World J Oncol

World Journal of Oncology, ISSN 1920-4531 print, 1920-454X online, Open Access

Article copyright, the authors; Journal compilation copyright, World J Oncol and Elmer Press Inc

Journal website https://wjon.elmerpub.com

Original Article

Volume 16, Number 4, August 2025, pages 365-374

Development and Validation of KN-DIOC: A Novel Preoperative Diagnostic Index Using Ultrasound, Complete Blood Count, and Cancer Antigen 125 for Ovarian Cancer

↓ Figure 2. ROC curves of KN-IOC. KN-DIOC: KMUTT-NMU Diagnostic Index for Ovarian Cancer; ROC: receiver operating characteristic.

↓ Figure 3. Comparison of ROC curves: KN-IOC, RMI I-IV, ROMA, and R-OPS. KN-DIOC: KMUTT-NMU Diagnostic Index for Ovarian Cancer; RMI: Risk of Malignancy Index; ROC: receiver operating characteristic; ROMA: Risk of Ovarian Malignancy Algorithm; R-OPS: Rajavithi-Ovarian Cancer Predictive Score.

↓ **Table 1.** Numbers of Histological Types in Development and Validation Datasets
Histological type	Development dataset (n = 53)	Validation dataset (n = 17)
High-grade serous carcinoma	19	4
Mucinous adenocarcinoma/carcinoma	8	1
Clear cell carcinoma	7	5
Endometrioid adenocarcinoma	8	5
Undifferentiated adenocarcinoma	7	0
Mixed cell type	3	1
Mucinous borderline tumor	1	1

↓ Table 1. Numbers of Histological Types in Development and Validation Datasets

Histological type

Development dataset (n = 53)

Validation dataset (n = 17)

High-grade serous carcinoma

Mucinous adenocarcinoma/carcinoma

Clear cell carcinoma

Endometrioid adenocarcinoma

Undifferentiated adenocarcinoma

Mixed cell type

Mucinous borderline tumor

↓ **Table 2.** Logistic Regression Analysis of CBC and Ultrasound Features (Development Dataset)
Predictors	Coefficient	OR	95% CI	P-value*
*Significant at P < 0.05. CBC: complete blood count; CI: confident interval; OR: odds ratio.
CBC
Platelets counts	0.009	1.009	1.005 - 1.013	< 0.001
Constant	-3.692	0.025	-	< 0.001
Ultrasound features
Solid area	1.868	6.475	2.488 - 16.851	< 0.001
Papillary projection	2.395	10.974	4.117 - 29.250	< 0.001
Ascites	1.490	4.439	1.362 - 14.474	0.013
Constant	-2.757	0.063	-	< 0.001

↓ Table 2. Logistic Regression Analysis of CBC and Ultrasound Features (Development Dataset)

Predictors

Coefficient

95% CI

P-value*

*Significant at P < 0.05. CBC: complete blood count; CI: confident interval; OR: odds ratio.

CBC

Platelets counts

0.009

1.009

1.005 - 1.013

< 0.001

Constant

-3.692

0.025

< 0.001

Ultrasound features

Solid area

1.868

6.475

2.488 - 16.851

< 0.001

Papillary projection

2.395

10.974

4.117 - 29.250

< 0.001

Ascites

1.490

4.439

1.362 - 14.474

0.013

Constant

-2.757

0.063

< 0.001

↓ **Table 3.** Result of Logistic Regression Analysis for the KN-DIOC (Development Dataset)
Predictors	Coefficient	OR	95% CI	P-value*
*Significant at P < 0.05. CA125: cancer antigen 125; CI: confident interval; KN-DIOC: KMUTT-NMU Diagnostic Index for Ovarian Cancer; OR: odds ratio.
Postmenopausal	0.874	2.396	0.795 - 7.219	0.121
Platelets counts	0.008	1.008	1.002 - 1.013	0.010
Solid area	1.484	4.410	1.449 - 13.423	0.009
Papillary projection	2.446	11.547	3.753 - 35.527	< 0.001
Multilocular cyst	1.389	4.009	1.264 - 12.715	0.018
CA125	0.002	1.002	1.001 - 1.004	0.007
Constant	-6.527	0.001	-	< 0.001

↓ Table 3. Result of Logistic Regression Analysis for the KN-DIOC (Development Dataset)

Predictors

Coefficient

95% CI

P-value*

*Significant at P < 0.05. CA125: cancer antigen 125; CI: confident interval; KN-DIOC: KMUTT-NMU Diagnostic Index for Ovarian Cancer; OR: odds ratio.

