One can tell a lot about how a story is going to be from its lead quote. This HealthDay story on a new study indicating potential cancer prevention benefits from bone density drugs — quoted Dr. Gad Rennert, the study’s lead author, sounding “These [new] findings are meaningful because they point to a possible protective effect of this class of drugs being relevant to prevention of many different cancers. … This is [similar] to the effect that we and others have shown for [cholesterol-lowering] statins.” From there on, Rennert is allowed to pump up the benefits of these drugs and to sweep aside any concern about their risks or broad application to a large population. Contrast that with the Reuters Health story which chose to quote Eric Jacobs from the American Cancer Society saying, “The lower risk of colorectal cancer risk seen among bisphosphonate users in this study is intriguing….However, these results should be interpreted with caution and require confirmation by additional studies.” From that point on, the story took a cautious, objective look at the study’s findings. We wish both stories had done a better job parsing the evidence, but we think that, overall, Reuters Health provided better context for readers.
Roughly 1 out of every 20 people in the US will develop colorectal cancer at current rates. If taking a simple pill for $10 a month can keep cancer at bay, the world would be a much better place. Because solutions to significant health challenges are usually not that simple, this story and others that covered the same study should have been more cautious in explaining the results and showing readers why they might not translate to an immediate benefit for them.
Unlike the Reuters Health story, this story did not discuss costs. This is a shame because if the monthly cost is $10, as Reuters Health notes, that may be cheap on an individual level. As a public health policy, though, $120 a year across a huge population could add significantly to an already overspent health care system.
The lead says, “People who take drugs called bisphosphonates to prevent bone loss may also reduce their risk of developing colorectal cancer by almost 60 percent compared to those not on the drugs, a new study suggests.” What this story and the Reuters Health story failed to do was give the raw numbers that are provided in the study itself. The story should have said that 138 women in the non-cancer group took biophosphonates and 97 in the cancer group took them, meaning that 41 women appear to have benefited from taking the drugs. If the study had found that 97 women had taken these drugs in both groups, the study would not have made headlines. Also, it might have been helpful to show that there were actually larger differences in some of the other factors that were studied. For example, 120 women in the group of cancer patients had a history of colorectal cancer in the family compared to 75 women in the control group.
This story did a better job of mentioning “The magnitude of the reduced risk is less important because this is an association study…” But then it goes on to say that the magnitude of the benefit is similar to cholesterol lowering medicines. The main difference is that this story, despite the caveats mentioned, is more enthusiastic about the findings than the Reuters story.
We give this story and the Reuters Health story credit for at least mentioning some of the risks of taking bisphosphonates. “The researchers noted, however, that the risks of using bisphosphonates include the possibility, in rare cases, of osteonecrosis of the jaw (destruction of the jawbone or jaw tissue). Bisphosphonates used for osteoporosis have also been linked to a rare fracture of the thigh, according to the U.S. Food and Drug Administration.” But neither story quantified the harms in any way. This story also failed to point out, as the Reuters Health story did, that “earlier study from the UK had found no link between bisphosphonate and colon cancer. Indeed, it found a higher risk of throat cancer in patients on the medication.”
The story makes a good attempt at explaining the quality of the evidence. It says, “For the study, Rennert’s team collected data on almost 1,900 postmenopausal women who took part in the Molecular Epidemiology of Colorectal Cancer study, which is a population-based trial in northern Israel….The researchers found that taking bisphosphonates, mostly Fosamax, for at least a year was associated with a significant 59 percent reduction in relative risk for colorectal cancer.” The story added a nice detail missed by Reuters Health, saying, “The findings in this study show that bisphosphonates are associated with a reduced risk of developing colorectal cancer, but they cannot confirm a causal effect — that is, the study doesn’t prove that the use of bisphosphonates is responsible for the lower risk of colorectal cancer.” But both stories fail to point out that this study did not look at 933 women who took the drugs and 933 who did not. Of those 1,866 women, only 97 of the cancer patients took the drugs, and only 138 of the women without cancer had taken them. So, yes, the researchers were able to find what appears to be a statistically significant risk reduction, but they also found differences in physical activity, body mass index, vegetable intake and the use of statins and aspirin. The study highlights the biophosphonate connection, but the story should have explained why a difference of 41 women without cancer taking these drugs out of a total of nearly 2,000 would be enough evidence to support some of the cheerleading in the story.
Though this story, in some ways, provided more information on the quality of the evidence, it too missed the point that the biggest limitation of the study is that factors related to the women’s underlying risk of cancer were lower in those taking bisphosphonates, and that the authors did not collect adequate information to control for those differences. This is why one needs a randomized trial. And the mention that such a study should be “relatively easy” to do is not likely to be true. One will need a very large population to detect any difference on top of routine screening with a colonoscopy. One cannot do a study and not offer the control patients current standard of care. That means everyone needs to be screened first. This will be a very hard, expensive study to do.
Neither story engaged in disease-mongering.
Both stories quoted the exact same sources: the lead author and Eric Jacobs, Strategic Director of Pharmacoepidemiology at the American Cancer Society. But both stories used their comments in very different ways. The Reuters Health story did not allow Rennert to run wild with enthusiasm. The HealthDay story did. For example, when the story notes that “A randomized trial is needed to prove that bisphosphonates are protective against colorectal cancer, Rennert said.” It follows that sobering bit of news up immediately with, “It should be relatively easy, as it seems that all that is needed is a year of treatment to see the effect,” he said. Should be relatively easy? Ask any drug company how much time it takes and what it costs to bring a drug to market and no one will tell you that clinical trials are easy. This is especially troubling given that a previous study just last year showed no benefit, and, remember, we are talking about just 41 women who appear to have staved off cancer by taking these drugs.
Both stories relied on Jacobs from the American Cancer Society for the same bit of context. “Fortunately, there are other proven ways to help lower risk of colorectal , he said. “In particular, all Americans, 50 or older, should get a screening test so that precancerous polyps can be detected and removed before they turn into cancer.”
Both stories make it clear that these are drugs currently on the market. This story provided even more detail, saying, “Bisphosphonates include such common drugs as Fosamax (alendronate), Boniva (ibandronate), Actonel (risedronate) and Reclast (zoledronic acid). These drugs work by increasing bone thickness, thereby reducing the risk of fractures, the researchers said.”
This story made it clear that the findings are part of a series of findings, some of them contradictory, about the side benefits of different drugs for cancer prevention. It says, for example, “However, the lowered risk of colorectal cancer seen with bisphosphonates may be due to the way the drug acts in the body, which is similar to how cholesterol-lowering drugs called statins work, according to Rennert.”
Neither story relied on a news release.