One of the strategies of the Trump presidency has been to label the information presented by multiple mainstream media outlets “fake news.” This is not a one-time extemporaneous response to any specific, offending reporter. Rather, the approach seems to emanate from serious forethought. One senses that President Donald Trump is rigorously staying on-message when he barks out “fake news!” while parrying questions at press conferences, or when inserting the term into his Twitter feeds.“Fake news” implies deliberate deception or intentional hoaxes that are masquerading as genuine news. By painting with this brush, Trump is assailing the reliability and trustworthiness of his perceived inquisitors.In my business, cancer medicine, physicians are often tasked with the delivery of bad news. Several strategies have been proposed to soften the transmission of unfavorable information, but it is never easy to tell someone they have a tumor, that treatment has failed or that they have only a few months to live. For this reason, many of us learn to play artfully with patient expectations or to use fancy medical jargon to blur prognostic lines or caretaking goals. In so doing, we are turning bad news into fake news.Society is now grappling with the notion of fake news and this means that Trump has been very successful. Why has this issue preoccupied not only journalists but also the layperson? The impression that we are being fed fake news perturbs our sensibility. While we understand that news is never completely objective since it is delivered by human beings who harbor inherent bias, we want to believe that we are mostly receiving facts that we can then assess. Once the suspicion of fake news has been planted, however, we are disoriented because we do not know whom to trust.Trust is also a linchpin that holds together the complex cases that I treat. Taking another chemotherapy drug off the shelf, or raising the dose of radiation is the easy part of my job. Cultivating and maintaining trust is far more demanding. When physicians realize that they must impart bad news, they worry that trust will be eroded and hopes will be dashed.Several years ago, my colleague Dr. Tom Smith carried out an important study at Virginia’s Massey Cancer Center.A group of 27 patients was about to receive bad news. Smith and his co-investigators administered a validated questionnaire that measured hopefulness to these patients before and after the bad news was shared. For almost all patients, hopefulness did not decrease. Smith concluded that hope could be sustained provided the bad news was conveyed with authenticity.As real news.Sometimes, though, bad news is simply too stark. In those encounters, a seasoned clinician might gradually break off bite-sized pieces of bad news or even allow patients and family members to engage in a bit of denial. Acknowledgment of cultural mores is also critical since data demonstrate that certain ethnic groups simply do not want to exchange bad news and are willing to forgo truth for the sake of shielding a loved one. But the latter is a rare phenomenon. Most of us crave authenticity and see a link between truth and trust.Thus, as a general rule in my professional world, when bad news is cast as fake news, it’s "bad news."It seems to me that both within and beyond hospital walls, it’s risky business – if not cruel – to liberally apply the label of fake news. Most of us want to believe that political leaders as well as the members of the press who cover them – and of course, the physicians who treat us! – have integrity and are worthy of our trust. We deserve this.The author is a professor of oncology at Tel Aviv University’s School of Medicine and the co-founder of the NGO Life’s Door.