Differences according to age and sex among patients with malignant pleural effusion as a presentation form of cancer

OBJECTIVE: To analyze the characteristics of patients diagnosed of malignant pleural effusion (MPE) without a previously known tumor. In this study we looked for differences according to sex and age. METHODS: Retrospective multicentre study of patients that had a cancer, which form of presentation was a MPE. Clinical characteristics, diagnostic tools and origin of the tumour where collected. We excluded patients with a previous known tumor, and those with the diagnosis performed in a different organ. RESULTS: 402 patients were diagnosed of cancer through a MPE, 241 male (M) and 161 female (F). Mean age was 70 years (SD 12.9). 84% of M and 34% of F had a previous or current history of tobacco use. Women complained more frequently of extra thoracic symptoms (44% vs. 32%, p 0.019). Adenocarcinoma was the predominant histological feature at any ages and in both sexes, more in F (66%) than in M (53%). Lung cancer was the most common primary tumour in both sexes: 59% in M, 47% in F patients. A history of tobacco use was more frequent among patients over 65 (76% vs. 60%, p CONCLUSIONS: - In our series, the most frequent tumour that had a MPE as the first manifestation of cancer was lung cancer. - In this cohort MPE was a presentation form of cancer more frequently among men and they had higher exposure to tobacco. - Adenocarcinoma was the predominant histological finding in both sexes and at all ages. - No differences were found among the study techniques that were used.