Choosing Alternative Medicine Instead of Cancer Treatment: What Studies Found About Outcomes
What US registry studies and NCCIH guidance say about using unproven treatments instead of standard cancer care, with the limits of that research and where to find supportive options.
Content last updated . This page has not been medically reviewed.
A cancer diagnosis is frightening, and wanting a gentler or more natural path is understandable. This page sets out what published studies found, so that you can make decisions with your cancer team. It is information only and is not medical advice. If you have a new symptom that worries you, see a doctor promptly.
The key distinction: instead of, or alongside
NCCIH calls a non-mainstream approach "complementary" when it is used together with conventional medicine and "alternative" when it is used in place of it. [1] The research below is about the second situation, and mostly about people who refused standard treatment.What NCCIH says
- No complementary health approach has been shown to prevent or cure cancer. [2]
- Do not use unproven products or practices to replace or delay medical treatment for cancer. [2]
- Guidelines it cites say some approaches, used in addition to conventional therapies, help to control symptoms and well-being. They warn that unproven methods should not replace conventional treatment because delayed treatment reduces the likelihood of a remission or cure. [2]
- Some herbs may make chemotherapy drugs less effective. [2]
What studies found
All three studies below are observational, so they show associations and cannot prove cause.| Study | Who and what was compared | Finding | Limits |
|---|---|---|---|
| Johnson et al., J Natl Cancer Inst, 2018 [3] | 281 patients with nonmetastatic breast, prostate, lung or colorectal cancer who chose "alternative medicine" as their only anticancer treatment, matched to 560 who received conventional treatment | Alternative medicine use was associated with a greater risk of death (hazard ratio 2.50, 95% CI 1.88 to 3.27); higher in breast (5.68), lung (2.17) and colorectal cancer (4.57) | Observational registry study; authors call this use rare |
| Johnson et al., JAMA Oncology, 2018 [4] | 258 patients using "complementary medicine" (defined as unproven treatments given by nonmedical personnel) alongside some conventional treatment, matched to 1,032 | Refusal rates were higher, for example chemotherapy 34.1% vs 3.2%; 5-year survival 82.2% vs 86.6%. After refusal or delay was accounted for, the survival link was no longer significant (HR 1.39, 95% CI 0.83 to 2.33) | Retrospective; authors concluded the extra risk was mediated by refusing conventional treatment |
| Ambrosone et al., J Clin Oncol, 2020 [5] | 1,134 women with breast cancer in a chemotherapy trial, asked about supplement use | Antioxidant supplement use was associated with a possibly higher chance of recurrence (HR 1.41, 95% CI 0.98 to 2.04, P = .06); vitamin B12 and iron use were linked to poorer outcomes; multivitamin use was not | Borderline for antioxidants; associations only |
Evidence label: evidence of harm when standard treatment is refused or replaced (observational data); insufficient evidence for any alternative approach as a cancer treatment. The abstracts we read do not break results down by the type of practitioner consulted, so they say nothing about naturopathic doctors or any other group as a whole; they also did not state how the alternative treatments were chosen or who gave them. [4] [3]
Spotting a cure claim
The FDA lists phrases that often signal a fraudulent cancer product, such as "treats all forms of cancer," "selectively kills cancer cells," "shrinks malignant tumors" and "more effective than chemotherapy." [6] NCCIH adds that some fraudulent products are harmful in themselves, and others harm indirectly because people delay care or the product interferes with proven treatment. [2]Support that can sit beside treatment
The guidelines NCCIH cites say that some approaches used in addition to conventional therapies help to control symptoms and enhance well-being. [2] NCCIH asks anyone diagnosed with cancer to talk with their health care providers before starting any new complementary approach. [2] See integrative oncology supportive care guidelines and integrative care during cancer treatment.Practical steps
- Tell your oncology team about everything you use, including supplements. NCCIH says vitamin and mineral supplements, including antioxidants, may interfere with chemotherapy, so discuss them first. [2]
- If you are afraid of side effects or unsure about a plan, ask your team to explain the options, or consider a second opinion. See second opinions.
- Prevention and screening matter too: NCCIH lists avoiding tobacco, a healthy weight, hepatitis B and HPV vaccines and appropriate cancer screening tests as ways to reduce cancer risk. [2]
More on claims: claim check: natural treatments cure cancer and natural cancer cure and clinic claims.
Frequently asked questions
Can an alternative treatment cure cancer?
NCCIH says no complementary health approach has been shown to prevent or cure cancer. [2]
What happened to people who chose alternatives instead of treatment?
In one US registry study, choosing alternative medicine as the sole treatment was associated with a greater risk of death than conventional treatment. [3] It was an observational study, so it cannot prove cause.
Is it the alternative therapy itself or refusing treatment that raises risk?
In the JAMA Oncology study, the survival difference was no longer significant once treatment refusal or delay was counted, and the authors concluded refusal mediated the risk. [4]
Can I use supplements during chemotherapy?
Ask your oncology team first. NCCIH says supplements, including antioxidants, might interfere with chemotherapy. [2]
Where can I get support without giving up treatment?
Ask your team about supportive approaches used alongside treatment, which NCCIH says may help control symptoms. [2]
References
- Complementary, Alternative, or Integrative Health: What's In a Name?, NCCIH. Read 2026-10-22.
- Cancer and Complementary Health Approaches: What You Need To Know, NCCIH. Read 2026-10-22.
- Johnson SB et al. Use of Alternative Medicine for Cancer and Its Impact on Survival. J Natl Cancer Inst 2018. Read 2026-10-22.
- Johnson SB et al. Complementary Medicine, Refusal of Conventional Cancer Therapy, and Survival Among Patients With Curable Cancers. JAMA Oncol 2018. Read 2026-10-22.
- Ambrosone CB et al. Dietary Supplement Use During Chemotherapy and Survival Outcomes of Patients With Breast Cancer Enrolled in a Cooperative Group Clinical Trial (SWOG S0221). J Clin Oncol 2020. Read 2026-10-22.
- Products Claiming to "Cure" Cancer Are a Cruel Deception, US Food and Drug Administration. Read 2026-10-22.