Predictors of germline status for hereditary melanoma: 5 years of multi-gene panel testing within the Italian Melanoma Intergroup.

BACKGROUND: The incidence of cutaneous melanoma is increasing in Italy, in parallel with the implementation of gene panels. Therefore, a revision of national genetic assessment criteria for hereditary melanoma may be needed. The aim of this study was to identify predictors of susceptibility variants in the largest prospective cohort of Italian high-risk melanoma cases studied to date. MATERIALS AND METHODS: From 25 Italian centers, we recruited 1044 family members and germline sequenced 940 cutaneous melanoma index cases through a shared gene panel, which included the following genes: CDKN2A, CDK4, BAP1, POT1, ACD, TERF2IP, MITF and ATM. We assessed detection rate according to familial status, region of origin, number of melanomas and presence and type of non-melanoma tumors. RESULTS: The overall detection rate was 9.47% (5.53% analyzing CDKN2A alone), ranging from 5.14% in sporadic multiple melanoma cases (spoMPM) with two cutaneous melanomas to 13.9% in familial cases with at least three affected members. Three or more cutaneous melanomas in spoMPM cases, pancreatic cancer and region of origin predicted germline status [odds ratio (OR) = 3.23, 3.15, 2.43, P < 0.05]. Conversely, age > 60 years was a negative independent predictor (OR = 0.13, P = 0.008), and was the age category with the lowest detection rate, especially for CDKN2A. Detection rate was 19% when cutaneous melanoma and pancreatic cancer clustered together. CONCLUSIONS: Gene panel doubled the detection rate given by CDKN2A alone. National genetic testing criteria may need a revision, especially regarding age cut-off (60) in the absence of strong family history, pancreatic cancer and/or a high number of cutaneous melanomas.

Molecular characterization of an Italian series of sporadic GISTs.

PURPOSE: Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the gastrointestinal tract. Most (80 %) contain activating mutations in the KIT receptor tyrosine kinase, roughly 10 % in platelet-derived growth factor receptor-alpha (PDGFRA). In a small subset, BRAF mutations are an alternative molecular pathway. GISTs respond well to imatinib, but low response is seen in patients with wild-type KIT or PDGFRA. Resistance has also been reported as a result of mutations in downstream effectors such as BRAF. METHODS: We provide here a molecular characterization of a series of primary GISTs from Italian patients. Of 121 GIST cases diagnosed between 2000 and 2012, 83 were evaluated by PCR amplification and direct sequencing for mutations in KIT exons 8, 9, 11, 13, and 17, PDGFRA exons 12, 14, and 18, and BRAF exon 15. Eighty-one GISTs also underwent K-RAS testing. RESULTS: Sixty-four GISTs were positive: 55 had mutations in KIT and 9 in PDGFRA; 16 patients were mutation negative. Three samples came from NF1 patients and were KIT- and PDGFRA negative. Overall, we identified six novel mutations in KIT (p.K550_M552delinsL, p.Q556_W557delinsG p.Q556_G575del, p.W557_V559delinsQ p.P573_R588dup, p.G592_K593dup) and one novel mutation in PDGFRA (p.D842_N848delinsVDV), thus contributing to widening the spectrum of known mutations in GIST tumors and confirming the most frequently altered regions underlying GIST development. CONCLUSIONS: Among the 64 KIT- and PDGFRA-positive sporadic patients in our series, no BRAF or KRAS mutations were identified, suggesting that co-occurrence of these mutations is likely to be rare in the northwestern Italian population and not a frequent cause of primary resistance to imatinib in KIT-positive GIST patients.

Long-term survival in patients with metastatic breast cancer receiving intensified chemotherapy and stem cell rescue: data from the Italian registry.

