Published online Oct 14, 2016. doi: 10.3748/wjg.v22.i38.8576
Peer-review started: July 7, 2016
First decision: August 19, 2016
Revised: August 24, 2016
Accepted: September 14, 2016
Article in press: September 14, 2016
Published online: October 14, 2016
Processing time: 97 Days and 5 Hours
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.
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.
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).
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.
Core tip: Magnetic resonance imaging (MRI) to determine the stage of rectal cancer has been shown to be accurate and reproducible. The patients who showed MRI-detected extramural vascular invasion (EMVI) positivity had worse survival outcomes than those with EMVI negativity. However, the survival rates of patients with an EMVI-positive histology varies dramatically, which suggests that this factor does not relate to each individual tumor in terms of the biology or molecular features. The ideal staging system evolves from the consideration of them and the correlation of the prognosis with patient-specific tumor biomarkers. In this study, we hypothesized that the combination of imaging evidence of EMVI and biomolecular factors could provide additional predictive value in clinical practice, especially for non-advanced cancer patients.