RESUMEN
BACKGROUND: Worldwide, cancer pain management follows the World Health Organization (WHO) three-step analgesic ladder. Using weak opioids (e.g. codeine) at step 2 is debatable with low-dose strong opioids being potentially better, particularly in low- and middle-income countries where weak opioids are expensive. We wanted to assess the efficiency, safety and cost of omitting step 2 of the WHO ladder. PATIENTS AND METHODS: We carried out an international, open-label, randomised (1 : 1) parallel group trial. Eligible patients had cancer, pain ≥4/10 on a 0-10 numerical rating scale, required at least step 1 (paracetamol) of the WHO ladder and were randomised to the control arm (weak opioid, step 2 of the WHO ladder) or the experimental arm (strong opioid, step 3). Primary outcome was time to stable pain control (3 consecutive days with pain ≤3). Secondary outcomes included distress, opioid-related side-effects and costs. The primary outcome analysis was by intention to treat and the follow-up was for 20 days. RESULTS: One hundred and fifty-three patients were randomised (76 control, 77 experimental). There was no statistically significant difference in time to stable pain control between the arms, P = 0.667 (log-rank test). The adjusted hazard ratio for the control arm was 1.03 (95% confidence interval 0.72-1.49). In the control arm, 38 patients (53%) needed to change to a strong opioid due to ineffective analgesia. The median time to change was day 6 (interquartile range 4-11). Compared to the control arm, patients in the experimental arm had less nausea (P = 0.009) and costs were less. CONCLUSION: This trial provides some evidence that the two-step approach is an alternative option for cancer pain management.
Asunto(s)
Analgésicos Opioides , Neoplasias , Humanos , Analgésicos Opioides/efectos adversos , Acetaminofén , Dolor/tratamiento farmacológico , Dolor/etiología , Neoplasias/tratamiento farmacológico , Organización Mundial de la SaludRESUMEN
Mouse studies showed a synergy of thymosin alpha1 (Talpha1) and a natural cytokine mixture (IRX-2) in increasing T lymphocyte number and responses. Clinical studies with IRX-2 showed increases of T lymphocytes in lymphocytopenic cancer patients but relatively little effect on irradiated, lymphocytopenic patients. The present phase 1 and 2 study shows that Talpha1 enhances the effect of IRX-2 in these lymphocytopenic patients. Patients (seven) were treated with subcutaneously injected IRX-2 (200 units IL-2 equivalence), Talpha1 (1.6 mg/day) (four patients), or the combination of IRX-2 and Talpha1 (seven patients) daily for 10 days. Peripheral blood lymphocytes (T, B, NK) and subsets (CD4, CD8) were measured at the start of treatment and on day 11. IRX-2 and Talpha1 had little or no significant effect. The combination markedly increased various lymphocyte populations (>350 cells/microL). Four patients followed for 6 weeks displayed sustained increases involving both naïve and memory T cells. Responses to persistent infections were observed in three of the four patients and no significant toxicity was observed. Talpha1 and IRX-2 synergize to increase safely T cells in lymphocytopenic patients.
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Citocinas/farmacología , Citocinas/uso terapéutico , Linfopenia/tratamiento farmacológico , Linfocitos T/inmunología , Timosina/análogos & derivados , Animales , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Humanos , Linfopenia/inmunología , Ratones , Linfocitos T/efectos de los fármacos , Timalfasina , Timosina/farmacología , Timosina/uso terapéuticoRESUMEN
It is now well established that the clinical and histopathological characteristics of non-Hodgkin's lymphomas may vary significantly throughout the world. However, only a few reports have been published in Latin American countries. In this work, the clinical and pathologic findings of 264 patients with non-Hodgkin's lymphomas in Mexico City were analyzed. Diffuse large (14%) and diffuse mixed cell types (20%) predominated among nodal lymphomas. Within the group of patients with high grade malignancies, immunoblastic sarcomas were the most common (40/48). It is important to mention that follicular lymphomas were sporadic (4.5%). Among extranodal lymphomas the most commonly involved site was the gastrointestinal tract (11.3%), followed by the midline (6%). Molecular analysis of 65 cases with immunoglobulin and T-cell receptor gene probes showed that most lymphomas were of B-cell lineage (66%). The remaining group was composed of T-cell (25%) and bigenotypic malignancies (9%). All attempts to establish a correlation between the clinical stage and histopathological types with the genetic findings were not successful. However, pre-B and bigenotypic lymphomas were observed mainly in patients over 60 years of age. This study highlights some relevant characteristics of non-Hodgkin's lymphomas in Mexico.
