An abstract is a summary of a research study that allows readers to quickly learn about the important aspects of a study. In medical journals, an abstract is usually presented at the beginning of the published article. Abstracts are also a main vehicle of communication at scientific meetings. Although the intended audiences for most abstracts are medical and scientific professionals, it is becoming more common for patients and their friends and family members to read abstracts while learning about cancer and researching treatment options. Unlike most journal articles, abstracts are easier to search online and can usually be accessed free of charge.

An abstract often includes the following sections:

• Purpose or Objective, which explains why the study was done
  
  
• Methods, which describes the following:
  
  • The type of study that was done, such as a phase II clinical trial
    
    
  • The type and stage of the study participants' cancer, such as stage I lung cancer
    
    
  • Other characteristics of the study participants, such as age and gender
    
    
  • How much and how often the treatment was given (if a treatment was being tested)
    
    
  • What outcome was measured, such as survival, tumor shrinkage, treatment side effects, or quality of life as a way to meet the objectives of the study
    
    
    • If not a treatment study, outcome measures could include number of new cancer cases or number of patients who experienced a specific side effect from a treatment.

• Results, which summarizes the data that was collected from each participant focusing on the most important findings of the study
  
  
• Conclusions, which describes what the results mean in relation to the purpose of the study (for example, were the objectives met) and also places them in the larger context of cancer knowledge

Finding abstracts

One way to find published articles and abstracts about cancer is to search ASCO's medical journal, the Journal of Clinical Oncology. You may search by keyword, author, year of publication, or by topic. You can browse abstracts and the table of contents for every issue. Articles that are older than one year are available free of charge.

You can also search ASCO's abstracts database, which includes cancer research from ASCO's scientific meetings (for example, ASCO's Annual Meeting, Gastrointestinal Cancers Symposia, Genitourinary Cancers Symposia, Breast Cancer Symposia, and Prostate Cancer Symposia). Unlike abstracts found in journal articles, the information in meeting abstracts is typically not accompanied by a complete journal article. Often, meeting abstracts summarize early, unpublished data (for example, a second-year analysis of a five-year clinical trial), so take extra caution when interpreting the findings from meeting abstracts. In many cases (such as for large clinical trials), the complete results are published later, but this is not always true for other studies.

Another way to find published articles and abstracts about cancer is on PubMed. PubMed is a service of the National Library of Medicine that includes more than 16 million citations from a wide variety of science and medical journals. Users may search by topic, author, or journal name. Using this database may be more challenging, as it includes articles from all health-related topics, not just cancer. It is possible, however, to limit a search to cancer topics by clicking on the "Special Queries" link on the PubMed home page. In order to use the search function most effectively, scientific or medical terms may be needed instead of plain language terminology (for example, renal cell carcinoma vs. kidney cancer), but PubMed has a feature that "translates" the most common cancer terms into the appropriate scientific terms.

Types of medical studies described in abstracts

Several types of study designs are found in medical abstracts.

• Epidemiologic studies examine factors that affect public health. They focus on identifying risk factors for disease, such as linking tobacco use with lung cancer. Epidemiologic studies also identify the best way to treat cancer when there are multiple choices. There are several subtypes of epidemiologic studies. Three common ones are case-control, cohort, and case-series studies.

• Case-control studies compare two groups of people, such as those who have cancer (the case), and those who do not (the control). Researchers look for lifestyle or genetic differences between the two groups that may explain why one group has cancer and the other does not. These studies are done retrospectively, meaning the event they are studying has already happened.
  
  
• Cohort studies are prospective (the event has not yet happened). These studies monitor a group of people for a long time and track any new cases of cancer. This approach is often used to study whether certain vitamins or supplements can prevent cancer. Also, this approach can be used to identify cancer risk factors, such as the use of hormone replacement therapy and an increased risk of breast cancer.
  
  
• Case-series studies are compilations of detailed descriptions of a patient's diagnosis and treatment history. These individual patient descriptions are called case reports. If many patients are given a similar treatment, each case report may be combined to form a case series. Information compiled from individual case reports may include patient's age, gender, diagnosis, treatment, response to treatment, and follow-up care. Outcomes from case-series studies are descriptions of patients' experiences within a specific population and should not be used to determine treatment options. Case-series studies can describe both case-control and cohort studies.

• A clinical trial is a medical or health-related research study in people that can either test the safety or effectiveness of a new treatment or prevention method, or be observational as with many of the epidemiologic studies. Learn more about clinical trials.
  
  
• A meta-analysis combines the results of several studies on the same topic. By combining studies, a meta-analysis has the ability to find trends that may not be apparent in smaller studies. However, if the individual studies are poorly done, the results of a meta-analysis may not be useful. Also, these analyses are normally performed on research studies which have been published; this may mean there is a limitation to the data as studies considered less significant on the same topic may not be published and therefore not included in the meta-analysis.

Evaluating the information

Evaluating the information you find in an abstract can be difficult. The following tips may help:

• Find out where the study was published and if the journal uses a peer-review process when reviewing publication submissions. Results from a study are more reliable if they are peer-reviewed, meaning that other researchers not affiliated with the study have reviewed the design and methods, and agreed that the results and conclusions are important enough to be published.
  
  
• Look at the length of the study and the number of people involved. A study is more applicable and believable if the same results occur in many people over a long time. An exception is studies of rare cancer types or cancers with a poor prognosis (chance of recovery). In these cases, there may only be a small number of people for doctors to study. Also, when considering the length of the study, it may be appropriate for some clinical trials to be shorter rather than long-term studies. For instance, cancer prevention trials are often much longer than treatment clinical trials.
  
  
• Try to determine if this study supports or contradicts the research that is already available. New results are exciting, but other researchers must validate the results before the medical community accepts them as fact. Review articles known as "systematic reviews" may be of particular interest because, although they do not typically involve new research, they provide an analysis and draw conclusions across all the published research.
  
  
• Watch out for conclusions that overstate the results. Each study is a small piece of the research puzzle, and medical practice rarely changes because of the results of one study.
  
  
• Do not stop or change medication based on results you see in an abstract. Always talk with your doctor about the information you find in an abstract.

Additional Resources

National Cancer Institute's Cancer Topic Searches

National Cancer Institute's Dictionary of Cancer Terms

Medline Plus Medical Dictionary and Encyclopedia

More Information

Drug Development and Approval (Part I)

Drug Development and Approval (Part II)

Part I: Cancer Terms to Know: Basic Oncology Terms

Part II: Cancer Terms to Know: Newly Diagnosed

Part III: Cancer Terms to Know: During Treatment

Part IV: Cancer Terms to Know: After Treatment

Medical News: How to Know If It's Accurate

Clinical Trials: Medicine's Method for Answering Questions