Florida entrepreneur documents his heartbreaking battle with lymphoma in his 20s - as doctors warn cancer patients keep getting younger: 'I had to sit with my father and write my will at 25'

Jace Yawnick is far from your typical terminal cancer patient.

He's 25, is in superb physical shape and only eats grass-fed meat and whole foods. 

So when he first began feeling chronic fatigue last year, he attributed it to being a 'workaholic,' having recently co-founded a marketing agency and working for an organic food delivery company.

He then developed a cough, which doctors figured was acid reflux, and back pain that were dismissed at golf and sports injuries.

Scans later revealed stage 2 tumors were putting pressure on his lungs and spine

Mr Yawnick was finally diagnosed with a rare and aggressive type type of blood cancer in February. His tragic case highlights the changing face of cancer - with much younger and healthier people now being diagnosed with the disease.

And many doctors are feared to be missing the rising number of cases in young people because they aren't screening them or evaluating their symptoms properly.

Jace Yawnick said he first began feeling symptoms about eight to 12 months ago, but couldn't be exactly sure because they started out mildly 

Mr Yawnick shared that his hair had begun to fall out and shaved his head with his father live on social media

Mr Yawnick has shown remarkable resilience and a positive attitude in his videos, accumulating a following of 500,000 people on his Instagram and TikTok, where viewers offer support, prayers, advice and share their own experience with cancer at a young age.

He documents his chemotherapy, losing his hair, treatment side effects and how cancer has impacted his social and professional life. 

In his first video, posted to his TikTok on February 1, he said: 'I'm 25 years old and I just found out I have cancer. It's the worst thing you can hear - doesn't matter how old you are.

'I want to make a page to document my journey as I go through it because it's going to be intense.

'I'm going to beat this. It's going to be really hard. It's going to suck.'

He was diagnosed with stage 2 primary mediastinal B-cell lymphoma, a rare type of non-Hodgkin's lymphoma (NHL) that kills three to four people out of 10 within five years of diagnosis.

The condition comprises just two to three percent of all NHL cases.

Videos posted in the last week show Mr Yawnick skinny and with no hair. They are a stark comparison to his first handful of videos in which he appears fit and with a full head of hair and beard

He went from an avid runner living a physically active lifestyle to dropping 20 pounds and extremely fatigued from his chemotherapy treatments. 

In one video, posted after his first round of chemo, Mr Yawnick revealed he had written a will with his father in the event of his death.

It was determined his cancer was stage 2 because it had not spread past his diaphragm but the masses were very large

Mr Yawnick said in a video: 'My heart was drowning in fluid so [the doctor] said it would have killed me'

Mr Yawnick first began feeling symptoms about eight to 12 months ago, but couldn't be exactly sure because they started out mildly. 

He began to feel fatigued, but figured it was because he is a 'workaholic' and travels a lot for his business. 

He continued to ignore his symptoms. 

As an avid runner, he'd never had a problem exercising before, but began to have chest pains and trouble breathing. 

Then he developed pain in his shoulder blades, which was being caused by his tumors pressing up against his spine, but doctors thought it was a sports-related injury.

As he visited more providers, Mr Yawnick said his primary care physician would prescribe him medications but wasn't thoroughly examining him.

Eventually, he began having night sweats and lost 20 pounds very quickly - both key indicators a person could have cancer.

He said: 'If you think something is wrong with you, be an advocate for yourself. Say "I would like this test" or "I would like to check for this to make sure" because the earlier you catch cancer the better and the more treatable it can most likely be and sometimes primary care physicians can be caught up. 

'That's what happened to me. We are here now and I thankfully was an advocate for myself and listened to my body.'

Following tests, doctors discovered he had three masses around heart and his chest cavity. A biopsy was done to confirm it was lymphoma. 

He then underwent a PET scan, which creates 3D images of the inside of the body, to determine which kind of lymphoma he had. Those results showed it was primal mediastinal B-cell lymphoma (PMBCL).

It was determined the 25-year-old's cancer was stage 2 because it had not spread past his diaphragm but the masses were very large. 

Mr Yawnick said in a video: 'My heart was drowning in fluid so [the doctor] said it would have killed me.'

That amount of fluid could have been deadly if he wasn't as active and healthy as he was, doctors said.  

PMBCL is not common and medical research on the disease is very limited. 

It most often occurs in people between 30 to 40 years old, affecting about one in 500,000 people. About eight-in-10 patients survive past five years. 

It is a fast-growing cancer that develops in the lymph nodes in the center of the chest - called the mediastinum.  

In a majority of cases, PMBCL is treated with chemotherapy, radiation, immunotherapy and steroids. 

While the cancer has a high survival rate, a 2020 study found approximately 10 to 30 percent of PMBCL patients experience recurrence of the cancer after their first course of treatment. 

To stay 'mentally strong,' the 25-year old said he has a strong support system of family, friends and online community, and he also practices meditation and recites mantras

Mr Yawnick began sharing videos of himself in February after receiving a diagnosis of stage 2 primal mediastinal B-cell lymphoma, a rare and aggressive type of non-Hodgkin's lymphoma

Mr Yawnick began receiving chemotherapy in early February after he was rushed to the emergency department for severe chest pains. One week later, he was able to go home, where he and his girlfriend celebrated the end of his first round of chemotherapy. 

Since then, he has completed a second week-long cycle of chemo, undergone multiple spinal taps, a lumbar puncture and had more fluid drained from his heart and spine. 

Mr Yawnick shared that his hair had begun to fall out and he decided to shave his head with his father live on social media.

Following treatments, he experiences intense fatigue, nausea, lack of appetite and headaches. 

In an emotional video uploaded in mid-February, Mr Yawnick revealed part of his cancer journey included writing a will with his father in the event of his death.

He said: 'I had to sit down with my father at 25 and write my will and tell him what I wanted to parents to have. It's one the the craziest things you can do - to write your will while you're so young. 

'All the things that you cherish in your possessions and who they go to and you realize that they don't mean anything. They don't mean anything because all you want is to just spend time with the people that you love because you can't take any of the stuff with you. You can't take any of it with you.

'If you have friends of family in your life, know that they're the most valuable thing in the whole world. And make sure you tell them that.' 

However, he declared: 'I'm not going to have to use that will because we're going to beat this thing.' 

To stay 'mentally strong,' Mr Yawnick said he has a strong support system of family, friends and online community, and he practices meditation and recites mantras. 

In the most recent update, he detailed his frame of mind on his new 'normal.'

He said: 'I've heard a lot recently about finding the new normal when you have cancer and I found this to be interesting because cancer is a battle and a problem that can very easily take over your mind and your day-to-day life. 

'I am finding a way to accept my new normal. Allowing cancer to rule my mind and day is not something that I allow.'