MANILA (UPDATED) - Cardiologist Dr. Willie Ong has revealed that he is undergoing treatment for cancer after doctors found a huge mass in his abdomen. 

In a video message done last August 29 and uploaded Saturday morning, the former vice-presidential candidate said he first experienced symptoms in 2023 during a routine medical mission. 

"Napansin ko noong April 2023 medyo hirap na ko mag medical mission. Kapag mainit, hindi ko na kaya. Ayoko na ng mainit," he said in the 24-minute video. 

In the video, Ong is noticeably thinner, which he has also pointed out and first concluded as a sign of aging. 

Ong said he later experienced an excruciating back pain, which caused him to lose sleep. Blood tests initially ruled out anything serious but he noticed the back pain moving up to another part.

A month later, he was admitted and he received a cancer diagnosis. The growth, he said was large and was the biggest doctors had ever seen. 

Ong said the tumor was hidden behind the heart and in front of the spine.

He added that the mass blocked his esophagus, Inferior vena cava vein, and his heart's right atrium.

"Ngayon, naka-chemo ako. Ayoko lokohin mga followers ko," he said. 

Despite this, however, Ong is hopeful that things will look up. 

"Suwerte nga ako may asawa ako nagbabantay. Suwerte ako may anak ako, binabantayan ako. I'm so blessed," he said.