Melanoma is one of the most aggressive skin cancers due to its potential to metastasize widely in the body. The risk of metastasis is increased with later detection and increased thickness of the primary lesion, thus early identification and surgical removal is critical for higher survival rates for patients. However, even with appropriate treatment, some patients will develop recurrence which may be difficult to identify until advanced or causing symptoms. Recent advances in liquid biopsy have proposed less-invasive alternatives for cancer diagnosis and monitoring using minimal/zero invasion at sample collection, and circulating tumor cells(CTCs) have been considered a promising blood-based surrogate marker of primary tumors. However, previous CTC technologies relying on epithelial-cell adhesion molecules have limited to epithelial cells, thus hampering use of CTCs for non-epithelial cancers such as melanoma. Here, we used the Melanoma-specific OncoBean platform(MelanoBean) conjugated with melanoma specific antibodies(MCAM and MCSP). The device was used in comprehensive studies for diagnosing melanoma and evaluating surgery efficacy based on change in the number and characteristics of CTCs and CTC-clusters pre- and post-surgical treatment. Our study demonstrated that melanoma patients(n=45) at all stages(I-IV) have a noticeable number of MCTCs as well as MCTC-clusters compared to healthy donors(n=9)(P=0.0011), and surgical treatment leads to a significant decrease in the number of CTCs(P<0.0001). The CTCs recovered from the device underwent molecular profiling for melanoma-associated genes expression using multiplexed qRT-PCR, demonstrating the ability to monitor molecular signature through treatment. The presented MelanoBean and the comprehensive approach will empower prognostic value of CTCs in melanoma in much larger cohort studies.
Keywords: Surgical treatment efficacy evaluation using microfluidic CTC isolation.