Systemic chemotherapy and survival in patients with metastatic low‐grade appendiceal mucinous adenocarcinoma

Abstract

Background Appendiceal cancer is a rare malignancy that exhibits a wide range of histology and treatment response. Given the rarity and heterogeneous nature of the disease, it has been difficult to define optimal treatment strategies. Our goal is to examine the association between use of systemic chemotherapy and survival in patients with metastatic low‐grade mucinous appendiceal adenocarcinoma. Methods The National Cancer Database (2004‐2015) was queried, and patients with mucinous, grade 1, stage IV appendiceal adenocarcinoma were identified. The Kaplan‐Meier method was used to calculate survival, and a Cox regression model was used to identify predictors of survival. Results Six hundred and thirty‐nine patients were identified. Five‐year overall survival (OS) for patients undergoing no chemotherapy vs chemotherapy was 52.9% and 61.3%, respectively. After adjusting with Cox proportional hazards model, chemotherapy was not associated with OS (HR:1.1, 95% CI:0.82‐1.40, P = 0.61). Patients who underwent surgical resection (HR:0.40, 95% CI:0.28‐0.57, P < .001) or were female (HR:0.61, 95% CI:0.5‐0.8, P < .001) had improved survival in adjusted analysis. Conclusions There is no association between undergoing chemotherapy and OS in this cohort of patients with stage IV low‐grade mucinous appendiceal adenocarcinoma. Development of national treatment guidelines is urgently needed for more consistency in the management of patients with appendiceal cancers.

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

“…Kolla et al recently reported that in a study of 103 patients with appendiceal adenocarcinoma, adjuvant chemotherapy following complete cytoreduction significantly improved overall survival compared to cytoreduction alone [ 12 ]. In contrast, other studies reported no beneficial effect of chemotherapy in the treatment of appendiceal adenocarcinoma [ 6 , 13 , 14 ].…”

“…Though surgery is the first option in the treatment of appendiceal cancer, chemotherapy has been applied using a protocol similar to that used to treat colorectal cancer [ 3 , 4 ]. The rarity and high heterogeneity make it difficult to examine the effect of chemotherapy in treatment of appendiceal cancer in systematic studies [ 5 , 6 ]. Most previous studies had a limited sample size from a single institution, and only included certain histological types [ 7 – 10 ].…”

Integrated clinico-molecular profiling of appendiceal adenocarcinoma reveals a unique grade-driven entity distinct from colorectal cancer

“… 7 , 13 , 16 , 32 This distinction has important clinical implications, given that low-grade AA tend to be unresponsive to traditional cytotoxic chemotherapy and in light of a recent large retrospective analysis ( N = 639) showing no association of chemotherapy with improved OS. 34 Additionally, new guidelines from the American Society of Colon & Rectal Surgeons now suggest avoiding chemotherapy for low-grade AA. 35 …”

Sustained Stable Disease with Capecitabine plus Bevacizumab in Metastatic Appendiceal Adenocarcinoma: A Case Report

“…No clear benefit when using bevacizumab was observed in this report, with a trend towards longer OS in non-bevacizumab regimens (p = 0.41) and significant results in PFS favouring bevacizumab-free regimens (p = 0.01) [13]. A recent retrospective review of 639 patients with well-differentiated metastatic appendiceal adenocarcinoma achieved significant results in terms of OS for patients who underwent initial surgery (HR 0.40, 95% CI 0.28-0.57) and also for female sex, but not in the case of patients receiving chemotherapy (HR 1.1, 95% CI 0.56-0.94), probably related to a slow cell growth with less chemotherapy activity in this subgroup [14]. A non-significant trend towards an increase in 5-year OS was observed for chemotherapy versus observation (61.3 vs. 52.9%, respectively).…”