Chemotherapy in the treatment of different histological types of appendiceal cancers: a SEER based study

Abstract

Background Due to its rarity and high heterogeneity, neither established guidelines nor prospective data are currently available for using chemotherapy in the treatment of appendiceal cancer. This study was to determine the use of chemotherapy and its potential associations with survival in patients with different histological types of the cancer. Methods Patients with histologically different appendiceal cancers diagnosed during 1998–2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The role and effect of chemotherapy were examined in the treatment of the disease. The Kaplan-Meier method was applied to construct survival curves and significance was examined by Log-rank test. Cox proportional hazard models were used to analyze the impact of chemotherapy and other variables on survival in these patients. Results A total of 8733 appendiceal cancer patients were identified from the database. Chemotherapy was administrated at highly variable rates in different histological types of appendiceal cancer. As high as 64.0% signet ring cell carcinoma (SRCC), 46.4% of mucinous adenocarcinomas (MAC), 40.6% of non-mucinous adenocarcinoma (NMAC) and 43.9% of mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) were treated with chemotherapy, whereas only 14.7% of goblet cell carcinoma (GCC), 5% neuroendocrine tumors (NETs) and 1.6% carcinomas (NEC) received chemotherapy. In all patients combined, chemotherapy significantly improved overall survival during the entire study period and cancer-specific survival was improved during in cases from 2012–2016. Further multivariate analysis showed that both cancer-specific and overall survival was significantly improved with chemotherapy in patients with MAC, NMAC and SRCC, but not for patients with GCC, MiNENs, NETs and NECs. Number (> 12) of lymph node sampled was associated with survival of patients with most histological types of cancer under study. Other prognostic factors related to individual histological types were identified. Conclusions Chemotherapy is administrated at highly variable rates in different histological types of appendiceal cancer. Efficacy of chemotherapy in the treatment of these cancers has been improved in recent years and is significantly associated with better survival for patients with NMAC, MAC, and SRCC. Adequate lymph node sampling may result in a survival benefit for most of these patients.

Goblet Cell Adenocarcinoma of the Appendix: A Systematic Review and Incidence and Survival of 1,225 Cases From an English Cancer Registry

“…In studies classifying GCA as local, regional, or metastatic disease, 51%–64% of cases were described as local ( 3 , 16 , 17 , 26 ). While metastases were found in only a relatively small proportion of cases in the registry studies (7%–18.7%) ( 3 , 11 , 12 , 16 – 20 , 23 , 26 ), stage IV disease was more common in retrospective studies and case series ( 7 , 37 , 39 , 44 , 49 , 52 , 58 , 73 ). It is likely that this finding is the result of referral bias, as higher rates of metastatic disease were reported by tertiary centres, with lower rates reported by district general hospitals and national registry studies ( 52 ).…”

“…Only one large registry study reported a median age out of this range at 43 years ( 23 ). GCA is more common in Caucasian patients, who account for 80-90% cases ( 3 , 11 , 12 , 14 – 20 , 25 , 26 ). There was no sex preponderance in most studies ( 3 , 11 , 12 , 14 , 16 , 18 , 20 , 23 , 25 , 26 ); however, this was variable in the smaller retrospective studies and case series.…”

“…GCA is more common in Caucasian patients, who account for 80-90% cases ( 3 , 11 , 12 , 14 – 20 , 25 , 26 ). There was no sex preponderance in most studies ( 3 , 11 , 12 , 14 , 16 , 18 , 20 , 23 , 25 , 26 ); however, this was variable in the smaller retrospective studies and case series. Infection with schistosomiasis was the only potential environmental risk factor identified, although it should be noted that only three cases of combined appendiceal schistosomiasis and GCA were included in this study ( 63 ).…”

“…Authors rarely specified whether staging was based upon index or completion surgery. In larger registry studies using the TNM system, most tumours presented with stage II disease ( 14 , 18 – 20 , 28 , 39 , 52 , 58 ); T3 tumours were found in 49%–60% and N0 in 81%–87% of cases ( 11 , 12 , 23 ). In studies classifying GCA as local, regional, or metastatic disease, 51%–64% of cases were described as local ( 3 , 16 , 17 , 26 ).…”

“…Chromogranin A and B is rarely raised ( 39 , 102 ). Elevated serum carcinoembryonic antigen (CEA), Carbohydrate antigen 19-9, and CA-125 were reported in some studies ( 12 , 39 , 52 , 54 , 74 , 102 ), although there is a paucity of prospective data to demonstrate their clinical utility in monitoring for recurrence. Given the increased incidence of synchronous or metachronous colonic malignancy ( 103 ), some authors suggest performing follow-up colonoscopies.…”