The median survival of women with metastatic breast cancer (MBC) is 18-24 months, and fewer than 5% are alive and disease free at 5 years. We report toxicity and survival in a cohort of MBC patients receiving high-dose chemotherapy (HDC) with autologous hematopoietic SCT (AHSCT) in Italy between 1990 and 2005. Data set for survival analysis has been obtained for 415 patients. Clinical parameters including probability of transplant-related mortality (TRM), PFS and OS. With a median follow-up of 27 months (range 0-172), OS and PFS at 5 and 10 years in the whole population were 47/23 and 32/14%, respectively. A total 239 patients are alive with a median follow-up of 33 months (range 2-174). Survival was significantly more pronounced in patients harboring hormone receptor positive tumors (P=0.028), without visceral metastases (P=0.009) and in women with chemosensitive disease (P<0.0001). Sixty eight patients (20.4%) who received HDC in partial response, stable or progressive disease underwent conversion to CR. TRM was 2.5% overall and 1.3% since 2000. Our findings suggest that could be a role for HDC and AHSCT in delaying disease progression and possibly cure a subset of MBC patient harboring chemosensitive tumors.

Role of angiogenesis inhibitors in colorectal cancer: sensitive and insensitive tumors.

Angiogenesis is a key factor in the carcinogenesis process. In oncological practice, angiogenesis inhibition, mainly through the blockade of the VEGF family and its receptors, has been robustly demonstrated to produce clinical benefits and, in specific disease subsets such as colorectal cancer, to extend the overall survival of treated patients. VEGF is a multifunctional growth factor that mediates its functions through cognate receptors on endothelial cells and it has been discovered for its capability to induce macromolecule hyperpermeability in veins and venules. Several approaches have been taken to target angiogenesis in cancer: drugs that target one or more soluble ligands of the VEGF family, drugs that selectively inhibit one or more receptors of the VEGF receptor family, and drugs that inhibit VEGF receptor(s) among other, non VEGF-related targets. At present, two compounds have shown significant clinical activity, bevacizumab, Avastin® and aflibercept, Zaltrap®, and only one of these (bevacizumab) has so far been registered for use in clinical practice. In the present review, we explore and summarize the main features of the angiogenetic process, concerning in particular a common and potentially lethal disease as colorectal cancer. We overview the molecular pathways that characterize angiogenesis, focusing on VEGF family, the current applications and limitations of its blockade in oncology, and the hypothetical future perspectives of anti-angiogenic therapy.

Synthetic lethality-based therapeutics: perspectives for applications in colorectal cancer.

Over the past two decades, progresses in colorectal cancer treatment have significantly improved patient survival and quality of life. However, unresectable metastatic colorectal cancer remains virtually incurable, making the search for new effective therapeutics mandatory. An important limitation to the development of new agents has been the difficulty to exploit mutated tumor suppressors or "undruggable" oncogenes as a target. Recently, evidence that mutations in tumor suppressors, such as BRCA1/2, make cancer cells highly susceptible to inhibitors of a compensatory DNA repair pathway [poly-(ADP-ribose) polymerase 1 (PARP1)] has broadened the range of possible therapeutic targets by extending it to gene products that are in a "synthetic lethal" relationship with oncogenes and tumor suppressors. Inhibition of such targets blocks specific buffer-mechanisms that are required for survival in the presence of defined oncogenic mutations, but not in their absence. As a consequence, selective elimination of mutation-bearing cells results. This approach has led to identify compounds that are highly active in the presence of different types of mutated tumor suppressors and oncogenes, including DNA repair genes, RAS, and Myc. In addition, ongoing studies promise to identify new mechanisms which, when pharmacologically interfered with, will selectively eradicate mutated cancer cells. Here, we revise and discuss these new aspects of cancer biology and highlight their potential applications in colorectal cancer treatment.

Patient-tailored treatments with anti-EGFR monoclonal antibodies in advanced colorectal cancer: KRAS and beyond.

