Lung cancer patients are currently treated according to the clinical stage of their cancer. In clinical staging, doctors perform a number of tests to determine how advanced the cancer is. The stages range from I to IV, with IV being the most advanced. The current treatment for stage IB, II, or IIIA non-small-cell lung cancer (NSCLC, the most common type of lung cancer), for example, is surgery followed by chemotherapy to reduce the risk of recurrence. For stage IA cancers, chemotherapy after surgery is not standard treatment, even though about 25% of people with stage IA lung cancers have a recurrence. If there were a better method for predicting who among these patients is likely to suffer a recurrence, chemotherapy could be reserved for them.

A new study in the August 10, 2006 New England Journal of Medicine found that genetic information from lung tumors could predict the risk of recurrence more accurately than conventional use of clinical characteristics.

About the Study

This study included 198 people with NSCLC who were participating in three separate studies. The researchers used samples of the participants’ tumor tissue to analyze genetic information thought to be related to the risk of cancer recurrence. With the genetic information, they made a model designed to predict the risk of recurrence. They also gathered clinical characteristics of the patients, including cancer stage (tumor size or the presence of cancer cells in the lymph nodes), cancer cell type, age, sex, and smoking history.

In all three groups of study participants, the gene model was superior to any of the clinical characteristics in predicting cancer recurrence. The chances of the model accurately predicting a recurrence was 93%, 72%, and 79% in the three study groups, compared with only 64% using clinical characteristics. Among the participants with stage IA tumors, the survival rate at four years was approximately 70%; but the survival rate in those with stage IA tumors classified as high risk for recurrence by the gene model was less than 10%.

How Does This Affect You?

These findings suggest that genetic information may be more accurate than clinical characteristics in predicting cancer recurrence in people with NSCLC. The hope is that a gene model will enable doctors to better identify patients at high risk for recurrence from any type of cancer, and plan chemotherapy accordingly. This could potentially reduce the risk of recurrence in high risk patients with stage IA cancer, while sparing low risk patients the toxic effects of chemotherapy.

Using genetic information to predict recurrence risk in cancer patients is an exciting area of research. This study may represent the beginning of a new era in which doctors routinely use genetic information to plan treatment for cancer patients. The next step will be to follow stage IA lung cancers patients predicted to be at high risk for recurrence by a gene model. If treating them with surgery plus chemotherapy results in better outcomes than the current standard of surgery alone, the information gathered may lead to more personalized—and more effective—lung cancer treatment.