Biological monitoring of low-dose interleukin 2 in humans: soluble interleukin 2 receptors, cytokines, and cell surface phenotypes.

Different immunotherapy regimens using s.c. recombinant interleukin-2 (rIL-2) were studied in 76 patients with progressive metastatic renal carcinoma, malignant melanoma, colorectal cancer, B-cell lymphoma, or Hodgkin's disease. To assess the immunomodulatory capacity of rIL-2, we measured serum levels of soluble interleukin-2 (sIL-2) receptors, gamma-interferon, tumor necrosis factor-alpha, and various lymphocyte subsets expressing the CD25 Tac IL-2 receptor and the CD56 natural killer (NK) associated antigen. Additionally, we measured serum antibodies specific to rIL-2 in order to evaluate immunogenicity of rIL-2. In all patients, a significant increase in sIL-2 receptor levels could be observed when comparing values on day 0 and after one treatment course. Patients developing a neutralizing anti-rIL-2 antibody exhibited significantly lower serum sIL-2 receptor levels than patients without antibody. Soluble IL-2 receptors correlated with the percentage of CD25 IL-2 receptor-positive peripheral blood lymphocytes. Both soluble and cell surface IL-2 receptors exhibited a significant increase during rIL-2 therapy but did not correlate with the percentage of CD56-positive peripheral blood lymphocytes. Measurement of treatment-induced secondary cytokines showed significant increases in gamma-interferon serum levels in a proportion of patients tested, although with considerable interindividual variability. No significant increase in mean tumor necrosis factor-alpha levels was observed during rIL-2 treatment in vivo. The percentage of CD56-positive NK cells correlated with the clinical outcome of rIL-2 therapy. Thus, partial or complete responders had an increase from a mean of 20% NK cells prior to therapy up to a mean of 40% after the first treatment course. In contrast, patients with progressive disease had a mean of 22 and 24% NK cells before and after treatment, respectively.

Activity of cytostatic drugs in two heterotransplanted human testicular cancer cell lines with different sensitivity to standard agents.

Two established human testicular cancer cell lines were used in a mouse xenograft model to assess the antitumour activity of 15 anticancer agents. Line H 12.1 was highly sensitive to cisplatin, bleomycin and vinblastine, resembling non-pretreated testicular tumours, whereas line H 23.1 showed resistance to cisplatin and vinblastine, comparable to tumours with acquired or intrinsic drug resistance. In line H 12.1 several drugs were highly active, including cyclophosphamide, ifosfamide, nimustine and vincristine; carmustine, vindesine, doxorubicin, epidoxorubicin, pirarubicin, mitoxantrone, carboplatin and iproplatin had only moderate activity. In line H 23.1 only cyclophosphamide, ifosfamide, nimustine, vincristine and bleomycin had antitumour activity. These two cell lines represent a useful model for preclinical evaluation of new agents with presumed activity in testis cancer.

Titanocendichloride activity in cisplatin and doxorubicin-resistant human ovarian carcinoma cell lines.

The activity of a new organometallic compound, titanocendichloride, was evaluated in doxorubicin- and cisplatin-resistant human ovarian carcinoma cell lines in vitro. Titanocendichloride showed no cross resistance to doxorubicin in two multidrug resistant sublines of A2780. Furthermore, the cell line A2780 CP3, which is about 20-fold resistant to cisplatin was only 2.5-fold resistant to titanocendichloride, indicating a lack of cross resistance between the two metal compounds. These results were confirmed in vivo where titanocendichloride showed a much stronger inhibitory effect in cisplatin-resistant human ovarian carcinoma xenografts than cisplatin.

Bilateral testicular tumours: prevalence and clinical implications.