Personalized medicine emphasizes the practice of considering individual patient characteristics as opposed to that centered on standards derived from epidemiological studies which, by definition, do not take into account the variability of individuals within a given population. When applied to oncology, personalized medicine is an even more complex concept because it extends the variability beyond the individual patient to the individual tumor. Indeed, the great genotypic and phenotypic variability (both in primary and metastatic sites of cancer) the development of targeted therapies, and the growing availability of biological assays complicate the scenario of personalized medicine in the oncological field. In this paper we review the results of anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb) therapy in metastatic colorectal cancer (mCRC) in the context of tumor biology, delineating the future prospects of patient-tailored medicine in this area. In particular, we deal with EGFR inhibition by Cetuximab, a chimeric mouse human IgG1 mAb, and panitumumab, a fully human IgG2 mAb. We discuss the clinical impact of anti-EGFR mAbs on wild-type (WT) KRAS mCRC, also taking into account the feasibility of novel multi-marker approaches to treatment decision-making, aimed at increasing the predictive power of pre-therapy biomarkers. Experimental topics and fields of ongoing research, such as targeting microRNAs (miRNAs) with novel anticancer drugs and epigenetics in CRC are also addressed.

A multi-scale approach to colorectal cancer: from a biochemical- interaction signaling-network level, to multi-cellular dynamics of malignant transformation. Interplay with mutations and onco-protein inhibitor drugs.

This review article is part of a special Current Cancer Drug Targets issue devoted to colorectal cancer and molecularly targeted treatments. In our paper we made an attempt to connect more basic aspects with preclinical, pharmacological / therapeutic and clinical aspects. Reconstruction of a Molecular Interaction Map (MIM) comprising an important part of the G0 - G1 - S cell cycle transition, was a major component of our review. Such a MIM serves also as a convenient / organized database of a large set of important molecular events. The frequency of mutated / altered signaling-proteins indicates the importance of this signaling-network region. We have considered problems at different scale levels. Our MIM works at a biochemical-interaction level. We have also touched the multi-cellular dynamics of normal and aberrant colon crypts. Until recently, dynamic simulations at a biochemical or multi-cellular scale level were considered as a sort of esoteric approach. We tried to convince the reader, also on the basis of a rapidly growing literature, mostly published in high quality journals, that suspicion towards simulations should dissipate, as the limitations and advantages of their application are better appreciated, opening the door to their permanent adoption in everyday research. What is really required is a more interdisciplinary mentality and an interdisciplinary approach. The prize is a level of understanding going beyond mere intuition.

DNA damage response pathways and cell cycle checkpoints in colorectal cancer: current concepts and future perspectives for targeted treatment.

Although several drugs have been designed in the last few years to target specific key pathways and functions in colorectal cancer (CRC), the backbone of CRC treatment is still made up of compounds which rely on DNA damage to accomplish their role. DNA damage response (DDR) and checkpoint pathways are intertwined signaling networks that arrest cell cycle, recognize and repair genetic mistakes which arise during DNA replication and transcription, as well as through the exposure to chemical and physical agents that interact with nucleic acids. The good but highly variable activity of DNA damaging agents in the treatment of CRC suggests that intrinsic alterations in DDR pathways and cell cycle checkpoints may contribute differentially to the way cancer cells react to DNA damage. In the present review, our aim is to depict the recent advances in understanding the molecular basis of the activity of DNA damaging agents used for the treatment of CRC. We focus on the known and potential drug targets that are part of these complex and intertwined pathways. We describe the potential role of the checkpoints in CRC, and how their pharmacological manipulation could lead to chemopotentiation or synergism with currently used drugs. Novel therapeutic agents playing a role in DDR and checkpoint inhibition are assessed. We discuss the possible rationale for combining PARP inhibition with DNA damaging agents, and we address the link between DDR and EGFR pathways in CRC.

Dynamic simulations of pathways downstream of ERBB-family, including mutations and treatments: concordance with experimental results.

