DAVOS, Switzerland - Sundar Pichai, the CEO of Alphabet Inc and its Google subsidiary, said on Wednesday that healthcare offers the biggest potential over the next five to 10 years for using artificial intelligence to improve outcomes, and vowed that the technology giant will heed privacy concerns.

U.S. lawmakers have raised questions about Google's access to the health records of tens of millions of Americans. Ascension, which operates 150 hospitals and more than 50 senior living facilities across the United States, is Google's biggest cloud computing customer in healthcare.

"When we work with hospitals, the data belongs to the hospitals," Pichai told a conference panel at the World Economic Forum in Davos, Switzerland.

"But look at the potential here. Cancer if often missed and the difference in outcome is profound. In lung cancer, for example, five experts agree this way and five agree the other way. We know we can use artificial intelligence to make it better," Pichai added.

Google has spent several years developing artificial intelligence to automatically analyse MRI scans and other patient data to identify diseases and make predictions aimed at improving outcomes and reducing cost.

The U.S. lawmakers asked the company in November to provide information about other health systems that provide information to Google, whether Ascension clients will be allowed to opt out of the project, and whether the data be used for advertising.

Pichai said there was already strong privacy protecting regulations in place that provide a framework for Google to operate.

Google clinched a deal in November to acquire Fitbit Inc for $2.1 billion, aiming to enter the wearables segment and invest in digital health. The acquisition is expected to be scrutinized closely by regulators before it is allowed to close.

(Reporting by Greg Roumeliotis in Davos, Switzerland; Editing by Alex Richardson) ((Greg.Roumeliotis@thomsonreuters.com; +1 646 223 6022; Reuters Messaging: greg.roumeliotis.thomsonreuters.com@reuters.net))