Juan Antonio Santos Miranda

We model the interaction between the immune system and tumor cells including a time delay to simulate the time needed by the latter to develop a chemical and cell mediated response to the presence of the tumor. The results are compared with those of a previous paper, concluding that the delay introduces new instabilities in the system leading to an uncontrolable growth of the tumour. Then a cytokine based periodic immunotherapy treatment is included in the model and the effects of its dossage are studied for the case of a weak immune system and a growing tumour. We find the existence of metastable states (that may last for tens of years) induced by the treatment, and also of potentially adverse effects of the dossage frequency on the stabilization of the tumour. These two effects depend on the delay, the cytokine dose burden and other parameters considered in the model.

Metastability

10.48550/arxiv.q-bio/0604008

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Radioterapia tras prostatectomía radical: factores descriptivos, evolutivos y de pronóstico en una práctica asistencial emergente

Archivos Españoles de Urología (2007)

Maria Victoria De Torres Olombrada Carmen González San Segundo Juan Antonio Santos Miranda Carmen Ibáñez Villoslada Juan Ignacio Martínez‐Salamanca

OBJECTIVES: Recently it has been reported in the EORTC (European Organisation for Research and Treatment of Cancer) trial 22911 and the SWOG (Southwest Oncology Group) 8794, the evidence that radiotherapy (RT) is an effective treatment after the prostatectomy in patients with high risk of biochemical failure. We analyze predictor factors of biochemical relapse and the potential benefits induced by rescue treatment are the main purposes of our study. METHODS: From 1993 to 2003, 597 prostatectomy were followed at Hospital Universitario Gregorio Marañón de Madrid, identifying 166 patients (p) (28%) of biochemical failure (defined as PSA ≥0’5 ng/ml, including post-surgical persistent values). 42 p received RT (78% due to delayed PSA relapse). The median total dose was 66 Gy [60-74].RESULTS: Clinical variables: Median age: 68 years [49-80], median PSA at diagnosis: 29,8 ng/ml [2,6-475]; presurgical Gleason ≥7: 65%. Histological variables: Prostatectomy induces stage migration to superior T (pT3-T4: 95%) and Gleason categories (≥7: 81%). 83% of relapsed p had positive margins and 90% had pT3-pT4. Outcome variables: median time to biochemical recurrence was 22,2 months. Median time interval between biochemical failure and RT was 10,5 months. Overall survival (5 years) was 86±6%. Freedom-frombiochemical failure at 5 years was 76±4%. RT had poor survival in p with PSA >2 ng/ml preRT (p=0,03), post-prostatectomy persistant disease (p=0,05) and Gleason score ≥7 (p=0,01). No increased grade 3-4 uro-rectal toxicity was observed. CONCLUSIONS: RT after prostatectomy improves freedom-from-biochemical failure in p with PSA values below 2 ng/ml. In our experience, Gleason score ≥7 is a negative predictor of response. There is no severe toxicity in our series. Improvement of the staging presurgery, the role of the adjuvant androgen deprivation and selection of patients for adjuvant RT focus current studies on treatment after prostatectomy.

10.4321/s0004-06142007000600004

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Retrasos e interrupciones: La dificultad para irradiar en el tiempo ideal

Clinical & Translational Oncology (2005)

Carmen González San Segundo Felipe A. Calvo Juan Antonio Santos Miranda

10.1007/bf02710009

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El Siempre Controvertido Tratamiento del Cáncer de Pulmón Inoperable

Revista de Oncología (2001)

Carmen González San Segundo Juan Antonio Santos Miranda