Detección y tipificación de virus papiloma humano en lesiones preneoplásicas de cuello uterino / Human papillomavirus genotyping of cervical uterine preneoplastic lesions in a high risk area

The relationship between human papillomavirus (HPV) and uterine cervical cancer (UCC) is widely known and accepted. Aim: To determine the frequency of genotypes of HPV in cervical preneoplastic lesions in a high risk area of UCC. Material and Methods: Using a combination of PCR and Reverse Line Blot technique, 235 formalin fixed paraffin embedded samples, with diagnosis of low-grade squamous intraepithelial lesion (LSIL) or high-grade squamous intraepithelial lesion (HSIL) were genotyped. Results: HPV was detected in 61.2 percent of LSIL and 78.1 percent of HSIL. The main genotypes found were HPV 16, 18, 31, 45, 56 y 58. HPV 16 was the most common in both LSIL (18.1 percent) and HSIL (36.9 percent). HPV 16 or 18 were present in 25.1 percent and 47.1 percent of the LSIL and HSIL respectively. In both LSIL and HSIL, the predominant viral genotypes were those types classified as with a high oncogenic risk. Conclusions: HPV genotypes 16, 18, 31, 45, 56 y 58 were the most common in our series. HPV 16 and 18, viral types with high oncogenic risk and included in commercial vaccines, were found in 25.1 percent and 47.1 percent of LSIL and HSIL, respectively.

Genotipificación del virus papiloma humano en mujeres con adenocarcinoma cervical de la Región de La Araucanía-Chile / Human papillomavirus genotyping in cervical adenocarcinoma in the Region of La Araucanía-Chile

El virus papiloma humano (VPH) es el principal factor causal del cáncer cervicouterino (CCU). Así, detectar y genotipificar el VPH es importante para conocer la frecuencia de los genotipos presentes en la región. En este trabajo se estudiaron 44 biopsias de adenocarcinoma cervical (ACC). Para la detección del VPH se empleó una reacción de polimerasa en cadena anidada dirigida al gen L1 (RPCL1), para la genotipificación viral se utilizaron enzimas de restricción (Rsa I, Dde I, Pst I) y secuenciación. Se detectó ADN viral mediante RPCL1 anidada en 100 por ciento de las biopias. Se logró tipificar 38/44 casos: 81,6 por ciento VPH 16; 13,2 por ciento VPH 18; 2,6 por ciento VPH 33 y 2,6 por ciento VPH 18/33. Conclusiones: La metodología fue exitosa para identificar el tipo viral en 86 por ciento de las biopsias. Se observó una estrecha asociación ACC-VPH, especialmente con el tipo viral 16, detectado en 81,6 por ciento de los casos tipificados.

Human papillomavirus (HPV) is the main cause of cervical cancer. Thus, HPV detection and typing becomes important in order to know the frequency of genotypes present in the region. In this paper we studied 44 biopsies of cervical adenocarcinoma. For HPV detection nested polymerase chain reaction (PCR) was used to amplify the L1 gene. For viral typing restriction enzymes (Rsa I, Dde I, Pst I) and DNA sequencing were used. Viral DNA was detected by nested L1 PCR in 100 percent of biopsies; 38/44 cases could be typed: 81.6 percent HPV16; 13.2 percent HPV 18; 2.6 percent VPH 33 and 2.6 percent HPV 18/33. Conclusions: The technique was successful in identifying the virus type in 86 percent of biopsies. There was a strong association ACC-HPV, especially with the viral type 16, detected in 81.6 percent of established cases.

Detección y tipificación de virus papiloma humano en lesiones preneoplásicas del cuello uterino mediante PCR-RFLP / Detection and typification of human papilloma virus in pre cancerous cervical lesions

Background: The association of different genotypes of human papilloma virus (HPV) with cervical cancer is well known. However, there is little information about their association with pre-cancerous lesions. Aim: To assess the frequency of different HPV genotypes in pre cancerous cervical lesions. Material and methods: A cervical sample was obtained by cytobrush in 15 women with low grade lesions and 40 women with high grade lesions, subjected to conization by loop electrical excision procedure (LEEP). Detection and typification of HPV was done by polymerase chain reaction and restriction fragment length polymorphism. Results: All women were infected with HPV. Eighty five percent of samples were typified. A unique HPV subtype was found in 76 percent of women. Fourteen percent had an infection with multiple subtypes and in 10 percent, the viral genotype was not identified. The most common subtypes found were HPV 16, HPV 52 and HPV 53. Conclusions: There is a high rate of infection with HPV with a high oncogenic risk among these women.

