Five years, $467 million, 14 floors and 497,000 square feet after plans for its construction were first announced, the Smilow Cancer Hospital at Yale-New Haven Hospital is just days away from admitting its first patient.

Yale-New Haven’s latest addition will officially open this afternoon in a ceremony held outside the new building. The hospital, the first cancer treatment facility in New England to house inpatient and outpatient care under the same roof, is expected to bolster Yale’s reputation in medical treatment and research, hospital and University administrators said. The facility was jointly funded by the University and Yale-New Haven, with a gift from Joel Smilow ’54.

“It’s a state-of-the-art facility in every respect,” University President Richard Levin said. “The aspiration is to make cancer care and research at Yale in the same class as the very top cancer hospitals in the country.”

Besides a special center for gynecological cancer and breast cancer, the Smilow Hospital will contain outpatient treatment rooms, operating rooms, diagnostic imaging services, therapeutic radiology and 112 inpatient beds when all its sections open in April 2010.

The Smilow Hospital falls under the umbrella of the Yale Cancer Center, one of only 40 “comprehensive cancer centers” designated by the National Cancer Institute. The hospital brings Yale’s various research and clinical care facilities — including medical oncology, surgical oncology, diagnostic and therapeutic radiology and pathology — into one building. Before, the facilities had been scattered among five buildings.

The facility is named after Smilow, who gave $75 million to the project, Levin said.

Smilow, the former president and CEO of Playtex Products Inc., has donated funds to renovate Yale athletics facilities as well as other medical facilities throughout the country. But Smilow said in an interview that supporting this hospital was particularly meaningful because it is at Yale and near his current home in Southport, Conn.

“It had so many things that were near and dear to my heart that I found that it was an easy decision to make,” Smilow said.

Though he has no family history of cancer, many of Smilow’s friends and acquaintances have suffered from the disease, he said.

The cancer center has a long history of advances in treatment: In 1942, it became the first facility in the world to use chemotherapy successfully to treat patients. The brand-new hospital marks another significant step forward in Yale’s efforts to become a world leader in medicine, School of Medicine Dean Robert Alpern said.

“Having a beautiful new hospital with the latest in equipment and amenities will be an advantage in whatever we do,” he said. “It will allow us to attract patients and physicians, and clinical practice and research will grow.”

Though the cancer center is already highly ranked, it still has room to grow. Because Yale-New Haven currently offers only comprehensive medical treatment, it does not rank with elite specialized cancer hospitals like the University of Texas’s MD Anderson Cancer Center and Memorial Sloan-Kettering Cancer Center in New York, Alpern said.

The new hospital is one part of a broad strategy to improve Yale-New Haven’s standing, along with recruiting doctors and developing research facilities, Alpern said.

Indeed, the promise of leading a state-of-the-art hospital brought Yale Cancer Center Director and hospital physician in chief Thomas Lynch Jr. ’82 MED ’86 to campus from Harvard Medical School in April. In February, when Lynch was appointed, Alpern called the lung cancer expert a “steal,” adding that he had not expected Lynch ever to leave Harvard.

Lynch said the Smilow Hospital will propel Yale into the upper tiers of cancer center rankings. U.S. News & World Report currently ranks Yale-New Haven 21st in the nation in cancer treatment.

“There are very few things Yale is proud to be 21st in,” Lynch said. “This will bring Yale into the top-five discussion.”

Columbia University, Dartmouth College, Harvard University and the University of Pennsylvania are all affiliated with comprehensive cancer centers, though none has a dedicated cancer hospital. Harvard is affiliated with a clinical care center slated to open in 2011.

And despite University-wide cutbacks and delays in construction projects, Yale-New Haven and the School of Medicine have continued to support hiring and other Smilow expenditures, reflecting the University’s commitment to medical work on campus, Lynch said.

“I have not been slowed one iota since I’ve been here,” he said, referring to development projects at the cancer center. “I’ve been given the green light on everything.”

The Smilow Hospital’s growth has not always been so smooth. Yale-New Haven first announced plans for the new hospital in December 2004. But the city did not approve the construction project until March 2006, concluding nearly a year of hard-fought negotiations over the scope of the hospital’s involvement in the neighboring community.

Vice President for New Haven and State Affairs Bruce Alexander ’65, who played a key role in the hospital negotiations between Yale and the city, said Monday that the arrival of patients, families, doctors, nurses and other staff in downtown New Haven will encourage economic development.

The hospital was projected to create more than 500 permanent jobs and annual revenue of $5 million for the city, on top of its $4.5 million in one-time construction fees, Yale-New Haven spokesman Vin Petrini told the News when construction began in September 2006.