The pathways downstream of ErbB-family proteins are very important in BC, especially when considering treatment with onco-protein inhibitors. We studied and implemented dynamic simulations of four downstream pathways and described the fragment of the signaling network we evaluated as a Molecular Interaction Map. Our simulations, enacted using Ordinary Differential Equations, involved 242 modified species and complexes, 279 reversible reactions and 111 catalytic reactions. Mutations within a single pathway tended to be mutually exclusive; only inhibitors acting at, or downstream (not upstream), of a given mutation were active. A double alteration along two distinct pathways required the inhibition of both pathways. We started an analysis of sensitivity/robustness of our network, and we systematically introduced several individual fluctuations of total concentrations of independent molecular species. Only very few cases showed significant sensitivity. We transduced the ErbB2 over-expressing BC line, BT474, with the HRAS (V12) mutant, then treated it with ErbB-family and phosphorylated MEK (MEKPP) inhibitors, Lapatinib and U0126, respectively. Experimental and simulation results were highly concordant, showing statistical significance for both pathways and for two respective endpoints, i.e. phosphorylated active forms of ERK and Akt, p one tailed = .0072 and = .0022, respectively. Working with a complex 39 basic species signaling network region, this technology facilitates both comprehension and effective, efficient and accurate modeling and data interpretation. Dynamic network simulations we performed proved to be both practical and valuable for a posteriori comprehension of biological networks and signaling, thereby greatly facilitating handling, and thus complete exploitation, of biological data.

Peripheral blood vs. bone marrow for molecular monitoring of BCR-ABL1 levels in chronic myelogenous leukemia, a retrospective analysis in allogeneic bone marrow recipients.

Molecular monitoring of the BCR-ABL1 transcript in chronic myelogenous leukemia (CML) using quantitative real-time PCR (RQ-PCR) can be performed using either bone marrow (BM) or peripheral blood (PB). However, a recent report by Stock et al. [International Journal of Oncology 28 (2006) 1099] questioned the reliability of PB samples for BCR-ABL1 detection as performed by RQ-PCR. We report a study on 114 CML patients who received allogeneic stem cell transplantation (ASCT), and who were monitored by RQ-PCR using paired samples of BM and PB: the total number of determinations was 428, with a median follow-up after transplant of 8 years. BCR-ABL1 transcript was undetectable or <0.1%, in 106 (49.57%) and 62 (29%) paired determinations, respectively. BCR-ABL1 was >0.1% in 36 (16.8%) paired determinations and was discordant in 10 (4.7%). Agreement between PB and BM results was quantified by the kappa test (k = 0.85; 95% CI 0.76-0.94). This study shows that BCR-ABL1 RQ-PCR monitoring of CML patients after ASCT with PB is concordant with BM in 95.3% of cases, and thus may be used to monitor the disease. This may be relevant when discussing both quality of life issues and the need for post-transplant monitoring with the patient.

Molecular diagnosis and monitoring of chronic myelogenous leukemia: BCR-Abl and more.

The current treatment of chronic myelogenous leukemia (CML) is one of the most successful examples of molecularly targeted therapy in cancer. The identification of the fusion oncogene BCR-ABL allowed the discovery of small molecule inhibitors of its tyrosine kinase activity which, in turn, have literally revolutionized the treatment of this disease. However, large part of a successful clinical management of CML relies on appropriate diagnosis, molecular monitoring and identification of mutations potentially leading to drug resistance. These issues are discussed here together with an overview on how patients treated with tyrosine kinase inhibitors should be monitored.

Proteasome inhibitors: antitumor effects and beyond.

Proteasome inhibitors are emerging as effective drugs for the treatment of multiple myeloma and possibly certain subtypes of non-Hodgkin's lymphoma. Bortezomib (Velcade) is the first proteasome inhibitor proven to be clinically useful and will soon be followed by a second generation of small molecule inhibitors with improved pharmacological properties. Although it is now understood that certain types of malignancies have an exquisite dependence on a functional proteasome for their survival, the underlying reason(s) remain unclear as of now. In this context, addiction to nuclear factor-kappaB (NF-kappaB)-induced survival signals, activation of the unfolded protein response as well as a reduced proteasomal activity in differentiated plasma cells have all been proposed to justify proteasome inhibitors' activity in susceptible tissues. In addition to their anticancer properties, bortezomib and related drugs modulate inflammatory and immune responses by affecting function and survival of immune cells such as lymphocytes and dendritic cells. The present review offers an overview of the biological effects that have been involved in proteasome inhibitors' antitumor activity and suggests prospective future applications for these drugs based on their recently characterized anti-inflammatory and immunomodulatory effects.

