Commentary: Prognostication of uveal melanoma based on molecular diagnosis - Are we there yet?

In their review on the cancer genome atlas classification (TGCA), Shields et al. have diligently explained how this new classification system will help in prognostication of the disease, over the American Joint Committee on Cancer (AJCC) classification.[1] The TGCA is an accomplished program started in 2005 to elaborate the molecular genomics of few cancers.[2] It was later on expanded to include several other cancers including uveal melanoma (UM).[3]

The tissue obtained with fine-needle aspiration biopsy was subjected to molecular testing. The UM were divided into four categories: A, B, C, and D based on the presence or absence of chromosome 3 disomy and then further based on the presence and degree of chromosome 8q gain.[34] Category D had the worst prognosis with high rates of metastasis and cancer-related deaths.[3] By prognostication of the disease, the patient can be counseled regarding the nature of the disease. The frequency of follow-up also can be individualized. Chemotherapeutic drugs targeting these genetic variations or their genetic products are being explored and may be available in the near future.[5]

Though it is a landmark program, currently molecular diagnostics may not be economical in developing countries such as India where resources for cancer treatment are limited. Hence, we will have to continue to rely on the AJCC classification, which is a clinical classification. The genetic variation in UM in Indian patients may be different from that tested in TGCA.

Also, there is no treatment at hand targeting the disease at its molecular level. In the Indian scenario, only predicting the outcome of the disease with no change in treatment strategy may not be an alluring diagnostic test for the patient. The real-world benefit of this classification system is yet to be proved.