Johnson SB, et al. - Researchers compared patients with cancer receiving conventional cancer treatment (CCT) alone or in addition to complementary medicine (CM) with respect to overall survival and adherence to treatment. In addition, they compared characteristics of patients receiving CCT with or without CM. Patients who received CM showed a higher tendency for refusal to other CCT and were at a higher risk of death than no CM. However, adherence to all recommended conventional cancer therapies may mediate this survival difference.

Methods

• Data from the National Cancer Database on 1,901,815 patients from 1,500 Commission on Cancer–accredited centers across the United States who received a diagnosis of nonmetastatic breast, prostate, lung, or colorectal cancer between January 1, 2004, and December 31, 2013 were included in this retrospective observational study.
• They matched patients according to age, clinical group stage, Charlson-Deyo comorbidity score, insurance type, race/ethnicity, year of diagnosis, and cancer type.
• From November 8, 2017, to April 9, 2018, researchers conducted statistical analysis.
• They defined use of CM as “Other-Unproven: Cancer treatments administered by nonmedical personnel” in addition to at least one CCT modality (defined as surgery, radiotherapy, chemotherapy, and/or hormone therapy).
• Main outcomes and measures included overall survival, adherence to treatment, and patient characteristics.

Results

• Researchers analyzed a cohort of 1,901,815 patients with cancer (258 patients in the CM group and 1,901,557 patients in the control group).
• In the main analyses following matching, the CM group included 258 patients, and the control group included 1,032 patients.
• Among patients who chose CM, no longer delay to initiation of CCT but higher refusal rates of surgery, chemotherapy, radiotherapy, and hormone therapy were evident.
• In a multivariate model that did not include treatment delay or refusal, the investigators identified use of CM to be associated with poorer 5-year overall survival vs no CM and had an independent association with greater risk of death.
• However, no significant association was identified between CM and survival, once treatment delay or refusal was included in the model.