St. Nektarios the Wonderworker is an Orthodox Saint whose intercessions are sought by those seeking healing from cancer. You may listen to an account of his life on Ancient Faith Radio. A brochure on "St. Nectarius the Wonderworker: Patron of Cancer Sufferers" is available from the All Saints of North America Orthodox Church (OCA) in Ontario, Candada.Saint-Nectarios-of-Aegina.org has provided several valuable resources, including a biographical account with photos and the text of Saint Nektarios: The Saint of Our Century.
Part of a Paraclesis (supplicatory service) to St. Nektarios sung by the Boston Byzantine Choir can be found on Youtube.
Here is a selection from the "Akathist to St. Nectarios, Wonderworker of Aegina and Pentapolis":
Kontakion 12
Multitudes of the faithful from all lands continually flee to your shrine, O holy one, and from your precious relics faithfully obtain divine grace and answers for their every petition. O Father, as you know how, fulfill you also the petitions of those who now cry: Alleluia!
Ikos 12
Singing praises we glorify you, O all-praised Nektarios; for in you God Who is glorified in the Trinity is wonderfully glorified. But even if we were to offer you a multitude of psalms and hymns composed from the soul, O holy wonderworker, we should do nothing to equal the gift of your miracles, and amazed by them we cry unto you:
Rejoice, you who conquered all the snares of the Evil One;
Rejoice, you who were sanctified both in soul and body!
Rejoice, speedy helper of those in need;
Rejoice, restoration of health to the sick!
Rejoice, healer of diseases by the Grace of God;
Rejoice, helper of those that suffer cruelly!
Rejoice, O Father Nektarios, model of patience and lover of virtue.
Kontakion 13 [3 times]
As a partaker in the life of heaven and a dweller with the angels, O Father Nektarios, in that you labored to please God, accept our present offering, and unceasingly intercede for your flock and for all the Orthodox who honor you, that we may be healed of all diseases of both body and soul, that together with you in the eternal Kingdom we may unceasingly cry: Alleluia!
