Impact of FDG PET for staging of Ewing sarcomas and primitive neuroectodermal tumours.

AIM: High-grade Ewing sarcomas and Primitive neuroectodermal tumours (PNET) make up the tumours of the Ewing family. Our purpose was to evaluate the value of [18F]fluorodeoxyglucose positron emission tomography (FDG PET) in patients with Ewing tumours. PATIENTS AND METHODS: Twenty-four patients who had PET because of a suspected Ewing tumour during a 5-year period were included in this retrospective study. The images of 33 whole-body FDG PET investigations performed in primary or secondary diagnostics were analysed visually and semi-quantitatively by using standardized uptake values (SUVs). In 14 cases, PET was compared to bone scintigraphy regarding bone lesions. The final diagnosis was based on histology, imaging and follow-up. RESULTS: Histologically, the primary lesions were 10 Ewing sarcoma, 13 PNET and one osteomyelitis. The sensitivity and specificity of an examination-based analysis (presence of Ewing tumour and/or its metastases) were 96 and 78%, respectively. Altogether, 163 focal lesions were evaluated. Sensitivity and specificity regarding individual lesions were 73 and 78%. This lower sensitivity is mainly due to small lesions. In true-positive cases, the mean SUV was 4.54+/-2.79, and the SUVs in two false-positive cases were 4.66 and 1.60. True-positive and false-positive cases could not be differentiated definitively based on SUVs because of overlap and low values in true-positive lesions. In four cases, PET depicted 70 while bone scintigraphy depicted only eight bone metastases. CONCLUSION: An FDG PET investigation is a valuable method in the case of Ewing tumours. PET is superior to bone scintigraphy in the detection of bone metastases of Ewing tumours. For the depiction of small lesions, mainly represented by pulmonary metastases, PET is less sensitive than helical computed tomography. Determination of the role of whole-body FDG PET in diagnostic algorithm needs further investigation.

[Aromatase inhibitors and inactivators in the treatment of advanced breast cancer] / Aromatázgátlók és aromatázinaktivátorok az elôrehaladott emlôrák kezelésében.

Advanced breast cancer remains incurable. For these patients, durable response and minimal toxicity are the main goals of current therapy. The antiestrogen tamoxifen has proved to be a significant advance in the treatment of breast cancer. Due to its partial estrogen activity, long term medication with tamoxifen has been found to cause endometrium proliferation wich can result in cancer in some patients. Reduction of estrogen production identified the aromatase inhibitors. Both steroidal substrate analog, type I inactivator, wich inactivate the enzyme and non-steroidal competitive reversible, type II inhibitors, are now avaiable. Two new 3(rd) generation aromatase inactivators have recently completed phase III evaluation (anastrozole and letrozole) and we have some results investigating one of the new 3(rd) generation aromatase inhibitors (exemestane). The 3(rd) generation aromatase inhibitors and inactivators are better tolerated and more effective than each of our current standard 2(nd) line endocrin therapies. These agents are being directly compared with standard adjuvant medication, tamoxifen, or are being evaluated in different sequences.

[Role of Iphosphamide in the treatment of breast cancer] / Az ifoszfamid szerepe az emlôrák kezelésében.

Breast cancer is the most frequent solid tumor in women. Predictive and prognostic factors play an important role in the treatment of this cancer. We focused on high risk and heavily pre-treated metastatic breast cancer patients, trying to find the best combination of cytotoxic drugs with high efficacy and low toxicity. Ifosfamide is chemically related to nitrogen mustard and is a synthetic analogue of cyclophosphamide. Ifosfamide has a wide range of antitumor activity. Since ifosfamide as monotherapy has introduced significant tumor reduction in 1(st) line chemotherapy for advanced breast cancer, some studies started with high-dose continuous infusion of ifosfamide,or combined with paclitaxel or vinorelbine. Patients with poor prognosis primary breast cancer treated with high-dose chemotherapy supported by peripheral blood progenitor cell (PBSC) transplantation have lower risk for local relapse and longer disease-free-survival. Ifosfamide working in the mobilization regimen has effective anti-tumor activity while mobilizing sufficient PBPCs in the majority of patients. In combination with other cytotoxics showed to be effective in high-dose protocols.