Appendicitis as an early manifestation of subsequent malignancy: an asian population study

Shih-Chi Wu; William Tzu-Liang Chen; Chih-Hsin Muo; Fung-Chang Sung

doi:10.1371/journal.pone.0122725

Appendicitis as an early manifestation of subsequent malignancy: an asian population study

PLoS One. 2015 Apr 27;10(4):e0122725. doi: 10.1371/journal.pone.0122725. eCollection 2015.

Authors

Shih-Chi Wu¹, William Tzu-Liang Chen², Chih-Hsin Muo³, Fung-Chang Sung⁴

Affiliations

¹ Trauma and Emergency Center, China Medical University Hospital, Taichung 404, Taiwan; College of Medicine, China Medical University, Taichung 404, Taiwan.
² College of Medicine, China Medical University, Taichung 404, Taiwan; Division of Colorectal Surgery, Department of Surgery, China Medical University Hospital, Taichung 404, Taiwan.
³ College of Medicine, China Medical University, Taichung 404, Taiwan; Management Office for Health Data, China Medical University and Hospital, Taichung 404, Taiwan.
⁴ Management Office for Health Data, China Medical University and Hospital, Taichung 404, Taiwan; Institute of Clinical Medical Science, China Medical University College of Medicine, Taichung 404, Taiwan.

Abstract

Background & aims: Cancer risk after appendectomy in patients with appendicitis remains unclear. This study examined the role of appendicitis as an early manifestation harbingering the distant malignancy.

Methods: From the insurance claims data of Taiwan, we identified a cohort of 130,374 patients newly received appendectomy from 2000-2009, without cancer diagnosis. A comparison cohort of 260,746 persons without appendectomy and cancer was selected from the same database, frequency matched by age, sex, comorbidity and index year. We monitored subsequent cancers with a12-month follow-up.

Results: Over all, 1406 and 616 cancer cases were identified in the appendectomy cohort and comparisons, respectively, with all cancers incidence rate 4.64-fold higher in the appendectomy cohort (9.06 vs. 1.96 per 1000 person-months). Digestive and female genital organs harbored 80.9% of cancer cases in the appendectomy cohort. The Cox model measured site-specific hazard ratio (HR) was the highest for female genital cancers (23.3), followed by cancers of colorectum (14.7), small intestine (10.1), pancreas (7.40), lymphoma (5.89) and urinary system (4.50), all significant at 0.001 level. The HR of all cancers decreased from 13.7 within 3 months after appendectomy to 1.37 in 7-12 months after the surgery. In general, relative to the comparison cohort, younger appendectomy patients tended to have a higher HR than older patients.

Conclusions: The high incident cancers identified soon after appendectomy suggest the acute appendicitis is the early sign of distant metastatic malignancy. The risk of colorectal cancer, female genital cancer and haemopoietic malignancy deserve attention.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Appendectomy / methods
Appendicitis / complications*
Appendicitis / surgery
Asian People
Female
Follow-Up Studies
Humans
Male
Middle Aged
Neoplasms / etiology*
Retrospective Studies
Risk Factors
Taiwan

Grants and funding

The study is supported in part by Taiwan Ministry of Health and Welfare Clinical Trial and Research Center of Excellence (MOHW104-TDU-B-212-113002), China Medical University Hospital, Academia Sinica Taiwan Biobank Stroke Biosignature Project (BM104010092), NRPB Stroke Clinical Trial Consortium (MOST 103-2325-B-039 -006), Tseng-Lien Lin Foundation, Taichung, Taiwan, Taiwan Brain Disease Foundation, Taipei, Taiwan, Katsuzo and Kiyo Aoshima Memorial Funds, Japan and the National Sciences Council, Executive Yuan (NSC 100-2621-M-039-001). The funding agencies had no role in study design, data management and analyses, and results interpretation and publication of this study.