WASHINGTON (Reuters) – A leading U.S. cancer lobby group is urging the Surgeon General to conduct a sweeping study of the impact of sugar-sweetened beverages on consumer health, saying such drinks play major role in the nation’s obesity crisis and require a U.S. action plan. In a letter to U.S. Health Secretary Kathleen Sebelius, the American Cancer Society’s advocacy affiliate on Tuesday called for a comprehensive review along the lines of the U…