Chapter 082. Infections in Patients with Cancer (Part 1)

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Harrison's Internal Medicine Chapter 82. Infections in Patients with Cancer Infections in Patients with Cancer: Introduction Infections are a common cause of death and an even more common cause of morbidity in patients with a wide variety of neoplasms. Autopsy studies show that most deaths from acute leukemia and half of deaths from lymphoma are caused directly by infection. With more intensive chemotherapy, patients with solid tumors have also become more likely to die of infection. Fortunately, an evolving approach to prevention and treatment of infectious complications of cancer has decreased rates of infection-associated mortality and will probably continue to...

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Chapter 082. Infections in Patients with Cancer (Part 1) Harrison's Internal Medicine > Chapter 82. Infections in Patients with Cancer Infections in Patients with Cancer: Introduction Infections are a common cause of death and an even more common cause of morbidity in patients with a wide variety of neoplasms. Autopsy studies show that most deaths from acute leukemia and half of deaths from lymphoma are caused directly by infection. With more intensive chemotherapy, patients with solid tumors have also become more likely to die of infection. Fortunately, an evolving approach to prevention and treatment of infectious complications of
cancer has decreased rates of infection-associated mortality and will probably continue to do so. This accomplishment has resulted from three major steps: 1. The concept of "early empirical" antibiotics reduced mortality rates among patients with leukemia and bacteremia from 84% in 1965 to 44% in 1972. With better availability (and early use) of broad-spectrum antibiotics, this figure has recently dropped to 20–36%. 2. "Empirical" antifungal therapy has lowered the incidence of disseminated fungal infection; in trial settings, mortality rates now range from 7 to 21%. An antifungal agent is administered—on the basis of likely fungal infection—to neutropenic patients who, after 4–7 days of antibiotic therapy, remain febrile but have no positive cultures. 3. Use of antibiotics for afebrile neutropenic patients as broad- spectrum prophylaxis against infections promises to decrease both mortality and morbidity even further. A physical predisposition to infection in patients with cancer (Table 82-1) can be a result of the neoplasm's production of a break in the skin. For example, a squamous cell carcinoma may cause local invasion of the epidermis, which allows bacteria to gain access to the subcutaneous tissue and permits the development of cellulitis. The artificial closing of a normally patent orifice can also predispose to infection: Obstruction of a ureter by a tumor can cause urinary tract infection, and
obstruction of the bile duct can cause cholangitis. Part of the host's normal defense against infection depends on the continuous emptying of a viscus; without emptying, a few bacteria present as a result of bacteremia or local transit can multiply and cause disease. Table 82-1 Disruption of Normal Barriers that May Predispose to Infections in Patients with Cancer Type Speci Cells Organ Can Disease of Defense fic Lesion Involved ism cer Associatio n Physi Brea Skin Staphy Hea Cellulitis cal barrier ks in skin epithelial lococci, d and neck, , extensive skin cells streptococci squamous infection cell carcinoma Empt Occl Lumi Gram- Ren Rapid, ying of fluid usion of nal negative al, ovarian, overwhelmingb
collections orifices: epithelial bacilli biliary tree, acteremia; ureters, bile cells metastatic urinary tract duct, colon diseases of infection many cancers Lym Node Lymp Staphy Bre Cellulitis phatic dissection h nodes lococci, ast cancer function streptococci surgery Splen Splen Splen Strepto Hod Rapid, ic clearance ectomy ic coccus gkin's overwhelming of reticuloendo pneumoniae, disease, sepsis microorgani thelial cells Haemophilus leukemia, sms influenzae, idiopathic Neisseria thrombocyt meningitidis, openic Babesia, purpura Capnocytoph aga canimorsus
Phag Lack Gran Staphy Hair Bacterem ocytosis of ulocytes lococci, y cell, ia granulocyte (neutrophils) streptococci, acute s enteric myelocytic organisms, , and acute fungi lymphocyti c leukemias Hum Lack B S. Chr Infection oral of antibody cells pneumoniae, onic s with immunity H. influenzae, lymphocyti encapsulated N. c leukemia, organisms, meningitidis multiple sinusitis, myeloma pneumonia Cellu Lack T Mycob Hod Infection lar of T cells cells and acterium gkin's s with immunity macrophage tuberculosis, disease, intracellular s Listeria, leukemia, bacteria, fungi, herpesviruses, T cell
fungi, other lymphoma parasites intracellular parasites