{'fraction_non_alphanumeric': 0.020903010033444816, 'fraction_numerical': 0.01839464882943144, 'mean_word_length': 5.415549597855228, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Clinicopathologic and prognostic features in appendiceal malignancies: Tumor invasiveness matters.

OBJECTIVE
Appendiceal tumors are rare and mostly present as acute appendicitis. Its estimated lifetime prevalence has been reported as 8%, and the annual incidence is approximately 0.1% in Western countries. The only treatment approach is still surgery, but surgical management still remains unclear in appendiceal malignancy.


MATERIAL AND METHODS
Histopathological examination of 2840 specimens obtained from patients who underwent appendectomy between January 2012 and December 2015 was investigated. Data from 23 patients diagnosed with the malignancy had been analyzed in terms of age, gender, and preoperative and postoperative clinical parameters. The overall survival rates of the patients and prognostic parameters affecting survival were also evaluated. Statistical analyses were performed using the SPSS software. The study was performed according to the Declaration of Helsinki.


RESULTS
The overall median age of the patients was 28 years with a male/female ratio of 1.55. Pediatric group between 1 and 6 years, late pediatric group between 7 and 11 years, and adolescent group between 12 and 17 years did not present appendix tumors. Carcinoid tumors were reported in 17 patients. Adenocarcinoma of the appendix was reported in 6 patients. Patients with carcinoid tumors were significantly younger than those with adenocancer (p=0.01). The mean tumor size of the carcinoid group was significantly smaller than that of the adenocancer group (p=0.02). Patients with adenocancer were significantly more likely to have tumor extension beyond the appendix (p=0.05). All patients in the adenocancer group and 4 patients in the carcinoid group with mesoappendix invasion underwent right hemicolectomy. Univariate analyses demonstrated that serosal invasion, advanced tumor stage, and tumor invasion depth were associated with poor survival rates.


CONCLUSION
Tumor subtype and tumor invasiveness are important risk factors for survival in appendiceal malignancies. Appendectomy alone presents satisfactory results, but complete staging of the tumor should always be considered. In addition, surgical choice is not presented as an effective factor for improved clinical outcomes and survival rates. Further prospective studies are needed to evaluate the proper staging of the tumors.