Converstion with St. Paisios about his illness : cancer

–– Geronda, the final diagnosis has been made. Your tumor is cancerous and it's aggressive.
–– Bring me a handkerchief so that I may dance to the song: "I bid farewell to you, O poor world!" I have never danced in my life, but now I will dance for joy as my death approaches.
–– Geronda, the doctor said that first he wants to use radiation to shrink the tumor and then do surgery.
–– I understand! First the air force will bombard the enemy, and then the attack will begin! I'll go up then and bring you news! Some people, even the elderly, when told by the doctor, "You will die," or "You have a fifty percent chance of surviving" get very distressed. They want to live. And then what? I wonder! Now, if someone is young, well , this is justifiable, but if someone is old and is still desperately trying to hang on, well, this I just don't understand. Of course, it's quite different if someone wants to undergo therapy in order to manage pain. He's not interested in extending life; he only wants to make the pain somewhat more bearable so that he can take care of himself until he dies –– this does make sense.
–– Geronda, we are praying that God may give you an extension on your life.
–– Why? Doesn't the Psalmist say, "The days of our years are threescore years and ten?"
–– But the Psalmist adds the following, "And if by reason of strength they be foreshore years..."
–– Yes, but he adds the following, "Yet is their strength labor and sorrow," in which case it is better to have the peace of the other life.
–– Geronda, can someone, out of humility, feel spiritually unprepared for the other life and wish to live longer in order to get prepared?
–– This is a good thing, but how can he know that, even if he does live longer, he won't become spiritually worse?
–– Geronda, when can we say that a person is reconciled with death?
–– When Christ lives inside him, then death is a joy. But one must not rejoice in dying just because he has become tired of this life. When you rejoice in death, in the proper sense, death goes away to find someone who's scared! When you want to die, you don't. Whoever lives the easy life is afraid of death because he is pleased with worldly life and doesn't want to die. If people talk to him about death, he reacts with denial: "Get away from here!" However, whoever is suffering, whoever is in pain, sees death as a release and says, "What a pity, Charon has not yet come to take me... He must have been held up!"
Few are the people who welcome death. Most people have unfinished business and don't want to die. But the Good God provides for each person to die when he is fully matured. In any case, a spiritual person, whether young or old, should be happy to live and be happy to die, but should never pursue death, for this is suicide.
For a person who is dead to worldly matters and has been spiritually resurrected, there is never any agony, fear or anxiety, for he awaits death with joy because he will be with Christ and delight in His presence. But he also rejoices in being alive, again because he is united with Christ even now and experiences a portion of the joy of Paradise here on earth and wonders whether there is a higher joy in Paradise than the one he feels on earth. Such people struggle with philotimo and self-denial; and because they place death before themselves and remember it every single day, they prepare more spiritually, struggling daringly, and defeating vanity.

Reference: Elder Paisios of Mount Athos Spiritual Councils IV: Family Life, pp 274-276.