Asunto(s)
Linfoma no Hodgkin/epidemiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , ADN de Neoplasias/genética , ADN Viral/aislamiento & purificación , Países en Desarrollo , Infecciones por Virus de Epstein-Barr/epidemiología , Femenino , Reordenamiento Génico , Herpesvirus Humano 4/aislamiento & purificación , Humanos , Ganglios Linfáticos/patología , Linfoma no Hodgkin/clasificación , Linfoma no Hodgkin/genética , Linfoma no Hodgkin/patología , Linfoma no Hodgkin/virología , Masculino , México/epidemiología , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Cutáneas/epidemiologíaRESUMEN
A Phase II trial in 42 patients with squamous cell cancer of the head and neck (H and NSCC) was performed using a combination immunotherapy with 10-20 days of perilymphatic injections of a natural cytokine mixture (NCM: IRX-2; 200 units IL-2 equivalence) preceded by low dose cyclophosphamide (CY; 300 mg/m(2)) and followed by daily oral indomethacin (25 mg t.i.d.) and zinc (65 mg in a multivitamin preparation). Thirty-nine patients underwent subsequent surgical resection and 22 stage IV patients received additional radiotherapy. Forty-two percent were adjudged to have complete and partial clinical responses (>50% tumor reduction); an additional five patients had minor responses for a total of 58%. Comparison of post-treatment biopsies or surgical specimens showed 90% of patients had reduction in tumor area from 79% to 48% (over half of which was fragmented) and increased area of leukocyte infiltration from 9% to 32% (79% of which was lymphoid). The treatment with IRX-2 was not associated with significant side effects and 24 of patients showed improvement in eating, breathing or phonation or reduced pain and bleeding. Fifteen patients with lymphocytopenia (lymphocyte counts [LC] less than or equal to 1500 mm(3)) showed significant increases in LC, CD3+, CD4+ and CD8+ T lymphocytes of 401, 147, 95 and 100/mm(3), respectively. Analysis of outcome of 32 on protocol patients after 36 months versus 32 concurrent institutional H and NSCC controls showed delayed recurrences and significant increases in mean survival time (MST) and survival (p's<0.02). The data document immunotherapy induced regression of H and NSCC with delayed recurrence and improved mean survival time.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Células Escamosas/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Ciclofosfamida/administración & dosificación , Citocinas/administración & dosificación , Supervivencia sin Enfermedad , Femenino , Neoplasias de Cabeza y Cuello/inmunología , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/patología , Humanos , Inmunoterapia/métodos , Indometacina/administración & dosificación , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias de Células Escamosas/inmunología , Neoplasias de Células Escamosas/mortalidad , Neoplasias de Células Escamosas/patología , Zinc/administración & dosificaciónRESUMEN
Clinical and experimental data demonstrate that local cytokines are able to induce tumor regression and in some cases antitumor systemic immune response. IRX-2 is a cell-free mixture of cytokines obtained from unrelated donor lymphocytes with demonstrated ability to induce immune mediated regression of squamous cell carcinomas of head and neck. The objective of this study was to evaluate the antitumor activity and toxicity of IRX-2 in untreated early stage cervical cancer patients. Ten consecutive patients clinically staged IB1, IB2 and IIA were treated with a neoadjuvant immunotherapy regimen that consisted in a single IV dose of cyclophosphamide at 300 mg/m2 on day 1, oral indomethacin or ibuprofen and zinc sulfate were administered from days I to 21 and 10 regional perilymphatic injections of IRX-2 on days 3 to 14. All patients were scheduled for radical hysterectomy on day 21. The clinical and pathological responses, toxicity and survival were evaluated. Clinical response was seen in 50% of patients (three partial responses, two minor responses). Seven patients underwent surgery and pathological tumor reduction associated with tumor fragmentation was found in five cases. Histological studies demonstrated a rather heterogeneous cell type infiltrating pattern in the tumor which included lymphocytes, plasma cells, neutrophils, macrophages and eosinophils. Immunohistochemical analysis of the surgical specimens demonstrated an increase of tumor infiltrating CD8+ cells. The treatment was well tolerated except for mild pain and minor bleeding during injections and gastric intolerance to indomethacin. At 31 months of maximum follow-up (median 29), eight patients are disease-free. Our results suggest that the immunotherapy approach used induces tumor responses in cervical cancer patients. Further studies are needed to confirm these results as well as to elucidate the mechanisms underlying these effects.
Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Carcinoma Adenoescamoso/tratamiento farmacológico , Carcinoma de Células Escamosas/tratamiento farmacológico , Citocinas/uso terapéutico , Terapia Neoadyuvante/métodos , Neoplasias del Cuello Uterino/tratamiento farmacológico , Adenocarcinoma/inmunología , Adenocarcinoma/patología , Adulto , Carcinoma Adenoescamoso/inmunología , Carcinoma Adenoescamoso/patología , Carcinoma de Células Escamosas/inmunología , Carcinoma de Células Escamosas/patología , Femenino , Humanos , Persona de Mediana Edad , Terapia Neoadyuvante/estadística & datos numéricos , Proyectos Piloto , Neoplasias del Cuello Uterino/inmunología , Neoplasias del Cuello Uterino/patologíaRESUMEN
OBJECTIVES: To test the efficacy of a natural cytokine mixture (IRX-2), cyclophosphamide, indomethacin, and zinc to induce immune regression of squamous cell carcinoma (SCC) of the head and neck (H&N) prior to conventional therapy and to characterize the responses. PATIENTS AND DESIGN: A phase 2 trial was performed in 15 adults with recently diagnosed, biopsy-confirmed H&N SCC (3 with stage II disease, 6 with stage III disease, and 6 with stage IV disease). The patients were treated with 20 days of perilymphatic injections of IRX-2 (administered subcutaneously at the base of the skull) in combination with contrasuppression consisting of a low-dose infusion of cyclophosphamide (300 mg/m2), and daily oral indomethacin and zinc (StressTabs) in a 21-day cycle before surgery and/or radiotherapy. Tumor dimensions, toxic effects, and disease-free survival were monitored. The tumor sections were histologically examined after surgery, and tumor reduction, fragmentation, and lymphoid infiltration were assessed. RESULTS: All 15 patients responded clinically to the 21-day IRX-2 protocol: 1 with a complete response, 7 with a partial response, and 7 with a minor response. All 15 patients responded pathologically with tumor reduction (mean, 42%) and fragmentation (mean, 50%) in the histological section and increased lymphoid infiltration. The adverse effects of the IRX-2 protocol were negligible except for an allergic skin rash (n = 1) and parotiditis (n = 1). Indomethacin caused gastritis in 1 patient. Reduction of pain and ulceration and bleeding were observed in 8 and 4 patients, respectively. Four of 5 patients with lymphopenia showed increased CD3, CD4, and CD8 cell counts. After surgery (n = 13) and/or radiotherapy (n = 10) and with a mean follow-up of 17 months, 3 patients have had recurrences, 1 patient has died of disease, 1 patient has been re-treated with immunotherapy and has no evidence of disease, and 1 patient is alive with disease. Two patients died of other causes with no evidence of disease. CONCLUSIONS: The IRX-2 immunotherapy induced lymphocyte mobilization and infiltration in H&N SCC associated with clinical and histological tumor responses indicative of immune regression in all 15 patients. Minimal toxic effects were observed, and overall survival may have been improved. A phase 3 trial seems warranted.
