Senden, 46, withdrew from the Zurich Classic earlier this week and said that he has no timetable for a return to the Tour.
“Our son is undertaking the biggest challenge of his life thus far,” Senden said in a statement released by the Tour. “As a family, we appreciate the support and kindness that everyone has offered us at this difficult time.
“Together, we will stand strong to tackle this disease and look forward to the day when Jacob is cancer free. We are grateful for the outpouring of love we have experienced and ask that you keep Jacob in your prayers and hearts.”