EVEN THOUGH Dr. Daniel E. Dosoretz is the chief executive officer of Fort Myersbased 21st Century Oncology, a massive chain of cancer treatment centers, with 180 locations in seven countries, he still sees patients two days per week.

“I consider my job to be a doctor,” he says. “I love my patients.

21st Century is proud of the fact that it’s a “physicianled company,” which may be part of the reason employees tend to stick with it. “It’s very hard for a non-physician to tell highly trained doctors and nurses what to do and how to do it,” Dosoretz says. The company has around 4,000 employees nationwide; some 800 of them have been with the company more than a decade. “Once you join us, you don’t leave us,” he says.

Dosoretz was born in Argentina and went to medical school in Buenos Aires. He moved to the United States and became an attending physician at Massachusetts General Hospital. (His father was a radiation oncologist, and his son and daughter are radiation oncologists.)

Since Dosoretz and some colleagues from Boston opened their first radiation center in 1982, 21st Century Oncology has grown tremendously. It offers a range of cancer services, and focus on providing the same technology and quality of care found at large hospitals, but in a community setting. It’s now the largest radiation oncology provider in the United States, with offices in 17 states, plus six countries in Latin America. In Florida, nearly one-third of 21st Century Oncology’s employees are minorities, 20 percent of that number are Hispanic.

One of the keys to the company’s growth, Dosoretz says, is that its focus isn’t on growth. It’s on patients. And to that end, they care for everyone: “Medicare, Medicaid—we never discriminate on the basis of having the ability to pay,” Dosoretz says.

In oncology, “you fight [alongside] them, and they’re courageous people,” he says. “I see a lot of patients who put in perspective what life is all about. If you think you’re having a bad day, come to my office and see what a bad day is.”