A pharmaceutical composition for treating, inhibiting, or preventing cancer can include an indole-3-carbinol derivative compound in a pharmaceutically acceptable carrier that is configured for oral administration. The indole-3-carbinol derivative compound can have antitumor activity, and oral administration can provide blood bioavailability of about 0.5% to about 25%. The pharmaceutically acceptable carrier can include a hydroxyl-fatty acid PEG monoester and/or diester. The carrier can be a hydroxyl-fatty acid PEG ester that includes 12-hydroxy stearate. The carrier can be a hydroxyl-fatty acid PEG ester that includes a PEG having from about 100 MW to about 200,000 MW. The indole-3-carbinol derivative can be 2,10-dicarbethoxy-6-methoxy-5,7-dihydro-indolo-(2,3-b)carbazole.
