Changes in serum hydroxyvitamin D levels of breast cancer patients during tamoxifen treatment or chemotherapy in premenopausal breast cancer patients.
BACKGROUND
We investigated the effect of breast cancer adjuvant treatment on vitamin D status, as measured by serum hydroxyvitamin D (25OHD).


METHODS
Premenopausal patients (n=483) diagnosed with non-metastatic breast cancer in 2009 at Asan Medical Center had serum 25OHD levels prospectively analysed at diagnosis and 6 and 12months after surgery. We excluded patients who took vitamin D supplements or received neoadjuvant chemotherapy. Vitamin D sufficiency was defined as a serum level of ⩾30ng/ml, insufficiency as 20-29ng/ml and deficiency as <20ng/ml.


RESULTS
Compared with baseline serum 25OHD, patients who received chemotherapy had decreased serum 25OHD levels at 6months (-5.52ng/ml, p=0.003) and 12months (-1.24ng/ml, p=0.517) and patients who received anti-hormone therapy had significantly increased serum 25OHD levels at 6months (+3.00ng/ml, p=0.681) and 12months (+6.47ng/ml, p=0.002, respectively). Among patients who received chemotherapy, 49.5% were vitamin D sufficient at diagnosis but only 26.9% were sufficient 6months after finishing chemotherapy and this percentage increased to 45.2% at 12months.


CONCLUSIONS
Vitamin D levels decrease during chemotherapy but recover after treatment ends. Anti-hormone therapy with tamoxifen causes serum vitamin D levels to increase. Whether the increased serum vitamin D affects the antitumour effect of the tamoxifen has yet to be determined.
Department of Surgery, College of Medicine, University of Ulsan and Asan Medical Center, Republic of Korea.
Hee Jeong
HJ
Kim
Department of Surgery, College of Medicine, University of Ulsan and Asan Medical Center, Republic of Korea.
Beom Seok
BS
Koh
Department of Surgery, College of Medicine, University of Ulsan and Asan Medical Center, Republic of Korea.
Jong Han
JH
Yu
Department of Surgery, College of Medicine, University of Ulsan and Asan Medical Center, Republic of Korea.
Jong Won
JW
Lee
Department of Surgery, College of Medicine, University of Ulsan and Asan Medical Center, Republic of Korea.
Byung Ho
BH
Son
Department of Oncology, College of Medicine, University of Ulsan and Asan Medical Center, Republic of Korea.
Sung Bae
SB
Kim
Department of Surgery, College of Medicine, University of Ulsan and Asan Medical Center, Republic of Korea. Electronic address: ahnsh@amc.seoul.kr.
Sei Hyun
SH
Ahn
D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood*; D008875:Middle Aged; D017697:Premenopause; D011446:Prospective Studies; D013629:Tamoxifen / Q000627:therapeutic use*; D055815:Young Adult
D018931:Antineoplastic Agents, Hormonal; D006887:Hydroxycholecalciferols; D013629:Tamoxifen
Breast cancer; Chemotherapy; Tamoxifen; Vitamin D