Cancer Incidence in Merida, Mexico 2015-2018: First Report from the Population-based Cancer Registry.

BACKGROUND: Cancer registries are essential for monitoring cancer burden and patterns, and document changes in time for cancer control. Hereby, we present the first results of four years of the Merida population-based cancer registry in Mexico. METHODS: The registry collects data on all new cancers diagnosed since 2015 using both active and passive methods including a total of 104 information sources. Definitions and coding follow international standards. Using CanReg5 software, age-standardized incidence rates (ASR/100,000 person years) were computed by direct method using the world standard population. RESULTS: A total of 5684 new cancer cases were registered during 2015-2018, 2321 in males and 3363 in females corresponding to age-adjusted incidence rates (ASR per 100,000) of 128.5, and 153.1, respectively. Most frequent cancers among males were prostate cancer (ASR 29.8), lymphomas (ASR 10.9) and colorectal cancer (ASR 9.7) while among females it was breast cancer (ASR 49.3), cervical cancer (ASR 17.5) and corpus uteri (ASR 11.5). Childhood cancers (0-14 year) represented 2.9% of all cancers, with leukemias accounting for 52% of the new cases. Overall, 87.6% of new cases were microscopically verified. CONCLUSIONS: The data reported provide information on the cancer profile in Merida. Prostate and breast cancer are the main incident cancers. Cervical cancers present high rates among women, while lymphomas and liver cancer data merit further exploration. Efforts to support the Merida cancer registry as well as other registries in Mexico need to be pursued in order to have locally recorded data to support cancer control measures.

Detection of psychosocial distress in cancer patients: A survey of Mexican oncologists.

Purpose: Identification of patients' distress is relevant for an on-time referral to psychosocial treatment. The objective was to assess the implementation of the guidelines for distress managing in Mexican oncologists based on the NCCN guidelines.Design: The study was non-experimental and cross-sectional.Sample: Two hundred thirty-one oncologists participated with an average age of 38 ± 11 years.Methods: The likelihood of distress assessment was quantitatively evaluated.Findings: A high percentage of oncologists knew and used procedures to assess psychosocial discomfort. However, a smaller percentage used a valid and reliable instrument. Factors associated with performing distress identification procedures were knowing the distress guidelines and lack of time. Factors for questionnaire usage are the availability of brief instruments and the percentage of patients suffering from stress.Implications for Psychosocial Providers: Psychosocial providers should develop strategies to educate and ensure that oncologists are familiar with guidelines on distress in oncology. More dissemination of screening procedures and referral to psychosocial programs in oncology is required. Integrating a distress screening program involving psychosocial providers and oncologists should be approached as a routine in high-quality cancer care, to reduce the stigma associated with mental health services.

Ultrastructural changes in giant cell tumor of bone cultured cells exposed to quercetin.

Giant cell tumor of bone (GCTB) is a primary bone tumor that affects skeletally mature people and whose main treatment is surgical. Because there are few pharmacological alternatives for the treatment of this tumor to find other molecules or compounds that could be potential therapeutic agents is desirable. Quercetin is a flavonoid with described antitumoral effect in different types of cancer cell lines that could be a possible option in GCTB treatment. However, there is no literature about the effect of quercetin on GCTB. In the present paper, we reported the ultrastructural changes in GCTB cells exposed to quercetin and also determined the expression of RIP1K, Caspase 3 and Caspase 8 on the exposed cells. For this purpose, GCTB sample was obtained from one patient and cultured. Quercetin affected all the histological components of the GCTB. The ultrastructural changes consisted mainly in necroptosis, autophagocytosis and secondary necrosis. This is the first report about quercetin effects on giant cell tumor of bone cultured cells. Further studies in other models could be done to support the use of quercetin as a complementary treatment in giant cell tumor of bone.Abbreviations: Giant cell tumor of bone (GCTB); transmission electron microscopy (TEM); reverse transcription - polymerase chain reaction (RT-PCR); receptor interacting protein kinase 1 (RIP1K); Dulbecco's Modified Eagle's Medium (DMEM).

