Table 2. Changes in Concordance, Interobserver Agreement, and Intraobserver Reproducibility When Comparing AJCC 7 With AJCC 8.
| AJCC Cancer Staging Manual Edition | Total Invasive Melanoma Cases for Consensus, No. | % (95% CI) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Concordance With Consensus Reference Diagnosis | Interobserver Agreement | Intraobserver Reproducibility for Same Case at 2 Time Points | |||||||
| Underinterpretation | Concordance | P Valuea | Overinterpretation | Concordance | P Valuea | Reproducibility | P Valuea | ||
| AJCC 7 | |||||||||
| T1a (MPATH-Dx class IV) | 55 | 46 (43-50) | 44 (41-48) | 9 (8-12) | 41 (39-44) | 59 (56-63) | |||
| T1b or greater (MPATH-Dx class V) | 61 | 28 (25-31) | 72 (69-75) | NA | 67 (64-69) | 74 (71-76) | |||
| AJCC 8 | |||||||||
| T1a | 70 | 39 (36-42) | 54 (51-57) | <.001 | 7 (6-8) | 51 (48-53) | <.001 | 64 (62-67) | .006 |
| T1b or greater | 46 | 22 (20-25) | 78 (75-80) | <.001 | NA | 69 (66-73) | .02 | 77 (74-79) | .11 |
Abbreviations: AJCC 7, AJCC Cancer Staging Manual, 7th edition; AJCC 8, AJCC Cancer Staging Manual, 8th edition; MPATH-Dx, Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis; NA, not applicable.
a
P values for test of concordance, interobserver agreement, and intraobserver reproducibility rate differences between AJCC 7– and AJCC 8–based mappings.