[Respiratory infection and bronchial cancer].

Respiratory infections are very frequent in the course of lung cancer. The diagnosis is often difficult because of the existence of a chronic inflammatory process and of radiologic abnormalities related to lung cancer. Clinical symptomatology is atypical: no clear distinction between fever due to inflammation or infection, productive cough linked with chronic bronchitis often associated.... Radiological abnormalities are difficult to interpret: infectious lobar infiltrate or atelectasis, nature of a pleural effusion.... Biological data bear little interest because of their lack of specificity. Depending on their evolution, respiratory infections have particular characteristics. Before treatment, the problem is more often related to a fever and/or a radiological abnormality. During the post-operative period, fever generally corresponds to infectious phenomena, not necessarily originating from the lung. Among patients treated by radiotherapy and/or chemotherapy, it is sometimes difficult to conclude among several diagnosis possibilities: infectious lung condition, secondary infectious sites, iatrogenic interventions. The various possibilities that can be encountered can be divided into three main categories: in the case of lung infection in a non-neutropenic patient the organisms are those of a common community-acquired respiratory infection and it is logical to suggest a treatment based on penicillin A possibly associated with an inhibitor of beta-lactamases. In the case of a localised lung infection in a neutropenic subject, it is essential to cover gram negative bacilli by adding a beta-lactam and an aminoside. Finally, in the case of interstitial lung involvement, opportunistic bacteria are likely and it is essential to propose an endoscopic examination before initiating a therapeutic scheme.(ABSTRACT TRUNCATED AT 250 WORDS)