JAMA Ophthalmology, August 2019
Physicians who stage cancer recognize the need for collaborative data sharing and the importance of validating cancer staging systems that are used to standardize patient care. Jain et al. tested the accuracy of content in the eighth (2018) edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual for estimating mortality and metastasis rates for conjunctival melanoma. They found that the manual’s content is accurate.
For this registry-based international study, the authors pooled data from 10 ophthalmic oncology centers representing 288 patients (mean age, 59.7 years) with conjunctival melanoma. The patients were diagnosed from 2001 through 2013; treatments included excision biopsy, cryotherapy, topical chemotherapy, radiation therapy, enucleation, and exenteration. Main outcome measures were metastasis rates and the five- and 10-year Kaplan-Meier mortality rates according to the clinical T (cT) categories and subcategories. Data were analyzed in 2018.
With regard to tumor category, 218 patients (75.7%) had cT1 tumors, 34 (11.8%) had cT2 disease, 15 (5.2%) had cT3 tumors, and 21 (7.3%) were classified as having cTx disease. No patients had cT4 tumors. The pathologic T category (pT) was pTis in 43 patients (14.9%), pT1 in 169 (58.7%), pT2 in 33 (11.5%), pT3 in 12 (4.2%), and pTx in 31 (10.8%).
At presentation, metastasis was noted in five patients (1.7%). During follow-up, metastasis had occurred in 24 patients (8.5%) after a median of 4.3 years (interquartile range [IQR], 2.9-6.0 years). Twenty-nine (10.1%) of the 288 patients died of a melanoma-related cause, at a median time of 5.3 years (IQR, 1.8-7.0 years). Patients with T3 disease were the only group with mortality in the first year.
The highest mortality rates were found among patients with cT2 and cT3 conjunctival melanoma, compared with those presenting with cT1 tumors. Specifically, cumulative mortality rates for patients with cT1 tumors were 0% at 1 year, 2.5% at 5 years, and 15.2% at 10 years. For patients with cT2 tumors, the mortality rates were 0% at 1 year, 28.6% at 5 years, and 43.6% at 10 years. Among those with cT3 tumors, mortality rates were 21.1% and 31.6% at 1 and 5 years, respectively (10-year data were not available).
The risk of death was higher for patients with ulcerated melanoma (hazard ratio, 7.58; p = .04).
This study suggests that the eighth edition of the AJCC Cancer Staging Manual is an accurate resource for staging conjunctival melanoma and for estimating metastasis and mortality rates. The findings support use of this information to guide patient care and future research. (Also see related commentary by Bita Esmaeli, MD, in the same issue.)
The original article can be found here.