KRAS mutation as the biomarker of response to chemotherapy and EGFR-TKIs in patients with advanced non-small cell lung cancer: clues for its potential use in second-line therapy decision making.

OBJETIVE: In patients with non-small cell lung cancer (NSCLC), knowledge of the epidermal growth factor receptor (EGFR) mutation status is fundamental for selecting the treatment involving EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Little information is available regarding the response and progression-free survival (PFS) in platinum-based chemotherapy (CT) versus EGFR-TKIs in the presence or absence of KRAS mutation, particularly in patients without EGFR mutation. METHODS: From 2007 to 2010, 353 patients with NSCLC were treated with first-line CT, EGFR-TKIs were used in the second or third line of treatment. Tests were performed for EGFR and KRAS mutation and the results of the mutations were obtained 3 to 4 months after the start of the treatment. We analyzed clinical characteristics, mutation profile, response and PFS to CT and EGFR-TKIs, and overall survival. The protocol is registered with ClinicalTrials.gov, number NCT01023828. RESULTS: Presence of the wild-type (WT) KRAS was independently associated with increased response rate to first-line CT when compared with KRAS mutation (41.4% vs. 14.7%; P=0.001). The EGFR mutation (57.8% vs. 11.7%; P<0.001) and WT-KRAS (39.6% vs. 3.3%; P=0.001) were associated with the EGFR-TKIs response. PFS of patients with WT-EGFR and KRAS mutation treated with EGFR-TKIs was shorter when compared with patients with WT-EGFR and WT-KRAS (P<0.001). CONCLUSIONS: KRAS mutation status is a good biomarker for response to EGFR-TKIs in patients with NSCLC. KRAS mutational status could impact the decision to give CT or EGFR-TKIs as a second line of treatment to patients with NSCLC, particularly in patients with WT-EGFR.

Breast cancer in young women in Latin America: an unmet, growing burden.

BACKGROUND: Breast cancer (BC) is the leading cause of malignancy-related deaths among women aged ≤ 45 years. There are unexplored and uncertain issues for BC in this particular group in Latin America. The aim of this study is to evaluate BC incidence and mortality among young women and related clinicopathological and survivorship aspects in this region. MATERIALS AND METHODS: Data were obtained from Globocan 2008 and the International Agency for Research on Cancer's Cancer Incidence in Five Continents series plus databases. We requested collaboration from the 12 different national cancer institutes in Latin America through SLACOM, the Latin American and Caribbean Society of Medical Oncology, and conducted a systematic literature review to obtain local data regarding the prevalence of BC among young women and their characteristics, outcomes, and survivorship-related issues. RESULTS: BC incidence and mortality proportions for Latin American women aged <44 years were higher when compared with those of developed countries (20% vs. 12% and 14% vs. 7%, respectively). We found only a few Latin American series addressing this topic, and prevalence varied between 8% and 14%. Stage II and III disease, high histological grade, and triple-negative and HER2 BC were features frequently observed among young Latin American BC patients. CONCLUSION: The rising incidence and mortality of BC in young Latin American women is a call to action in the region. It is necessary to monitor the epidemiological and clinical data through reliable cancer registries and to consider the implementation of protocols for education of patients and health professionals. This unmet, growing burden must be considered as a top priority of the national programs in the fight against BC, and models of specialized units should be implemented for this particular group of patients to provide better care for this emergent challenge.

Breast cancer in young women in Latin America: an unmet, growing burden.

UNLABELLED: Breast cancer (BC) is the leading cause of malignancy-related deaths among women aged ≤45 years. There are unexplored and uncertain issues for BC in this particular group in Latin America. The aim of this study is to evaluate BC incidence and mortality among young women and related clinicopathological and survivorship aspects in this region. MATERIALS AND METHODS: Data were obtained from Globocan 2008 and the International Agency for Research on Cancer's Cancer Incidence in Five Continents series plus databases. We requested collaboration from the 12 different national cancer institutes in Latin America through SLACOM, the Latin American and Caribbean Society of Medical Oncology, and conducted a systematic literature review to obtain local data regarding the prevalence of BC among young women and their characteristics, outcomes, and survivorship-related issues. RESULTS: BC incidence and mortality proportions for Latin American women aged <44 years were higher when compared with those of developed countries (20% vs. 12% and 14% vs. 7%, respectively). We found only a few Latin American series addressing this topic, and prevalence varied between 8% and 14%. Stage II and III disease, high histological grade, and triple-negative and HER2 BC were features frequently observed among young Latin American BC patients. CONCLUSION: The rising incidence and mortality of BC in young Latin American women is a call to action in the region. It is necessary to monitor the epidemiological and clinical data through reliable cancer registries and to consider the implementation of protocols for education of patients and health professionals. This unmet, growing burden must be considered as a top priority of the national programs in the fight against BC, and models of specialized units should be implemented for this particular group of patients to provide better care for this emergent challenge.

