The other colon cancer: a population-based cohort study of appendix tumour trends and prognosis.

AIM: Appendiceal neoplasms are rare subtypes of colorectal tumours that mainly affect younger patients some 20 years earlier than other colon tumours. The aim of this study was to gain more insight into the histological subtypes of this rare disease and include cases previously excluded, such as mucinous neoplasia. METHOD: The cohort study included 1097 patients from the Munich Cancer Registry (MCR) diagnosed between 1998 and 2020. Joinpoint analysis was used to determine trend in incidence. Baseline demographic comparisons and survival analyses using competing risk and univariate/multivariate methods were conducted according to tumour histology: adenocarcinoma (ADENO), neuroendocrine neoplasia (NEN), mixed adeno-neuroendocrine carcinoma (MANEC), and low- (LAMN) and high-grade mucinous neoplasia (HAMN). RESULTS: Up to 2016 the number of cases increased significantly [annual per cent change (APC) = 6.86, p < 0.001] followed by a decline in the following years (APC = -14.82, p = 0.014; average APC = 2.5, p = 0.046). Comparison of all patients showed that NEN (48.4%) and mucinous neoplasms (11.6%) had a considerably better prognosis than ADENO (36.0%) and MANEC (3.0%, p < 0.0001). A multivariate analysis within the NEN and ADENO subgroups revealed that further histological classification was not prognostically relevant, while older age and regional tumour spread at diagnosis were associated with a poor prognosis. ADENO histology with high tumour grade and appendectomy only was also associated with poorer survival. CONCLUSION: Appendiceal neoplasms are histologically heterogeneous; however, this diversity becomes less relevant compared with the marked difference from cancers of the remaining colon. The previously observed increase in cases appears to be abating; fewer cases of appendicitis and/or appendectomies or changes in histopathological assessment may be behind this trend.

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

Background: Goblet cell adenocarcinoma (GCA) of the appendix is a rare and aggressive tumour with varying nomenclature and classification systems. This has led to heterogeneity in published data, and there is a lack of consensus on incidence, survival, and management. Methods: We provide an overview of GCA with a comprehensive systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology and a retrospective analysis of all cases recorded in the English National Cancer Registration and Analysis Service database between 1995 and 2018. The Kaplan-Meier estimator was used to calculate overall survival, and Cox proportional hazards regression was used to identify prognostic factors. Results: The systematic review demonstrated an incidence of 0.05-0.3 per 100,000 per year among North American registry studies. The 1-, 3-, and 5-year survival rate was 95.5%, 85.9%-87.6%, and 76.0%-80.6%, respectively. Age, stage, and grade were identified as prognostic factors for survival. Our analysis included 1,225 cases. Age-standardised incidence was 0.0335 per year in 1995 and gradually rose to 0.158 per year in 2018. The 1-, 3-, and 5-year survival rate was 90.0% [95% confidence interval (95% CI): 85.4-94.0], 76.0% (95% CI: 73.8-80.9), and 68.6% (95% CI: 65.9-72.2), respectively. On univariate Cox regression analyses, female sex, stage, and grade were associated with worse overall survival. On multivariate analysis, only stage remained a statistically significant prognostic factor. Conclusions: GCA of the appendix is rare, but incidence is increasing. We report a lower incidence and survival than North American registry studies. Higher stage was associated with decreased survival. Further prospective studies are required to establish optimal management.

Elevated tumour markers are normalized in most patients with pseudomyxoma peritonei 7 days after complete tumour removal.

AIM: Elevation of the preoperative tumour markers in pseudomyxoma peritonei (PMP) is common and is a risk factor for recurrence. There has, however, been no documentation of the effect of complete tumour removal on tumour markers levels after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The aim of the study was to compare the tumour markers 7 days after surgery in patients with elevated preoperative levels. METHOD: This was an observational prospective study of patients with PMP of appendiceal origin treated in one of the UK National Referral Centres for this condition. Thirty patients [median age = 61 (range: 31-74) years; six men] with an elevated preoperative level of carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA-125) and/or carbohydrate antigen 19-9 (CA19-9) underwent repeated estimation, 7 days after CRS and HIPEC for PMP. RESULTS: The median preoperative CEA level of 12 µg/l fell to 0.75 µg/l postoperatively (P < 0.0001), CA-125 fell from 45 to 31 kU/l (P = 0.183) and CA19-9 fell from 134 to 37 kU/l (P = 0.003). The CEA was raised in 22 (73%) of 30 patients preoperatively and in two (7%) of 30 patients 7 days after surgery (P < 0.0001). The corresponding data for CA-125 were 18 (60%) and 13 (43%) (P = 0.196) and for CA19-9 they were 24 (80%) and 16 (53%) (P = 0.028). CONCLUSION: This is the first documentation of a reduction or normalization of CEA 7 days after CRS, but not for CA19-9 or CA-125. This may indicate completeness of surgical resection and could aid selection for adjuvant therapy and predict prognosis. Long-term follow-up is, however, necessary to determine the significance of this observation.