Dataset Information

Changes in vitamin D and calcium metabolism markers in patients undergoing adjuvant chemotherapy for breast cancer.

ABSTRACT:

Background

Changes in calcium metabolism and calcium urinary excretion during chemotherapy have not been thoroughly assessed in patients with early breast cancer (EBC), a population who frequently present vitamin D insufficiency. As hypercalciuria is a classical contra-indication to vitamin D (VD) supplementation, this study evaluated changes in VD and calcium metabolism parameters in patients with EBC undergoing adjuvant chemotherapy (CT).

Methods

In patients with EBC who received six cycles of adjuvant CT, VD and calcium parameters were monitored at inclusion, and then every 3 weeks, at each CT cycle initiation. The primary endpoint was the percentage of patients showing hypercalciuria during adjuvant CT (between Day 1, Cycle 1 [D1C1] and Day 1, Cycle 6 [D1C6]).

Results

The primary endpoint could be evaluated in 82 patients. Most patients (n = 66, 80.5%) had VD insufficiency (< 30 ng/mL) at baseline. Hypercalciuria was detected in 29 patients (35.4%; 95% CI: 25.6-46.5) between D1C1 and D1C6, but was not clinically significant in any of the affected patients. The percentage of hypercalciuria events was not different between patients with sufficient and insufficient baseline VD levels (34.8% vs. 37.5%), and between patients who received or not VD supplementation (37.5% vs. 34.5%,).

Conclusions

This comprehensive study on VD and calcium parameter changes in patients with EBC during adjuvant chemotherapy shows that hypercalciuria is a frequent abnormality in this setting, although asymptomatic. Therefore, it should not be considered as a limitation for high dose VD supplementation in this population.

Trial registration

EudraCT:2014-A01454-43 . Registered 29 august 2016.

SUBMITTER: Viala M

PROVIDER: S-EPMC8283899 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:ImportanceAdjuvant chemotherapy improves outcomes of patients with breast cancer. However, the optimal timing of chemotherapy initiation is unknown. Delayed administration can decrease the benefit of cytotoxic systemic therapies.ObjectiveTo identify the determinants in delayed chemotherapy initiation and to determine the relationship between time to chemotherapy (TTC) and outcome according to breast cancer subtype. We hypothesized that prolonged TTC would be associated with adverse outcomes.Design, setting, and participantsIn an observational, population-based investigation using data from the California Cancer Registry, we studied a total of 24 843 patients with stage I to III invasive breast cancer diagnosed between January 1, 2005, and December 31, 2010, and treated with adjuvant chemotherapy. Data analysis was performed between August 2014 and August 2015.Main outcomes and measuresTime to chemotherapy was defined as the number of days between surgery and the first dose of chemotherapy, and delayed TTC was defined as 91 or more days from surgery to the first dose of adjuvant chemotherapy. We evaluated overall survival and breast cancer-specific survival. Logistic regression and Cox proportional hazard models were used.ResultsIn all, 24 843 patients were included. Median age at diagnosis was 53 years, and median was TTC was 46 days. Factors associated with delays in TTC included low socioeconomic status, breast reconstruction, nonprivate insurance, and Hispanic ethnicity or non-Hispanic black race. Compared with patients receiving chemotherapy within 31 days from surgery, there was no evidence of adverse outcomes among those with TTC of 31 to 60 or 60 to 90 days. Patients treated 91 or more days from surgery experienced worse overall survival (hazard ratio [HR], 1.34; 95% CI, 1.15-1.57) and worse breast cancer-specific survival (HR, 1.27; 95% CI, 1.05-1.53). In a subgroup analysis according to subtype, longer TTC caused patients with triple-negative breast cancer to have worse overall survival (HR, 1.53; 95% CI, 1.17-2.00) and worse breast cancer-specific survival (HR, 1.53; 95% CI 1.17-2.07).Conclusions and relevanceFor patients with breast cancer, adverse outcomes are associated with delaying initiation of adjuvant chemotherapy 91 or more days. Delayed TTC was particularly detrimental among patients with triple-negative breast cancer. The determinants of delays in chemotherapy initiation appeared to be sociodemographic, and clinicians should provide timelier care to all patients.