New WHO classification system for lung cancer used by researchers to identify people that may benefit from chemotherapy
Lung adenocarcinoma is the most common form of lung cancer in Canada. Early forms of this cancer can be treated with surgery. Several clinical trials have shown that, in some patients, post-operative chemotherapy increases the likelihood of curing the cancer; however, researchers are unable to identify which patients would benefit from the more intense treatment plan.
The World Health Organization (WHO) has recently published a new classification system that categorizes lung adenocarcinoma into one of five subtypes, based on the appearance of the cancerous tissue viewed under a microscope. Using this system, an international team lead by PM Lung Pathologist and Senior Scientist Dr. Ming-Sound Tsao has shown that patients diagnosed with one of two subtypes of lung adenocarcinoma may live longer if they receive chemotherapy after their cancer is surgically removed.
The research team collected cancerous lung tissues that had been surgically removed from 575 patients who participated in lung cancer clinical trials. They examined the tissues under a microscope and classified each patient's cancer as one of the five subtypes. They determined that two subtypes, known as 'micropapillary' and 'solid', were the most aggressive and were associated with poorer survival rates. Importantly, the team found that surgery followed by chemotherapy improved cancer survival rates for patients with these two subtypes.
"Although these findings need to be further validated in prospective clinical trials, they could help doctors prescribe better treatments to each patient and improve their chance of being cured," says Dr. Tsao.
This work was supported by la Ligue contre le cancer (France), le Programme National d'Excellence Spécialisé Cancer du Poumon de l'Institut National du Cancer (France), the National Cancer Institute (USA), the Canadian Cancer Society, Sanofi, the Goustave Roussy Foundation, the European Union's Seventh Framework Programme for Research and The Princess Margaret Cancer Foundation.
Subtype classification of lung adenocarcinoma predicts benefit from adjuvant chemotherapy in patients undergoing complete resection. Tsao MS, Marguet S, Le Teuff G, Lantuejoul S, Shepherd FA, Seymour L, Kratzke R, Graziano SL, Popper HH, Rosell R, Douillard JY, Le-Chevalier T, Pignon JP, Soria JC, Brambilla EM. Journal of Clinical Oncology. 2015 Apr 27. [Pubmed abstract]