Bone health and adherence to vitamin D and calcium therapy in early breast cancer patients on endocrine therapy with aromatase inhibitors.
OBJECTIVE
Randomized trials involving aromatase inhibitors (AIs) in the adjuvant treatment of breast cancer patients have reported increased osteoporosis risk. Bone loss can be reduced with appropriate life style, vitamin D and calcium supplements, and with bisphosphonate therapy. The aim of this analysis was to investigate adherence to vitamin D and calcium in postmenopausal breast cancer patients receiving adjuvant non-steroidal AIs, and oncologists' adherence to the bone health guidelines.


METHODS
This prospective study included 438 newly diagnosed patients and those who have already been receiving non-steroidal AIs for up to 3.5 years. Median endocrine therapy duration before recruitment in the study was 10.5 months (interquartile 4.8-26.6).


RESULTS
Densitometry was performed on 142 patients (32.4%) before initiation of endocrine therapy, and on additional 38 (8.6%) patients at second study visit. Densitometry was not performed on 258 (59%) patients. Vitamin D and calcium were prescribed to 329/438 (75.1%) patients at some point during the study. Patients who took more than 80% of the prescribed dose were considered adherent. Self-reported adherence was 88.4%. Osteoporosis was diagnosed in 24 patients (5.5%) of the total study population, bearing in mind that 258/438 (59%) patients did not have densitometry. Bisphosphonates were prescribed to 54/438 (12.3%) patients, whilst only 19 (35.2%) of those had osteoporosis.


CONCLUSIONS
In this analysis, lack of oncologists' adherence to the bone health guidelines was observed. In addition, a significant proportion of the patients did not adhere to the vitamin D and calcium.
Clinic for Oncology and Radiotherapy, University Hospital Split, Spinčićeva 1, HR-21000 Split, Croatia. Electronic address: lidija.boskovic123@gmail.com.
Lidija
L
Bošković
PLIVA Croatia Ltd., Prilaz baruna Filipovića 25, HR-10000 Zagreb, Croatia. Electronic address: maja.gasparic@pliva.com.
Maja
M
Gašparić
Clinic for Oncology and Radiotherapy, University Hospital Rijeka, Krešimirova 42, HR-51000 Rijeka, Croatia. Electronic address: marija.petkovic@ri.t-com.hr.
Marija
M
Petković
Clinic for Oncology and Radiotherapy, University Hospital Osijek, Huttlerova 4, HR-31000 Osijek, Croatia. Electronic address: damir.gugic7@gmail.com.
Damir
D
Gugić
Clinic for Oncology and Radiotherapy, University Hospital Rijeka, Krešimirova 42, HR-51000 Rijeka, Croatia. Electronic address: ingrid.belac@ri.t-com.hr.
Ingrid Belac
IB
Lovasić
Clinic for Oncology and Nuclear Medicine, University Hospital Sestre Milosrdnice, Vinogradska cesta 29, HR-10000 Zagreb, Croatia. Electronic address: zeljko.soldic@kbcsm.hr.
Željko
Ž
Soldić
Clinic for Oncology and Radiotherapy, University Hospital Split, Spinčićeva 1, HR-21000 Split, Croatia. Electronic address: brapemi@gmail.com.
Branka Petrić
BP
Miše
Clinic for Oncology and Nuclear Medicine, University Hospital Sestre Milosrdnice, Vinogradska cesta 29, HR-10000 Zagreb, Croatia. Electronic address: nina.dabelic@kbcsm.hr.
Nina
N
Dabelić
Clinic for Tumors, University Hospital Sestre Milosrdnice, Ilica 197, HR-10 000 Zagreb, Croatia. Electronic address: ljubica.vazdar@gmail.com.
Ljubica
L
Vazdar
Clinic for Oncology and Radiotherapy, University Hospital Split, Spinčićeva 1, HR-21000 Split, Croatia. Electronic address: edo.vrdoljak@gmail.com.
Eduard
E
Vrdoljak
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D047072:Aromatase Inhibitors / Q000009:adverse effects; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000523:psychology; D002118:Calcium / Q000008:administration & dosage / Q000592:standards; D017523:Croatia; D019587:Dietary Supplements / Q000592:standards; D004164:Diphosphonates / Q000008:administration & dosage / Q000592:standards; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D004359:Drug Therapy, Combination / Q000592:standards; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006801:Humans; D008875:Middle Aged; D010024:Osteoporosis / Q000139:chemically induced / Q000517:prevention & control*; D017410:Practice Guidelines as Topic; D011446:Prospective Studies; D014807:Vitamin D / Q000008:administration & dosage / Q000592:standards; D014815:Vitamins / Q000008:administration & dosage / Q000592:standards; D016903:Drug Monitoring
D047072:Aromatase Inhibitors; D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D014815:Vitamins; D014807:Vitamin D; D002118:Calcium
Aromatase inhibitors; Bone health; Breast cancer; Calcium; Vitamin D