Six months ago, he was involved in a struggle for his life. It was February when Horst went in for a routine physical and his doctor called him to let him know that some numbers were elevated. On March 13, he was given the diagnosis: prostate cancer.

On June 23, 36 years and a day after he enlisted in the Army, Horst took command here in Washington, D.C., having faced his disease with medical treatment at Walter Reed Army Medical Center, and with a new outlook on life.

‘‘I certainly don’t take anything for granted,” Horst said Monday at the Pentagon, while discussing his fight with media members. ‘‘My Family, my faith, the Army, I’m thankful for it all.”

Horst said that before he took the physical, he was contemplating retirement and was thinking about the next phase of his life. The response from the Army in the wake of his diagnosis reaffirmed his commitment to the Army.

‘‘The fact that I was sick and the Army put their arms around me and said they needed to take care of me. What followed was an opportunity to command and that caused me to stay in the Army,” Horst said. ‘‘It re-instilled my confidence and my commitment to the Army.”

Horst was treated by Col. (Ret.) David G. McLeod M.D., director at the Center of Prostate Research at Walter Reed. He treated Horst as he has treated hundreds of men and women in the 35 years he has been part of the Army Medical Department.

‘‘What we did with [General Horst] epitomizes what we do up there at Walter Reed,” McLeod said. ‘‘There’s a motto in the medical community called ‘conserving the fighting strength.’ I think we epitomized that with [General Horst], we kept him on active duty, we eradicated the disease.”

McLeod stressed the equal access to medical care, saying that they see ‘‘7,900 people per year, and we have made the diagnosis all the way from E-7 level all the way to O-10.”

Horst spoke at the Pentagon to kick off National Prostate Cancer Awareness Month, which takes place this month. As someone who has been physically fit throughout his life, Horst thought it was his responsibility to speak out about his disease to stress the importance of early detection.

‘‘The reason I think it’s important to speak out is that ... roughly 80 percent of us males have a chance of contracting prostate cancer, so if we’re in the majority, we’ve got to be talking about it to help each other out,” Horst said. ‘‘I’m fortunate because I can never get prostate cancer now, but there are a whole lot of you out there who are vulnerable.”

The American Cancer Society estimates that 192,280 men will be diagnosed with prostate cancer this year, and that 27,360 men will die from it this year. The key in this large gulf is early detection, which is why regular physicals are so important.

Horst called the assignment in Washington, D.C. an honor a privilege and a challenge, given the important nature of this area to the country as a whole.

‘‘The challenge I face every day is supporting the civilian authorities here in the National Capital Region to ensure that we have a safe and secure environment here for this government to operate in,” Horst said. ‘‘With units like The Old Guard and the U.S. Army Band, and Arlington National Cemetery and those very important, very visible missions, we are the face of the United States Army.”