Milton resident Kevin Martin has completed four world marathons since learning his prostate cancer had spread to roughly 40 sites in his bones, the Milton Times first reported Thursday.

Doctors gave Martin a prognosis of two to four years to live after a PET scan revealed the cancer had metastasized. He had joined the Dana-Farber Boston Marathon team about a month before the diagnosis worsened.

"Almost overnight, I went from having the greatest life I could ever imagine, to feeling like it was crumbling around me," Martin told the Milton Times.

Martin has since run Boston, London, Chicago and New York. He is chasing the Abbott World Marathon Majors Six Star Medal, awarded to runners who complete all six major world marathons: Tokyo, Boston, London, Berlin, Chicago and New York. Berlin is next, where he plans to run with his two children. Tokyo in March 2027 would complete the set.

Martin also climbed Mount Kilimanjaro with the nonprofit ZERO Prostate Cancer. The eight-day expedition raised half a million dollars.

His wife, Lisa Martin, was featured in the Milton Times' Sept. 3 edition for her book "Our Healing Home," which documents 360 lifestyle changes the family made after Kevin's diagnosis. All proceeds go to cancer research.

Martin told the Milton Times he has stopped projecting years ahead. Berlin with his children comes first.