Risk of lymphoid neoplasms in a Swedish population-based cohort of 337,437 patients undergoing appendectomy

• Objective: Appendectomy remains one of the most common surgical procedures, but possible long-term consequences for health and disease are incompletely investigated. The appendix forms part of the secondary lymphoid system and appendectomy has been associated with increased risks of hematolymphoproliferative malignancies in some studies.Materials and methods: We examined the risk of lymphoid neoplasms in a large cohort of 337,437 appendectomised patients <60 years of age in Sweden 1975-2009. We estimated relative risks of non-Hodgkin lymphoma (NHL) and major subtypes, Hodgkin lymphoma (HL), chronic lymphocytic leukaemia (CLL), myeloma, and acute lymphoblastic leukaemia (ALL) versus the general population using standardised incidence ratios (SIRs) with 95% confidence intervals (CIs).Results: There was no increased risk of NHL (SIR = 0.97, 95%CI 0.88-1.06), major NHL subtypes, CLL (SIR = 0.87, 95%CI 0.70-1.06), myeloma (SIR = 1.14, 95%CI 0.96-1.33) or ALL (SIR = 1.10, 95%CI 0.80-1.47) following appendectomy. An increased risk of HL was observed among patients diagnosed with appendicitis (SIR = 1.29, 95%CI 1.07-1.54, p=0.007), especially individuals aged <20 years at surgery (SIR = 1.43, 95%CI 1.11-1.82), and for the nodular sclerosis subtype of HL (SIR = 1.55, 95%CI 1.01-2.27). A marginally increased risk of myeloma was noted among men, but the association was limited to the first few years of follow-up.Conclusion: Appendectomy is not associated with any notable increase in risk of lymphoid neoplasms. A small increased risk of HL following appendicitis (rather than appendectomy per se) could reflect a true association, or shared susceptibility to infection/inflammation among individuals prone to develop HL. The association observed for myeloma may be explained by chance or surveillance bias.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Folkhälsovetenskap, global hälsa, socialmedicin och epidemiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Public Health, Global Health, Social Medicine and Epidemiology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Adult Appendectomy/*adverse effects Female Follow-Up Studies Humans Incidence Lymphoma/epidemiology/*etiology Male Middle Aged *Population Surveillance Retrospective Studies Risk Assessment/*methods

Risk Factors Sweden/epidemiology

Young Adult

Acute lymphoblastic leukaemia

Hodgkin lymphoma

appendectomy appendicitis

chronic lymphocytic leukaemia

myeloma

non-Hodgkin lymphoma

Epidemiology

Epidemiologi

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)