Coexistence of pernicious anemia and prostate cancer - 'an experiment of nature' involving vitamin B₁₂modulation of prostate cancer growth and metabolism: a case report

Abstract

Abstract 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.