Infectious Complications in Association with Cytoreductive Chemotherapy for Malignant Diseases

Abstract

Patients treated for cancer with cytoreductive agents experience more or less severely impaired immune deficiency, the severity and type of which depends both on the art and extent of the primary tumour and the art and extent of therapy. Most important is granulocytopenia. Granulocyte concentration below 0.1×10⁹/L for more than a week is almost invariably associated with severe infections and also with recurrent infections, both bacterial and fungal. Other parts of the immune system are always affected. B‐ and T‐cell deficiencies may be present for months and even years after cytoreductive therapy, affecting the defence against viruses, intracellular bacteria and some fungi, notably Pneumocystis carinii. Parallel to the neutropenia there is more or less injury to mucous membranes, mucositis, permitting increased translocation of bacteria from the gastrointestinal tract to the blood. The course of bacteraemia may be fulminant but focal symptoms may be discrete or atypical due to lack of immunological response. Gram negative bacteria, including P. aeruginosa and Grampositive bacteria like S. aureus and α‐streptococci are most commonly involved. The initiation of empiric therapy immediately when a neutropenic patient gets fever is today a cornerstone in the management of neutropenic fever and has dramatically reduced a previously very high mortality rate. The patients must be closely monitored and changes in general condition, focal symptoms and laboratory reports must be taken into account. Pulmonary infections have an especially serious prognosis. Many infectious agents may be involved, but the aetiology is often difficult to establish and therapy may be complicated. Severe viral infections are seen in patients treated with especially T‐cell toxic regimens, such as those used for bone marrow transplant recipients. Herpes viruses are most important, but severe infections with adenoviruses and respiratory viruses may also be encountered.

Bacteraemia is diagnosed with acceptable sensitivity, but the results will most often take 18–48 h before being reported and susceptibility report another 24–48 h. For fungal and many viral infections both low sensitivity for identification and the delay of diagnosis are problematic. Moreover, almost half of the patients with neutropenic fever probably do not have any infectious disease at all and the therapy is only causing toxicity, emergence of resistance and prolonged hospital stay. More rapid and reliable identification of infectious agents in immunocompromised hosts therefore have a great potency for improving precision and effectiveness of therapy.

• Cancer Malignancy Cytoreductive therapy Infection Bacteria Fungi Virus Pulmonary infections