Low-grade mucinous neoplasms (LAMN) of the appendix in Germany between 2011 and 2018: a nationwide analysis based on data provided by the German Center for Cancer Registry Data (ZfKD) at the Robert Koch Institute (RKI)

Abstract

Introduction Low-grade appendiceal mucinous neoplasms (LAMN) are semi-malignant tumors of the appendix which are incidentally found in up to 1% of appendectomy specimen. To this day, no valid descriptive analysis on LAMN is available for the German population. Methods Data of LAMN (ICD-10: D37.3) were collected from the population-based cancer registries in Germany, provided by the German Center for Cancer Registry Data (Zentrum für Krebsregisterdaten—ZfKD). Data was anonymized and included gender, age at diagnosis, tumor staging according to the TNM-classification, state of residence, information on the performed therapy, and survival data. Results A total of 612 cases were reported to the ZfKD between 2011 and 2018. A total of 63.07% were female and 36.93% were male. Great inhomogeneity in reporting cases was seen in the federal states of Germany including the fact that some federal states did not report any cases at all. Age distribution showed a mean age of 62.03 years (SD 16.15) at diagnosis. However, data on tumor stage was only available in 24.86% of cases (n = 152). A total of 49.34% of these patients presented with a T4-stage. Likewise, information regarding performed therapy was available in the minority of patients: 269 patients received surgery, 22 did not and for 312 cases no information was available. Twenty-four patients received chemotherapy, 188 did not, and for 400 cases, no information was available. Overall 5-year survival was estimated at 79.52%. Patients below the age of 55 years at time of diagnosis had a significantly higher 5-year survival rate compared to patients above the age of 55 years (85.77% vs. 73.27%). Discussion In this study, we observed an incidence of LAMN in 0.13% of all appendectomy specimen in 2018. It seems likely that not all cases were reported to the ZfKD; therefore, case numbers may be considered underestimated. Age and gender distribution goes in line with international studies with females being predominantly affected. Especially regarding tumor stage and therapy in depth information cannot be provided through the ZfKD-database. This data analysis emphasizes the need for further studies and the need for setting up a specialized registry for this unique tumor entity to develop guidelines for the appropriate treatment and follow-up.

Congenital Tooth Agenesis and Risk of Early-Onset Cancer

“…Among young adults, we also observed associations with carcinomas of the appendix (a rare cancer type that is often a low-grade incidental finding in young individuals undergoing appendectomy) and carcinomas of the bladder. These associations with adult-onset carcinomas could be unrelated or could reflect one shared genetic predisposition (either a novel cancer predisposition syndrome or a broader phenotype of an established syndrome).…”

“…(OMIM 609309)-related Lynch syndrome, 27 and carcinomas of the appendix are associated with occurrence of other malignant tumors of the gastrointestinal tract. 25,26 In embryonic development, teeth, skin, and melanocytes are of ectodermal origin, which could be part of the underlying mechanism of the apparent association with malignant melanoma.…”

“…These associations with adult-onset carcinomas could be unrelated or could reflect one shared genetic predisposition (either a novel cancer predisposition syndrome or a broader phenotype of an established syndrome). A shared genetic cause is not implausible because colorectal and bladder cancers are known to co-occur in MSH2 (OMIM 609309)–related Lynch syndrome, and carcinomas of the appendix are associated with occurrence of other malignant tumors of the gastrointestinal tract …”

A giant low-grade appendiceal mucinous neoplasm (LAMN) presenting as ileocecal intussusception: a case report

“…LAMNs are semi-malignant tumors of the appendix, diagnosed as an incidental finding in up to 1% of appendectomy specimens, at a mean age of 62.03 years, and with females being predominantly affected [ 9 ]. The term LAMNs applies to lesions without infiltrative invasion, instead of lesions with infiltrative invasion, such as ‘mucinous adenocarcinoma’ [ 5 ].…”

Active surveillance for low-grade appendiceal mucinous neoplasm (LAMN)

“…Appendiceal tumors are infrequent, representing approximatively 0.5 % of all tumors of the gastrointestinal tract [ 1 ]. While neoplasms may be found in 0.9–1.7 % of appendectomy specimens [ 2 , 3 ], almost half of them can be characterized as low-grade appendiceal mucinous neoplasms (LAMNs) [ 4 ].…”