In a series of 773 patients with the diagnosis of a testicular germ cell tumour, treated at Hannover University Medical School between 1972 and 1985 and with a median follow-up of 9 years (60-210 months), bilateral testicular tumours occurred in 27 (3.5%) patients. None of 157 patients receiving chemotherapy for metastatic disease of the first tumour developed a metachronous bilateral tumour. Of 24 patients with metachronous tumours 23 had stage I and 1 patient had stage II at the time of initial diagnosis. The second testicular tumour was stage I in 18 patients, stage II in 5 and stage IV in 1 patient. 3 patients (13%) relapsed after treatment for their second germ cell tumour (surveillance 13 patients, radiotherapy 7 patients, lymph node dissection 2 patients and chemotherapy 2 patients), 1 of which died after refusing further treatment. The cure rate was 96% in patients with bilateral disease. Routine biopsy of the contralateral testis to identify existing carcinoma in situ (CIS) is recommended. Patients with CIS must be informed about their increased risk of a second testicular tumour. Irradiation of CIS or close clinical follow-up might both constitute appropriate strategies for the management of these patients.

Lack of therapeutic efficacy of tamoxifen in advanced renal cell carcinoma.

In the present study, we treated a total of 62 patients with advanced renal cell carcinoma with high-dose tamoxifen (100 mg/m2/day). Patients were treated in the outpatient setting, and were evaluated 8-12 weeks after initiation of therapy or sooner, when clinical disease progression was evident; a total of 15 patients were seen at short regular intervals for evaluation of clinical and laboratory parameters. Of these 62 patients, 59 were evaluable for treatment response, survival and systemic toxicity. One partial remission was achieved (1.7%; 95% confidence interval, 0.04-9.09%), response duration was 3 months. 10 patients presented with stable disease, for a median duration of 4.0 months, and 48 patients exhibited disease progression upon and after therapy. Systemic toxicity was significant; severe fatigue occurred in 5% of patients, and moderate anaemia, dyspnea, alopecia and malaise in almost 20% of patients. Antineoplastic efficacy of tamoxifen at this dosage in this cohort of patients was at best marginal and well in the range associated with the occurrence of spontaneous remissions. Toxicity was substantial, and it was not balanced by therapeutic benefit. This is consistent with the known lack of therapeutic efficacy of endocrine therapy in advanced renal cell carcinoma.

Interleukin-2 in combination with interferon-alpha and 5-fluorouracil for metastatic renal cell cancer.

Recent clinical trials for the biological therapy of solid tumours have used recombinant human cytokines in combination with conventional chemotherapy. In patients with progressive metastatic renal cell carcinoma, we established a three-drug combination comprising interferon-alpha (IFN-alpha), interleukin-2 (IL-2) and 5-fluorouracil (5-FU), using a regimen which allows outpatient therapy. Treatment consisted of 8 weeks each of IFN-alpha [6-9 MU/m2 once to three times weekly subcutaneously (sc)] combined sequentially with IL-2 (5-20 MU/m2 thrice weekly sc for 4 weeks) and 5-FU [750 mg/m2 intravenously (i.v.) weekly for 4 weeks]. Among the first 35 patients treated, there were 4 complete (11.4%) and 13 partial responders (37.1%), with an overall objective response rate of 48.6% (95% confidence interval 32-66%). Regressions occurred in local relapse, in lung, lymph node, bone, pleural, renal and thyroid metastases. Median response duration was calculated at 7+ months. An additional 13 patients (37.1%) were stable throughout therapy and thereafter (median of 6+ months). Response rate of this three-drug combination regimen compared favourably with single agent IFN-alpha (objective response rate approximately 16%) and against the sc IFN-alpha/IL-2 combination (objective response rate approximately 28%). Systemic toxicity was mild to moderate with no severe 5-FU-related mucositis and no dose-limiting adverse effects of sc IL-2. While the exact mechanisms of the potentially additive or synergistic effects of 5-FU and IFN-alpha/IL-2 remain to be established in more detail, it appears that the sequential use of IFN-alpha/IL-2 and IFN-alpha/5-FU in metastatic renal carcinoma further enhances the therapeutic index of IFN-alpha/IL-2-based biological therapy. Based on the present data, combined biochemotherapy may be a promising new approach to the therapy of advanced renal cancer.

Effects of cytokines on in vitro colony formation of primary human tumour specimens.

