TOKYO, June 1 (Reuters) - Japan's Nikkei average fell in early trade on Friday, heading for a ninth straight week of losses to match its longest such run in 20 years, after soft U.S. data added to concerns over global growth as Europe struggled with a debt crisis. The Nikkei dropped 1 percent to 8,457.80 after shedding 1.1 percent on Thursday to log its worst monthly fall in two years. The index is down 1.4 percent this week. The broader Topix fell 1.1 percent to 711.74. It is down 1.4 percent this week, on track for a ninth straight week of losses to mark its worst weekly losing streak since 1975.