Asunto(s)
Carcinoma de Células Escamosas/terapia , Citocinas/uso terapéutico , Neoplasias de Cabeza y Cuello/terapia , Inmunoterapia/métodos , Terapia Neoadyuvante , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/inmunología , Carcinoma de Células Escamosas/patología , Terapia Combinada , Ciclofosfamida/efectos adversos , Ciclofosfamida/uso terapéutico , Citocinas/efectos adversos , Supervivencia sin Enfermedad , Combinación de Medicamentos , Femenino , Neoplasias de Cabeza y Cuello/inmunología , Neoplasias de Cabeza y Cuello/patología , Humanos , Indometacina/efectos adversos , Indometacina/uso terapéutico , Metástasis Linfática , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/inmunología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Zinc/efectos adversos , Zinc/uso terapéuticoRESUMEN
OBJECTIVE: To induce tumor regression with immunotherapy and to characterize the histology. SETTING: National Institute of Cancerology, Mexico City, Mexico. PATIENTS: Thirteen patients with advanced squamous cell carcinoma of the head and neck region. INTERVENTION: A 21-day cycle of preoperative immunotherapy, including a single intravenous infusion of low-dose cyclophosphamide (300 mg/M2), 10 daily perilymphatic injections of a natural cytokine mixture (approximately 150 units interleukin-2 equivalence by enzyme-linked immunosorbent assay), daily oral indomethacin, and daily oral zinc with multivitamins. OUTCOME MEASURES: Pretreatment biopsies were performed to confirm the diagnosis and to characterize the lesion by standard pathologic criteria, including the degree of tumor-associated lymphocytes. Clinical responses were assessed at surgery, and the specimen was analyzed with respect to changes in tumor morphology and lymphoid and inflammatory infiltration (T and B lymphocytes, plasma cells, macrophages, granulocytes, and giant cells). The presurgical and postsurgical characteristics were ascribed percentages based on a representative section. RESULTS: Prior to treatment, on average the biopsies demonstrated 77% solid tumor with 14% stroma and 9% sparse infiltration of lymphocytes. After treatment, one patient had a complete clinical response and showed only residual inflammatory cells and fibrosis. One patient had no clinical or histologic response. Of the remaining 11 patients, 4 had partial, 6 had minor, and 1 had no response. Tumors were reduced an average of 41% (16% solid and 25% fragmented) and lymphoid infiltration increased to 45% without change in residual stroma. CONCLUSIONS: The pathologic changes viewed in the context of the clinical findings indicate that this immunotherapy protocol induces immune regression of the tumor, mediated predominantly by T and B lymphocytes, and thus elicits a tumor-specific immune reaction.
Asunto(s)
Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , Citocinas/uso terapéutico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/patología , Anciano , Carcinoma de Células Escamosas/inmunología , Carcinoma de Células Escamosas/cirugía , Quimioterapia Adyuvante , Ciclofosfamida/administración & dosificación , Citocinas/administración & dosificación , Combinación de Medicamentos , Femenino , Neoplasias de Cabeza y Cuello/inmunología , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Indometacina/administración & dosificación , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Zinc/administración & dosificaciónRESUMEN
Human transformed T cell lines were able to induce polyclonal B cell activation and immunoglobulin (Ig) secretion from peripheral blood mononuclear cells, spleen cells and tumor-infiltrating lymphocytes (TIL). Cells from one of the lines tested, MOT, did not require any exogenous stimuli to induce maximal responses and under similar conditions induced higher levels of response than peripheral blood T cells or other T cell lines. MOT-induced B cell activation and Ig secretion required cell contact and factors present in the MOT culture supernatant. MOT cells induced B cell responses from TIL in the three tumors tested (melanoma, ovarian and colon cancer) and HIV-specific immunoglobulin secretion by spleen cells from an HIV+ patient.