Clinical and pathological characteristics, outcome and mutational profiles regarding non-small-cell lung cancer related to wood-smoke exposure.

HYPOTHESIS: Although smoking is the major risk factor for non-small-cell lung cancer (NSCLC), other factors are also associated with lung carcinogenesis, such as wood-smoke exposure (WSE). This article has been aimed at suggesting that lung cancer related to cigarette smoking and lung cancer related to WSE have different clinical and genetic characteristics. EXPERIMENTAL DESIGN: A cohort of 914 lung cancer patients was prospectively studied; they had been treated at Mexico's National Cancer Institute between 2007 and 2010. The associations of WSE and cigarette smoking with clinical characteristics, mutation profile, response to chemotherapy, and epidermal growth factor receptor tyrosine kinase inhibitors were analyzed, and overall survival (OS) rate was calculated. The trial was registered with ClinicalTrials.gov: NCT01023828. RESULTS: Of the lung cancer patients studied, 95.1% were classified as coming within the NSCLC histology subtype; 58% of the patients smoked cigarettes, 35% had a background of WSE (exposure to both cigarette smoke and wood smoke was documented in 12.1% of all patients), and 19.4% patients had no smoke-exposure background. WSE was associated with NSCLC and adenocarcinoma histology, and was also more frequently associated with epidermal growth factor receptor-mutations than cigarette-smoking patients were (50.0% cf. 19.4%), whereas KRAS mutations were less common in WSE patients (6.7%) than in smokers (21%). WSE patients had a higher epidermal growth factor receptor tyrosine kinase inhibitor response rate (39.7%) than smokers (18.8%). The NSCLC patient WSE group's OS was longer (22.7 months) than that for smokers (13.8 months). CONCLUSION: NSCLC patients who smoked tobacco/cigarettes differed from those having a background of WSE regarding tumor histology, mutation profile, response rate, and OS, indicating that different carcinogenic mechanisms were induced by these two types of smoke exposure.

Treatment outcomes and prognostic factors in mexican patients with endometrial carcinoma with emphasis on patients receiving radiotherapy after surgery: an institutional perspective.

Aim. To analyze the clinical characteristics and treatment outcomes in patients with endometrial carcinoma treated in a Latin American institute with emphasis in patients receiving adjuvant radiotherapy. Methods. A total of 412 patients with endometrial carcinoma admitted to our hospital between 1998 and 2008 were evaluated, retrospectively. The mean age was 55 years (28-87). Two hundred seventy patients received RT following surgery. Stage distribution was as follows: 221 patients (54%) stage I, 86 patients (21%) stage II, and 103 patients (24.5%) stage III and 2 patients (0.5%) stage IVA. Results. Overall survival rate was 95% at 2 years, 84% at 5 years, and 79% at 10 years. By the end of followup, 338 patients (82%) were disease-free, and 13 (3%) were alive with disease. Univariate and multivariate analyses identified age, grade, serosal and adnexial involvement as significant predictors for overall survival. Conclusion. The results of our study suggests that early-stage, low-grade endometrial cancer with no risk factors should not receive external beam radiotherapy, intermediate risk patients should receive only vaginal vault brachytherapy, and the use of chemotherapy with radiotherapy for patients high-risk and advanced-stage carcinoma the addition of radiotherapy is associated with a better survival being an effective therapeutic option.

Oxidative phosphorylation as a target to arrest malignant neoplasias.

