Gene polimorphisms and biological factors as possible predictors for patients with pleural metastatic breast cancer

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Background: Pronosis of breast cancer varies widely in patients with similar clinical features. Therefore, we investigated other factors with possible prognostic value. The CYP17 gene has a polimorphism related to a increased susceptibility to breast cancer (single T; A1 allele to C; A2 allele). ( Mitrunen et al. Cancer Epidemiol Biomarkers Prev 2000,9;12;1343–8). On the other hand, it has been found in the MTHFR gene a common C-T substitution at nucleotide 677 that is associated with reduced enzyme activity and increased risk of breast cancer (Capmbell et al., Breast Cancer Research 2002;4,6:R14). Other genes such as GSTT1 and GSTM1 variant genotypes have a controversial association to breast cancer. We have analyzed the genotype and biological factors in a group of patients with pleural metastatic cancer of the breast and compared it to a control group of women with no cancer. Methods: Forty-six patients with breast cancer and forty women as controls were includes in the study. Age at diagnosis of the primary tumor, TNM staging, interval free of disease, estrogen and progesteron receptors, Ki67, p53 and Her-2neu expression were recorded, as well as survival from the time of diagnosis and polimorphism of CYP17, MTHFR, GSTT1 and GSTM1 genes. Results: Mean survival differed significantly between patients having pleural effusion as the first site of relapse as compared to those with other sites of relapse (28’9 vs 11’9 months, p = 0’004). A high Ki67 expression correlated best with longer survival after talc pleurodesis. We detected a high frequency in the CYP17 A2 variant genotype in patients with metastatic breast cancer compared to the control group. As for MTFHR gene, we found a high frequency for the T/T genotypes variant in breast cancer group. No significant differences between control and cancer group were found in either GSTT1 and GSTM1 gene variations. Conclusions: Genotype and biological factors, such as factors investigated in this study, play an important role as predictors for patients with pleural metastatic breast cancer.

No significant financial relationships to disclose.

Lung cancer and ipsilateral pleural effusion

Lung cancer presenting with ipsilateral pleural effusion is considered to have a poor prognosis. Thoracoscopy has been invoked as a useful tool for staging those cases before proceeding to thoracotomy, especially in patients with large pleural effusions. In cases where there is only a small effusion or no effusion at all, direct thoracotomy would be the choice, with pleural lavage during the operation and immediate cytology investigation. We performed thoracoscopy in 76 patients with lung cancer and ipsilateral pleural effusion (55 cytologically positive and the remaining negative), and we found only five cases with potentially resectable tumor. They were submitted to thoracotomy and resection could be accomplished in none of them, due to direct mediastinal tumor invasion. On the other hand, we found visceral pleura involvement without effusion in 31 out of 167 patients submitted to thoracotomy for lung cancer in our Institution. The tumor could be resected in all but one of these cases. Talc pleurodesis was performed in all patients who were found to have pleural effusion and non-resectable tumor at thoracoscopy, and we obtained a 68% success rate in cases with no trapped lung, as opposed to 56% in patients with trapped lung (massively covered by fibrin and/or tumor). Pleural fluid glucose and pH are good predictors of the outcome of pleurodesis.