Study Finds High Dose Vitamin D3 Does Not Benefit Survival for Metastatic Colorectal Cancer

Researchers at the European Society for Medical Oncology 2024 conference (ESMO) announced that high-dose vitamin D3 did not provide benefits for individuals with metastatic colorectal cancer. The results were found in a multicenter, double-blind, randomized phase 3 clinical trial that assessed vitamin D in combination with standard chemotherapy with bevacizumab (Avastin; Genentech) among patients who were not previously treated for metastatic colorectal cancer.¹

3d rendered illustration of bowel cancer 3D illustration - Image credit: appledesign | stock.adobe.com

Colorectal cancer has recently become the most common cancer globally and the second leading cause of cancer-associated death. Study authors noted that in 2020, data found a 10% incidence of colorectal cancer worldwide and about 9.4% of deaths could have been a direct cause of colorectal cancer.² Metastatic colorectal cancer (mCRC) is an advanced stage of colorectal cancer that has already spread from the colon or rectum to other areas in the body.³ Symptoms of mCRC include changes in bowel movements, blood in the stool, fatigue, weight loss, nausea, abdominal pain, and bloating. mCRC is a fatal disease with a 14% 5-year survival rate. Colorectal cancer can typically be cured with surgery, radiation therapy, chemotherapy, and targeted therapy, but once in the metastatic stage, treatment options become less effective.^3-5

Vitamin D has shown benefits through sun exposure as the body attains 80% to 90% of vitamin D via ultraviolet light exposure and 10% to 20% from nutrients consumed in food sources. Foods high in vitamin D include salmon, mackerel, eel, tuna, eggs, milk, yogurt, and mushrooms.²

Previous studies have found a connection between high levels of vitamin D and reduced risk of colorectal cancer and improved survival. However, study authors noted that most studies were conducted on mice and human studies only included a limited number of participants.² The current SOLARIS (Alliance A021703) trial, led by Dana-Farber Cancer Institute, included more than 450 individuals.¹

“One study recruiting a large cohort of patients with advanced or metastatic CRC revealed that higher plasma 25(OH)D levels are associated with improved overall and progression-free survival. However, the effects of Vitamin D supplementation on incidence and mortality of CRC remain inconclusive,” study authors said in a news release.²

The study was conducted across hundreds of cancer centers in the US and designed to test the use of high-dose vitamin D3 versus standard treatment in individuals with untreated mCRC. The investigators created this study in support of research that suggested treatment with high levels of vitamin D in the blood contributed to improved survival among individuals with mCRC.¹

Approximately 450 individuals were randomly assigned to receive standard chemotherapy with bevacizumab with either high dose or standard dose of vitamin D3. The results found that after a median 20-month follow up, the addition of high-dose vitamin D3 with standard treatment did not delay the progression of cancer compared with the standard dose of vitamin D3. However, further results found that high-dose vitamin D3 did show benefits among individuals with primary tumors that occur in the descending colon, sigmoid colon, or rectum, according to study authors.¹

High dose vitamin D was not reported to cause any concerning adverse effects or toxicities, but it cannot be recommended as a treatment option for individuals with untreated metastatic colon cancer, the study authors noted.¹

REFERENCES

1. High-Dose vitamin D3 does not provide benefit for metastatic colorectal cancer. EurekAlert!. News release. September 15, 2024. Accessed October 8, 2024. https://www.eurekalert.org/news-releases/1057959.

2. Vitamin D and Colorectal Cancer: Current Perspectives and Future Directions. J Cancer Prev. News release. September 30, 2022. Accessed October 8, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9537583/.

3. Metastatic colorectal cancer: mechanisms and emerging therapeutics. Trends Pharmacol Sci. News release. July 24, 2023. Accessed October 8, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10365888/#:~:text=Metastatic%20colorectal%20cancer%20(mCRC)%20remains,limitations%20of%20available%20therapeutic%20interventions.

4. Diagnosis and Treatment of Metastatic Colorectal Cancer. JAMA Network. News release. February 16, 2021. Accessed October 8, 2024. https://jamanetwork.com/journals/jama/fullarticle/2776334#:~:text=When%20Is%20Immunotherapy%20an%20Appropriate,does%20not%20respond%20to%20immunotherapy.

5. Metastatic colorectal cancer (stage 4). City of Hope. News release. April 13, 2022. Accessed October 8, 2024. https://www.cancercenter.com/cancer-types/colorectal-cancer/types/metastatic-colorectal-cancer.