Since Warburg proposed in 1956 that cancer cells exhibit increased glycolysis due to mitochondrial damage, numerous researchers have assumed that glycolysis is the predominant ATP supplier for cancer cell energy-dependent processes. However, chemotherapeutic strategies using glycolytic inhibitors have been unsuccessful in arresting tumor proliferation indicating that the Warburg hypothesis may not be applicable to all existing neoplasias. This review analyzes recent information on mitochondrial metabolism in several malignant neoplasias emphasizing that, although tumor cells maintain a high glycolytic rate, the principal ATP production may derive from active oxidative phosphorylation. Thus, anti-mitochondrial drug therapy may be an adequate adjuvant strategy to arrest proliferation of oxidative phosphorylation-dependent neoplasias.

Effectiveness and prognosis of initial pericardiocentesis in the primary management of malignant pericardial effusion.

We retrospectively reviewed the records of 100 patients with malignant disease and symptomatic pericardial effusion initially treated with pericardiocentesis at the National Cancer Institute of Mexico between 1985 and 2009. We analyzed predictive factors for recurrence of pericardial effusion by bi- and multivariate analyses. The group comprised 74 women and 26 men. Twenty patients had developed malignant pericardial effusion at the time of primary cancer diagnosis. Recurrence rate after pericardiocentesis was 33%. Progression-free survival for pericardial effusion at one year was 59% (range, 47-71%). Median overall survival (OS) after pericardiocentesis was 40.3+/-7.9 weeks (95% Confidence interval, 24.9-55.7). The sole factor that correlated with increased progression-free survival for pericardial effusion was the presence of bloody pericardial effusion. For OS, multivariate analysis yielded that female gender and presence of pericardial effusion at time of primary malignancy diagnosis were associated with higher life expectancy. Initial pericardiocentesis can provide successful management of patients with a control rate of 67%. In spite of the high effectiveness of the primary management of pericardial effusion with pericardiocentesis in oncologic patients, it might be considered for initial treatment, especially those with poor prognosis, leaving pericardial window as a secondary strategy for recurrence.

[Usefulness of combining universal oligonucleotides in detecting human papillomavirus in cervical cancer and premalignant lesions]. / Utilidad en la combinación de oligonucleótidos universales para la detección del virus del papiloma humano en cáncer cervicouterino y lesiones premalignas.

OBJECTIVE: To determine the prevalence of human papillomavirus (HPV) infection at different stages of the natural history of cervical cancer. Also, to optimize its detection by means of different sets of general primers. MATERIAL AND METHODS: A descriptive, cross-sectional study was conducted between January and December 1999. Samples were processed and analyzed at the Instituto Nacional de Cancerología (National Cancerology Institute) in Mexico City. A comparative analysis was performed using Student's t for continuous values and the chi-squared test for proportions. A contingency analysis was made between biopsy and cervical exudates with the Kappa statistic. HPV detection was done by PCR with general primers which recognize different regions of the L1 gene (MY09/11; GP5/6; L1C1/2) and with HPV16- and HPV18- specific primers, as well as direct sequencing of PCR products. RESULTS: In total, 154 samples were analyzed: 65 (42.2%) of them showed normal cytology; 45 (29.2%) high and low grade lesions; and 44 (28.6%) invasive cervical cancer. HPV was detected in 95.5% of invasive cervical cancers, in 91.6% of high grade lesions, in 66.7% of low grade lesions, and in 23.1% of normal smears, by PCR with at least one set of oligonucleotide primers. HPV detection was more efficient in biopsy specimens than in cervical scrapes. The total percentage of HPV detection using only one set of universal oligonucleotides (37.6%) increased to 60.4% when the other two sets of universal oligonucleotides were used. CONCLUSIONS: The frequency of high risk HPV is high even in women with reported normal cytology. HPV detection improves when different sets of general primers directed to the L1 region are used. HPV DNA screening in cervical scrapes may be a good alternative HPV diagnostic tool when the samples are appropriately taken.