Although under study to alleviate chemotherapy-induced bone marrow toxicity, cytokines can stimulate in vitro growth of solid human tumour cell lines. The effects of granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF) and interleukin-3 (IL-3) on in vitro colony formation of primary human tumours was studied in a capillary soft-agar cloning system. Of 108 tumour specimens from 100 patients, 85 specimens were tested against all three factors at concentrations ranging from 0.1 to 1000 ng/ml. 44 of 100 tumours showed adequate growth in controls. 8 out of 43 (19%) specimens were significantly stimulated by GM-CSF, 6 of 40 (15%) by G-CSF and 10 of 44 (23%) by IL-3. Sensitivity to all three cytokines was observed in 4 of 44 (9%) specimens. By light microscopy the appearance of colonies from stimulated specimens was identical to that of controls. Sensitivity to cytokines was independent from sensitivity to epidermal growth factor, transferrin or insulin. Sensitivity to GM-CSF, G-CSF and IL-3 may be aberrantly expressed in a subgroup of solid human tumours.

Antitumour effect and symptomatic control with interferon alpha 2b in patients with endocrine active tumours.

26 patients with progressive neuroendocrine tumours received 3 x 10(6)U/m2 interferon alfa (IFN-alpha 2b) subcutaneously thrice weekly, until progression, as outpatients with moderate toxicity. 4/16 carcinoids and none out of 10 endocrine pancreatic tumours showed objective regression. Another 17 patients (68%) had no change. For a median of 34 weeks symptom control was excellent: 9 of 17 patients had major relief from pain, 11 of 13 from diarrhoea, and 7 of 7 from flushing. Thus, low-dose INF-alpha 2b given thrice weekly might be as effective as daily treatment with higher dosages. Treatment was only administered to patients with progression or major symptoms and this did not seem to adversely affect remission quality and survival.

Chemoimmunotherapy of advanced malignant melanoma: sequential administration of subcutaneous interleukin-2 and interferon-alpha after intravenous dacarbazine and carboplatin or intravenous dacarbazine, cisplatin, carmustine and tamoxifen.

Both chemotherapy and interleukin-2 and/or interferon-alpha produce objective responses in a proportion of advanced malignant melanoma patients. While duration of response to chemotherapy is short, i.e. usually below 4 months, immunotherapy has resulted in a small number of long-lasting remissions in patients with metastatic melanoma. In two consecutive phase II trials in a total of 67 patients, we assessed the potential synergism between both modalities, i.e. chemo- and immunotherapy. Treatment consisted of intravenous (i.v.) carboplatin (CBDCA, 400 mg/m2) and dacarbazine (DTIC, 750 mg/m2) given twice (i.v. bolus over 30 min) at 3-week intervals, or 4 cycles of DTIC (220 mg/m2 i.v. 3 days), cisplatin (DDP, 35 mg/m2 i.v. 3 days), carmustine (BCNU, 150 mg/m2 i.v. cycles 1 and 3) and tamoxifen (TAM, 20 mg oral/daily) at 3-week intervals. Chemotherapy was followed by immunotherapy with combined subcutaneous (s.c.) interleukin-2 (rIL-2) and SC interferon-alpha 2 (rIFN-alpha). Among 40 patients who received a full cycle of chemotherapy with CBDCA/DTIC and sequential immunotherapy, there were 3 (7.5%) complete remissions (CRs) with a median duration of 19 months (range 13-26+). Partial remissions (PRs) were noted in 11 (27.5%) patients with a median response duration of 8 (range 5-14) months. Among 27 patients who received DTIC/DDP/BCNU/TAM and rIL-2/rIFN-alpha, there were 3 (11%) complete remissions and 12 (44.5%) partial remissions. Duration of complete and partial remissions ranged from 9+ to 13+ (median, 11+), and 5 to 15+ (median, 7+) months, respectively. Chemotherapy produced mostly moderate toxicity. Thrombocytopenia was common with the nadir after a median time of 18 days following start of CBDCA/DTIC and DTIC/DDP/BCNU, respectively. 10 patients required transfusion of thrombocytes. Nausea and vomiting due to chemotherapy were well tolerated using concomitant ondansetrone (8 mg i.v.). Immunotherapy was self-administered at home with mild to moderate side effects; malaise, fever, chills, nausea/vomiting, diarrhoea, anorexia and arthralgias were most frequent, but were spontaneously reversible after ending rIL-2/IFN-alpha. A mean 87 and 88% of the projected doses of rIL-2 and rIFN-alpha were administered on either protocol. There were no life-threatening complications and no treatment-related deaths. The sequential combination of chemotherapy and rIL-2 plus rIFN-alpha had at least additive therapeutic activity against metastatic malignant melanoma. The schedules produced long-lasting remissions and were tolerated well overall. These trials substantiate a potential role for low to intermediate dose immunotherapy in maintaining and consolidating therapeutic effects of chemotherapy in metastatic melanoma.

