Doesn't a husband afflicted with cancer have the right to know his condition so that he can make a will, draw closer to God, and even fulfill his obligations of rights and debts?

It is stipulated for the impermissibility of informing the patient of his illness that it entails harm for him, such as increasing his illness and affecting him psychologically. If it is known that this will not affect him, then there is no objection to informing him. It is possible to achieve what is hoped for from his will and his drawing closer to God without informing him of the illness that entails harm for him, such as by alerting and urging him to write his will and to [take advantage of] the virtue of drawing closer to God through good deeds. Averting harm takes precedence over attaining benefit when they conflict.