Postmenopausal

0.874

2.396

0.795 - 7.219

0.121

Platelets counts

0.008

1.008

1.002 - 1.013

0.010

Solid area

1.484

4.410

1.449 - 13.423

0.009

Papillary projection

2.446

11.547

3.753 - 35.527

< 0.001

Multilocular cyst

1.389

4.009

1.264 - 12.715

0.018

CA125

0.002

1.002

1.001 - 1.004

0.007

Constant

-6.527

0.001

< 0.001

↓ **Table 4.** Discriminative Performance of Preoperative Diagnosis Indices (Validation Dataset)
Test result indices	Cutoff point	AUC	P-value^a	95% CI	P-value^b	AUC difference
Significant at P < 0.05. ^aNull hypothesis: true area = 0.5. ^bNull hypothesis: true area difference = 0. ^cPremenopausal/postmenopausal cut-off points. AUC: area under the curve; CI: confident interval; KN-DIOC: KMUTT-NMU Diagnostic Index for Ovarian Cancer; OR: odds ratio; RMI: Risk of Malignancy Index; ROMA: Risk of Ovarian Malignancy Algorithm; R-OPS: Rajavithi-ovarian cancer predictive score.
KN-DIOC	0.25	0.866	< 0.001	0.750 - 0.982	Ref.	Ref.
RMI I	200	0.853	< 0.001	0.720 - 0.986	0.857	0.013
RMI II	200	0.833	< 0.001	0.706 - 0.959	0.614	0.033
RMI III	200	0.853	< 0.001	0.731 - 0.974	0.846	0.013
RMI IV	450	0.857	< 0.001	0.744 - 0.971	0.881	0.009
ROMA	11.4/29.9^c	0.900	< 0.001	0.795 - 1.000	0.558	-0.033
R-OPS	330	0.828	< 0.001	0.705 - 0.951	0.452	0.038

↓ Table 4. Discriminative Performance of Preoperative Diagnosis Indices (Validation Dataset)

Test result indices

Cutoff point

AUC

P-value^a

95% CI

P-value^b

AUC difference

Significant at P < 0.05. ^aNull hypothesis: true area = 0.5. ^bNull hypothesis: true area difference = 0. ^cPremenopausal/postmenopausal cut-off points. AUC: area under the curve; CI: confident interval; KN-DIOC: KMUTT-NMU Diagnostic Index for Ovarian Cancer; OR: odds ratio; RMI: Risk of Malignancy Index; ROMA: Risk of Ovarian Malignancy Algorithm; R-OPS: Rajavithi-ovarian cancer predictive score.

KN-DIOC

0.25

0.866

< 0.001

0.750 - 0.982

Ref.

RMI I

200

0.853

< 0.001

0.720 - 0.986

0.857

0.013

RMI II

200

0.833

< 0.001

0.706 - 0.959

0.614

0.033

RMI III

200

0.853

< 0.001

0.731 - 0.974

0.846

0.013

RMI IV

450

0.857

< 0.001

0.744 - 0.971

0.881

0.009

ROMA

11.4/29.9^c

0.900

< 0.001

0.795 - 1.000

0.558

-0.033

R-OPS

330

0.828

< 0.001

0.705 - 0.951

0.452

0.038

↓ **Table 5.** Diagnostic Test Performance Metrics Based on Validation Dataset
	KN-DIOC	RMI I	RMI II	RMI III	RMI IV	ROMA	R-OPS
Acc: accuracy; FN: false negatives; FP: false positives; KN-DIOC: KMUTT-NMU Diagnostic Index for Ovarian Cancer; LR+: positive likelihood ratio; LR-: negative likelihood ratio; NPV: negative predictive value; OR: odds ratio; PPV: positive predictive value; RMI: Risk of Malignancy Index; ROMA: Risk of Ovarian Malignancy Algorithm; R-OPS: Rajavithi-ovarian cancer predictive score; Sn: sensitivity; Sp: specificity; TN: true negatives; TP: true positives.
TP	15	11	13	11	11	13	10
FP	6	2	9	3	6	4	7
FN	1	5	3	5	5	3	6
TN	22	26	19	25	22	24	21
Sn (%)	93.75	68.75	81.25	68.75	68.75	81.25	62.5
Sp (%)	78.57	92.86	67.86	89.29	78.57	85.71	75.0
Acc (%)	84.09	84.09	72.73	81.82	75.0	84.09	70.45
PPV (%)	71.43	84.62	59.09	78.57	64.71	76.47	58.82
NPV (%)	95.65	83.87	86.36	83.33	81.48	88.89	77.78
LR+	4.375	9.625	2.528	6.417	3.208	5.688	2.5
LR-	0.080	0.337	0.276	0.35	0.398	0.219	0.5
OR	55	28.6	9.15	18.33	8.067	26	5

↓ Table 5. Diagnostic Test Performance Metrics Based on Validation Dataset

KN-DIOC

RMI I

RMI II

RMI III

RMI IV

ROMA

R-OPS

Acc: accuracy; FN: false negatives; FP: false positives; KN-DIOC: KMUTT-NMU Diagnostic Index for Ovarian Cancer; LR+: positive likelihood ratio; LR-: negative likelihood ratio; NPV: negative predictive value; OR: odds ratio; PPV: positive predictive value; RMI: Risk of Malignancy Index; ROMA: Risk of Ovarian Malignancy Algorithm; R-OPS: Rajavithi-ovarian cancer predictive score; Sn: sensitivity; Sp: specificity; TN: true negatives; TP: true positives.

Sn (%)

93.75

68.75

81.25

68.75

81.25

62.5

Sp (%)

78.57

92.86

67.86

89.29

78.57

85.71

75.0

Acc (%)

84.09

72.73

81.82

75.0

84.09

70.45

PPV (%)

71.43

84.62

59.09

78.57

64.71

76.47

58.82

NPV (%)

95.65

83.87

86.36

83.33

81.48

88.89

77.78

LR+

4.375

9.625

2.528

6.417

3.208

5.688

2.5

LR-

0.080

0.337

0.276

0.35

0.398

0.219

0.5

28.6

9.15

18.33

8.067