alpha-Interferon and interleukin-2 in renal cell carcinoma: studies in nonhospitalized patients.

We have studied the safety, tolerance, and clinical effects of the combined administration of subcutaneous recombinant human interleukin-2 and alpha-interferon in 34 patients with metastatic renal cell carcinoma who had undergone tumor nephrectomy. Treatment courses consisted of a 2-day interleukin-2 pulse (14.4 to 18.0 million IU/m2/d), followed by 3.6 to 4.8 million IU/m2/d, 5 days per week, over 6 consecutive weeks, and alpha-interferon at 3.0 to 6.0 million U/m2, administered 2 to 3 times weekly for 6 weeks. Patients received more than 90% of the projected dose of interleukin-2 and alpha-interferon, respectively. Of 34 patients with metastatic progressive renal cell carcinoma in this study, four had complete response and six had greater than 50% reduction in tumor size (ie, partial response). There were, in addition, 13 patients with stable disease. So far, all complete responses have been durable, with a median duration of 23+ months. Clinical responses were associated with a mean peripheral blood eosinophil count of more than 1,000/microliters (P less than .05). The predominant toxicities included fever, chills, nausea, anorexia, and hypotension, and were limited to World Health Organization grades 1 and 2 in more than 80% of patients treated. No treatment-related deaths occurred. This combination of subcutaneously administered recombinant interleukin-2 and alpha-interferon has significantly reduced the side effects normally observed with high-dose intravenous recombinant interleukin-2. It can induce objective tumor regressions in patients with progressive metastatic renal cell carcinoma. Unlike the intravenous schedules developed by Rosenberg and West, which require admission to hospital, all the patients in this study were treated in an outpatient setting.

The role of schedule dependency of 5-fluorouracil/leucovorin combinations in advanced colorectal cancer.

The dose intensity in cancer monochemotherapy is probably the most important prognostic factor. In combination chemotherapy, in which interactions between agents do occur, response, survival, and toxicity might vary between different schedules. In a literature review of all published data of folinic acid and 5-fluorouracil intravenous bolus therapy in colorectal cancer with comparable dose intensity, an attempt was made to characterize the possible differences of the variations of schedules used. The antitumor activity increased significantly from 19% to 30%-35% when the two drugs were used concomitantly in multiple fractions per cycle rather than on a single day. However, fractionation changed the type of dose-limiting toxicity from hematologic and neurologic to gastrointestinal side effects. The different schedules did not differ significantly in the overall frequency of severe toxicities; however, recommending a certain schedule outside of controlled trials should be done cautiously.

A 3-day schedule of 5-fluorouracil and folinic acid in metastatic progressive colorectal cancer and its impact in terms of palliation.