Cardiac toxicity of trastuzumab in metastatic breast cancer patients previously treated with high-dose chemotherapy: a retrospective study.

HER-2 overexpression is associated to a poor prognosis in high-risk and metastatic breast cancer (MBC) patients treated with high-dose chemotherapy (HDC). HER-2 status is also a predictive factor and when trastuzumab is administered in combination with or sequentially to chemotherapy, a significant disease-free and/or overall survival improvement has been observed in HER-2+ early and MBC. Unfortunately, in both settings, trastuzumab is associated with an increased risk of cardiac dysfunction (CD). We have reviewed the clinical charts of HER-2-overexpressing MBC patients treated with trastuzumab after HDC. Age, baseline left ventricular ejection fraction (LVEF), radiation therapy on cardiac area, exposure to anthracycline, single or multiple transplant, high-dose agents, trastuzumab treatment duration were recorded as potential risk factors. In total, 53 patients have been included in the analysis. Median LVEF at baseline was 60.5%; at the end of trastuzumab (data available for 28 patients only), it was 55% (P = 0.01). Five out of the 28 (17.9%) patients experienced CD. Two out of 53 (3.8%) patients developed a congestive heart failure. Age > or = 50 years and multiple transplant procedure were potential risk factors for CD. The overall incidence of CD observed in this population of HER-2+ MBC patients treated with trastuzumab after HDC is not superior to that reported with concomitant trastuzumab and anthracyclines. However, patients with age > or = 50 years or receiving multiple course of HDC should be considered at risk for CD.

Effect of different cytokines on mammaglobin and maspin gene expression in normal leukocytes: possible relevance to the assays for the detection of micrometastatic breast cancer.

In cancer patients, the ability to detect disseminated tumour cells in peripheral blood or bone marrow could improve prognosis and consent both early detection of metastatic disease and monitoring of the efficacy of systemic therapy. These objectives remain elusive mainly due to the lack of specific genetic markers for solid tumours. The use of surrogate tissue-specific markers can reduce the specificity of the assays and give rise to a clinically unacceptable false-positive rate. Mammaglobin (MAM) and maspin are two putative breast tissue-specific markers frequently used for detection of occult tumour cells in the peripheral blood, bone marrow and lymph nodes of breast cancer patients. In this study, it was evaluated whether MAM and maspin gene expression may be induced in the normal blood and bone marrow cells exposed to a panel of cytokines, including chemotactic factors (C5a, interleukin (IL)-8), LPS, proinflammatory cytokines (TNF-alpha, IL-1beta) and growth factors (IL-3, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor). The experimental data show that all cytokines included in the panel, except for IL-8, were able to induce maspin expression; on the contrary, MAM gene was never induced. These results suggest that MAM is more specific than maspin and that the possible interference of cytokines should be taken into account in interpreting molecular assays for detection of isolated tumour cells.

Reverse-transcriptase polymerase chain reaction of the maspin gene in the detection of bone marrow breast carcinoma cell contamination.

BACKGROUND: Maspin is a molecular marker used for the detection of contaminating breast carcinoma (BC) cells in peripheral blood and lymph nodes. However, its specificity has been questioned recently. The objective of this study was to verify the specificity of this marker and to determine the incidence of positive bone marrow results in patients with BC who are eligible for high-dose chemotherapy (HDT) both in early and advanced disease stages and before and after treatment. METHODS: Bone marrow specimens from 41 patients with BC as well as from 35 normal volunteers and 17 patients with hematologic tumors were examined for maspin transcript expression by a modified nested reverse transcriptase-polymerase chain reaction technique. RESULTS: Maspin transcript was found in all normal and neoplastic breast tissues and in none of the 35 normal bone marrow specimens (specificity, 100%; 95% confidence interval, 90-100%). However, the transcript was found in 40% of the bone marrow samples from patients with hematologic malignancies. Thus, this marker appears very specific for discriminating between normal controls and patients with BC, but it cannot be considered disease specific. Among patients with BC, bone marrow was positive for the maspin transcript in 32% of patients with early-stage disease and in 75% of patients with metastatic disease before chemotherapy. After treatment, in 75% of patients with early-stage disease and in 50% of patients with metastatic disease, the bone marrow results became maspin negative. CONCLUSIONS: On the basis of the current data, although it is not disease specific, maspin is a reliable marker for detecting bone marrow molecular disease in patients with BC and should be considered for prospective studies as a prognostic indicator and as an assay for monitoring residual disease.

