(HealthDay News) — Greater reproducibility and higher concordance are seen for melanoma staging with the American Joint Committee on Cancer (AJCC) classification of cancer staging, the AJCC Cancer Staging Manual, 8th edition (AJCC 8), which includes revisions to definitions of T1a versus T1b or greater, according to a study published online May 18 in JAMA Network Open.
Joann G. Elmore, M.D., M.P.H., from the University of California, Los Angeles, and colleagues compared AJCC 8 with the AJCC Cancer Staging Manual, 7th edition (AJCC 7) in a diagnostic study. A total of 187 pathologists interpreting melanocytic skin lesions completed 4,342 independent case interpretations of 116 invasive melanoma cases.
The researchers found that for T1a diagnoses, participating pathologists’ concordance with the consensus reference diagnosis increased from 44 percent with AJCC 7 criteria to 54 percent with AJCC 8 criteria. For cases of T1b or greater, the concordance increased from 72 to 78 percent. There was also an improvement in intraobserver reproducibility of diagnoses, increasing from 59 to 64 percent and from 74 to 77 percent for T1a and T1b or greater invasive melanoma cases, respectively.
“Improved classification of invasive melanoma can be expected after implementation of AJCC 8, suggesting a positive impact on patients. However, despite improvement, concordance and reproducibility remain low,” the authors write.
Two authors disclosed ties to the biotechnology industry.