Frequency of Combined Deficiencies of Vitamin D and Holotranscobalamin in Cancer Patients

Should we be more cautious about replacement of vitamin B12 in patients with cancer receiving cytotoxic chemotherapy?

Vitamin B12 (Cbl) deficiency may cause hematologic and neurologic dysfunction. Replacement therapy is effective in correcting hematologic abnormalities and improving neurologic symptoms. Cbl is known to have antioxidant activity. This antioxidant activity may antagonize the effects of chemotherapeutics (i.e. genotoxic effects of paclitaxel) on tumor DNA. We claim that Cbl replacement should be done more cautiously in patients receiving cytotoxic chemotherapy.

Prevalence of serum vitamin D deficiency and insufficiency in cancer: Review of the epidemiological literature

Vitamin D deficiency has been found to be associated with a variety of cancers, including prostate, multiple myeloma, colorectal and breast cancer. Several studies have shown vitamin D levels to have an inverse relation with cancer mortality, while others have considered it a potential risk factor. Vitamin D is believed to influence cancer prevalence, risk and survival; hence the need to assess vitamin D levels in cancer. Although numerous studies have been conducted to demonstrate vitamin D deficiency as a risk factor for cancer, relatively few have studied its prevalence. Moreover, studies estimating prevalence differ from each other, with respect to study population, sample size, study design, definition of vitamin D deficiency used and method of vitamin D assessment (with most studies limited to one particular type of cancer with relatively small sample sizes). Therefore, we qualitatively reviewed the epidemiological evidence in the oncology literature on the prevalence of vitamin D deficiency and insufficiency as measured by serum vitamin D concentrations.

Coexistence of pernicious anemia and prostate cancer - 'an experiment of nature' involving vitamin B(12 )modulation of prostate cancer growth and metabolism: a case report

Introduction

This report presents the clinical and laboratory course of a patient with prostate cancer and severe vitamin B₁₂ deficiency undergoing watchful waiting for prostate cancer. The possible interaction between therapy for B₁₂ deficiency and the natural course of prostate cancer is presented.

Case presentation

We present the case of a 75-year-old Chinese man with prostate cancer and pernicious anemia. His serum vitamin B₁₂ level was 32 pg/ml (300-900 pg/ml) and holotranscobalamin was 0 pg/ml (>70 pg/ml). There was an unexpected rapid progression of Gleason's score during 10 months of watchful waiting. After the diagnosis of pernicious anemia was made, therapeutic injections of vitamin B₁₂ were started. We observed a significant acceleration in prostate-specific antigen and prostatic acid phosphatase and a shortening of prostate-specific antigen doubling time after initiation of B₁₂ therapy.

Conclusion

We propose that the relatively short period of watchful waiting before histological progression of Gleason's score (GS [3+2] = 5 to GS [3+4] = 7 over 10 months) may have been a result of depleted holotranscobalamin 'active' B₁₂. Replacement of B₁₂ was associated with an initial rapid increase in serum prostate-specific antigen and prostatic acid phosphatase followed by stabilization. The patient represents an 'experiment of nature' involving vitamin B₁₂ metabolism and raises the question as to whether rapid histological progression of Gleason's score was related to absence of serum holotranscobalamin while prostate-specific antigen and prostatic acid phosphatase, markers of cell growth, were accelerated by vitamin B₁₂ replacement. To our knowledge, this is the first report of a possible cellular kinetic interaction between an epithelial malignancy and vitamin B₁₂ metabolism.

Triple negative breast cancer patients presenting with low serum vitamin D levels: a case series

Introduction

Serum vitamin D levels measured as 25-hydroxyvitamin D have been shown to be low in cancer patients, including breast cancer patients. However, the vitamin D status has yet to be studied in different breast cancer phenotypes: luminal A, luminal B, HER2+/ER-, and triple negative comprising the majority of basal-like.

Case presentation

Fifteen triple-negative breast cancer patients have presented to our medical oncology office in the last five years. Thirteen of these fifteen patients (87%) were found to be vitamin D deficient, defined as serum 25(OH)D less than 80 nmol/L, prior to initiation of adjuvant therapy. Ninety-one breast cancer patients from our office were classified as: luminal A (ER+ &/or PR+ and HER2-), luminal B (ER+ &/or PR+ and HER2+), HER2+/ER- (ER-, PR-, and HER2+), and triple-negative or basal-like (ER-, PR-, and HER2-). A normal mean was found from 78 volunteers. The breast cancer patients were found to be statistically different than the normal population. The triple-negative phenotype was found to be the most statistically different than the normal population.

Conclusion

The triple-negative breast cancer phenotype has the lowest average vitamin D level and the highest percentage of patients that are vitamin D deficient. These data suggests that low vitamin D levels are characteristic of the triple-negative phenotype.

Antioxidants and Other Micronutrients in Complementary Oncology

Many patients being treated for cancer use micronutrient supplements, with the intention to complement their cancer treatment or help them cope with the therapy- and disease-associated side effects. The majority are adding antioxidants without the knowledge of the treating physician. There are many concerns that antioxidants might decrease the effectiveness of chemotherapy, but increasing evidence suggests a benefit when antioxidants are added to conventional cytotoxic therapies. However, it is imperative that physicians explore the use of antioxidant and other micronutrient supplements with their cancer patients and educate them about potentially negative as well as potentially beneficial effects.