UK Stocks-Factors to watch on Tuesday

Britain's FTSE 100 index is seen opening 11 points lower at 7,448 on Tuesday, according to financial bookmakers. * ASTRAZENECA: AstraZeneca's immunotherapy drug Imfinzi has been approved in Europe for use in lung cancer patients with inoperable disease that had advanced locally but not spread widely around the body, the drugmaker said on Monday. * JOHN LAING: The shareholders of John Laing Infrastructure voted to approve a takeover by funds Dalmore Capi