Continuous low-dose GM-CSF as salvage therapy in refractory recurrent breast or female genital tract carcinoma.

Granulocyte-macrophage colony-stimulating factor (GM-CSF, sargramostim [Leukine]) is a powerful cytokine that is able to stimulate the generation of dendritic cells. Adjuvant treatment with continuous low-dose GM-CSF has been shown to prolong survival of stage III/IV melanoma patients. Data on continuous low-dose GM-CSF therapy in tumors other than prostate cancer are still lacking. This pilot trial was initiated in order to evaluate the efficacy and tolerability of continuous low-dose GM-CSF as salvage in various chemotherapy-refractory carcinomas. A total of 19 patients who had failed a median of 4 prior chemotherapies were included. Their malignancies included metastatic breast cancer, recurrent ovarian carcinoma, metastatic endometrial carcinoma, and recurrent squamous cell cancer of the cervix uteri. Continuous low-dose GM-CSF was delivered subcutaneously at a daily starting dose of 125 microg. GM-CSF was increased at 25-microg increments until a maximum of 250 microg was reached or when mild leukocytosis (10-20 g/L) was achieved, providing that the relative eosinophil count did not exceed 15%. Therapy was continued until progression or refusal by the patient. Toxicity was generally mild. Only one patient was withdrawn due to grade 3 fatigue. In three additional patients, temporary dose reduction was necessary because of grade 1 injection site reactions, which recovered spontaneously. Mild to moderate leukocytosis was obvious in 10 patients. Systemic hypersensitivity-like reactions did not occur and no patient required hospitalization for other life-threatening side effects. The objective response rate was 37%: 1 complete and 6 partial responses, 4 disease stabilizations, 8 progression of disease. Median response duration was 6 months. Notably, 6 of 7 responders but only 1 of 8 patients with disease progression developed leukocytosis during therapy. Therefore, we conclude that continuous low-dose GM-CSF has substantial activity in heavily pretreated patients with either metastatic breast cancer or female genital tract cancer. Achievement of mild leukocytosis seems to be a predictor of response.

ATP chemosensitivity testing in ovarian and breast cancer: early clinical trials.

After disappointing results achieved with older chemosensitivity tests such as the human tumor clonogenic assay (HTCA) during the 1980s, the last decade has seen a renaissance of the concept of individualized chemotherapy in oncology, markedly stimulated by the development of newer nonclonogenic assays. These methods appear to be able to overcome major technical limitations associated with older assays, now allowing for successful testing of most of the tumor specimens submitted. Currently, the ATP-based tumor chemosensitivity assay (ATP-TCA) can be regarded as the most sophisticated assay to investigate both solid samples and effusions derived from patients with various organ tumors. During the last 5 years, the ATP-TCA has been used successfully to screen for novel drug combinations for further clinical use in both ovarian and breast cancer such as mitoxantrone plus paclitaxel (NT) and treosulfan plus gemcitabine (TG), respectively. Clinical trials that have been set up in heavily pretreated patients with recurrent ovarian or breast cancer have convincingly confirmed the high activity of these combinations previously demonstrated in preclinical investigations using the ATP-TCA. In a recent phase II trial performed in 59 patients with relapsed ovarian carcinoma, ATP-TCA-directed therapy was able to triple the response rate and to double the survival time, compared with published empirical chemotherapy regimes. Preliminary results with ATP-TCA-directed therapy in breast cancer also evidenced promising response rates. These results have been confirmed by additional prospective clinical trials using other types of modern nonclonogenic assays. A phase III trial that is now actively recruiting patients with platinum-refractory ovarian cancer to verify the promising phase II studies will prove the further value of the ATP-TCA as a predictor applicable in routine clinical oncology.

Chemosensitivity of normal human trophoblasts evaluated by a newly developed ATP-based luminescence assay.

Trophoblast injury may be one of the possible causes of fetal distress associated with chemotherapy administered during pregnancy. The purpose of this study was to investigate the ex vivo chemosensitivity of normal trophoblasts (NTB) against commonly used antineoplastic agents. Using the newly developed ex vivo ATP-based trophoblast assay (ATP-TBA), 31 NTB freshly sampled from human placentas (gestational week 7-42) were tested against dactinomycin (Act-D), 5-fluorouracil (5-FU), 4-OOH-cyclophosphamide (4-HC), vincristine (VCR) and methotrexate (MTX) alone or in combination with calcium folate (LV). All agents were studied at concentrations relevant to clinical dosages normally used for chemotherapy of solid neoplasms. Of 31 samples studied with the ATP-TBA, 20 (65%) were evaluable. VCR, Act-D and 4-HC were the most active drugs with 55, 45 and 45% of samples responding ex vivo. Antimetabolites were less active, producing ex vivo response rates of 25 (MTX) and 20% (5-FU), respectively. MTX activity was largely neutralized by adding LV. The chemosensitivity of NTB showed considerable inter-individual variations and did not decrease with increasing gestational age. We therefore conclude that NTB of any gestational age exhibit considerable ex vivo sensitivity against common anticancer agents which is comparable to that observed for various solid tumors. The ATP-TBA may be helpful in planning future trials with both single agents and drug combinations in order to standardize and optimize chemotherapy during pregnancy.