BackgroundBreast cancer is a complex multifactorial genetic disease. Among other factors, race and, to an even greater extent, viruses are known to influence the development of this heterogeneous disease. It has been reported that MMTV-like (HMTV) gene sequences with a 90 to 98% homology to mouse mammary tumor virus are found in several populations with a prevalence range of 0 to 74%. In the Mexican population, 4.2% of patients with breast cancer exhibit the presence of HMTV (MMTV-like) sequences. The aim of this study was to evaluate the presence and current prevalence of retroviral HMTV (MMTV-like) sequences in breast cancer in Mexican women.MethodsWe used nested PCR and real-time PCR with a TaqMan probe. As a positive control, we used the C3H MMTV strain inserted into pBR322 plasmid. To confirm that we had identified the HMTV sequences, we sequenced the amplicons and compared these sequences with those of MMTV and HMTV (GenBank AF033807 and AF346816).ResultsA total of 12.4% of breast tumors were HMTV-positive, and 15.7% of the unaffected tissue samples from 458 patients were HMTV-positive. A total of 8.3% of the patients had both HMTV-positive tumor and adjacent tissues. The HMTV-positive samples presented 98% similarity to the reported HMTV sequence.ConclusionsThese results confirm that the HMTV sequence is present in breast tumors and non-affected tissues in the Mexican population. HMTV should be considered a prominent causative agent of breast cancer.
Evaluar la tasa de respuesta patológica completa (RPc) posterior a la quimioterapia neoadyuvante (QN) con antraciclinas con o sin taxanos en el manejo del cáncer de mama localmente avanzado (CMLA). Método: Se incluyeron pacientes con CMLA. Una cohorte recibió cuatro ciclos de FEC (5-fluorouracilo 500 mg/m 2 , epirubicina 75 mg/m 2 , ciclofosfamida 500 mg/m 2 ) cada 3 semanas seguido por cuatro ciclos de docetaxel (D) 75 mg/m 2 en infusión intravenosa de 1 hora cada 3 semanas. Otra cohorte recibió seis ciclos de FE 100 C (500, 100 y 600 mg/m 2 ). Se realizó cirugía posterior a la quimioterapia. resultados: No hubo diferencia estadísticamente significativa en las tasas de respuesta objetiva (78.5 vs. 85.0%; p = 0.299) ni en la respuesta clínica completa (20.6 vs. 33.3%; p = 0.103) para 4FEC→4D comparado con 6FE 100 C, respectivamente. En cambio, hubo una mejora significativa en la tasa de RPc (30.2 vs. 16.7%; p = 0.049) y en los ganglios linfáticos axilares negativos (51.6 vs. 35%; p = 0.03) para 4FEC→4D en comparación con 6FE 100 C, respectivamente. La toxicidad grave fue baja y no significativa en ambas cohortes. Los modelos multivariados de regresión logística mostraron que los principales predictores significativos para obtener una RPc fueron la QN con 4FEC→4D (odds ratio [OR]: 2.7; p = 0.019) y el estadio IIIA (OR: 3.8; p = 0.002). Conclusión: Este estudio mostró que el régimen 4FEC→4D con dosis convencional es muy activo y bien tolerado en pacientes con CMLA en nuestro hospital.
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