606P - BRAF and NRAS mutations are associated with poor prognosis in Asians with acral-lentiginous and nodular cutaneous melanoma

Background

Cutaneous melanoma is considered a rare but lethal cancer among Asians. Prognosis is generally worse with high rates of recurrences and mortality. Clinical presentations show striking differences with cutaneous melanoma among Caucasian. Acral lentiginous and nodular melanoma are the most common subtypes among Asian. Patterns of mutations and molecular alterations and the association with prognosis are not yet known among melanoma patients in Indonesia. This study aims to analyze association between BRAF dan NRAS mutations with overall survival of melanoma patients in Indonesia.

Methods

DNA from formalin-fixed paraffin embedded tissues from melanoma patients were extracted. PCR and pyrosequencing were performed to detect mutations in the BRAF dan NRAS genes.

Results

Of 51 melanoma patients, 44 patients (86.3%) were diagnosed with Breslow thickness more than 4 mm (T4). In the primary cutaneous melanoma lesions, 33 (67%) patients had ulceration, 47 patients (92.2%) had diameter more than 6 mm, and 30 patient (58.2%) had positive regional lymph nodes. In this study, BRAF mutations were found in 26 patients (56%) and NRAS mutations were found in 5 patients (9.8%). BRAF mutations were found in older age than 65 years although the difference was not significant (OR 2.205, 95%CI: 0.558-8.717, P=0.259). BRAF mutations were associated with significantly lower overall survivals compared to wild-type (median survivals were 18 vs 34 months, P=0.042). Although patients with NRAS mutations had shorter survival, the difference was not statistically significant (P=0.120). Patients with BRAF or NRAS were associated with significant lower overall survivals compared to those with wild-type (Median survivals were 19 vs 35 months, P=0.044).

Conclusions

BRAF and / or NRAS mutations were associated with shorter survival among cutaneous melanomas in Indonesia with predominant subtypes of acral lentiginous and nodular melanomas. Larger study from Asian population is required to extend our finding to establish a prognostic marker as well as a potential targeted treatment.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Gadjah Mada University.

Funding

Gadjah Mada University.

Disclosure

All authors have declared no conflicts of interest.