High expression of a specific protein is associated with an improved 5-year survival rate of almost 28% in gastric cancer, according to new research published in PLOS One (online August 30, 2017; doi:10.1371/journal.pone.0183868).
A protein that is intimately involved in the development of multiple organs is PROX1. Prior research has shown that PROX1 also plays a critical role in the progression of colorectal cancer. Further research is needed to better understand the extent of the prognostic role of PROX1 expression in gastric cancer.
A group of Finnish researchers led by Alli Laitinen, department of surgery, University of Helsinki, conducted a trial to evaluate PROX1 expression in gastric cancer. Researchers analyzed the immunohistochemistry of tumor-tissue microarrays—including tumor specimens—from 283 patients who underwent surgery for gastric cancer at the Helsinki University Hospital. The potential association between PROX1 expression and clinicopathologic variables, as well as patient survival, were assessed.
Researchers reported that cytoplasmic PROX1 reactivity was high in 20.5% of patients (n = 56) and low in 79.5% of patients (n = 217). They further noted that low PROX1 immunostaining was associated with diffuse cancer subtype (P = .002).
Results of the study showed that high PROX1 expression was associated with a disease-specific 5-year survival of 65.6% (95% CI, 52.7-78.5), compared with 37.1% (95% CI, 30.2-44.0) for patients with low PROX1 expression (P = .004). A multivariable analysis confirmed this finding (HR, 0.56; 95% CI, 0.35-0.90; P = .017).
An additional subgroup analysis showed that PROX1 was a significant marker of better prognosis in patients aged less than 66 years (P = .007), in patients with intestinal cancer (P = .025), among men (P = .019), and in tumors less than 5 cm in diameter (P = 0.030).
Researchers concluded that PROX1 expressions correlates strongly with improved 5-year survival rates in gastric cancer. This finding should guide treatment decision-making at initial diagnosis, they wrote.—Zachary Bessette