Study objective: To find out whether patients with different types of metastatic pleural carcinomas have significant differences in survival, as related to pleural fluid glucose and pH. A second objective was to evaluate the outcome of talc poudrage for pleurodesis.
Design: Cohort analytic prospective study; follow-up of patients from thoracoscopic diagnosis and evaluation to death.
Setting: Pulmonary department at a referral medical center.
Patients: One hundred twenty-five patients with metastatic pleural carcinoma diagnosed by thoracoscopy were evaluated prospectively. One patient was lost to follow-up.
Interventions: Thoracoscopy was performed in every patient, with talc pleurodesis performed at the end of each procedure.
Measurements and results: On the same day as thoracoscopy or the previous day, glucose levels and pH of both the blood and pleural fluid were determined. The outcome of talc poudrage was that pleural effusions were controlled in 104 out of 119 patients (87 percent). Pleurodesis failed in 43 percent (6/14) of the patients with a pleural fluid pH lower than 7.20, as opposed to 9 percent (8/92) of failures in patients with a pH above this limit (p < 0.01). Average survival was as follows: nonsmall cell lung cancer (n = 40), 4.3 months (range, 1 to 15 months); small cell lung cancer (n = 8), 3.7 months (1 to 12 months); breast carcinoma (n = 30), 7.4 months (1 to 29 months); and ovarian carcinoma (n = 8), 9.4 months (1 to 29 months). There was a significant difference in survival between patients with breast carcinoma and patients with cancer not sensitive to chemotherapy (7.4 vs 4.7 months; p < 0.02), although the pleural tumor lesion rating was even greater in the first group. We found no significant differences between lung carcinomas and those from other origins. Patients with a low pleural fluid glucose level and low pH had significantly shorter survival than the group with high glucose and high pH levels (1.9 vs 5.7 months, respectively; p < 0.005).
Conclusions: We confirmed our previous data demonstrating poor survival in patients with pleural effusions with low glucose and pH levels. The outcome of talc pleurodesis correlated to these same parameters. These results apply to all kinds of metastatic pleural carcinomas.