New predictors of prognosis in colon cancer?

The current study examined whether the proteins versican and lumican were predictive of prognosis among colon cancer patients.

Colon cancer treatments vary depending on the type and stage of the disease. Patients with advanced cancer, which has invaded the surrounding lymph nodes, usually receive chemotherapy along with surgery, while patients with early stage cancer, which has not spread beyond the colon, are not always treated with additional therapies besides surgery. However, 20 to 30% of early stage colon cancer patients experience a recurrence of the disease following surgery, indicating that new methods of determining which patients should receive additional chemotherapy are needed.

Some molecular features of cancer cells are known to be useful in determining disease prognosis. Two proteins, versican and lumican, have recently been identified as important factors in the development of the tumor stroma (the tumor environment, including blood vessels, connective tissue, and additional cells and compounds necessary for tumor growth). High levels of versican and lumican in the tumor environment have been associated with colon cancer in several studies. The current study examined whether levels of versican and lumican could aid in predicting the prognosis of colon cancer patients, or assist in the determination of which patients would benefit most from additional chemotherapy.

This study analyzed samples from 386 patients with stage II (226 patients), or stage III (160 patients), colon cancer who underwent surgical resection of the tumor. Of these, 122 patients were also treated with additional chemotherapy. Overall, 32.9% of patients experienced cancer recurrence.

Versican was found to be expressed in the stroma of 81.9% of tumors sampled. Stage III patients whose tumors expressed high levels of versican were 2.5 times less likely to experience early cancer recurrence compared to patients whose tumors expressed low levels of versican. Among stage III patients not receiving chemotherapy, high versican expression was associated with significantly longer disease free survival time (the time between treatment and disease recurrence). Among stage III patients receiving additional chemotherapy, versican expression was not predictive of prognosis.

Lumican was found to be expressed in the stroma of 91.6% of tumors sampled. Lumican expression was not found to be associated with prognosis among advanced stage colon cancer patients. However, among stage II patients, high levels of lumican were associated with significantly longer disease free survival. Stage II patients expressing high levels of lumican were 2.4 times less likely to experience disease recurrence compared to patients whose tumors expressed low levels of lumican.

This study concluded that expression of versican and lumican could be used as a positive prognostic marker among colon cancer patients.