RWE in oncology: Benefits and drawbacks 

In recent years, real-world data (RWD) and real-world evidence (RWE) are having a renaissance in cancer treatment. However, real-world evidence comes with its own pros and cons, raising important questions. Why is RWE becoming more widely used, and what should you consider when using it in your oncology practice? 

Clinical trial data is a pivotal aspect of cancer treatment. Clinical trials have long been a central guidepost for the approval and use of oncology therapies1, whether honing in on drug dosages, evaluating cancer treatments for safety, or determining their effectiveness. However, such clinical trials are not without limitations.  

RWD and RWE can be an advantage to the oncology field, often filling the gaps left by the inherent faults of clinical trial data. Recent legislation2, such as the 21st Century Cures Act, aims to improve data sharing and use. This could translate to greater use of real-world evidence in the drug development cycle.  

The Federal Drug Administration (FDA) defines real-world evidence3 as clinical evidence that provides information about a medical product’s benefit or risk according to real-world data. RWD4may be any health information gathered during clinical care, patient billing, and other electronic health records (EHR).  

The use of RWE can support cancer treatment effectiveness. Since RWE is gathered differently, it often holds certain advantages over the constraints inherent in clinical trials. RWE developed from real world oncology data provides a broader spectrum of information.  

Oncologists report differences in patient outcomes compared to clinical trials
Oncologists report differences in patient outcomes compared to clinical trials

The problem with clinical trials 

Clinical trials are still considered the most definitive way to test whether a new cancer treatment works. Yet, unfortunately, they present some limitations.  For one, clinical trials can be costly and time-consuming.  

Additionally, clinical trials may not always accurately reflect the diverse patient population you see in real life as an oncologist. In fact, many Sermo physicians surveyed reported that patient outcomes differed from what they expected based on clinical trial data5. 56% of physicians reported differing outcomes in five patients or less, 15% reported an incidence of differing outcomes in five to 10 patients, and 10% felt that outcomes almost always differed. Notably, 19% of surveyed physicians never felt their patients had unexpected outcomes based on clinical trials.  

To compound the issues surrounding clinical trial data, your patients may come from all walks of life and varying socioeconomic statuses. Unfortunately, not every patient has the same access to healthcare. 40% of Sermo physicians surveyed reported that 10-25% of their patients have experienced worse cancer outcomes related to poor healthcare access. 10% felt that number was closer to 25-50% of their patients, 17% felt it was up to 75%, and 4% reported noting worse outcomes in more than 75% of their patients. 

In addition, clinical trials6 are frequently performed at academic medical centers or other research-focused establishments. Yet, this isn’t where most patients receive their care in real life. In a Sermo physician survey, only 13% of oncologists said that they provide care at academic research centers. The majority of surveyed physicians — 40% — provide care in an inpatient hospital setting. The second most common place was in outpatient clinic settings, with 26% of physicians caring for patients there. 13% cared for oncology patients in an NCI-designated cancer center, and 9% of physicians provide care in another setting not listed in the survey.  

Moreover, barriers to entering clinical trials are all too real for some patients. Many randomized controlled clinical trials (RCTs) are highly selective about who they accept. An RCT may not represent the range of patients seen in real-world clinical practice, where patients may exhibit lower tolerance, adherence, or worsening conditions. In a survey of Sermo physicians, 77% reported that their patients have had difficulty getting accepted to clinical trials based on factors such as comorbidities. Considering that such barriers exist, how can you be confident the study results apply to all of your patients?  

In some instances, patients in clinical practice have fared worse than those that took part in an RCT. For instance, one analysis of patients7 with castration-resistant prostate cancer revealed that a regimen of docetaxel and prednisone yielded higher toxicity levels and worse survival rates in practice than within the clinical trial. Such results may be due to the patients chosen for RCTs lacking the heterogeneity of patients in clinical practice. This is where real-world evidence comes into play.

The value of real-world evidence in oncology patient care 

RWE is essential because it’s pulled from real-world data.  As RWD is not limited to certain populations, researchers can analyze cancer data from a variety of demographics, and not just clinical trials. In some cases, RWE backs up the efficacy8 of cancer treatments. And in other cases, RWE improves patient care and helps streamline care delivery.  

For example, real-world data recently led to FDA approval of a biweekly dosing regimen9 of cetuximab for patients with metastatic colorectal cancer. Previously, patients needed to come in weekly for the drug. But RWE showed the efficacy of biweekly dosing, saving patients time and allowing them to more easily coordinate their appointments. 

There are also many instances of RWE reinforcing the results of clinical trials. When used appropriately, real-world evidence in oncology is a boon to cancer care. RWE can also shed light on several significant issues, like how treatment complexity, cost, and patient demographics affect patients’ compliance with their treatment regimens. The Oncology Center of Excellence Real World Evidence Program10 now seeks to advance the use of RWE in developing cancer treatments within a regulatory context.  

When data is collected from real-world sources, researchers can obtain a more comprehensive picture of treatment outcomes in clinical practice. Yet, despite its great value, RWE also has its negative side. Clinicians need to approach using RWD with some critical considerations. 

Drawbacks of real-world evidence in cancer treatment 

Just like any methodology, real-world evidence has its limitations. For instance, researchers face lower quality data collection and sources than those of clinical trials. On top of that, RWD lacks control groups, meaning it’s harder to compare treatment efficacy to any standard or other treatments.  

Another limitation of real-world data is that oncologists sometimes  under-report11 subjective patient symptoms in clinical practice. Therefore, information pulled from electronic charts pertaining to adverse events may be less accurate. On the other hand, participants in a clinical trial are carefully monitored for any subjective or objective adverse symptoms. 

Overall, safety data within RWD may be less accurate than in a clinical trial as well. It’s also harder to establish cause and effect between a drug and an adverse event just from analyzing RWD.  

The future of RWE and oncology 

RWE that follows clinical trials is in-demand as it provides the best of both worlds — clinical trial data and evidence gathered in the field. RWE packs the most power when it’s backed by clinical trials, and vice versa. However, as an oncology practitioner, you may not always have access to a clinical trial information alongside real-world evidence. If you’re using RWE that’s not backed by clinical trials, it’s important to keep in mind the limitations of these datasets.  

Being part of a collaborative community like Sermo is an opportunity to tap into the invaluable experiences of likeminded colleagues. Through our interactive platform, doctors like you from all over the world can glean firsthand knowledge and share their wisdom with each other.  

Sermo empowers you to make a difference by being an active participant in the conversation. Although clinical trials will remain the gold standard for assessing the efficacy of oncology care, there is much to be learned from the sharing of real-world observations and evidence. 

community of doctors discuss real world evidence in oncology on sermo
Community of doctors discuss real world evidence in oncology on Sermo

As the future grows nearer, RWE is becoming an integral part of evidence-based practice. We all want the best for our patients, and medical advances are happening at an unprecedented rate. In medicine, it will always be vital to look at things that did or didn’t work, both historically and more recently, to provide patients the most effective care possible. With Sermo, you can be part of a global community of physicians striving to do so every day.


  1. Friends of Cancer Research
  2. Friends of Cancer Research
  3. U.S. Food & Drugs Administration
  4. Friends of Cancer Research
  5. Sermo
  6. AJMC
  7. National Library of Medicine
  8. National Library of Medicine
  9. AJMC
  10. U.S. Food & Drugs
  11. National Library of Medicine