At 27, Trey Mancini was at the peak of his career.

In March 2020, the six-foot-four baseball star had just started spring training for his fifth season with the Baltimore Orioles when he underwent a round of routine bloodwork.

When the results came back showing ‘extremely low’ hemoglobin – a protein that helps red blood cells carry oxygen throughout the body – team doctors were concerned. 

Mancini’s father had beat colon cancer nearly a decade earlier at 58, so the Orioles medical team ‘took the initiative’ and pushed for a colonoscopy. 

Just days later, on his 28th birthday, the results blindsided him: the professional athlete in the prime of his life had stage three colon cancer.

Even more shocking, despite his late-stage diagnosis he had no symptoms. 

Mancini, now 33, told DailyMail.com: ‘If I wasn’t playing baseball, I never would have known until it was too late.’ 

Now, back on the field as a World Series champion and father-to-be, Mancini is warning other young people that colon cancer can strike anyone – even elite athletes – without warning.

Trey Mancini, pictured here during his time with the Baltimore Orioles, was in peak condition when he was shockingly diagnosed with colon cancer on his 28th birthday

Doctors have grown increasingly alarmed by a mysterious rise in aggressive colorectal cancers in younger, otherwise healthy adults. 

From 1999 to 2018, the rate of colorectal cancer in the under-50 population rose from 8.6 cases per 100,000 people to 13 cases per 100,000 people.

Colorectal cancer diagnoses in 20- to 34-year-olds is set to increase by 90 percent between 2010 and 2030, and rates for teenagers have surged 500 percent since the early 2000s. 

Lifestyle factors like diet, lack of exercise and sedentary lifestyle have all been blamed, though these causes fail to explain why physically fit people like Mancini have increasingly been diagnosed with colorectal cancer. 

The latest evidence, published in April, also suggests childhood exposure to a toxin released by E. coli bacteria could increase the risk of colorectal cancer by triggering inflammation and altering the balance of the gut microbiome. 

Marijuana was also linked to colorectal cancer in a recent study, as it is thought to block tumor-suppressing cells.  

Mancini has a family history of the disease, as his father, Tony, had been diagnosed with stage two colorectal cancer in 2011 at age 58. 

However, testing shows the younger Mancini has no specific genes thought to increase the risk of cancer.

Due to his family history, Mancini was due to receive his first colonoscopy at 35 years old, 10 years earlier than the recommended age.  

He told this website: ‘It was just family history and bad luck.’ 

Stage three colon cancer has a 73 percent five-year survival rate.  

Mancini, pictured here after (left) and during (right) treatment, was diagnosed with ‘aggressive’ stage three colon cancer. He told DailyMail.com if he had not had routine bloodwork done for baseball, he may not have been diagnosed ‘until it was too late’

Mancini, pictured here in 2020 with now wife Sara, completed cancer treatment after six months. He is now five years cancer free

A few days after his colonoscopy, Mancini underwent surgery in March 2020 to remove a portion of the tumor in his colon and he started chemotherapy about a month later.  

Every two weeks for six months he traveled from Washington DC to Johns Hopkins Hospital in Baltimore, Maryland, for 4.5-hour chemotherapy infusions. 

He said: ‘I’d have three or four days of really feeling sick and unideal, and then I’d have nine days to kind of recover and feel like myself. I got used to the routine of it. 

‘It obviously was something I never imagined going through, never thought I was going to go through, but you have to take it day by day and really appreciate the days that you feel healthy and try to live a normal life when you can in between.’

Mancini’s cancer meant he had to sit out the 2020-2021 season with the Orioles, though his teammates would hold Zoom meetings so he could stay involved with the team.

At the end of his six-month treatment regimen, his teammates gifted him a signed team picture frame with an image of them all wearing ‘#F16HT’ t-shirts, a reference to his uniform number of 16.

He said: ‘It was really helpful to have some semblance of still being on a team throughout all of this.

‘Having that strong support system and people that care about you really helps you get through it a lot. Being vulnerable and letting others help you out is paramount to getting through and in your recovery.’

Mancini is pictured here on his wedding day to wife Sara. The couple is expecting their first child, a baby girl, this fall

Mancini completed cancer treatment in September 2020 and was declared disease-free. And by the time the 2021-2022 season began, he was back on the field with the Orioles and then the Houston Astros.

He even helped the Astros win the World Series in 2022.  

After taking a year off from baseball, he now plays for Reno Aces, a minor league affiliate of the Arizona Diamondbacks, with hopes of making it back to the major leagues.

‘I feel great physically,’ he told DailyMail.com.

While working on his physical health, he has cut processed foods and seed oils out of his diet, as recent research suggests they could raise the risk of colon cancer.  

Now five years cancer free, Mancini undergoes scans every six months and bloodwork every three months to check for recurrence. Though he’s back in prime shape, he admits the fear of his cancer returning takes a toll.

Mancini told this website: ‘It’s something that never truly leaves you.

‘Whenever you’re going through it, you’re in fight or flight mode, and it’s great to finish chemotherapy, but the journey is not really over.

‘It’s a years-long process. It’s not just a six month thing that you go through.’

Mancini also mentors other colon cancer patients, much like others did for him during his treatments. Most of those who reach out, he said, are under 50. His nonprofit, the Trey Mancini Foundation, also provides resources for detecting colon cancer symptoms, which typically include blood in the stool, abdominal pain and sudden weight loss. 

He said: ‘I took it as a responsibility to help others and spread awareness and be there, because that’s what helped me. When I was going through it was talking to former survivors that really gave me hope. 

‘So if I can do that for others, it’s the least I can do.’

But his most important milestone is coming this fall: his first child, a baby girl. Nothing else compares to that, he said, including winning the World Series.

Mancini told this website: ‘I can’t wait to be a father. Five years ago, I wasn’t sure how long I was going to live. So to be here now and to have a baby girl on the way, I just wake up every day, and I’m so appreciative, and can’t wait to meet her this fall. 

‘I’m really appreciative to be where I am right now.’