Treating aggressive lung cancer with the diabetes drug metformin along with radiation and chemotherapy may slow tumor growth and recurrence, suggests new preliminary findings from researchers at the Perelman School of Medicine at the University of Pennsylvania being presented during an oral abstract session October 28 at the 15th World Conference on Lung Cancer. 

The preclinical and clinical results, which have set the stage for a first-of-its-kind prospective study, point to metformin as an effective radiosensitizer—adrug that makes tumor cells more sensitive to radiation therapy—to treat stage III non-small cell lung cancer (NSCLC).  Because of poor local response and five-year survival rates around 15 percent in late-stage NSCLC patients, well-tolerated, combination therapies are greatly needed.

The abstract is being presented by Ildiko Csiki, MD, PhD, an assistant professor of Radiation Oncology at Penn’s Abramson Cancer Center.

Metformin, the most-widely used drug for type-2 diabetes, has been shown to have anti-cancer effects on a number of cancers, including prostate and colon. It activates AMP-related pathways, leading to inactivation of mTOR and suppression of its downstream effectors, a crucial signaling pathway for proliferation and survival of cancer. However, little data exists to support its role in NSCLC.  And its role as a radiosensitizer in lung cancer is even less understood.

For this study, clinical evidence from 16 diabetic patients treated at the Hospital of the University of Pennsylvania between June 2008 and June 2013 with stage III A and B NSCLC and diabetes demonstrated that chemoradiation therapy in combination with metformin dramatically improved local recurrence. With a median follow-up time of 10.4 months, only two local recurrences have occurred.

Researchers also observed a survival benefit with the combination.

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