Over 90% of adult pulmonary LCH occurs in young adults who smoke, often more than 20 cigarettes per day.[10,11]
Solvent exposure in parents and perinatal infections have a weak association with LCH, but there is no increase in cases after viral epidemics. An increased frequency of family members with thyroid disease has been reported.
Prognosis is closely linked to the extent of disease at presentation and whether high-risk organs (liver, spleen, and/or bone marrow) are involved. Patients with single-system disease and low-risk multisystem disease do not usually die from LCH, but recurrent disease may result in considerable morbidity and significant late effects.
Prognostic factors in LCH have been identified and can be categorized as follows:
- Age at diagnosis: Although age younger than 2 years was once thought to portend a worse prognosis, data from the LCH-II study showed that patients aged 2 years or younger without high-risk organ involvement had the same response to therapy as older patients. By contrast, the overall survival (OS) was poorer in neonates with risk-organ involvement compared with infants and children with the same extent of disease.
- Response to treatment: Response to therapy at 6 to 12 weeks has been shown to be a more important prognostic factor than age. The overall response to therapy is influenced by the duration and intensity of treatment.[1,2]
- Organ involvement: Involvement of craniofacial bones including orbital, mastoid, and temporal bones is associated with an increased risk of diabetes insipidus in addition to increased frequency of anterior pituitary hormone deficiencies and neurologic problems. (Refer to the Endocrine system subsection in the Multisystem Disease Presentation section of this summary for more information on diabetes insipidus.)
- Gadner H, Grois N, Arico M, et al.: A randomized trial of treatment for multisystem Langerhans' cell histiocytosis. J Pediatr 138 (5): 728-34, 2001.
- Gadner H, Grois N, Pötschger U, et al.: Improved outcome in multisystem Langerhans cell histiocytosis is associated with therapy intensification. Blood 111 (5): 2556-62, 2008.
- Carstensen H, Ornvold K: The epidemiology of Langerhans cell histiocytosis in children in Denmark, 1975-89. [Abstract] Med Pediatr Oncol 21 (5): A-15, 387-8, 1993.
- Salotti JA, Nanduri V, Pearce MS, et al.: Incidence and clinical features of Langerhans cell histiocytosis in the UK and Ireland. Arch Dis Child 94 (5): 376-80, 2009.
- A multicentre retrospective survey of Langerhans' cell histiocytosis: 348 cases observed between 1983 and 1993. The French Langerhans' Cell Histiocytosis Study Group. Arch Dis Child 75 (1): 17-24, 1996.
- Stålemark H, Laurencikas E, Karis J, et al.: Incidence of Langerhans cell histiocytosis in children: a population-based study. Pediatr Blood Cancer 51 (1): 76-81, 2008.
- Guyot-Goubin A, Donadieu J, Barkaoui M, et al.: Descriptive epidemiology of childhood Langerhans cell histiocytosis in France, 2000-2004. Pediatr Blood Cancer 51 (1): 71-5, 2008.
- Aricò M, Nichols K, Whitlock JA, et al.: Familial clustering of Langerhans cell histiocytosis. Br J Haematol 107 (4): 883-8, 1999.
- Alston RD, Tatevossian RG, McNally RJ, et al.: Incidence and survival of childhood Langerhans cell histiocytosis in Northwest England from 1954 to 1998. Pediatr Blood Cancer 48 (5): 555-60, 2007.
- Tazi A, Soler P, Hance AJ: Adult pulmonary Langerhans' cell histiocytosis. Thorax 55 (5): 405-16, 2000.
- Vassallo R, Ryu JH, Colby TV, et al.: Pulmonary Langerhans'-cell histiocytosis. N Engl J Med 342 (26): 1969-78, 2000.
- Nicholson HS, Egeler RM, Nesbit ME: The epidemiology of Langerhans cell histiocytosis. Hematol Oncol Clin North Am 12 (2): 379-84, 1998.
- Bhatia S, Nesbit ME Jr, Egeler RM, et al.: Epidemiologic study of Langerhans cell histiocytosis in children. J Pediatr 130 (5): 774-84, 1997.
- Haupt R, Nanduri V, Calevo MG, et al.: Permanent consequences in Langerhans cell histiocytosis patients: a pilot study from the Histiocyte Society-Late Effects Study Group. Pediatr Blood Cancer 42 (5): 438-44, 2004.
- Minkov M, Prosch H, Steiner M, et al.: Langerhans cell histiocytosis in neonates. Pediatr Blood Cancer 45 (6): 802-7, 2005.