, although the HER2 expression measured with immunohistochemistry was more discordant. A switch to a negative HER2 receptor in up to 43% of the patients was reported when NAC was combined with trastuzumab. Until more comparable studies are being published, retesting the receptor status of the residual tumor after NAC should be considered in order to improve future tailored adjuvant therapies.

Bisphosphonate treatment of aggressive primary, recurrent and metastatic Giant Cell Tumour of Bone

BackgroundGiant cell tumour of bone (GCTB) is an expansile osteolytic tumour which contains numerous osteoclast-like giant cells. GCTB frequently recurs and can produce metastatic lesions in the lungs. Bisphosphonates are anti-resorptive drugs which act mainly on osteoclasts.MethodIn this study, we have examined clinical and radiological outcomes of treatment with aminobisphosphonates on 25 cases of aggressive primary, recurrent and metastatic GCTB derived from four European centres. We also analysed in vitro the inhibitory effect of zoledronic acid on osteoclasts isolated from GCTBs.ResultsTreatment protocols differed with several different aminobisphosphonates being employed, but stabilisation of disease was achieved in most of these cases which were refractory to conventional treatment. Most inoperable sacral/pelvic tumours did not increase in size and no further recurrence was seen in GCTBs that had repeatedly recurred in bone and soft tissues. Lung metastases did not increase in size or number following treatment. Zoledronic acid markedly inhibited lacunar resorption by GCTB-derived osteoclasts in vitro.ConclusionOur findings suggest that bisphosphonates may be useful in controlling disease progression in GCTB and that these agents directly inhibit GCTB - derived osteoclast resorption. These studies highlight the need for the establishment of standardised protocols to assess the efficacy of bisphosphonate treatment of GCTB.

First-line chemotherapy for malignant peripheral nerve sheath tumor (MPNST) versus other histological soft tissue sarcoma subtypes and as a prognostic factor for MPNST: an EORTC Soft Tissue and Bone Sarcoma Group study

BACKGROUND the role of chemotherapy in advanced malignant peripheral nerve sheath tumor (MPNST) is unclear. PATIENTS AND METHODS chemotherapy-naive soft tissue sarcomas (STS) patients treated on 12 pooled nonrandomized and randomized European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group trials were retrospectively analyzed. Clinical outcomes, overall survival, progression-free survival (PFS) and response were determined for MPNST and other STS histotypes and compared. Additionally, prognostic factors within the MPNST population were defined. Studied cofactors were demographics, sarcoma history, disease extent and chemotherapy regimen. RESULTS after a median follow-up of 4.1 years, 175 MPNST out of 2675 eligible STS patients were analyzed. Outcome was similar for MPNST versus other STS histotypes, with a response rate, median PFS and overall survival of 21% versus 22%, 17 versus 16 weeks and 48 versus 51 weeks, respectively. Performance status was an independent prognostic factor for overall survival. Chemotherapy regimen was an independent prognostic factor for response (P < 0.0001) and PFS (P = 0.009). Compared with standard first-line doxorubicin, the doxorubicin-ifosfamide regimen had the best response, whereas ifosfamide had the worst prognosis. CONCLUSION this series indicates the role of chemotherapy in treatment of advanced MPNST. This first comparison showed similar outcomes for MPNST and other STS histotypes. The apparent superiority of the doxorubicin-ifosfamide regimen justifies further investigations of this combination in randomized trials.

The Clinical Approach Toward Giant Cell Tumor of Bone

We provide an overview of imaging, histopathology, genetics, and multidisciplinary treatment of giant cell tumor of bone (GCTB), an intermediate, locally aggressive but rarely metastasizing tumor. Overexpression of receptor activator of nuclear factor κB ligand (RANKL) by mononuclear neoplastic stromal cells promotes recruitment of numerous reactive multinucleated giant cells. Conventional radiographs show a typical eccentric lytic lesion, mostly located in the meta-epiphyseal area of long bones. GCTB may also arise in the axial skeleton and very occasionally in the small bones of hands and feet. Magnetic resonance imaging is necessary to evaluate the extent of GCTB within bone and surrounding soft tissues to plan a surgical approach. Curettage with local adjuvants is the preferred treatment. Recurrence rates after curettage with phenol and polymethylmethacrylate (PMMA; 8%-27%) or cryosurgery and PMMA (0%-20%) are comparable. Resection is indicated when joint salvage is not feasible (e.g., intra-articular fracture with soft tissue component). Denosumab (RANKL inhibitor) blocks and bisphosphonates inhibit GCTB-derived osteoclast resorption. With bisphosphonates, stabilization of local and metastatic disease has been reported, although level of evidence was low. Denosumab has been studied to a larger extent and seems to be effective in facilitating intralesional surgery after therapy. Denosumab was recently registered for unresectable disease. Moderate-dose radiotherapy (40-55 Gy) is restricted to rare cases in which surgery would lead to unacceptable morbidity and RANKL inhibitors are contraindicated or unavailable.

Vaccination during myeloid cell depletion by cancer chemotherapy fosters robust T cell responses.