Utilidad en la combinación de oligonucleótidos universales para la detección del virus del papiloma humano en cáncer cervicouterino y lesiones premalignas / Usefulness of combining universal oligonucleotides in detecting human papillomavirus in cervical cancer and premalignant lesions

OBJETIVO: Determinar la frecuencia y distribución del virus del papiloma humano en los diferentes estadios que conforman la historia natural del cáncer cérvico uterino, y optimizar la detección mediante el uso de diferentes oligonucleótidos universales. MATERIAL Y MÉTODOS: Se trata de un estudio transversal, descriptivo, en el que las muestras fueron colectadas durante enero a diciembre de 1999. El procesamiento de las muestras y el análisis de los datos se realizaron en el Instituto Nacional de Cancerología en la Ciudad de México. Se hizo análisis comparativo con t de Student para valores continuos y con ji cuadrada para proporciones, y análisis de concordancia entre biopsia y exudado cervical con la prueba estadística de Kappa. Para la detección del virus se utilizó la técnica de la reacción en cadena de la polimerasa (PCR) con oligonucleótidos universales los cuales reconocen diferentes regiones del gen L1 (MY09/11; GP5/6; L1C1/2), y oligonucleótidos específicos para el VPH 16 y el VPH 18, así como secuenciación directa de los productos de la PCR. RESULTADOS: Se analizaron 154 muestras: 65 (42.2 por ciento) citologías normales, 45 (29.2 por ciento) lesiones de alto y bajo grado, y 44 (28.6 por ciento) de cáncer invasor. El VPH fue detectado en 95.5 por ciento de los casos de cáncer invasor, en 91.6 por ciento de lesiones de alto grado, en 66.7 por ciento de lesiones de bajo grado y en 23.1 por ciento de citologías normales, por la PCR con al menos uno de los juegos de oligonucleótidos utilizados. La detección fue más eficiente en las muestras obtenidas por biopsia que en los exudados cervicovaginales. El porcentaje total de detección del VPH con un juego de oligonucleótidos universales (37.6 por ciento) aumentó sustancialmente (60.4 por ciento) al combinarlo con otros dos juegos de oligonucleótidos universales. CONCLUSIONES: La presencia del VPH de alto riesgo es elevada inclusive en mujeres con epitelios cervicales con diagnóstico citológico normal. La detección del VPH mejora al utilizar distintos juegos de oligonucleótidos universales que reconocen la región L1 del VPH. Con una adecuada toma de muestra, el análisis para detección de ADN en exudado cérvico-vaginal es una buena alternativa de diagnóstico del VPH.

Lymph node histology in head and neck cancer: impact of immunotherapy with IRX-2.

OBJECTIVE: To determine if lymph nodes (LN) of patients receiving IRX-2 immunotherapy reflect changes in histology. SETTING: National Cancer Institute, Mexico City, Mexico. PATIENTS: Thirty patients with advanced squamous cell carcinoma of the head and neck (H and N SCC) and 10 non-cancer controls. INTERVENTION: A 21-day cycle of preoperative immunotherapy, including a single intravenous infusion of low-dose cyclophosphamide (300 mg/M(2)), 10 or 20 daily perilymphatic injections of a natural cytokine mixture (IRX-2) (approximately 200 U interleukin-2 equivalence by enzyme-linked immunosorbent assay), daily oral indomethacin, and daily oral zinc with multivitamins, followed by surgery (20 patients); surgery only (10 patients); LN biopsy controls (10). OUTCOME MEASURES: Pretreatment biopsies were performed to confirm the diagnosis. Clinical responses were assessed at surgery, and the specimen and a sample of lymph node were analyzed with respect to changes in morphology and lymphoid and inflammatory infiltration (T and B lymphocytes, plasma cells, macrophages, granulocytes, and giant cells). The postsurgical characteristics were ascribed percentages based on a representative section and compared. RESULTS: All 20 H and N SCC patients treated with IRX-2 showed the changes of immune regression of their tumors, previously characterized [Arch. Pathol. Lab. Med. 122 (1998) 447]. The 10 H and N SCC controls showed no such changes. Lymph node histology of the 10 H and N SCC controls showed, compared to non-cancer controls, reduced size, decreased T cell area and density and increased sinus histiocytosis. The lymph nodes of IRX-2-treated H and N SCC patients showed increased size (over both control groups), increased T cell area and density and decreased follicles and sinus histiocytosis. The T cell and/or B cell areas of LN of IRX-2-treated patients showed a high correlation with T and/or B cell infiltration into these tumors (p<0.001). CONCLUSION: The lymph nodes of patients with H and N SCC are distinguished by T cell depletion and sinus histiocytosis (SH). Immunotherapy reverses these changes and induces nodal expansion and lymphoid infiltration into the tumor that correlates with LN changes. The correlation of nodal expansion with tumor lymphoid infiltration and regression implies an effective immunization to host tumor antigens occurring at the level of the regional lymph node. The reversal of sinus histiocytosis, by IRX-2 treatment, in association with nodal expansion suggests that tumor antigen processing via dendritic cells is defective in cancer-bearing patients and that it is corrected by the treatment.

