Gastroenterol Res

Gastroenterology Research, ISSN 1918-2805 print, 1918-2813 online, Open Access

Article copyright, the authors; Journal compilation copyright, Gastroenterol Res and Elmer Press Inc

Journal website https://www.gastrores.org

Original Article

Volume 16, Number 1, February 2023, pages 9-16

Endoscopic Ultrasound Predicts Risk of Occult Intra-Abdominal Metastases in Localized Gastric Cancer: A Validation Study

Figure 1. (a) Radial EUS image of a T3 antral tumor showing normal gastric layers on EUS and the large tumor (between arrowheads) disrupting the normal layers and invading through the muscularis propria and into the serosa. This patient was classified as “high-risk” and ultimately was found to have M1 disease on DSL. (b) Linear EUS image of an N+ tumor showing a malignant appearing lymph node (arrow). EUS: endoscopic ultrasound; DSL: diagnostic staging laparoscopy.

Figure 2. Cytospin from peritoneal fluid shows a cluster of tumor cells with focal signet ring cell differentiation (arrow) (Papinocolou stain, × 600).

**Table 1.** Patient and Tumor Characteristics
Characteristic	Overall (n = 68)	Laparoscopy M0 (n = 51)	Laparoscopy M1 (n = 17)	P-value
GEJ: gastroesophageal junction.
Gender				0.773
Male	42 (62%)	31 (61%)	11 (65%)
Female	26 (38%)	20 (39%)	6 (35%)
Age (years)
Median (range)	64 (16 - 87)	65 (16 - 87)	64 (45 - 80)	0.639
≥ 60	47 (69%)	36 (71%)	11 (65%)	0.649
Ethnicity/race				0.370
Caucasian (White)	34 (50%)	26 (51%)	8 (47%)
African American	19 (28%)	16 (31%)	3 (18%)
Hispanic	8 (12%)	4 (8%)	4 (24%)
Asian	6 (9%)	4 (8%)	2 (12%)
Native American	1 (1%)	1 (2%)	0
Tumor location				0.088
Body	25 (37%)	20 (39%)	5 (29%)
Antrum	21 (31%)	16 (31%)	5 (29%)
Whole stomach	13 (19%)	6 (12%)	7 (42%)
Cardia	6 (9%)	6 (12%)	0
GEJ	3 (4%)	3 (6%)	0
Histology
Adenocarcinoma	67 (99%)	50 (98%)	17 (100%)
Laurens classification				0.495
Diffuse	28 (41%)	20 (39%)	8 (47%)
Intestinal	17 (25%)	15 (29%)	2 (12%)
Not reported	19 (28%)	13 (25%)	6 (35%)
Mixed	4 (6%)	3 (6%)	1 (6%)
Histologic differentiation				0.317
G1: Well-differentiated	1 (1%)	1 (2%)	0
G2: Moderately-differentiated	8 (12%)	8 (16%)	0
G3: Poorly-differentiated	53 (78%)	38 (74%)	15 (88%)
Not reported	6 (9%)	4 (8%)	2 (12%)
Signet ring cell morphology	27 (40%)	19 (37%)	8 (47%)	0.474

Table 1. Patient and Tumor Characteristics

Characteristic

Overall (n = 68)

Laparoscopy M0 (n = 51)

Laparoscopy M1 (n = 17)

P-value

GEJ: gastroesophageal junction.

Gender

0.773

Male

42 (62%)

31 (61%)

11 (65%)

Female

26 (38%)

20 (39%)

6 (35%)

Age (years)

Median (range)

64 (16 - 87)

65 (16 - 87)

64 (45 - 80)

0.639

≥ 60

47 (69%)

36 (71%)

11 (65%)

0.649

Ethnicity/race

0.370

Caucasian (White)

34 (50%)

26 (51%)

8 (47%)

African American

19 (28%)

16 (31%)

3 (18%)

Hispanic

8 (12%)

4 (8%)

4 (24%)

Asian

6 (9%)

4 (8%)

2 (12%)

Native American

1 (1%)

1 (2%)

Tumor location

0.088

Body

25 (37%)

20 (39%)

5 (29%)

Antrum

21 (31%)

16 (31%)

5 (29%)

Whole stomach

13 (19%)

6 (12%)

7 (42%)

Cardia

6 (9%)

6 (12%)

GEJ

3 (4%)

3 (6%)