Inestabilidad microsatelital en lesiones preneoplásicas y neoplásicas del cuello uterino: Correlación con el genotipo del virus papiloma humano / Microsatellite instability and human papilloma virus genotypes in preneoplastic and neoplastic uterine cervix lesions

Background: The association between some specific human papilloma virus (HPV) types and cervix cancer is well known. However, the genetic conditions that favor the development of cervical cancer are less well known. Aim: To determine the presence of satellite instability (MSI) in preneoplastic and neoplastic lesions of the cervix and correlate these findings with HPV genotypes. Material and methods: Biopsy samples of cervical lesions were studied. Sixteen had low grade lesions, 22 had high grade lesions and 28 had an epidermoid cancer. Viral types were identified with polymerase chain reaction, dot-blot hybridization and restriction fragment length polymorphism. MSI was determined using a panel of eight highly informative microsatellites. Results: Microsatellite instability in at least one locus was observed in 91, 56 and 69 percent of low grade lesions, high grade lesions and epidermoid carcinomas, respectively. MSI-High grade, MSI-Low grade instability and microsatellite stability were observed in 5, 60 and 46 percent of samples, respectively. Two of three samples with high grade instability had HPV 52 genotype. Other viral subtypes had frequencies that ranged from 78 percent to 100 percent, with the exception of HPV16 that was present in only 53 percent of samples with low grade instability. Conclusions: Two thirds of biopsy samples from cervical lesions had MSI, mechanism that can be involved in the first stages of cervical carcinogenesis. The low frequency of high grade instability, its association with HPV52 and the low frequency of HPV16 in samples with low grade instability, suggest different coadjutant mechanisms in cervical carcinogenesis

Estudio comparativo de detección del virus papiloma humano (VPH) en muestras citológicas y biopsias de cuello uterino / Detection of human papilloma virus in cytologic samples or biopsies of the cervix

Background: The DNA quality for the detection and typification of Human Papilloma Virus (HPV) varies according to the type of sample in which it is studied. This may affect the sensitivity and specificity of the method employed. Aim: To study the yield and specificity of HPV detection and typification in uterine cervical samples obtained by cervical brushing fresh frozen and formalin fixed tissue. Material and methods: Cytological, fresh frozen and fixed tissue samples from 44 patients (nine with low grade lesions and 35 with high grade lesions) were studied. Nested polymerase chain reaction for genes E6/E7 was used to typify HPV groups as low risk or high risk. Results: Of all the cytological samples obtained by brushing 84% of fixed samples and 43% of fresh frozen samples were positive for HPV. The yields were significantly different when comparing brushing with fixed tissue or fresh frozen tissue and fixed tissue with fresh frozen tissue (p <0.05). The frequency of high risk HPV fluctuated from 41% in fresh frozen tissue to 98% in cytological samples. Low risk HPV was detected in 16% of fresh frozen tissue and 68% of cytological samples. A mixed infection was detected in 66%, 41% and 14% of cytological, fresh frozen and fixed tissue samples respectively. Conclusions: Cytological samples obtained by brushing had the highest yield for the detection of cervical infection with HPV.

Tipificación del virus papiloma humano (VPH) en lesiones preneoplásicas y carcinoma del cuello uterino en mujeres de la IX Región-Chile / Human papilloma virus (HPV) typing in preneoplastic and neoplastic lesions of the uterine cervix in the IX region-Chile

Background: Uterine cervical cancer (UCC) is an important public health problem in Chile. Although HPV infection has been established as the main cause of UCC, little is known of its frequency and distribution in our population. Aim: To determine the presence and frequency of viral genotypes in uterine cervical specimens with preneoplastic and neoplastic lesions. Material and Methods: Two nested consensus PCRs followed by identification of amplified product by dot-blot hybridization and restriction fragment length polymorphism (RFLP) were used to analyze 175 biopsies. Results: Detection of HPV was 40% in cases without histological lesion, 88% in low grade lesions, 89% in high grade lesions (HGL) and 93.5% in invasive carcinoma. Of all HPV positive cases, 89.5% were classified as high risk and only a 4.9% of HPV cases were of low risk type. Six percent of cases had multiple infections. Distribution of viral genotypes according to RFLP was: HPV33 (25.3%), 16 (18.7%), 52 (13.3%), 31 (12%), 35 (6.6%), 18 (2.7%). Conclusions: Most HPV found in biopsies with HGL and UCC were of high risk genotype. The elevated presence of high risk HPV in patients without cervical lesions may be a factor that explains the high percentage of UCC cases in our region. Most common viral types were: HPV16, 31, 33 and 52. Viral detection and typing may provide valuable information for patient selection and follow up and for allocation of resources (Rev Méd Chile 2003; 131: 1382-90).

