November 10, 2015
Lung cancer is the number one cause of cancer-related death in North America. While prognosis for the most common form, adenocarcinoma, remains poor, scientists at Lawson Health Research Institute have found a link between the absence of a specific protein and improved patient outcomes.
The retinoblastoma tumor suppressor protein (pRB) is traditionally understood to help regulate cell division, preventing the growth of abnormal cells. However, recent studies have had conflicting results. Dr. Matthew Cecchini, a Pathology Resident at London Health Sciences Centre (LHSC), wanted to see if there was a correlation between the small percentage of adenocarcinoma patients who do not have this protein and long-term survivors.
Under the leadership of Lawson’s Dr. Fred Dick, Cecchini and a collaborative team of researchers performed a study on 91 adenocarcinoma patients who underwent chemotherapy and surgery. The study found pRB was not detected in 15% of patients. These patients experienced an improved survival rate of 92% at 5 years. This is in comparison to an average survival rate of 49% for those patients who expressed the RB protein.
“These results are surprising because pRB has traditionally been understood to be a suppressor of tumor growth,” said Dr. Dick. “This study illustrates that the absence of pRB actually results in significantly improved outcomes for adenocarcinoma patients who undergo chemotherapy and surgery.”
Given the harsh effects of chemotherapy, it is important to understand which patients respond best to the treatment. This research indicates that pRB can be used as a marker to determine if a patient will respond positively. Testing could therefore be used to determine the best treatment plan for individual patients.
“The next phase in the study is to test our findings in a larger patient cohort,” said Dr. Dick. “We will also be looking at the underlying mechanisms of pRB to understand what makes these patients more responsive to chemotherapy. This will help us to further improve treatment and patient outcomes.”
The study is published in Human Pathology.