How to evaluate cancer research

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Cancer research is like a giant jigsaw puzzle with many pieces still missing. Across the globe, researchers are asking, and answering, specific questions about every stage of the cancer journey. This is a slow, step-by-step process. But over time, researchers are discovering new pieces of the puzzle.

Researchers do their best to make sure research studies are fair, balanced and reproducible (can be copied) so others can test and build on their findings.

Even the highest quality research is still just a snapshot of knowledge – a single jigsaw piece. To be useful, that piece needs to be placed in context, alongside many other pieces of the research jigsaw. Only then do you start to see a full picture.

When reading about any research, try to think critically about a study's strengths and weaknesses.

You may want to consider the following questions when looking at a study.

How far along is the research?

Cancer research is a long and careful process. It might start in a laboratory or in animals, long before it is applied to humans. Even once a discovery or treatment is ready to be tested in humans, clinical trials can still take many years.

In fact, clinical trials are conducted in phases. These phases are designed to find out whether a new treatment is safe and effective, and how it compares to existing treatments. Clinical trials have 4 phases. In most cases, a new treatment needs to complete the first 3 phases before it can be made widely available.

What type of study is it?

The 2 main types of clinical cancer research are experimental studies and observational studies. In experimental studies, researchers use 2 groups. One group takes part in the experiment (for example, they might receive a new treatment). The second group is used for comparison. For this control group, nothing changes. In observational studies, the researchers watch different groups of people in an everyday setting to see what happens.

In general, experimental studies are more reliable than observational studies because the groups are chosen at random. This is known as a randomized controlled trial. In randomized controlled trials, participants are randomly assigned to one of the groups (for example, treatment or control). This process means that personal preferences and behaviours, outside of the issue being studied, are less likely to influence or bias the results.

But even a randomized controlled trial is just one puzzle piece. To get a good overview of research on a specific topic, many doctors use review articles. Review articles, sometimes called systematic reviews or meta–analyses, collate, evaluate and summarize the findings from many different studies on a certain topic to draw more reliable conclusions.

If it's a study in humans, how many people took part?

When researchers design a study, they can't investigate every person within a given population. Instead, they take a sample of that population. If the sample size is large, the results are more likely to reflect what would happen in the real world.

Where was the research published?

New research gets published in scientific journals. These journals help researchers share their findings and allow other researchers to test the results or use them in further research. The most respected journals use a process called peer review to make sure they only publish high-quality research. During peer review, subject matter experts review the study to make sure it is reliable and adds new knowledge to the field of study. If it does, the research is published.

There are many websites that share health messages and cancer information. Some, like the Canadian Cancer Society, draw on the best scientific evidence from many studies and work with respected healthcare professionals and researchers to interpret, check and approve the information they share. Others are not as rigorous. Where possible, rely on websites from reputable research and cancer organizations such as Cancer Research UK and the American Association for Cancer Research.

Who conducted the research?

Researchers are usually associated with universities, hospitals and research institutes. They may also be affiliated with pharmaceutical companies or other organizations. No matter where the research comes from, it's important to be aware of potential conflicts of interest. High-quality research will list all funding sources as well as potential conflicts of interest.

An exciting time for cancer research

It's an exciting time for cancer research. While it's important to think critically about research findings, it's also important to remember that research teams in Canada and around the world are moving us closer to the day when many cancers will be curable as well as preventable and others will be managed as chronic diseases like diabetes and asthma.

Through research, our collective knowledge grows and we make progress against cancer.

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

We do our best to make sure that the information we provide is accurate and reliable but cannot guarantee that it is error-free or complete.

The Canadian Cancer Society is not responsible for the quality of the information or services provided by other organizations and mentioned on, nor do we endorse any service, product, treatment or therapy.

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