Programa de detección y control de cancer uterino en Servicio de Salud Araucanía Sur / Detection and control program of uterine cancer in Servicio de Salud Araucanía Sur

Se analizan algunas caracteríticas del Programa de Cáncer de Cuello Uterino en el SS Araucania Sur. Se revisan los registros estadísticos de la Unidad de Oncología y Ginecología y de la Oficina de Informática del Servicio de Salud. Se aprecia que el cáncer de cuello uterino constituye el 68.19 por ciento de los cánceres ginecológicos, que la cobertura citológica promedio es de 56.2 por ciento, la focalización citológica en grupo de 25-64 años ha mejorado hasta un 89.67 por ciento, la proporción CIS/Ca incasor se ha incrementado desde 0.12 a 1.35, las etapas precoces de invasión (etapaI) ascendieron hasta el 62.5 por ciento, la mortalidad ha tenido un descenso de 34 por ciento (14.45 x 100000 en 1991, 9.46 x 100000 en 2000). Subsisten problema de calidad de la muetra citológica, necesidad de aumentar su cobertura y bajar en forma aun más significativa la mortalidad, objetivo último del programa

Histeroscopia en el estudio preoperatorio del cáncer de endometrio / Hysteroscopy in the preoperatory study of the endometrial cancer

Se estudia con histeroscopia en forma previa a la etapificación quirúrgica a 43 pacientes que ingresaron con el diagnóstico de cáncer de endometrio al Hospital Regional de Temuco, centro de referencia regional de la novena región de la Araucanía Chile, durante 43 meses comprendidos entre 1994 y 1997 de un universo de 52 pacientes. Se compara la extensión tumoral en superficie visto en el examen histeroscópico con el grado de penetración tumoral en miometrio informado en la pieza uterina postoperatoria e informada por el anátomo patólogo. Además se evalúa el estudio histeroscópico del canal cervical en pacientes con cáncer de endometrio. Se puede evidenciar una relación significativa entre la mayor extensión del tumor en superficie y la mayor penetración miometrial. Por otra parte el estudio histeroscópico tiene una sensibilidad de un 100 por ciento y una especificidad de un 87 por ciento para evaluar el compromiso del canal cervical. Llama la atención las características epidemiológicas del grupo, en donde se observan pacientes jóvenes, multíparas y no obesas

Carcinoma epidermoide de cuello uterino: anormalidades moleculares de los genes p53 y rb / Epidermoid carcinoma of the uterine cervix: molecular abnormalities of p53 and rb genes

The inactivation of p53 and rb genes has been implicated in the pathogenesis of cervix uteri carcinoma. Although this neoplasia presents high incidence and mortality rates in Chile, there are not studies about its molecular abnormalities. We investigated the frequency of loss of heterozygocity (LOH) at p53 and rb genes in 17 invasive aquamous cell carcinomas of the cervix uteri, using microdissection technique from microslides and microsatellite sequences amplification by PCR. Moreover, we investigated the immunohistochemical expression of p53 protein in 30 invasive squamous cell carcinomas. LOH was detected in 6/12 of informative cases (50 percent) at p53 gene and in 3/10 (30 percent) at rb gene. The p53 protein immunohistochemical expression was 47 percent (14/30 cases). LOH at p53 gene in cases without p53 protein immunohistochemical expression was observed. We concluded that p53 gene molecular abnormalities are important in the pathogenesis of squamous cell carcinoma of the cervix uteri in contrast than LOH at rb gene

Antígeno nuclear de proliferación celular en cáncer de cuello uterino y lesiones precursoras / Nuclear antigen of cellular proliferation in uterine cervix cancer and precursor lesions

The aim of this study was to study the degree of cellular proliferation quantifying the immunohistochemical expression of the proliferating cell nuclear antigen. We assessed paraffin embedded samples od 25 infiltrating epidermoid cervical carcinomas, 76 precursor lesions (34 of low and 42 of high grade), 29 normal and 13 metaplastic epidermoid epithelia. Mean values of proliferating cell nuclear antigen expression were 13.7 percent in normal epithelia, 15.7 percent in epidermoid metaplasia, 37.1 percent in low grade precursor lesions (35.3 percent in condilomas and 38.8 percent in mild dysplasia), 48.7 percent in high grade lesions (47.9 percent in moderate dysplasia, 50.5 percent in severe dysplasia and 50 percent in carcinoma in situ) and 54.7 percent in infiltrating carcinoma. There were differences in proliferating cell nuclear antigen expression and mitotic index between low grade precursor lesions and high grade lesions and infiltrating carcinoma. No correlation was observed between mitotic index and proliferating cell nuclear antigen expression. We conclude that infiltrating epidermoid cervical carcinoma and its precursor lesions have a high level of proliferative activity, demonstrated by a high percentage of cells in active phases of the cellular cycle

