A literature review: The role of plakoglobin as a biomarker to determine the invasive potential of ductal carcinoma in situ
DCIS is a heterogeneous disease exhibiting varying degrees of aggressiveness; approximately 40% of DCIS will progress into invasive cancer. Currently, no molecular marker is identified that can reliably predict the invasive potential of DCIS in an individual patient. Additionally, DCIS carries a recurrence rate of 3-17% within 10 years, and half of these recurrences could be invasive cancers. A biomarker that can reliably predict which DCIS lesions have a high likelihood of developing into invasive cancers can potentially prevent over- or undertreating patients. Method: A search of electronic databases 'MEDLINE' and 'PUBMED' for relevant published articles was undertaken in February 2015. Publications deemed sufficiently relevant to the topic and published between January 1990 and February 2015 were included in the review. Results: Desmosomes are molecular complexes that attach adjacent epithelial cells together by means of linking proteins together. Any disruption in desmosomal proteins can lead to certain diseases-such as cardiomyopathy and pemphigus and cancer progression. Plakoglobin (PG) is a desmosomal protein that has been implicated in malignant transformation associated with phenotypic features of reduced cell-cell adhesion, increased invasiveness, migration and cell proliferation. PG can be a potential biomarker for cancer progression, differentiating between chronic pancreatitis and pancreatic ductal adenocarcinoma (PDAC) cancer. Ellis et al. have reported reduced PG expression in invasive Paget's disease of the vulva, when compared to intraepidermal Paget's disease of the vulva. Conclusions: The loss of PG can serve as a potential biomarker to predict the invasive potential of DCIS. If PG is a reliable predictor of the invasive potential of DCIS lesions, this will help to tailor treatment for patients with DCIS according to its invasive potential. For example, patients with low-grade DCIS with a low invasive potential will not have to undergo disfiguring surgical treatment of mastectomy.