John: Hello, I'm John Hilton, senior editor at Cochrane. Music therapy is used for a variety of conditions and several Cochrane Reviews examine its effects. A team of music therapists with expertise in the use of music therapy with medical patients updated their review for cancer patients in October 2021. Joke Bradt from the department of Creative Arts Therapies at Drexel University in Philadelphia, USA tells us what they found in this Evidence Pod. She conducted the review with Cheryl Dileo from Temple University in Philadelphia, Katherine Myers-Coffman from Molloy College in Rockville Center, and Jacelyn Biondo, postdoctoral fellow in the department of Creative Arts Therapies at Drexel University.

Joke: People with cancer can experience intense emotional, physical and social distress. Many of these symptoms and the side effects of treatments impact on their physical well-being and quality of life. In addition, cancer patients often experience grief and depression in response to diagnosis and treatment. Therefore, their care needs to incorporate services that help address symptoms and meet their psychological, social and spiritual needs. Music therapy has been used in different medical fields to this end.
Our review now includes 81 trials with more than 5500 participants with cancer. Twenty-six trials included patients who underwent chemotherapy or radiation therapy, 23 examined the effects of music during procedures or surgery, and 25 included general cancer patients. Almost all the trials were with adults, with only seven examining music interventions for pediatric cancer patients. 
The use of music in cancer care can be situated along a continuum of care, from music listening initiated by patients, through pre-recorded music offered by medical personnel, to music interventions offered by a trained music therapist. Music therapists are specifically trained to select music interventions to offer emotional and spiritual support, facilitate communication and meaningful interactions between patients and their families, offer new coping strategies, and improve symptom management. Therapists may improvise music with the patients, help patients sing familiar and preferred songs, write original songs, or play live music selected by the patients. 
We categorized 43 of the studies we found as music medicine studies in which the participant simply listens to pre-recorded music offered by a medical professional, while 39 studies were music therapy studies.
The evidence shows that both types of intervention may have a beneficial effect on anxiety in adults with cancer, which is consistent with our three other Cochrane reviews on the use of music with coronary heart disease patients, mechanically ventilated patients, and for pre-operative anxiety. In regard to children with cancer, two trials suggest that music interventions may help reduce their anxiety as well.
The results for adults with cancer indicate that music interventions may reduce depression and fatigue and have a moderate pain-reducing effect. The pediatric trials did not include these outcomes except for one trial that reported pain-reducing effects of music on children with cancer. We also found that music interventions may have benefits on heart rate and blood pressure in adults.Results from single trials suggest that music interventions may reduce anesthetic and analgesic consumption in adult cancer patients undergoing surgery and shorten the length of hospital stay; and a single study also suggests that patients might recover quicker after surgery when a music therapist offers live, individualized music before and during surgery. However, more research is needed before we can draw solid conclusions about these outcomes.
We were also interested in examining if it mattered what type of intervention the participants received. Our subgroup analyses indicated that although music therapy interventions had a moderate effect on quality of life in adults, there was no support for an effect of music medicine interventions for this outcome. Likewise, for fatigue, we found a small to moderate effect for music therapy but not for music medicine studies. 
Overall, evidence from the trials included in this updated review suggest that music interventions may be offered as a complementary treatment to people with cancer and that music therapy interventions delivered by a trained music therapist may lead to more consistent results. However, because participants cannot be blinded to music interventions and subjective outcomes are measured by self-report measures, there was a high risk of bias for most studies meaning that these findings need to be interpreted with caution.
We have several research recommendations for future studies. Randomized trials are needed which directly compare music medicine versus music therapy interventions and examine the relationship between frequency and duration of interventions and their effects on a wide range of outcomes. We would also like to see more trials in pediatric cancer. Future research efforts should also aim to enhance understanding of how music therapy and music medicine interventions can be optimized for symptom management, how music interventions can best serve patients along the cancer treatment trajectory, and what unique aspects of music therapy and music medicine interventions contribute to the care of patients. Trials that use listening to pre-recorded music should describe the music selections made available to participants and exercise greater care in selecting music that reflects the patient's true preference. Finally, given that the findings regarding anxiety-reducing effects of music are quite robust, it is important that future studies focus on other outcomes included in this review.

John: To read more about the trial's in Joke's review and the range of music interventions that have been tested, visit Cochrane library dot com and run a simple search for 'music and cancer'.