Mutaciones del gen K-ras y expresión inmunohistoquímica de la proteína ras-p21 en cáncer de cuello uterino / Mutations of K-ras gene and immunohistochemical expression of ras-p21 protein in cervix uterine cancer

Con el objeto de determinar las alteraciones moleculares que intervienen en la patogenia del cáncer de cuello uterino en Chile, se estudió la incidencia de mutaciones puntuales del gen K-ras (cordones 12, 13 y 61) en 16 carcinomas epidermoides infiltrantes, mediante técnicas de microdisección de tejidos, PCR y RFLP. Además se estudió la expresión inmunohistoquímica de la proteína ras-p21 en 12 carcinomas epidermoides infiltrantes, 51 neoplasias intraepiteliales (NIE), 15 condilomas y 10 epitelios epidermoides normales. Se detectó mutación del codón 12 en 3/16 (19 por ciento) de los carcinomas invasores (transversión G a T), sin mutación en los restantes codones. Se encontró expresión inmunohistoquímica de la proteína ras-p21 sólo en 58 por ciento de los carcinomas infiltrantes y en 19 por ciento de las NIE III. Aunque la mutación puntual del gen K-ras pareciera no ser muy relevante en la patogenia de esta neoplasia la constante transversión G a T observada en los 3 casos con mutación del codón 12 sugiere que puede ser importante para un grupo de casos que se requiere identificar. La expresión inmunohistoquímica de la proteína ras-p21 permitiría diferenciar entre carcinoma infiltrante y sus lesiones precursoras

Expresión inmunohistoquímica del receptor del factor de crecimiento epidérmico RFCE en carcinoma epidermoide de cuello uterino y sus lesiones precursoras / Immunohistochemical expression of the epidermal growth factor receptor EGFR in cervical epidermoid carcinoma and its precursor lesions

Se determinó la expresión inmunohistoquímica del receptor del factor de crecimiento epidérmico en 24 carcinomas epidermoides infiltrantes de cuello uterino, 81 lesiones precursores, 47 de bajo y 34 de alto grado, 20 epitelios epidermoides normales, 11 epitelios epidermoides metaplásicos y 14 adenocarcinomas. Además, en 30 casos de estas lesiones se determinó mediante hibridación in situ la infección por tipos de VPH 6/11, 16/18 y 31/33/35. Se encontró mayor expresión de RFCE en lesiones de alto grado 64,7 por ciento, particularmente displasia moderada 72,2 por ciento, que en los epitelios controles 19,1 por ciento, lesiones de bajo grado 44,7 por ciento y carcinoma infiltrante 45,8 por ciento, con diferencias estadísticamente significativas sólo con los controles p<0,02. No se encontraron diferencias en la expresión de RFCE entre carcinoma epidermoide y nada, al menos inicialmente, al desarrollo del carcinoma de cuello uterino. por otro lado, el mayor porcentaje de infección de VPH tipos 16/18 que los otros tipos virales, en lesiones con expresión de RFCE, sugiere alguna asociación entre ambos factores

Dos casos infrecuentes de presentación del cáncer de endometrio / 2 atypical presentation cases of the endometrial cancer

Se analizan dos casos de cáncer de endometrio de presentación atípica, el primero en una mujer con radioterapia pelviana previa por un cáncer cérvicouterino, y el segundo en una paciente con antecedentes de terapia coadyuvante con tamoxifeno por un cáncer de mama. Se discute el riesgo de hacer segundos primarios en pacientes ya tratadas por una neoplasia y la eventual asociación de radioterapia pélvica y tamoxifeno con la subsiguiente aparición de un cáncer de endometrio

Efectos inmediatos del programa de control de cáncer cérvicouterino sobre la morbilidad en la IX Región de la Araucanía / Immediate effects of the cervico uterine cancer control program on morbidity in the IX Region of Araucanía

Se efectuó un estudio de los pacientes con patología cervical, neoplasia invasora y preinvasora, analizándose las diferencias en los casos sin citología previa (grupo de prevalencia) y en los casos con una o más citologías normales previas (grupo de incidencia). Se encontraron efectos positivos del programa de detección de cáncer de cuello uterino, revelado por la disminución en la frecuencia relativa de cánceres invasores, por estadios clínicos menos avanzados y por edad más precoz de diagnóstico en mujeres con citología previa normal. Una disminución de la tasa de mortalidad es el objetivo del programa a largo plazo