Nitro-substituted aromatic or hetero-aromatic compounds for use in cancer treatment

A method of treating hypoxic tumor cells in a solid tumor harbored by a mammal in need of such treatment, which method comprises administering to said mammal, in an amount effective to increase the sensitivity of said cells to radiation during radiotherapy or to a chemotherapeutic agent, a compound of formula (A):

• ##STR19## wherein X represents one of the groups:
• ##STR20## wherein R is hydrogen or an alkyl group with a one-electron reduction potential at pH 7 of from -250 to -500 mV;
• each of R'.sub.1 to R'.sub.5 independently represents hydrogen or an alkyl, hydroxyalkyl, aryl, aralkyl or alkaryl group;
• m is 0 or 1;
• n is 1 or 2;
• and
• Z' represents a leaving group selected from the group consisting of halogen, --OCOR.sub.6, --OSOR.sub.6, --OSO.sub.2 R.sub.5, --OPO.sub.3 (R.sub.6).sub.3 and OP(O)(N(R.sub.6).sub.2).sub.2 where R.sub.6 is selected from a group consisting of hydrogen, alkyl, haloalkyl, phenyl, aralkyl, thioalkyl, acyl and amino;
• aryloxy, --ONO.sub.2, --NHSO.sub.2 R.sub.7, --NHCOR.sub.7, --NHCO.sub.2 R.sub.7, --N(COR.sub.7).sub.2 and cyclic imide where R.sub.7 is selected from the group consisting of hydrogen, alkyl, phenyl and aralkyl;
• and --N.sup.+ R.sup.a R.sup.b R.sup.c and --N(O)R.sup.a R.sup.b where R.sup.a to R.sup.c are independently selected from the group consisting of alkyl, pyridine and imidazole;
• or a physiologically acceptable acid addition salt thereof.