Analysis of Clinical Characteristics of Low-Grade Appendiceal Mucinous Neoplasm (LAMN): A Retrospective Cohort Study of 51 LAMN Patients

Figures & data

Table 1. Clinical characteristics of 51 LAMN patients.

Clinical characteristics	Number of patients (percentage)
Gender
Male	6 (12%)
Female	45 (88%)
Clinical presentation
Abdominal pain	16 (31%)
Abdominal distention	11 (22%)
Abdominal mass	8 (16%)
Hematochezia	2 (4%)
Incidental finding	14 (27%)
Physical examination
Tenderness and rebound pain	3 (6%)
Tenderness without rebound pain	4 (8%)
Preoperative diagnosis
Appendiceal mucocele	20 (39%)
Appendicitis	3 (6%)
Adnexal mass	9 (18%)
Undefined mass in pelvic area	9 (18%)
Ovarian cancer with metastasis	10 (20%)
Surgical procedure
Appendectomy	15 (29%)
Right hemicolectomy	1 (2%)
Appendectomy and ileocecoectomy	23 (45%)
CRS involving hysterectomy plus bilateral salphingo-oophorectomy, mentectomy	12 (24%)
Potential to develop a malignant condition
Yes	18 (35%)
No	33 (65%)
Recurrence
Yes	8 (16%)
No	43 (84%)

Table 2. Clinical characteristics of patients with an intact appendix and patients with the potential to develop a malignant condition.

Pathology	Number of patients	Surgical procedure	Number of patients	Additional treatment after surgery	Current status	Number of patients
Patients with an intact appendix (n = 33)
Intact appendix		Appendectomy	14	none	Alive with no disease
		Appendectomy and ileocecoectomy	18
		Right hemicolectomy	1
Patients with the potential to develop a malignant condition (n = 18)
Mucin, cells, or both outside the appendix	3	CRS involving hysterectomy plus bilateral salphingo-oophorectomy, mentectomy	2	none	Alive with no disease
		Appendectomy and ileocecoectomy	1
Appendiceal rupture/perforation	4	appendectomy	1	none	Alive with no disease
		Appendectomy and ileocecoectomy	3
Positive margin	1	Appendectomy and ileocecoectomy		none	Alive with no disease
PMP	10	CRS involving hysterectomy plus bilateral salphingo-oophorectomy, mentectomy		HIPEC	Alive with disease	6
					death	1
					unknown	1
					Alive with no disease	2

Table 3. Comparison of serum tumor marker levels between patients with the potential to develop a malignant condition and patients with an intact appendix.

Serum tumor marker	Potential to develop a malignant condition(Mean ± SEM)	Intact appendix (Mean ± SEM)	Significance
CA125	90.7 ± 24.4	12.2 ± 1.6	p < 0.001***
CA19-9	59.0 ± 25.9	16.6 ± 4.2	p = 0.04*
CEA	59.0 ± 15.8	4.8 ± 1.3	p = 0.001**
Serum tumor marker	Potential to develop a malignant condition	Intact appendix (ratio of abnormal)	Significance
CA125	86% (n = 14)	0 (n = 17)	p < 0.001***
CA19-9	40% (n = 15)	9% (n = 23)	p = 0.04*
CEA	64% (n = 14)	23% (n = 22)	p = 0.02*

SEM, standard error of the mean.

Figure 1. OS and DFS of patients with metastasis to other organs or a ruptured appendix.

OS, overall survival; DFS, disease free survival. The Kaplan-Meier estimates of OS and DFS are shown in a and b. The Kaplan-Meier estimates of DFS by CA125, CA19-9 and CEA level are given in c, d and e.

Table 4. Univariate Cox proportional hazards model for the DFS of 46 patients.

Clinical characteristics		HR	95% CI	p
CA125	Abnormal versus normal	90.42	0.21, 29581	0.13
CA19-9	Abnormal versus normal	5.72	1.28, 25.55	0.02*
CEA	Abnormal versus normal	100.76	0.12, 87996	0.18
PMP	with versus without	977.93	0.02, 63910707	0.22
Age		0.97	0.92, 1.02	0.26
Appendectomy	Other surgical procedure versus single appendectomy	0.03	0.00, 14.94	0.26

DFS, disease free survival.