Immunological approach in the evaluation of regional lymph nodes of patients with squamous cell carcinoma of the head and neck.

In cancer, regional lymph node (LN) cells are one of the first components of the immune system to have contact with tumor cells or their products. Therefore, the phenotype and functional properties of hematopoietic cells present within the tumor-draining LN are important to understanding their role in the control of malignant cells. Based on the locoregional metastatic behavior of squamous cell carcinoma of the head and neck (SCCH&N) region, we analyzed tumor-draining lymph nodes from SCCH&N patients to obtain insights into regional tumor immunity. Using a three-color fluorescent labeling technique, surface antigen expression was visualized in mononuclear cells of lymph nodes that were obtained from head and neck cancer patients and compared to mononuclear cells of normal lymph nodes. Cell cycle analyses were performed using propidium iodide. Proliferation after phytohemagglutinin stimulation was measured by a sodium tetrazolium-based assay. LN histology was correlated with flow cytometric findings. Regional lymph nodes of head and neck cancer patients undergo morphologic and functional changes. Flow cytometry revealed a decrease in CD8(+) T cells and in some lymph nodes the presence of second or third populations of larger cells with distinct size and granularity that expressed both T (gammadelta/alphabeta) and different natural killer cell markers. Moreover, cell cycle analyses and proliferation assays showed a diminished response to mitogenic stimuli. These changes were found in both metastatic and hyperplastic lymph nodes from head and neck cancer patients; however, no alterations were found in control lymph nodes or peripheral blood mononuclear cells from noncancer patients. The immune alterations detected in lymphocytes present within the draining lymph nodes of head and neck cancer patients may improve our understanding of how tumor cells escape host immunosurveillance. However, this dysfunction in local draining lymph nodes may not be detected systemically.

Cytoplasmic estrogen and progesterone receptors in cervical carcinoma: comparison of squamous and adenosquamous carcinoma

Introducción. Se ha demostrado que el cérvix uterino normal y tumoral contienen receptores para estradiol (ER) y progesterona (PR). En neoplasias cervicales se han dado resultados controversiales acerca de su presencia y su relación con el pronóstico; sin embargo, no se han establecido conclusiones claras. Nuestro objetivo fue tratar de determinar la posible relación entre la presencia de estas proteínas y el tipo histopatológico en neoplasias cervicales. Material y métodos. Se procesaron 13 muestras de cérvix normal y 55 tumorales (45 epidermoides y 10 adenoescamosos) cuantificando la presencia de ER y PR mediante puntos únicos de saturación con carbón dextrán empleando hormona marcada radiactivamente. Resultados. Se observó un mayor porcentaje de muestras positivas para ER y/o PR en los cérvix normales (ER=62 por ciento y PR=54 por ciento) en comparación a los tumores epidermoides (ER=38 por ciento y PR=44 por ciento) o adenoescamosos (ER=10 por ciento y PR=30 por ciento) (estadísticamente significativo para ER en el tipo epidermoide, p<0.05). No se encontró correlación entre la presencia de estas proteínas y la etapa clínica, edad o estado menstrual de la paciente. Conclusiones. Nuestros resultados sugieren que la presencia de receptores para estrógenos y progesterona se pierde en el cáncer cervicouterino

