  Cancer ranks as one of the deadliest diseases worldwide. The high mortality
rate associated with cancer is partially due to the lack of reliable early
detection methods and/or inaccurate diagnostic tools such as certain protein
biomarkers. Cell-free nucleic acids (cfNA) such as circulating long non-coding
RNAs (lncRNAs) have recently been proposed as a new class of potential
biomarkers that could improve cancer diagnosis. The reported correlation
between circulating lncRNA levels and the presence of tumors has triggered a
great amount of interest among clinicians and scientists who have been actively
investigating their potentials as reliable cancer biomarkers. In this report,
we review the progress achieved (the Good) and challenges encountered (the Bad)
in the development of circulating lncRNAs as potential biomarkers for early
cancer diagnosis. We report and discuss the specificity and sensitivity issues
of blood-based lncRNAs currently considered as promising biomarkers for various
cancers such as hepatocellular carcinoma, colorectal cancer, gastric cancer and
prostate cancer. We also emphasize the potential clinical applications (the
Beauty) of circulating lncRNAs both as therapeutic targets and agents, on top
of diagnostic and prognostic capabilities. Based on different published works,
we finally provide recommendations for investigators who seek to investigate
and compare the levels of circulating lncRNAs in the blood of cancer patients
compared to healthy subjects by RT-qPCR or Next Generation Sequencing.