Treatment results in advanced colorectal cancer have improved during the last decade since the incorporation of agents like folinic acid, PALA, or interferon as active biomodulation of 5-fluorouracil (5-FU), the most potent drug in this disease. But essential prolongation of survival could not be demonstrated. To better define the need to initiate therapy and duration of treatment, a phase II study of high-dose folinic acid and 5-FU was initiated in patients with documented progression or severe tumor-related symptoms prior to start of therapy until best response was observed. The treatment plan was folinic acid 300 mg/m2 as a 10-minute intravenous infusion followed 50 minutes later by 5-FU 600 mg/m2 intravenous bolus days 1 to 3 every 3 to 4 weeks. Thirty-seven consecutive patients were treated during November 1986 and October 1987. Because of severe tumor-related symptoms, immediate treatment was considered mandatory in only eight patients. In the remaining 29 primarily asymptomatic patients, an observational period of a median duration of 8 weeks (range, 1-56) was possible before treatment seemed to be indicated. Most patients experienced some toxicity, mostly leukopenia and gastrointestinal side effects, of World Health Organization grades 3 and 4 during 156 treatment cycles (range, one to eight cycles). The calculated dose intensity was 535 mg/m2 5-FU per week. Of 36 evaluable patients, 14 responded at least with a partial remission (39%; confidence interval, 23% to 55%) of 7 months median duration. An additional 13 patients (36%) had stable disease, giving a rate of tumor stabilization in these progressive patients of 75%, for a median duration of 5.5 months. Median survival since start of therapy was 11 months. Results are comparable to data reported in the literature; survival and remission duration seem not to be mitigated in a patient population in which therapy was withheld until progression or symptoms occur. This patient population might be characterized by more homogeneously distributed risk factors.

No growth-stimulation of heterotransplanted human testicular cancer cell-lines by recombinant human granulocyte-macrophage colony-stimulating factor (gm-csf).

Hematopoietic growth factors such as granulocyte (G)- and granulocyte-macrophage (GM) colony-stimulating factor (CSF) are currently used as adjunct treatment for cancer chemotherapy in order to ameliorate neutropenia. The current investigation presented here focused on the in vivo effects of GM-CSF on two heterotransplanted human testicular cancer cell lines in a nude mouse model. GM-CSF was applied to tumor bearing mice in a dose range of 3 x 10(5) to 3 x 10(7) U/kg per day i.v. for 14 consecutive days. For all concentrations of GM-CSF a reduction of the tumor volume compared to untreated tumor bearing control mice was noted. The largest retardation of tumor growth was seen at the end of the experiments at day 30 with 3 x 10(7) U/kg of GM-CSF with a relative tumor volume of 72% +/- 8% for cell line H 12.1 and 73.5 +/- 9% for cell line H23.1 in comparison to untreated tumor bearing control mice. No side effects of GM-CSF application such as weight loss or fever were observed. Serum tumor necrosis factor (TNF) levels in mice treated with GM-CSF were considerably lower compared to untreated tumor carrying control animals. No growth stimulation of heterotransplanted human testicular germ cell tumors by GM-CSF has been observed in this nude mice tumor model. Further studies will have to demonstrate, whether GM-CSF is even possibly able to exhibit an antitumor effect. With respect to tumor cell kinetics the clinical use of GM-CSF in the treatment of patients with testicular cancer can be regarded as safe.

Treatment of adult osteosarcoma - single-center results in 47 patients.

Fourty-seven adult patients (median age 24 years; 16-66 years) with the diagnosis of osteosarcoma were treated at Hannover University Medical School between 1980 and 1991 according to the consecutive protocols of the Osteosarcoma Study Group (COSS-80 - COSS-86) irrespective of the fulfilment of study entry criteria. Patients received preoperative chemotherapy followed by surgical resection and adjuvant postoperative chemotherapy. Thirty-seven patients (79%) were treated for local tumors and 10 patients (21%) presented with disseminated metastatic disease. Twenty-one patients (45%) did not fulfil official study entry criteria. Thirty-four patients (72%) achieved an NED-status after therapy, 13 patients (28%) still had metastases and/or unresectable tumors. Seventeen of 34 patients (50%) relapsed after a median time of 18.5 months. Only 1 of 10 patients presenting initially with metastatic disease could be rendered long term tumor-free. The median overall survival of all patients was 42 months with a 2-year-survival rate of 64%. The projected 5-year-survival after a median follow-up of 59 months (8-121 months) was 49%. The presence of metastatic disease at initial diagnosis (p=0.04), an elevated alkaline phosphatase level at diagnosis (p=0.05), histologically 'poor response' to preoperative chemotherapy (p=0.04) and non-fulfilment of COSS-study entry criteria (p=0.046) were significantly worse prognostic factors during univariate analysis. The treatment results in unselected adult patients with osteosarcoma are inferior to those reported for patients included into osteosarcoma treatment study protocols. However, appoximately half of all patients (45%) seen at a large single center did not fulfil the eligibility criteria as official study patients. Even in these non-study patients the use of preoperative and/or adjuvant chemotherapy significantly improved survival compared to historical controls treated by surgery alone (58% and 38% 2- and 5-year-survival rates, respectively). The prognosis of patients with synchronous metastases at diagnosis remains poor despite the inclusion of chemotherapy into treatment strategies.

