Valor pronóstico de determinados marcadores biológicos en la supervivencia global y la respuesta al tratamiento del cáncer de mama con metástasis pleurales

Objective: 1. To study what type of biological markers have prognostic value in the global survival rate and response to treatment of breast cancer, regarding discovery of pleural metastases. 2. To examine the influence of the application of intrapleural talc. 3. To establish a therapeutic approach outline based on the different prognostic factors. Patients and methods: we studied a series of 126 patients with breast cancer and pleural metastasis. The classic factors of breast cancer were thoroughly examined. Also, we calculated the disease-free interval (DFI), the interval between the appearance of the pleural effusion and its thoracoscopic approach, the interval between pleurodesis with talc and death and the interval between the diagnosis of the first tumour and death. The biological factors (polymorphisms) were studied starting with the DNA of peripheral blood samples or cryopreservation of pleural liquid samples. Results: the pleural effusion was the first manifestation of a relapse of the disease in 77% of the cases. The disease-free interval (DFI) was 57.9 months (13.6-83.3). The survival rate (expressed as median) from the diagnosis of the first tumour was 77.5 months (0.83-384). The average follow-up after the application of talc was 14.6 months. We found a correlation between the appearance of breast cancer (p=0.003) at a young age and the presence of the A2/A2 allele (homozygote of the CYP-17). Conclusions: the ideal profile for candidates for pleurodesis is those patients with an age >50 years, long DFI, short interval of time between the appearance of the pleural effusion and the application of talc, absence of other metastasis at the time of thoracoscopy, positive ER (estrogen receptors) and PR (progesterone receptors) and a percentage of lymph nodes infiltrated/extracted less than 50%. The presence of mutated GSTM1 will be related with a more effective pleurodesis, and the presence of the A2/A2 allele is related with earlier manifestation of neoplasm.