Baseline Fatigue in Prostate Cancer Patients: What the FACIT-F Can Tell Us

By Rishabh Simhal, MD, Emily Menendez - February 10, 2023

GU Oncology Now spoke with Rishabh Simhal, MD, a research fellow in the Department of Urology at Thomas Jefferson University, about his recent study on the correlation between baseline fatigue and overall survival in patients with prostate cancer who have undergone stereotactic body radiation therapy (SBRT). The study utilized the Functional Assessment of Chronic Illness Therapy – Fatigue (FACIT-F) survey to determine the baseline fatigue levels of patients.

How can a patient’s fatigue affect their ability to undergo SBRT? Could SBRT potentially make fatigue worse for a patient?

Dr. Simhal: We found in our study that fatigue was actually pretty stable at the beginning. What we’re trying to get to the heart of, and what this paper is looking at, is how does that fatigue predict overall survival in these patients? Prostate cancer is the most common solid malignancy in men. Many patients with prostate cancer are of varying ages and at various stages of life, and not everybody needs to be treated. Treating a patient with radiation has its own inherent toxicity, side effects, and cost, so it might not be worth it for everyone to undergo radiation therapy.

If someone’s going to live much less than 10 years, or if they have another condition that may contribute to their mortality earlier, then it may not be worth putting them through radiation to treat their prostate cancer. We’re always looking for better ways to predict overall survival and better ways to predict who may or may not do well with radiation therapy. We’re looking for easier and simpler ways to do that. Seeing if you can figure out how fatigued someone is before treating them is key when you’re thinking, “Should I even be treating this person using radiation therapy?”

Is the FACIT-F survey commonly used for other diseases in the genitourinary oncology sphere?

Dr. Simhal: It hasn’t been used in the genitourinary oncology world very much, but it has been widely used in the neurosurgical oncology world. It’s been used in autoimmune diseases, rheumatoid arthritis, and in hematological malignancies, so it’s been used before in other fields. To my knowledge, this is the first time it’s being used in genitourinary oncology.

Do you think using the FACIT-F survey as a pretreatment assessment for patients with genitourinary cancer might be more common in the future?

Dr. Simhal: Yeah. I think a new trend is that providers are more interested in looking at patients’ baseline quality of life. In the prostate cancer sphere, the [Expanded Prostate Cancer Index Composite (EPIC)] questionnaire is most commonly used to determine how a patient is feeling after prostate cancer treatment, and it measures fatigue as well. Prostate cancer clinics regularly hand that out to patients, and that questionnaire picks up a lot of different domains of patient health.

Fatigue is an important metric in our baseline quality of life in predicting how patients are going to do, so measuring it can provide a further clinical utility, whether it’s through the actual FACIT questionnaire or another questionnaire such as EPIC.

How can the results of this study and analyzing patient fatigue affect the future of predicting risk in patients with prostate cancer?

Dr. Simhal: When we’re trying to figure out a patient’s overall clinical picture in guiding treatment, there are a lot of things that go into predicting risk, for example, the Charlson Comorbidity Index. This questionnaire can be cumbersome to calculate for a clinician quickly. You have to talk to [the patient’s primary care physicians] and figure out all the different diagnoses you have.

These current risk predictors look at common comorbidities in patients—for example, hypertension, diabetes, and congestive heart failure—but there are a lot of different diseases out there that can really affect someone’s overall health, such as rheumatological diseases that are commonly not questioned or other rare diseases. The good thing about this is that the impact that these diseases have on patients’ overall health may be related to fatigue, meaning that fatigue may actually help be a proxy for other comorbidities.

These risk calculators generally don’t go into how well-controlled a disease is, but fatigue may actually end up being a nice proxy for comorbidities that often aren’t captured, as well as the severity of those comorbidities. For example, someone who has uncontrolled depression may have worse baseline fatigue than someone who has moderate, well-controlled depression. Fatigue is an easy indication for a clinician to figure out because the patient is asked basic questions like “How tired are you right now?” or “How tired are you most days?” Analyzing a patient’s level of fatigue can potentially capture a lot of information that is otherwise hard to get at.