Phantom sensations after orchiectomy for testicular cancer.

Phantom sensations have been frequently reported after limb amputations, but they seemed to be rare events after urological operations. All 81 consecutive male patients (median age 28 years; 16-51), seen during their routine follow-up visit at the oncology outpatient department of Hannover University Medical School between January 1st and June 30th 1991, who had undergone unilateral orchiectomy for malignant germ cell tumors of the testis, were evaluated for the prevalence of testicular phantom sensations. Ten patients (12.3%) reported phantom sensations. One patient with subsequent bilateral orchiectomy developed phantom sensations after each operation. Neither tumor or treatment related factors nor social parameters were closely associated with the occurrence of testicular phantoms. Phantom sensations began within the first weeks after orchiectomy and in 7 of 11 (63.6%) patients the phantom feelings disappeared within 18 months after orchiectomy. Nine of the 11 patients experienced painful phantom sensations. Three patients reported a significant influence of the phantom feelings on their sexual life and one patient was surgically re-evaluated under the suspicion of a second testicular tumor because of persistant phantom pain. In conclusion, the occurrence of phantom sensations after orchiectomy has been neglected in this group of young cancer patients with good prognosis. With respect to treatment related side effects and the quality of life of testicular cancer patients, oncologists, urologists and neurologists should be aware of this phenomenon.

Metastatic leydig-cell tumors of the testis - report of 4 cases and review of the literature.

Leydig cell tumours constitute 1-2% of all testicular cancers and only 10% of patients with Leydig cell tumours will develop metastatic disease. They are considered refractory to chemo- and radiotherapy. The management of metastatic disease and the effects of systemic therapy have only been described in case reports. We report on four patients with metastic Leydig cell tumours, one of which was accompanied with excess sex hormone production. One patient was rendered tumour free by the surgical resection of retroperitoneal lymph nodes. and remains without recurrence for 10+ months. The other three patients received systemic treatment due to inoperable metastatic disease. One patient with progressive abdominal and supraclavicular lymph node metastases achieved a minor remission after 4 cycles of cisplatin-based chemotherapy, lasting for ten months. A second response to carboplatin-based chemotherapy was achieved in this patient at progression. The other two patients died 9 and 21 months after diagnosis of metastatic disease and never responded to chemotherapy. A review of the different treatment options for metastatic Leydig cell tumours is given. Surgery, which might include the resection of retroperitoneal lymph nodes or solitary pulmonary metastases, seems to be the only curative modality. Radiotherapy has apparently no effect and responses to systemic chemo- or hormonal therapy are infrequent and usually of short duration.

Effects of tumour necrosis factor alpha on bone marrow aspirates of patients with acute myelogenous leukemia determined by flow-cytometric cell-cycle analysis.

