The friend you’re looking for is Anthony Radziwill, John F. Kennedy Jr.’s cousin and closest friend, who battled cancer.

Quick Scoop

  • John F. Kennedy Jr.’s best friend with cancer was his cousin Anthony Radziwill.
  • Anthony was first diagnosed with testicular cancer in 1989 and later developed metastatic cancer.
  • He and JFK Jr. were extremely close; they grew up together and were often described as inseparable.
  • After Anthony’s cancer returned, JFK Jr. and his wife Carolyn were described as two of Anthony and his wife Carole’s biggest emotional supporters.
  • Anthony Radziwill died in August 1999, just a few weeks after JFK Jr. was killed in a plane crash.

A brief story-style snapshot

Anthony Radziwill and JFK Jr. weren’t just relatives; they were like brothers who shared childhood jokes, adult pressures, and the intense spotlight that followed the Kennedy family. When Anthony’s cancer worsened, John reportedly leaned on humor to keep his cousin’s spirits up, believing that if he ever stopped joking, Anthony might understand how serious things really were and lose hope. Even as Anthony underwent multiple treatments for metastatic cancer, John and Carolyn stayed close, offering support to Anthony and his wife Carole during some of their darkest days.

In later interviews, Carole Radziwill recalled how central John and Carolyn were as friends once Anthony’s cancer returned, emphasizing how present they were through hospital visits and treatments.

Related context (Kennedy family and cancer)

  • Anthony Radziwill’s battle with cancer is one of several high‑profile cancer stories in the extended Kennedy family, which has often been portrayed in the media as a family marked by both political power and repeated tragedy.
  • More recently, public attention has also focused on cancer diagnoses among other Kennedy descendants, keeping the topic in the news and on forums as people revisit earlier stories like Anthony’s.

TL;DR: The “JFK Jr. friend with cancer” you’re asking about is his cousin and best friend, Anthony Radziwill, who fought testicular and later metastatic cancer and died only weeks after JFK Jr. in 1999.

Information gathered from public forums or data available on the internet and portrayed here.