Infiltración linfocitaria tumoral como factor de buen pronóstico de supervivencia en pacientes con cáncer gástrico localmente avanzado / Tumor lymphocytic infiltration as a good prognostic factor for survival in patients with locally advanced gastric cancer

Introducción: La relación entre supervivencia e infiltración linfocitaria en el cáncer gástrico se ha determinado como factor pronóstico beneficioso, este estudio local tiene como objetivo determinar la probabilidad de supervivencia en los pacientes con cáncer gástrico estadios IB al IIIC de acuerdo con el porcentaje de infiltración linfocitaria tumoral. Metodología: El presente estudio longitudinal se realizó en el Hospital Oncológico Solón Espinosa Ayala Solca-Núcleo de Quito. El período de estudio de enero del 2013 a enero del 2016, el tiempo de seguimiento terminó en diciembre del 2018. El cálculo de la muestral fue no probabilístico en donde se incluyeron casos de pacientes mayores a 18 años con diagnóstico de cáncer gástrico con estadios clínicos IB al IIIC, que contaron con una muestra histopatológica de gastrectomías. Se usó la variable: "Porcentaje de infiltración" para el análisis la muestra y se dividió en 3 grupos: G1: infiltración linfocitaria leve, G2: moderada y G3: intensa. Las estimaciones de supervivencia se calcularon utilizando el método de Kaplan-Meier y la comparación entre los grupos con la prueba de rango logarítmico. Resultados: 173 pacientes con cáncer gástrico con estadios clínicos IB al IIIC, seguidos a 72 meses, el 60 % son hombres y el 40 % mujeres. Según el porcentaje de infiltración linfocitaria, el 52 % reportaron un porcentaje de infiltración leve, el 21 % moderada y el 27 % intensa. A los 72 meses de seguimiento la supervivencia en G1 fue del 31 %, en G2 fue del 48 %, y en G3 fue del 77 % (P= 0.001). Conclusión: Se encontró que el grado de infiltración linfocitaria intensa en los pacientes con cáncer gástrico estuvo asociado a una mejor supervivencia en el seguimiento a 72 meses.

Introduction: The relationship between survival and lymphocytic infiltration in gastric cancer has been determined to be a beneficial prognostic factor. This local study aims to assess the probability of survival in patients with gastric cancer stages IB to IIIC according to the percentage of lymphocytic infiltration. Methodology: This longitudinal study was conducted at the Solón Espinosa Ayala Solca-Núcleo Cancer Hospital in Quito. The study period was from January 2013 to January 2016; the follow-up time ended in December 2018. The sample calculation was nonprobabilistic and included cases of patients older than 18 diagnosed with gastric cancer with clinical stages IB at IIIC, which had a histo-pathological sample of gastrectomies. The variable "percentage of infiltration" was used to analyze the sample, and it was divided into three groups: G1: mild lymphocytic infiltration, G2: moderate, and G3: intense. Survival estimates were calculated using the Kaplan­Meier method and compared groups with the log-rank test. Results: A total of 173 patients with gastric cancer with clinical stages IB to IIIC were followed up for 72 months; 60% were men, and 40% were women. According to the percentage of lymphocytic infil-tration, 52% reported a rate of mild infiltration, 21% moderate, and 27% intense. At 72 months of follow-up, survival was 31% in G1, 48% in G2, and 77% in G3 (P= 0.001). Conclusion: The degree of intense lymphocytic infiltration in gastric cancer patients was associated with better survival at the 72-month follow-up.

Propylthiouracil-induced hypothyroidism delays apoptosis during the first wave of spermatogenesis

Mammalian germ cell apoptosis plays a key role in controlling the correct number of germ cells supported by Sertoli cells during the first wave of spermatogenesis in mammalian puberty. However, little is known about hormonal factors that could influence the rate of germ cell apoptosis during puberty or adulthood. In this work we evaluate germ cell apoptosis under hypothyroidism induced by goitrogen propylthiouracil (PTU) during the first wave of spermatogenesis. Neonatally administered PTU promoted a delay in the differentiation of Sertoli cells as evaluated by the expression of clusterin using immunohistochemistry and RT-PCR. Clusterin had different expression levels in control and PTU-treated animals, but under both conditions the highest levels were found in 35-day-old rats. In addition, clusterin displayed a cytoplasmic localization in control testes, but appeared located in the nucleus in PTU-treated animals. The wave of apoptosis (determined by caspase activity and quantification of apoptotic cells) characteristic of the first round of spermatogenesis was delayed by at least 10 days in these animals. The expression levels of proapoptotic genes like BAX or BAD were different between control and PTU-treated rats; although in both groups the highest level was found at the same age (days). Thus our results indicate that the characteristic pubertal apoptotic wave during rat spermatogenesis is delayed in neonatal hypothyroid rats.