Saint Peregrine is the Saint to pray to if you suffer from cancer, or wish to pray for someone who is suffering from it. Here is one of the prayers traditionally offered up to Saint Peregrine.

Prayer to Saint Peregrine

O great St. Peregrine, you have been called "The Mighty," "The Wonder-Worker," because of the numerous miracles which you have obtained from God for those who have had recourse to you.

For so many years you bore in your own flesh this cancerous disease that destroys the very fibre of our being, and who had recourse to the source of all grace when the power of man could do no more. You were favoured with the vision of Jesus coming down from His Cross to heal your affliction. Ask of God and Our Lady, the cure of the sick whom we entrust to you.
(Pause here and silently recall the names of the sick for whom you are praying)
Aided in this way by your powerful intercession, we shall sing to God, now and for all eternity, a song of gratitude for His great goodness and mercy.
Amen.

With thanks to those who are praying for my sister and our family

Blessings

:))

Faith