By ecancer reporter Sharan Sharma

Ubiquitin D (UBD) could serve as a new prognostic factor for forecasting colorectal cancer progression and disease recurrence, according to research first published in the British Journal of Cancer online (August 31, 2010). Colon cancer is a major cause of cancer morbidity and mortality and is the third most fatal malignancy worldwide. In certain parts of China where prevalence of colon cancer is high, its mortality has become the second leading cause of cancer death.

The standard therapy is surgery and tumour recurrence is mainly based on tumour node metastasis (TNM) staging. But even for patients diagnosed at the same stage the disease course is variable and thus there is a need for a novel factor for predicting recurrence at the time of operation so that individualised treatment can be instituted. This has led researchers to study the role of UBD in colon cancer.

They observed that the expression of UBD, a member of the ubiquitin-like modifier family, was upregulated in colon cancer parenchymal cells. Using quantitative PCR, tissue microarray (TMA), western blot analysis and immunohistochemical stain, they evaluated UBD mRNA and protein levels in tumour tissues from patients with colon cancer at different stages and in paired adjacent normal epithelium. They found that immunohistochemical detection of UBD on a TMA containing 203 paired specimens showed that increased cytoplasmic UBD was significantly associated with depth of cancer invasion, lymph node metastasis, distant metastasis, tumour histologic grade, advanced clinical stage and Ki-67 proliferative index.

The researchers note "We found patients with UBD-positive tumours to have significantly higher disease recurrence rate and poorer survival than patients with UBD-negative tumors after the radical surgery". UBD was found as an independent predictor for tumor recurrence in patients with stage II and III colon cancer.

According to them this is the first study to show the clinical significance of tumor UBD expression in colon cancer. They propose "UBD is an independent marker of increased recurrence and poor patient survival and its independent of tumor stage". "This preliminary study needs to be verified in a large, prospective controlled clinical study" they added further.