Histology

Adenocarcinoma

67 (99%)

50 (98%)

17 (100%)

Laurens classification

0.495

Diffuse

28 (41%)

20 (39%)

8 (47%)

Intestinal

17 (25%)

15 (29%)

2 (12%)

Not reported

19 (28%)

13 (25%)

6 (35%)

Mixed

4 (6%)

3 (6%)

1 (6%)

Histologic differentiation

0.317

G1: Well-differentiated

1 (1%)

1 (2%)

G2: Moderately-differentiated

8 (12%)

8 (16%)

G3: Poorly-differentiated

53 (78%)

38 (74%)

15 (88%)

Not reported

6 (9%)

4 (8%)

2 (12%)

Signet ring cell morphology

27 (40%)

19 (37%)

8 (47%)

0.474

**Table 2.** Endoscopic Characteristics
Characteristic	Overall	Laparoscopy M0	Laparoscopy M1	P-value
*Significant (P < 0.05).
Linitis plastica appearance	17 (25%)	9 (18%)	8 (47%)	0.015*
Ulceration	47 (69%)	36 (71%)	11 (65%)	0.649
Circumferential involvement	28 (41%)	17 (33%)	11 (65%)	0.023*
EUS T stage				0.494
T1	1 (1%)	1 (2%)	0
T2	5 (7%)	5 (10%)	0
T3	59 (87%)	42 (82%)	17 (100%)
T4	3 (4%)	3 (6%)	0
EUS N stage				0.024*
N0	20 (29%)	18 (36%)	2 (12%)
N1	25 (37%)	15 (29%)	10 (59%)
N2	17 (25%)	15 (29%)	2 (12%)
N3	6 (9%)	3 (6%)	3 (18%)
EUS M stage				1
M0	68 (100%)	51 (100%)	17 (100%)
EUS ascites	2 (3%)	2 (4%)	0	1

Table 2. Endoscopic Characteristics

Characteristic

Overall

Laparoscopy M0

Laparoscopy M1

P-value

*Significant (P < 0.05).

Linitis plastica appearance

17 (25%)

9 (18%)

8 (47%)

0.015*

Ulceration

47 (69%)

36 (71%)

11 (65%)

0.649

Circumferential involvement

28 (41%)

17 (33%)

11 (65%)

0.023*

EUS T stage

0.494

1 (1%)

1 (2%)

5 (7%)

5 (10%)

59 (87%)

42 (82%)

17 (100%)

3 (4%)

3 (6%)

EUS N stage

0.024*

20 (29%)

18 (36%)

2 (12%)

25 (37%)

15 (29%)

10 (59%)

17 (25%)

15 (29%)

2 (12%)

6 (9%)

3 (6%)

3 (18%)

EUS M stage

68 (100%)

51 (100%)

17 (100%)

EUS ascites

2 (3%)

2 (4%)

**Table 3.** Diagnostic Laparoscopy Characteristics
Characteristic	N	%
Peritoneal washing
Negative	51	75
Positive	16	24
Not done	1	1
Positive cytology
Metastatic adenocarcinoma	11	69
Atypical cells	5	31
Visible metastatic disease
No	62	91
Yes	6	9
Location of visible disease
Peritoneum	4	66%
Omentum	1	17%
Diaphragmatic caking	1	17%
Ascites
No	61	90%
Yes	7	10%
Overall laparoscopic M stage
M0	51	75%
M1	17	25%

Table 3. Diagnostic Laparoscopy Characteristics

Characteristic

Peritoneal washing

Negative

Positive

Not done

Positive cytology

Metastatic adenocarcinoma

Atypical cells

Visible metastatic disease

Yes

Location of visible disease

Peritoneum

66%

Omentum

17%

Diaphragmatic caking

17%

Ascites

90%

Yes

10%

Overall laparoscopic M stage

75%

25%

**Table 4.** Endoscopic Ultrasound High-Risk and Low-Risk Subdivision and Laparoscopic Identification of Occult M1 Disease
Endoscopic ultrasound	Laparoscopy M, n	Total, n
	1	0
High risk	17	46	63
Low risk	0	5	5
Total	17	51	68

Table 4. Endoscopic Ultrasound High-Risk and Low-Risk Subdivision and Laparoscopic Identification of Occult M1 Disease

Endoscopic ultrasound

Laparoscopy M, n

Total, n

High risk

Low risk

Total