Background: SCMs are prescribed based on symptom burden, but response is variable, possibly due to PGx. We investigated the association between symptom burden, SCM prescribing, and frequency of SCMs with PGx evidence. Methods: Cancer pts ≥ 18 years old and completing electronic distress screening within 90 days of intake between 1/1/2017-12/31/2017 were included. Anxiety was measured using Generalized Anxiety Disorder 2-item (0-6) and depression using Patient Health Questionnaire-2 (0-6). Fatigue, nausea, neuropathy, pain and sleep were measured on a 0-10 scale. SCM prescribing within 90 days of intake was documented. Logistic regression compared symptom scores and SCM prescribing. Receiver Operating Characteristics analysis estimated sensitivity/specificity. Optimal symptom thresholds were selected according to Youden’s J statistic. SCMs with PGx evidence level A or B (according to Clinical Pharmacogenetics Implementation Consortium) were summarized. Results: Of 6985 pts, 65% were female, 75% Caucasian, 20% African American and median age was 60. 49% reported ≥ 1 severe symptom, which correlated with SCM prescribing (p < 0.001). 3208 (46%) were prescribed SCM(s), mainly for pain (69%) or nausea (46%). Of these, 2759 (86%) received ≥ 1 SCM with PGx evidence and 2695 (84%) received a SCM metabolized by CYP2D6 - hydrocodone (47%), ondansetron (41%), and oxycodone (28%). Based on reported CYP2D6 allele frequencies conferring altered metabolism (~20%), 539 of the 2695 pts may have altered drug response. Threshold scores for each symptom are summarized in the table. Fatigue and nausea were not associated with SCM prescribing. Conclusions: Symptom burden is high in cancer pts and correlates with SCM prescribing. Many SCMs have PGx evidence, suggesting preemptive testing, particularly for CYP2D6, may have broad applicability in this population.

^ap < 0.001