A collaboration including researchers from Harvard University and the Karolinska Institute in Sweden looked at data for more than 4 million men in Sweden above the age of 30 and found that the diagnosis of prostate cancer -- something that occurred in over 160,000 of those men -- increased the relative risks for fatal heart problems 11 times and suicide by eight times in the week after diagnosis.
"Stress can be an important trigger for physiologic reactions, including increased risk of cardiovascular disease," said Dr. Meir Stampfer, professor of nutrition and epidemiology at the Harvard School of Public Health. "The diagnosis of cancer also can cause high enough stress to see a noticeable increase in both heart disease and suicide."
Given that suicide is generally rare, the study does not suggest that men commit it in great numbers following a prostate cancer diagnosis, but doctors say it does suggest a need for more careful monitoring and communication with patients following a diagnosis.
"This study is certainly a wakeup call that there are other issues…that somebody could be at increased cardiovascular risk or increased suicide risk," said Bruce Trock, an epidemiologist in the department of urology at Johns Hopkins. "The lesson [of the study] is more for physicians, that when they give out a diagnosis of prostate cancer, they should be thinking about this.
"It would be incumbent for a physician to try to keep tabs on what's going on with this patient," especially during the first month, he said. "Once somebody's diagnosed with prostate cancer, usually the first month is when they're trying to make up their mind about treatment."
But possible heart disease and suicidal thoughts are not the only potential problems for men after a prostate cancer diagnosis.
Bruce MacDonald, a social worker at Dana-Farber Cancer Institute in Boston, counsels men following a prostate cancer diagnosis. While he said in his eight years there he has only had one patient who attempted suicide, he far more frequently deals with patients who are depressed or have other problems following treatment.
Among men who have removal of the prostate, some men are left impotent permanently, while others have to deal with incontinence. He said others must take hormonal treatments when surgery fails to remove the tumor completely from the prostate, and the absence of testosterone can lead to impotence and a lack of libido.
MacDonald said a man who is 50 years old and is diagnosed with prostate cancer, then left without a libido by the surgery can be heavily affected by the change in sexual function.
"That, obviously, is a red flag when it comes to what can lead to depression," he said. "It's a real struggle for a man in terms of his self-image, which sometimes can change really overnight. If there is significant clinical depression, we do our best to help a man receive treatment for that."
MacDonald explained that those treatments could include medication and psychotherapy, and possibly couples therapy to deal with the changing relationship with a partner.
While men receiving a prostate cancer diagnosis abroad may react similarly to men in the United States, it's not clear how applicable this study would be, given differences in screening and treatments between the United States and Sweden.
For example, given that men in Sweden tend to be screened less, their disease is sometimes caught in later stages, making it more likely that hormonal therapy will be necessary, and the resultant side effects may create more anxiety.
"We're pursuing that actively, looking at the U.S. statistics," said Stampfer, although he said that data available for the United States is not as clear as that available in Sweden, and so doing a similar study would prove difficult. However, he said, "It looks like the overall, broad pattern would be similar in the U.S."
Stampfer said he was encouraged by the fact that men in later years of the study were less likely to suffer heart problems following a diagnosis of prostate cancer.
"In more recent times, the public has gotten more sophisticated, better information and realizes a cancer diagnosis is not a death sentence," he said. "It no longer carries as much of that horrible sense of doom that it used to."
But the drop in heart risks may mean problems in the study.
Dr. Nortin Hadler, a professor of medicine and microbiology/immunology at the University of North Carolina said that given the lack of screening in Sweden, it's possible that the increase in heart disease is because that was why patients were coming to the doctor in the first place.
He explained that patients getting a prostate test were likely to be at the doctor's office for another reason, and in later years, with more awareness of prostate cancer, that effect was lessened.
"We don't know why these particular individuals who are diagnosed with prostate cancer decided to get the diagnosis," Hadler said. "The answer may be that something else brought them to the doctor, and as part of the doctor's approach ... they did a much more general exam."
But others said that possibility did not confound the study.
"The suicide portion of it verifies an American study that was done several years ago," said Dr. Otis Brawley of the American Cancer Society. Suicide and heart risks are part of what physicians need to discuss with patients before prostate screening, he said.
"Although it's an important cause of death, most men who get prostate cancer don't die of it, and I think that knowledge is becoming more and more widespread," Stampfer said. "That was the initial motivation for our study, to explore further what the potential impact a diagnosis of cancer might bring."
Of course, not all diagnoses of cancer are even correct.
While focusing on men with prostate cancer, the study also casts some light on the perils of false positives resulting from increased cancer screening.
The topic of screening's possible perils drew headlines last month when a government task force suggested that mammograms may be unnecessary for younger women at a lower risk of breast cancer. Similar discussions are taking place, albeit less publicly, about other forms of cancer.
"Most of the controversy relies on whether the screening advances the people who were screened," Hadler said.
Hadler said he advocates diagnostic screening -- screening in response to a symptom the patient notices -- rather than general screening, "which is a response to a date on the calendar."
"The data suggests that we don't have to do screening, with mammography or PSA, to increase the likelihood of saving lives," he said, although he added that risks for incontinence and impotence following prostatectomy are better reasons than those listed in this study to reconsider screening.
But while prostate cancer screening guidelines recommend patients speak with their doctors about the risks and benefits of prostate cancer screening, in practice, primary care physicians do not have the time to have those conversations with their patients.
For that reason, Brawley said, he has asked staffers at the American Cancer Society to create a pamphlet to explain the risks and benefits to patients, since he realizes the problem of time, and said it may be better spent.
"I'd rather him talk about them not smoking and talk about them not gaining weight," he said.
But screening will present a problem as long as doctors cannot tell whether a tumor will kill a patient or whether it will grow so slowly that the patient will die of something else, and so treatment is unnecessary.
In the end, Brawley said, it isn't that screening is ineffective, but that it is not the magic bullet that it has been made out to be in saving lives.
"In many cancers, we have overly hyped screening," Brawley said. "It doesn't mean that screening is not beneficial; it means we promised more that screening cannot provide."
Ultimately, Hadler said, screening requires an answer to the question of how deadly the prostate cancer that may be found is in the first place, but doctors do not have that answer yet.
"Do I have a prostate cancer that I will die with, or do I have a prostate cancer that I will die from, and do we have a test available that will distinguish between the two possibilities?" he said.