Carcinoma epidermoide originado en teratoma quístico maduro de ovario. Informe de dos casos y revisión de la literatura / Epidermoid carcinoma derived from mature cystic teratoma of the ovary. Two case presentation and literature review

La frecuencia del desarrollo de malignidad en un teratoma quístico maduro de ovario es de 1-2 por ciento. La mayoría de los casos informados ocurren en mujeres posmenopaúsicas. En este artículo se comunican dos casos de carcinoma epidermoide originado en un teratoma quístico maduro de ovario, uno de los cuales se presentó en una mujer joven. En el otro caso podemos sustentar que el origen del componente carcinomatoso se encuentra en el epitelio columnar y en la epidermis de los tejidos propios del teratoma

Influencia de la ingestión de grasas y la administración de estradiol en el desarrollo de carcinoma mamario inducido con DMBA en ratas / Influence of the ingestion of grease and the estradiol administration in the grow up in mamary carcinoma induce by DMBA in rats

Datos epidemiológicos sugieren que la dieta rica en grasas es un factor promotor en el desarrollo del cáncer mamario y puede esta relacionado con el estímulo estrogénico. El objetivo del presente estudio es demostrar la acción de la dieta grasa en carcinomas mamarios inducidos con 1,2-dimetilbenza(a)antraceno (DMBA) como agente promotor único o asociado con estímulo estrogénico. Se emplearon tres grupos experimentales: 1) Grupo con dieta grasa (DG) con 20 por ciento de aceite de maíz, 2) grupo con dieta normal (DN), ambos ad libitum; y 3) grupo con dieta subnormal (DSN)(10 g alimento diario). Todos con y sin estímulo estrogénico (1 *g diario de 17ß-estradiol). Al comparar los tres grupos se observó que 19 de los 21 (93 por ciento) animales con DG desarrollaron tumores mamarios, con una aparición temprana (novena semana y con el mayor tamaño (6 cm en promedio)(p=0.009). Los grupos DN Y DSN presentaron comportamiento tumoral menos agresivo, en el primer grupo la prevalencia fue de 61 por ciento con un tamaño tumoral de 5.5 cm; en el segundo la prevalencia fue de 41 por ciento, la latencia mucho mayor (aparición promedio a la semana 17) y tamaño tumoral menor (2 cm). Nuestros resultados indican que la dieta rica en grasas es un factor promotor importante e independiente del estímulo estrogénico. En general la estimulación hormonal no provocó cambios significativos en el comportamiento tumoral, aunque cabe destacar que el grupo DG con estímulo estrogénico presentó la mayor prevalencia en comparación con el resto de los grupos.

Primary B cell lymphoma of the rectum in a patient coinfected with HIV-1 and HTLV-I

Este artículo describe el caso clínico de un enfermo con SIDA coinfectado por HTLV-1 que desarrolló un linfoma B del recto, variedad sarcoma inmunoblástico con diferenciación plasmacitoide. Las células malignas mostraron arreglo clonal de los genes de las CP (Jh) y CLk. La infección por el VEB fue demostrada serológicamente y por hibridación de un monitor específico con el ADN genómico de las células cancerosas. No se detectaron secuencias de HTLV-1 en el seno del tumor. Una remisión clínica completa, pero temporal, se obtuvo con siete ciclos de VACO-B. El enfermo abandonó el tratamiento y la sobrevida se desconoce.

Clinical, histologic and genetic characterization of non-Hodgkin's lymphomas in mexicans

En este artículo describimos la distribución anatómica, las características histológicas y moleculares de 32 casos de LNH. La estadificación clínica y clasificación histológica por grados se hizo de acuerdo a esquemas aceptados convencionalmente. Los arreglos detectados en genes que codifican para Ig o el RcT sirvieron para identificar la estirpe celular y el estadio de diferenciación de las células neoplásicas. El análisis de 26 muestras de suero reveló la existencia de anticuerpos contra epítopes de EBV; ocho de estos pacientes contenían secuencias virales integradas en el genoma del tumor. Nuestros estudios indican que el uso de diferentes métodos es fundamental para profundizar en el conocimiento de la historia natural de los LNH.