Therapeutic vaccination against HPV16 is effective with chemotherapy for advanced cervical cancer patients. Vaccinating cancer away Cervical cancer, a common killer of women worldwide, is most often caused by human papillomavirus type 16 (HPV16). Although a vaccine targeting this virus is available and very effective at preventing cervical cancer, it does not work once cancer is already established, and advanced cervical cancer is very difficult to treat. Welters et al. have developed a method of therapeutic vaccination, where they synthesize long peptides mimicking key oncogenic proteins from HPV16 and use them to treat patients. Although it is too early to tell how the new vaccine will affect patient survival, combining it with chemotherapy helped strengthen patients’ immune responses against the cancer, so it is a promising candidate for further clinical development. Therapeutic vaccination with human papillomavirus type 16 synthetic long peptides (HPV16-SLPs) results in T cell–mediated regression of HPV16-induced premalignant lesions but fails to install clinically effective immunity in patients with HPV16-positive cervical cancer. We explored whether HPV16-SLP vaccination can be combined with standard carboplatin and paclitaxel chemotherapy to improve immunity and which time point would be optimal for vaccination. This was studied in the HPV16 E6/E7–positive TC-1 mouse tumor model and in patients with advanced cervical cancer. In mice and patients, the presence of a progressing tumor was associated with abnormal frequencies of circulating myeloid cells. Treatment of TC-1–bearing mice with chemotherapy and therapeutic vaccination resulted in superior survival and was directly related to a chemotherapy-mediated altered composition of the myeloid cell population in the blood and tumor. Chemotherapy had no effect on tumor-specific T cell responses. In advanced cervical cancer patients, carboplatin-paclitaxel also normalized the abnormal numbers of circulating myeloid cells, and this was associated with increased T cell reactivity to recall antigens. The effect was most pronounced starting 2 weeks after the second cycle of chemotherapy, providing an optimal immunological window for vaccination. This was validated with a single dose of HPV16-SLP vaccine given in this time window. The resulting proliferative HPV16-specific T cell responses were unusually strong and were retained after all cycles of chemotherapy. In conclusion, carboplatin-paclitaxel therapy fosters vigorous vaccine-induced T cell responses when vaccination is given after chemotherapy and has reset the tumor-induced abnormal myeloid cell composition to normal values.

Early cessation of the clinical development of LiPlaCis, a liposomal cisplatin formulation

PURPOSE To evaluate the safety and tolerability of LiPlaCis, a liposomal formulated platinum compound, in patients with solid tumours and to determine the maximum tolerated dose (MTD) of intravenous (i.v.) LiPlaCis. and to assess plasma and urine pharmacokinetics and plasma biomarkers. PATIENTS AND METHODS Patients with solid tumours without standard therapeutic options were enrolled to receive LiPlaCis administered as a 1 h infusion without additional hydration every 3weeks until RECIST progression or unacceptable toxicity. Cohorts of 3-6 patients were treated at each dose level until MTD was reached. RESULTS Eighteen patients were enrolled and 64 cycles were delivered. At the first dose level 3 patients experienced an infusion reaction. Despite prophylactic pre-medication and prolongation of the infusion to 2 h in further patients, three other patients had mild acute infusion reactions. Toxicity at the fifth dose level of 120 mg consisted of grade 2 renal toxicity reversible after hydration in 2 patients and grade 4 thrombocytopaenia in one of these patients. Peak plasma concentrations and AUC were dose proportional. The interpatient variability in the clearance of total LiPlaCis-derived platinum was 41%. Platinum was excreted via the urine mainly during the first 24 h after administration. Investigated plasma biomarkers sPLA(2) and SC5b-9 were related to, but not predictive for, acute infusion reactions. CONCLUSION The observed safety profile suggests no benefit over standard cisplatin formulations and LiPlaCis will require reformulation to enable further development.

Monitoring regulatory T cells in clinical samples: consensus on an essential marker set and gating strategy for regulatory T cell analysis by flow cytometry

Regulatory T cell (Treg)-mediated immunosuppression is considered a major obstacle for successful cancer immunotherapy. The association between clinical outcome and Tregs is being studied extensively in clinical trials, but unfortunately, no consensus has been reached about (a) the markers and (b) the gating strategy required to define human Tregs in this context, making it difficult to draw final conclusions. Therefore, we have organized an international workshop on the detection and functional testing of Tregs with leading experts in the field, and 40 participants discussing different analyses and the importance of different markers and context in which Tregs were analyzed. This resulted in a rationally composed ranking list of “Treg markers”. Subsequently, the proposed Treg markers were tested to get insight into the overlap/differences between the most frequently used Treg definitions and their utility for Treg detection in various human tissues. Here, we conclude that the CD3, CD4, CD25, CD127, and FoxP3 markers are the minimally required markers to define human Treg cells. Staining for Ki67 and CD45RA showed to provide additional information on the activation status of Tregs. The use of markers was validated in a series of PBMC from healthy donors and cancer patients, as well as in tumor-draining lymph nodes and freshly isolated tumors. In conclusion, we propose an essential marker set comprising antibodies to CD3, CD4, CD25, CD127, Foxp3, Ki67, and CD45RA and a corresponding robust gating strategy for the context-dependent analysis of Tregs by flow cytometry.