Genta Shares Soar on Cancer Drug Data  CHICAGO (Reuters) - Shares of Genta Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=GNTA.O target=/stocks/quickinfo/fullquote"&gt;GNTA.O&lt;/A&gt; soared  nearly 50 percent on Monday after the biotechnology company  presented promising data on an experimental treatment for blood  cancers.