Asunto(s)
Linfocitos B/citología , Células Clonales/citología , Activación de Linfocitos , Cooperación Linfocítica , Linfocitos Infiltrantes de Tumor/citología , Linfocitos T/inmunología , Formación de Anticuerpos , Células Sanguíneas/citología , División Celular , Línea Celular Transformada , Células Cultivadas , Neoplasias del Colon/patología , Femenino , Anticuerpos Anti-VIH/biosíntesis , Seropositividad para VIH/inmunología , Humanos , Melanoma/patología , Neoplasias Ováricas/patología , Bazo/citologíaRESUMEN
This report describes a clinical case of a large cell, immunoblastic plasmacytoid malignant B-cell lymphoma of the rectum in an AIDS patient coinfected with HTLV-I. The malignant cells showed clonal genetic rearrangement of the HC (JH) and LCK genes. Infection by EBV was demonstrated serologically and with slot blots using genomic DNA of the cancer cells. Southern blot analysis with DNA extracted from the lymphoma cells were negative for HTLV-I. The patient received seven cycles of VACO-B which induced complete but transient clinical remission of the tumor. The final outcome of the patient is unknown.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/complicaciones , VIH-1 , Infecciones por HTLV-I/complicaciones , Virus Linfotrópico T Tipo 1 Humano , Linfoma Relacionado con SIDA/complicaciones , Linfoma Inmunoblástico de Células Grandes/complicaciones , Neoplasias del Recto/complicaciones , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bleomicina/administración & dosificación , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Etopósido/administración & dosificación , VIH-1/aislamiento & purificación , Herpesvirus Humano 4/aislamiento & purificación , Herpesvirus Humano 4/patogenicidad , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Virus Linfotrópico T Tipo 1 Humano/patogenicidad , Humanos , Linfoma Relacionado con SIDA/tratamiento farmacológico , Linfoma Relacionado con SIDA/microbiología , Linfoma Inmunoblástico de Células Grandes/tratamiento farmacológico , Linfoma Inmunoblástico de Células Grandes/microbiología , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Neoplasias del Recto/tratamiento farmacológico , Neoplasias del Recto/microbiología , Inducción de Remisión , Sobreinfección , Infecciones Tumorales por Virus/complicaciones , Vincristina/administración & dosificaciónRESUMEN
We describe the anatomical distribution, histological and molecular characteristics of 32 cases of NHL. Staging of the NHL was made according to conventionally accepted schemes. Histologically the NHL were classified in grades following the criteria defined by the Working Formulation. Rearrangements in one or more Ig or TcR receptor genes were detected in Southern blots and allowed us to determine the cell type and stage of differentiation. Serological analysis of 26 serum samples revealed the existence of antibodies against EBV epitopes; eight of these patients carried viral sequences in the tumor genome as determined by slot blot hybridization. Our studies indicate that the use of various methods is of paramount importance in order to improve our understanding of the natural history of NHL.
Asunto(s)
Linfoma no Hodgkin/epidemiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/análisis , Diferenciación Celular , Comorbilidad , ADN de Neoplasias/análisis , ADN Viral/análisis , Femenino , Reordenamiento Génico de Linfocito T , Genes de Inmunoglobulinas , Genes myc , Herpesvirus Humano 4/inmunología , Herpesvirus Humano 4/aislamiento & purificación , Humanos , Linfoma no Hodgkin/genética , Linfoma no Hodgkin/microbiología , Linfoma no Hodgkin/patología , Masculino , México/epidemiología , Persona de Mediana Edad , Estudios Retrospectivos , Infecciones Tumorales por Virus/epidemiologíaRESUMEN
The humoral immune response developed by C57BL/6J mice against the beta 2-microglobulin (beta 2m) and major histocompatibility complex (MHC) class I- and class II-deficient cell variant of L5178Y, LR.4, is strain specific, is not linked to a given haplotype and involves at least one antigenic determinant expressed on the cell membrane. Anti-LR.4 antibodies can be detected in the serum and ascitic fluid of tumour-bearing animals, and in the serum of mice immunized with mitomycin C (MC)-treated cells. In vitro, cytotoxic T lymphocytes (CTL) cannot be induced under different experimental conditions. However, recognition and lysis of LR.4 are mediated by an antibody-dependent cell-mediated cytotoxicity (ADCC) mechanism in which natural killer (NK) cells extracted from the spleen of resistant or susceptible strains are the effector cells. The NK cells responsible for ADCC against LR.4 are not inducible with polyinosinic-polycytidylic acid (poly(I:C)) and could represent a subset that is not detectable by conventional assays. In conclusion, the incapacity of BALB/c and possibly of other strains of mice to reject LR.4 is determined by the failure to mount a humoral immune response.
