Combination of three-gene immunohistochemical panel and magnetic resonance imaging-detected extramural vascular invasion to assess prognosis in non-advanced rectal cancer patients.

AIM: To identify a small, clinically applicable immunohistochemistry (IHC) panel that could be combined with magnetic resonance imaging (MRI)-detected extramural vascular invasion (EMVI) for assessment of prognosis concerning the non-advanced rectal cancer patients prior to operation.

METHODS: About 329 patients with pathologically confirmed rectal carcinoma (RC) were screened in this research, all of whom had been examined via an MRI and were treatment-naïve from July 2011 to July 2014. The candidate proteins that were reported to be altered by RC were examined in tissues by IHC. All chosen samples were adopted from the fundamental cores of histopathologically confirmed carcinomas during the initial surgeries.

RESULTS: Of the three proteins that were tested, c-MYC, PCNA and TIMP1 were detected with relatively significant expression in tumors, 35.9%, 23.7% and 58.7% respectively. The expression of the three proteins were closely connected with prognosis (P = 0.032, 0.003, 0.021). The patients could be classified into different outcome groups according to an IHC panel (P < 0.01) via these three proteins. Taking into consideration known survival covariates, especially EMVI, the IHC panel served as an independent prognostic factor. The EMVI combined with the IHC panel could categorize patients into different prognostic groups with distinction (P < 0.01).

CONCLUSION: These studies argue that this three-protein panel of c-MYC, PCNA, coupled with TIMP1 combined with MRI-detected EMVI could offer extra prognostic details for preoperative treatment of RC.