 - an important step in surgical staging for uterine cancer (FIGO 1988)  Stated as 

SIZE: LN size > 1 cm  abnormal enlargement  suspicious for pathologic conditions  reactive hyperplasia  tumor metastasis  inflammation etc.

“Can we truly rely on the size of LN to determine uterine cancer metastases?”

To evaluate the association between & To determine

 Pathologic sections of pelvic/paraaortic LNs of uterine cancer patients who had surgical staging between 1994 to 2004  Measuring:  maximal dimension of each LN  metastatic lesion in positive LN

 Pelvic 2941 nodes (68.7%)  Common iliac 592 nodes (13.8%)  Subaortic 86 nodes (2.0%)  Paraaortic 544 nodes (12.7%)  Miscellaneous groups 31 nodes (0.7%) 4280 LNs from 178 uterine cancer patients

Histology of uterine cancer N of LN (%) N of patient s (%) CARCINOMA Endometrioid carcinoma Endometrioid carcinoma with squamous differentiation Endometrioid mixed with serous or mucinous carcinoma Clear cell carcinoma Papillary serous carcinoma SARCOMA Malignant mixed mullerian tumor Other sarcomas* 3740 (87.4) 334 (7.8) 60 (1.4) 125 (2.9) 55 (1.3) 360 (8.4) 172 (4.0) 137 (77.0) 13 (7.4) 2 (1.1) 4 (2.2) 2 (1.1) 8 (4.4) 12 (6.8) TOTAL4280 (100) 178 (100) * Other sarcomas included endometrial stromal sarcoma, leiomyosarcoma, and not otherwise specified sarcoma

Total number of LNs (178 cases) = 4280 nodes Median LN yielded per case (range) = 23 (1-55) nodes 150 negative cases (n = 3670 nodes) = 23.0 (1-55) nodes 28 positive cases (n = 610 nodes) = 22.5 (6-38) nodes Median positive LN per case (range) = 2 (1-12) nodes Positive LN in 28 cases (15.7%) = 86 nodes (2.0%)

9/28 (32%) had only single positive LN Among 28 cases with positive LN 8/9 (88.9%) LNs - not the largest nodes from that case 5/9 (55.6%) LNs - sized < 1 cm

positive nodes: 9 mm (1-50 mm) Median size p  (n = 86 nodes) (n = 4194 nodes) negative nodes: 5 mm (1-35 mm)

Subgroups Size of LN Negative Positive (mm) (range) (mm) (range) P-value Grade I5 (1-27)8 (7-11)0.161 II-III5 (1-35)9 (1-50)<0.001 Histology Adenocarcinoma5 (1-35)9 (1-50)<0.001 Sarcoma 7 (1-29)10 (4-33)0.003 Note: No significant differences between positive LNs in tumors of:  grade I VS grade II-III  adenocarcinoma VS sarcoma

Size of LN Pathology of node Negative Positive n (% a ) n (% b ) % c of positive LN < 5 mm1672 (39.9)11 (12.8) mm1543 (36.8)34 (39.5)2.2 10–19 mm870 (20.7)32 (37.2)3.5 > 20 mm109 (2.6)9 (10.5)7.6 Total4194 (100.0)86 (100.0)2.0 a Percentages of negative nodes at different levels of LN size/ total negative LN b Percentages of positive nodes at different levels of LN size/ total positive LN c Percentages of positive nodes at different levels of LN size/ total nodes 52.3% 47.7%

Figure 1. Receiver-Operating curve of LN size to determine LN metastases in uterine cancer

Sensitivity 47.7% (46.2%-49.2%) Specificity 76.7% (75.4%-77.9%) Negative predictive value 98.6% (98.3%-99.0%) Positive predictive value 4.0% (3.4%-4.6%)

Median metastatic lesions: 5.5 mm (1-50 mm)  < 2 mm…… %  < 5 mm…… %  < 10 mm…… %

To evaluate the association between & To determine

An association between …….. No appropriate ……..

 Size of + LN was significantly larger than that of – LN (9 mm VS 5 mm)………. “ The difference is of questionable benefit in clinical practice ”

“We have to perform a complete LND”  If we base on nodal size of 10 mm as pathologic enlargement--- low sensitivity of 47.7% “ We would miss >1/2 of positive nodes ”  If we set it at 3 mm ---high sensitivity of 97.7%

Author N of positive LN studied Positive LN sized < 1 cm ( %) Microscopic positive LN (%) Single positive LN (%) Chuang, b NA39 b NA Girardi, NA Ayhan, Our study a Microscopic referred to size < 2-3 mm b Study of Chuang et al. presented the result as number of cases (not lymph node)

 Microscopic metastasis …… 31-37%  Subcentimeter positive LNs..… 48-57%  Single positive LNs ……….… 25-32% 89% of these single positive LNs were not the largest node from that case. Subcentimeter single positive LNs… %

 < 10% positive LNs --- grossly enlarged  36% positive LNs being missed by palpation Eltabbakh GH. Am J Obstet Gynecol 2001;184: Creasman et al. Cancer 1987;60:

False-negative rates ~ 19-26% Positive predictive values ~ 56-65% Eltabbakh GH. Am J Obstet Gynecol 2001;184: Khunnarong et al. J Med Assoc Thai 2004;87 (Suppl3):S80-4. adherence to surrounding tissue Shape consistency facilitate differentiation between post./ neg. LN

Selective LN resection might miss the target positive LN!!! LN size --- not a good predictor of LN metastasis Complete LN dissection --- for patients undergoing surgical staging, in whom LN assessment is indicated