Neoadjuvant chemotherapy (NAC) has been increasingly used for gastric cancer. JCOG1302A investigated whether cT3-4/ N1-3 was a suitable criterion for NAC minimizing the contamination of pStage I. In that study, 77.2% of tumors diagnosed as cT3-4 by a combination of endoscopy and computed tomography (CT) were pT3-4. The role of endoscopic ultrasonography (EUS) or additional options in diagnosis of invasion depth was unclear.
Using data of JCOG1302A, we evaluated accuracy of endoscopic or CT diagnosis of cT3-4 to detect pT3-4, by comparing positive predictive value (PPV), negative predictive value (NPV), and kappa index (KI) between conventional endoscopy (CE) with and without EUS, CT of 5 mm and 1 mm slice, and CT with and without foaming agent (FA).
Data from 1232 patients enrolled in 53 institutions were analyzed (Table). Overall, there is no remarkable difference in any comparison. More specifically, PPV and KI were slightly higher in CE alone rather than in CE combined with EUS. Although NPV was higher in 1 mm slice CT and CT with FA, PPV was higher in 5 mm slice CT and CT without FA. Table 1 Comparison of PPV, NPV, and KI between CE alone and CE combined with EUS, between 5 mm slice CT and 1 mm slice CT, and between CT without FA and CT with FA.Table: 656P
|CE alone (n = 1232)||CE combined with EUS (n = 91)|
|PPV||79.2% (76.2-81.9)||73.7% (60.3-84.5)|
|NPV||59.2% (54.3-63.9)||58.8% (40.7-75.4)|
|KI||0.38 (0.33-0.44)||0.32 (0.12-0.52)|
|5 mm slice CT (n = 1042)||1 mm slice CT (n = 255)|
|PPV||77.8% (74.6-80.7)||75.5% (68.9-81.4)|
|NPV||62.9% (57.1-68.5)||71.2% (57.9-82.2)|
|KI||0.38 (0.32-0.44)||0.39 (0.28-0.51)|
|CT without FA (n = 840)||CT with FA (n = 368)|
|PPV||78.6% (75.1-81.8)||75.1% (69.5-80.1)|
|NPV||60.9% (54.4-67.3)||69.7% (59.7-78.5)|
|KI||0.38 (0.31-0.44)||0.40 (0.30-0.50)|
95%CIs are shown in brackets
Additional options such as EUS, 1 mm slice CT, or FA in CT may not improve diagnostic accuracy of invasion depth in resectable advanced gastric cancer.
Clinical trial identification
Legal entity responsible for the study
Japanese Clinical Oncology Group.
National Cancer Center Research and Development Fund (23-A-16, 23-A-19 and 26-A-4) from the Ministry of Health, National Cancer Center Research and Development Fund from the Ministry of Health, Labour and Welfare.
Y. Sato, J. Mizusawa: Grants: Ministry of Health, Labour and Welfare, Japan, Japan Agency for Medical Research and Development (AMED). K. Nakamura: Grants: Ministry of Health, Labour and Welfare, Japan, Japan Agency for Medical Research and Development (AMED); Fees: Bayer Pharma, Chugai Pharmaceutical. All other authors have declared no conflicts of interest.