The investigators wanted to find out what patient characteristics are associated with use of SCAM for cancer and what is the association of SCAM with treatment adherence and survival. They thus compared the overall survival between patients with cancer receiving conventional treatments with or without SCAM and the adherence to treatment and characteristics of patients in both groups.
Their retrospective observational study used data from the National Cancer Database on 1 901 815 patients from 1500 Commission on Cancer–accredited centers across the United States who were diagnosed with nonmetastatic breast, prostate, lung, or colorectal cancer between January 1, 2004, and December 31, 2013. Patients were matched on age, clinical group stage, Charlson-Deyo comorbidity score, insurance type, race/ethnicity, year of diagnosis, and cancer type. Overall survival, adherence to treatment, and patient characteristics were the study endpoints.
The cohort comprised 1 901 815 patients with cancer (258 patients in the SCAM group and 1 901 557 patients in the control group). In the main analyses following matching, 258 patients were in the SCAM group, and 1032 patients were in the control group. Patients who chose SCAM did not have a longer delay to initiation of conventional therapies, but had higher refusal rates of surgery, radiotherapy, and hormone therapy. Use of SCAM was associated with poorer 5-year overall survival compared with no SCAM (82.2% [95% CI, 76.0%-87.0%] vs 86.6% [95% CI, 84.0%-88.9%]; P = .001) and was independently associated with greater risk of death (hazard ratio, 2.08; 95% CI, 1.50-2.90) in a multivariate model that did not include treatment delay or refusal. However, there was no significant association between SCAM and survival once treatment delay or refusal was included in the model.
The authors concluded that patients who received CM were more likely to refuse additional CCT, and had a higher risk of death. The results suggest that mortality risk associated with CM was mediated by the refusal of CCT.
This new evidence confirms previous papers: SCAM-use is associated with shorter survival of cancer patients. As it is based on a large sample size, its results are more compelling. They indicate that it is not SCAM per se, but the attitude of SCAM-users to conventional therapies that is the cause of the effect. As I have said and written hundreds of times: the most serious risk of SCAM is not a direct but an indirect one: the risk of neglecting effective therapies. Essentially, this means that better information targeted at vulnerable patients must be the way forward (one of the main ambitions of this blog, I hasten to add).