Some Apple Inc. investors are advocating the unthinkable: Apple Inc. without Steve Jobs running it. The charismatic chief executive, they said, should take on a new role when he returns in a week or two from a six-month medical leave -- as an adviser, thus removing him from the rigors of overseeing day-to-day operations. His impending return spurred fresh speculation about his health and the future of the Cupertino, Calif., computer, iPod and iPhone maker. Jobs, 54, reportedly underwent a liver transplant in Tennessee two months ago and has recovered enough to return to work on schedule at the end of the month, according to a story in The Wall Street Journal. Although investors welcomed the report as a sign that his health had improved, a few are openly discussing whether Jobs should surrender the title of chief executive to the man who has run the company successfully in his absence, Chief Operating Officer Tim Cook. They believe that Jobs, who co-founded Apple 33 years ago and has been credited with resuscitating the company in the late 1990s and turning its devices into lust objects, should conserve his fragile health by continuing to serve as chief visionary and technology evangelist. He would shape new product development and whip consumers into a frenzy when these gadgets hit stores. Jobs is 'an obsessive, visionary freak' who would run himself down were he to operate the company again, said Michael Obuchowski, chief investment officer for First Empire Asset Management Inc. 'As an investor, I want him to be behind the scenes, as the person who provides input, the person who drives everyone else insane because he has this obsessive, visionary idea,' Obuchowski said. It's a concept that is gathering momentum on Wall Street. 'If the rumors he received a liver transplant are true, it's great news the recovery is progressing nicely,' said analyst Brian Marshall at research firm Broadpoint AmTech. 'Having said that, it's clear he's not a very healthy individual. It makes sense for him to spend his energy and resources on the most important matters.' Richard Klugman, director of consumer technology for Majestic Research, said Cook demonstrated his operational strength throughout the year. Apple's recent quarterly profit surpassed Wall Street's expectations -- and the company's own forecast -- on strong sales of iPhones and iPods. 'The success that the company has had since the day (Jobs) disclosed his leave of absence gives a lot of people encouragement that there are signs that the company can not just survive, but can thrive, in his absence,' Klugman said. Jobs disclosed in August 2004 that he suffered from a type of pancreatic cancer that generally has a better prognosis for recovery than other types. In a memo to employees, he said the tumor had been removed and he planned to take a month off to recuperate. But over the last year, his increasingly gaunt appearance triggered fresh speculation about his health, causing volatility in the company's stock. In early January, Jobs said he suffered from a hormone imbalance that could be remedied through a 'relatively simple and straightforward' treatment. A week later, he said the condition was more complex, and he would take a leave. Apple has refused to provide information about Jobs' medical condition beyond his public statements. It would offer no comment Saturday about reports that Jobs had undergone a transplant. Treatment for neuroendocrine tumors usually includes surgery. When this type of cancer spreads to other organs, chemotherapy is usually recommended. In recent years, however, some doctors have attempted less conventional surgeries to treat patients whose cancer has spread to the liver, including reducing the blood supply to a tumor in the liver, removing parts of the liver containing tumors, and liver transplants. Although the transplant option has been called radical and even controversial by medical experts, several studies in recent years suggest it is appropriate for certain patients. One study examining the outcome of liver transplants for metastatic neuroendocrine tumors concluded that 'although cure is not impossible, it is improbable.' The paper, published in 2004 in the Journal of Gastrointestinal Surgery, examined transplants for 11 patients and found a one-year survival rate of 73 percent and a five-year survival rate of 36 percent. A more recent study of 17 patients found a one-year survival rate of 87 percent. That study was published in 2006 by researchers at the Mayo Clinic College of Medicine. Even with a liver transplant, the cancer can return, researchers noted. Guidelines for the United Network for Organ Sharing, which runs the nation's organ transplant system, permit liver transplant for people with cancer, said spokesman Joel Newman. 'One of the concerns and issues for somebody with liver cancer are the size and the number of tumors found in the liver and any indication that has spread outside of the liver,' Newman said. Jobs would have had to wait for an organ to become available. It is not known how long he may have been on the waiting list. 'Every decision, every allocation that is done, is done on the basis of medical criteria,' Newman said. 'We're prohibited from including any sort of social criteria, wealth or even insurance. It's purely based on medical and logistical criteria.' 