Asunto(s)
Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Rechazo de Injerto/inmunología , Antígenos H-2 , Ratones Endogámicos C57BL/inmunología , Subgrupos de Linfocitos T/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Línea Celular/inmunología , Femenino , Citometría de Flujo , Antígenos H-2/inmunología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/fisiología , Leucemia L5178/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Especificidad de la EspecieRESUMEN
Prior studies indicate that combination immunotherapy of squamous cell cancer (SCC) of head and neck (H&N) with cytokines is feasible (Hadden et al., 1994). To induce immune regression of H&N SCC 20 stage II-IV patients received 3 weeks prior to surgery low dose cyclophosphamide (300 mg/M2), then 10 daily perilymphatic injections of a natural cytokine mixture (IRX-2)(150 units of IL-2 equivalence) and daily oral indomethacin and zinc. Tumor responses, T-lymphocyte and subset counts, and toxicity were monitored. Six patients had major clinical responses (both complete [CR] and partial [PR]) without major toxicity. Five of 20 patients were lymphocytopenic (1242 +/- 88 mm3) prior to treatment and the immunotherapy induced marked significant increases in total lymphocyte counts, CD3+ T-cells, and both CD4+ and CD8+ T-cells as well as a population of CD3+, CD4-, and CD8- lymphocytes. The post treatment specimen of 18/20 patients showed histologically tumor fragmentation, overall reduction and diffuse infiltration with lymphocytes and plasma cells. Histologic tumor reductions in these patients averaged 44% and the lymphoid infiltration increased 4.7 fold from 9-42%. The immune infiltration of the tumor reflects varying degrees of both T- and B-cells and indicates immunization to the tumor. The immunization achieved may improve clinical control of H&N SCC by improving the possibility that surgical resection of advanced loco-regional disease will leave no viable tumor.
Asunto(s)
Carcinoma de Células Escamosas/terapia , Citocinas/uso terapéutico , Neoplasias de Cabeza y Cuello/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/inmunología , Carcinoma de Células Escamosas/cirugía , Quimioterapia Adyuvante , Ciclofosfamida/administración & dosificación , Citocinas/administración & dosificación , Neoplasias de Cabeza y Cuello/inmunología , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Inmunización , Indometacina/administración & dosificación , Recuento de Linfocitos , Subgrupos de Linfocitos T/inmunología , Linfocitos T/inmunologíaRESUMEN
Breast cancer is characterized by a distinct metastatic pattern involving the regional lymph nodes, bone marrow, lung and liver. Tumour cell migration and metastasis share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. Here we report that the chemokine receptors CXCR4 and CCR7 are highly expressed in human breast cancer cells, malignant breast tumours and metastases. Their respective ligands CXCL12/SDF-1alpha and CCL21/6Ckine exhibit peak levels of expression in organs representing the first destinations of breast cancer metastasis. In breast cancer cells, signalling through CXCR4 or CCR7 mediates actin polymerization and pseudopodia formation, and subsequently induces chemotactic and invasive responses. In vivo, neutralizing the interactions of CXCL12/CXCR4 significantly impairs metastasis of breast cancer cells to regional lymph nodes and lung. Malignant melanoma, which has a similar metastatic pattern as breast cancer but also a high incidence of skin metastases, shows high expression levels of CCR10 in addition to CXCR4 and CCR7. Our findings indicate that chemokines and their receptors have a critical role in determining the metastatic destination of tumour cells.