Adjuvant chemotherapy with high-dose cyclophosphamide, etoposide and cisplatin intensification without progenitor cell support in breast cancer patients with ten or more involved nodes: 5-year results of a pilot trial.

OBJECTIVES: The purpose of this study was to evaluate the clinical efficacy and tolerability of high-dose (HD) chemotherapy with growth factor support in primary breast cancer with extensive nodal involvement. PATIENTS AND METHODS: Fifty-three patients with ten or more involved nodes were recruited and were given three cycles of standard-dose fluorouracil, epidoxorubicin and cyclophosphamide followed by one single course of high-dose CEP (cyclophosphamide, etoposide and cisplatin). No autologous progenitor support was used. RESULTS: Five-year actuarial disease-free and overall survival were 40 and 60%, respectively. High-dose CEP required a median of 22 days of hospitalization and was associated with grade G3--4 nausea and vomiting in two thirds of the cases. Hematological toxicity was comparable to that of high-dose therapies delivered with autologous progenitor support. No therapy-related mortality was observed. CONCLUSIONS The efficacy of treatment was comparable to the best results of conventional therapy, with only a trend for improved survival. High-dose CEP was feasible with acceptable toxicity. Although this regimen does not require stem cell harvesting and storage, it requires clinical support comparable to autotransplantation procedures and side effects are not so manageable to recommend its use outside specialized units.

High-dose chemotherapy with tandem autologous transplantation as part of the initial therapy for aggressive non-Hodgkin's lymphoma.

The purpose of the present study was to evaluate the feasibility and the efficacy of employing a high-dose chemotherapy (HDT) regimen with tandem peripheral blood progenitor cells (PBPC) supported transplantation in the initial treatment of aggressive non-Hodgkin's lymphoma (NHL). HDT was preceded by a standard course of conventional dose chemotherapy in 17 out of the 25 patients treated, while in 8 cases it was delivered after only one or two cycles. HDT was a three-step procedure which included high-dose (6-7 g/m2) cyclophosphamide (CY) supported by haematopoietic growth factors, the first myeloablative course with mitoxantrone (NOV) 60, 75 or 90 mg/m2 plus melphalan (L-PAM) 140-180 mg/m2 with haematopoietic rescue, and the second myeloablative course with etoposide (VP) and carboplatin (CARBO) given at 1.5 g/m2 each with haematopoietic rescue. PBPC were collected after CY administration. Twenty-two patients (88%) completed the HDT, haematological reconstitution was rapid and complete at each step and there were no toxic deaths. The activity of the treatment was high with a CR rate over 90% in the entire patient population. The 2-year overall survival (OS) and failure-free survival (FFS) rates of patients in both Age-Adjusted International Prognostic Index (A-AIPI) groups 2 and 3 are 79% and the disease-free survival (DFS) rate for the CRs is 85%. In A-AIPI group 1 the 2-year OS and FFS rates are both 91%.

Effects of three cytokine regimens on hematologic recovery and progenitor cell mobilization after high-dose cyclophosphamide, etoposide, and cisplatin.

The aim of this study was to compare both the effects on hematologic recovery and circulating progenitor cell mobilization and the toxicity of three cytokine regimens administered after high-dose non-myeloablative chemotherapy with cyclophosphamide 5 g/m(2), etoposide 1.5 g/m(2) and cisplatin 150 mg/m(2). Thirty-five consecutive patients were non-random sequentially allocated to one of three treatment groups: (1) granulocyte colony-stimulating factor alone (n = 15); (2) granulocyte-macrophage colony-stimulating factor alone (n = 10), and (3) sequential interleukin-3 and granulocyte-macrophage colony-stimulating factor (n = 10). Neutrophil recovery in group 1 was significantly hastened as compared to the two other groups (median 2 days, p < 0.005), while no significant differences were observed between groups 2 and 3. CD34+ cells peaked about 2 days earlier in group 1 compared to the other groups (p = 0.0001), whereas the median peak value of CD34+ cells was similar in the three groups. In all patients, the toxicity related to cytokine administration was low and easily manageable with nonsteroidal anti-inflammatory drugs.

