I didnt have chemo; but during waiting for radiaiton and having radiation i worked but also overdid self care probably wasnt engaged fully in all my activities; i would let your intiution or gut feel lead you--if you feel energised by presenting then do so --and maybe either stick with script or have your personal experience in the centre of your presentation--ie has your dreams been influenced, or life threatening or sense of self --recently i did a webnair where range of speakers inclduing one who had several experiences of cancer-not breast--and she spoke about what was helpful to her as far as psychological or emotional realms which was quite different from the professionals canvased --enjoy your sydney sojourn