Infections in Cancer Patients with Solid Tumors: A Review

Solid tumors are much more common than hematologic malignancies. Although severe and prolonged neutropenia is uncommon, several factors increase the risk of infection in patients with solid tumors, and the presence of multiple risk factors in the same patient is not uncommon. These include obstruction (most often caused by progression of the tumor), disruption of natural anatomic barriers such as the skin and mucosal surfaces, and treatment-related factors such as chemotherapy, radiation, diagnostic and/or therapeutic surgical procedures, and the increasing use of medical devices such as various catheters, stents, and prostheses. Common sites of infection include the skin and skin structures (including surgical site infections), the bloodstream (including infections associated with central venous catheters), the lungs, the hepato-biliary and intestinal tracts, and the urinary tract, and include distinct clinical syndromes such as post-obstructive pneumonia, obstructive uropathy, and neutropenic enterocolitis. The epidemiology of most of these infections is changing with resistant organisms [MRSA, Pseudomonas aeruginosa, extended spectrum beta-lactamase (ESBL)-producing organisms] being isolated more often than in the past. Polymicrobial infections now predominate when deep tissue sites are involved. Conservative management of most of these infections (antibiotics, fluid and electrolyte replacement, bowel rest when needed) is generally effective, with surgical intervention being reserved for the drainage of deep abscesses, or to deal with complications such as intestinal obstruction or hemorrhage. Infected prostheses often need to be removed. Reactivation of certain viral infections (HBV, HCV, and occasionally CMV) has become an important issue, and screening, prevention and treatment strategies are being developed. Infection prevention, infection control, and antimicrobial stewardship are important strategies in the overall management of infections in patients with solid tumors. Occasionally, infections mimic solid tumors and cause diagnostic and therapeutic challenges.