Tumour necrosis factor alpha (TNF alpha) exerts cytotoxic and antiproliferative effects on neoplastic cells. It has been used as a therapeutic agent for solid tumours and haematological malignancies. We report on the ex vivo determination of the effect of recombinant human rhuTNF alpha on bone marrow aspirates by a bromodeoxyuridine/propidium iodide method. Cell samples were drawn after 0.5, 2, 4, 6, 8, 10, 22, and 25 h from short-term suspension bone marrow cultures from patients with acute myelogenous leukemia (AML). Flow-cytometric cell-cycle analysis was performed after double DNA staining with propidium iodide and anti-BrdU antibodies. By this method the effect of rhuTNF alpha on cell proliferation can be evaluated after only 35 h. In about two-thirds of the bone marrow aspirates of AML an inhibiting effect on rhuTNF alpha can be demonstrated, developing to its full extent after 10 h.

Five-day 4'-(9-acridinylamino)methanesulphon-m-anisidide and intermediate-dose cytosine arabinoside in high-risk relapsing or refractory acute myeloid leukemia.

Twenty-two patients with acute myeloid leukemia (AML), having a median age of 48.3 years (range 26-70; 10 male, 12 female), were treated with 4'-(9-acridinylamino) methanesulphon-m-anisidide (m-AMSA) 100 mg/m2 and cytosine arabinoside (AraC) 2 x 1000 mg/m2i.v. on days 1-5. There were 2M1,8 M2, 9 M4, 2M4 Eo, and 1 M5a. Of these, 12 achieved a complete remission, 3 a partial remission and 6 did not respond. The median remission duration was 9.0 months and the median overall survival 8.1 months. Side-effects of induction consisted mainly of haematological toxicity and infections with a median duration of WHO-grade-4 granulopenia and thrombopenia of 20 and 28 days respectively. Organ toxicity was mild with mucositis and cutaneous and liver toxicity being experienced by only a few patients. There was one treatment-related death. Five-day m-AMSA and intermediate-dose AraC is an easy-to-handle condensed treatment schedule with tolerable toxicity. Its effectiveness in relapsed and refractory AML is comparable to combinations of high-dose AraC with m-AMSA, anthracyclines or etoposide.

Analysis of a non-ras 21-kDa protein in patients with metastatic testicular germ-cell tumors.

A novel protein of 21 kDa (p21) has been detected in the sera of patients with different solid tumors. The serum levels of this p21 protein were measured in seven patients with metastatic testicular germ-cell tumors before and after chemotherapy using an enzyme-linked immunosorbent assay. In five out of six patients who responded to chemotherapy a concomitant decrease of p21 serum levels was found. The decrease of p21 was in accordance with the decline of the established tumor markers alpha-fetoprotein, human chorionic gonadotropin beta-subunit and lactate dehydrogenase in three patients with non-seminomatous tumors and with the decline of lactate dehydrogenase and the clinical response in two patients with seminoma. In one patient the predicted decline of p21 did not occur despite the patient's clinical response to chemotherapy. In the seventh patient, who relapsed directly after chemotherapy, no decline of either p21 levels or tumor markers was observed. The absolute amount of the p21 protein prior to chemotherapy did not correlate with the patients' tumor burden. Elevated levels of p21 were found in patients with seminomatous and non-seminomatous germ-cell tumors. Since seminoma patients do not secrete tumor markers like alpha-fetoprotein or human chorionic gonadotropin beta, the determination of p21 levels may help to evaluate the efficacy of chemotherapy in patients with seminomatous as well as in patients with marker-negative non-seminomatous germ-cell tumors. The biological role of p21 and its clinical significance will be further investigated.

Granulocyte colony-stimulating factor enhances the expression of CD62 on platelets in vivo.

The expression of CD41, CD42 and CD62 on platelets was determined in ten patients with and without G-CSF treatment. CD41 and CD42 is expressed in nearly 100% of the platelets without change after G-CSF treatment. The expression of CD62 on the platelets' surface is significantly enhanced by G-CSF indicating a depletion of the alpha-granules. No platelet aggregation was observed. The enhanced secretion of thrombocyte-specific proteins does not induce aggregation but may promote ADP-induced aggregation. Furthermore, the surface-bound and soluble CD62 binds specifically to macrophages and endothelial cells and is involved in the regulation of inflammatory processes. Thus indirect mechanisms may supplement direct effects of G-CSF after chemotherapy.