[Analysis of correlation factors and risk prediction for acute appendicitis associated with appendiceal neoplasms]

Objective: To examine the correlation factors of acute appendicitis associated with appendiceal neoplasms. Methods: Consecutive 712 patients with acute appendicitis who treated at Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University from January 2002 to December 2016 were analyzed retrospectively. There were 314 females and 398 males, aging (42.5±16.2) years (range: 14 to 94 years). Among the 712 cases, 36 patients were diagnosed with acute appendicitis associated with appendiceal neoplasms, the other 676 patients had no appendiceal neoplasm. The patients^' clinical baseline characteristics and clinical parameters were compared between the two groups. The correlation factors of acute appendicitis associated with appendiceal neoplasms were evaluated by using the univariate (χ² test or t test) and multivariate Logistic regression analysis. The area under curve of receiver operating characteristic curves was utilized to evaluate the discriminatory power of the predictive models. Results: According to the univariate analysis, gender, age, body mass index, the duration of chronic right low abdominal pains≥3 months, the frequency of recurrently acute right lower abdominal pain≥2, the frequency of acute right lower abdominal pain, past history of diabetes, hypertension or coronary heart disease, the level of neutrophils and leukocytes preoperatively, stercolith and periappendiceal effusion, and modified Alvarado score were positively correlated with appendiceal neoplasms (all P<0.05). Then four variables were incorporated into the model eventually by multivariate Logistic regression analysis, which were as follows: age (increased per decade) (OR=2.23, 95%CI: 1.68 to 2.95, P<0.01), gender (female) (OR=4.21, 95%CI: 1.74 to 10.19, P=0.001), the duration of chronic right low abdominal pains (more than 3 months) (OR=2.53, 95%CI: 1.01 to 3.37, P=0.048), and modified Alvarado score (decreased per 1 score) (OR=2.54, 95%CI: 1.87 to 3.34, P<0.01). The area of curve was 0.93 (95%CI: 0.88 to 0.97), which indicated that the model exhibits an excellent ability to discriminate between appendiceal neoplasms and acute appendicitis. Conclusions: The older age, female, the duration of chronic right low abdominal pains, and lower modified Alvarado score are independent correlation factors for acute appendicitis associated with appendiceal neoplasms. Clinicians should be alert for the above clinical characteristics and choose optimal treatment for acute appendicitis associated with appendiceal neoplasms.