Prognostic predictability of the new American Joint Committee on Cancer 8th staging system for distal bile duct cancer: limited usefulness compared with the 7th staging system

Abstract

The 8th AJCC staging for DBD cancer does not have better prognostic predictability than the 7th stage does. The previous pathologic results would become useless unless they were reviewed entirely. Therefore, introduction of the AJCC 8th staging has to be reconsidered, especially for new T staging.

Proposal of the optimal numbers of examined and positive lymph nodes to the 8th edition of American Joint Committee on Cancer (AJCC) staging for 758 patients with distal cholangiocarcinoma

“…Firstly, in Kiriyama M et al's paper [14], patients with PLNs � 4 were only 10% (37/370), and the patients from Japan was selected, which may not be suitable for European and American countries. Secondly, two large sample studies found no difference in prognosis between patients with PLNs � 4 and 1-3 [10,24], which was consistent with the results of this study. Thirdly, we found that among patients with ELNs � 5, using the optimal cut-off value of PLNs (0, 2) could accurately stratify patients (Fig 2C), but the recommendation of the number of PLNs by the AJCC (0, 3) could not ( Fig 2D).…”

Validation of the Eighth American Joint Committee on Cancer Staging System for Distal Bile Duct Carcinoma

“…Including our present study, several previous studies demonstrated the prognostic significance of the 3 tiered N category [13,22,23,25]. In present study, we observed significant survival differences among DBDC patients based on N category of the eighth AJCC staging system in overall comparison and in pairwise comparison between N0 and N1 patients, similar to the previous studies [13,22,23,25].…”

“…A few previous studies validated T category of the eighth AJCC staging scheme of DBDCs [13,25]. Moon et al [13] demonstrated the superiority of the eighth edition to the seventh edition for predicting patient prognosis, similar to our study.…”

“…However, there are discrepant results of patients’ survival between N1 and N2 groups. We did not find significant survival difference between N1 and N2 patients, which was concordant with that of Kang et al's study [25]. However, different with the present study, previous results of Moon et al [13] and Kiriyama et al [23] demonstrated significant differences in survival between patients with N1 and N2 tumors [13,23].…”

Proposal of the minimal number of retrieved regional lymph nodes for accurate staging of distal bile duct cancer and clinical validation of the three‐tier lymph node staging system (AJCC 8th edition)

“…Two external validation studies failed to show significant survival discrimination among the proposed 8th T stage criteria [27,29], and one of these studies proposed different cutoff values for tumor invasion depth, based on T stage [29]. A previous study revealed that the new 8th AJCC T stage did not have better prognostic predictability than the 7th [30]. To validate the proposed 8th T stage, researchers need to review all histologic slides again, which is timeconsuming and impossible; and therefore, the introduction of the proposed 8th AJCC T stage should be reconsidered.…”