Complex chromosome rearrangements may locate the bcr/abl fusion gene sites other than 22q11.

BACKGROUND AND OBJECTIVE: From 5-8% of Philadelphia (Ph) positive patients with chronic myeloid leukemia (CML) show variant translocations in which at least a third chromosome in addition to 9q34 and 22q11 is involved. The formation mechanisms and clinical significance of variant Ph translocations are still unclear. The BCR/ABL chimeric gene encoding for chimeric proteins is always present and maps on the 22q- regardless of the type of translocation. We studied two apparently Ph negative CML patients with unusual karyotypes both showing a typical b3a2 rearrangement. DESIGN AND METHODS: Dual-color fluorescence in situ hybridization (FISH) can visualize BCR and ABL genes and localize the BCR/ABL fusion gene. We used FISH to study the formation mechanisms of variant Ph translocations in two patients. RESULTS: The chimeric BCR/ABL gene was located on a locus other than the expected 22q11 in both patients. In the first case the fusion signal was present on the 9q34 band whereas in the second patient it was detected on chromosome 8, involved in masked Ph formation. INTERPRETATION AND CONCLUSIONS: The location of the hybrid BCR/ABL gene on chromosomes other than 22q- is a rare event which can only be observed using the FISH technique. When these unusual translocations occur the hypothesis most often put forward is that several consecutive cytogenetic events have taken place. The factors which regulate the formation of these breakpoints have yet to be clarified. The FISH technique allows the identification of chromosome rearrangements that could not otherwise be detected by conventional banding procedures. The location of the hybrid BCR/ABL gene on sites other than 22q11 represents a rare type of variant Ph translocation. The real frequency and clinical significance of such rearrangements need to be investigated.

Comparative effects of three cytokine regimens after high-dose cyclophosphamide: granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), and sequential interleukin-3 and GM-CSF.

PURPOSE: To compare the toxicity and effects on hematologic recovery and circulating progenitor cell mobilization of three cytokine regimens administered after high-dose cyclophosphamide (HD-CTX; 6 g/m(2)), given as the first step of a high-dose sequential chemotherapy. PATIENTS AND METHODS: Forty-eight patients with breast cancer or non-Hodgkin's lymphoma were randomized to receive granulocyte colony-stimulating factor (G-CSF) alone (arm 1), granulocyte-macrophage colony-stimulating factor (GM-CSF) alone (arm 2), or sequential interleukin-3 (IL-3) and GM-CSF (arm 3). Cytokines were administered as a single daily subcutaneous injection at a dose of 5 to 6 microg/kg/d. Progenitor cells were evaluated in peripheral blood as well as in apheretic product as both CD34(+) cells and granulocyte-macrophage colony-forming units (CFU-GM). RESULTS: Neutrophil recovery was faster in arm 1 as compared with arms 2 and 3 (P <.0001); no significant differences were observed between arms 2 and 3. In arm 3, a moderate acceleration of platelet recovery was observed, but it was statistically significant only as compared with arm 1 (P =.028). The peak of CD34(+) cells was hastened in a median of 2 days in arm 1 compared with arms 2 and 3 (P =.0002), whereas the median peak value of CD34(+) cells and CFU-GM was similar in the three patient groups. Administration of IL-3 and GM-CSF resulted in more significant toxicity requiring pharmacologic treatment in 90% of patients. CONCLUSION: The three cytokine regimens administered after HD-CTX are comparably effective in reducing hematologic toxicity and mobilizing the hematopoietic progenitor cells. G-CSF accelerates leukocyte recovery and progenitor mobilization. Although G-CSF-treated patients have somewhat slower platelet recovery, they definitely have fewer side effects.