Impact of Vitamin D Supplementation on the Rate of Pathologic Complete Response in Vitamin D Deficient Patients Receiving Neoadjuvant Chemotherapy for Operable Triple Negative Breast Cancer

Summary

A two arm pilot study investigating the rate of pathologic complete response in patients with vitamin D deficiency and triple negative breast cancer undergoing standard neoadjuvant chemotherapy + vitamin D supplementation, including an observational arm to describe response in patients who are not deficient. Investigators hypothesize that vitamin D supplementation during neoadjuvant chemotherapy in operable triple negative breast cancer patients with vitamin D deficiency, will increase the rate of pathologic complete response chain reaction to that of vitamin D sufficient patients based on historical controls.

Detailed description

Primary Objective: To determine if pathologic complete response in vitamin D deficient patients receiving vitamin D supplementation during neoadjuvant chemotherapy for operable triple negative breast cancer is greater than or equal to 60% or less than or equal to pathologic complete response in historical controls (30%) using a one-stage phase II design. Secondary Objective(s): * To estimate the proportion of patients with residual cancer burden (RCB) classes I, II, and III in vitamin D deficient patients receiving vitamin D supplementation during neoadjuvant chemotherapy for operable triple negative breast cancer. * To estimate pathologic complete response reaction in the observational arm of vitamin D sufficient patients receiving neoadjuvant chemotherapy for operable triple negative breast cancer. * To determine the feasibility of delivery of vitamin D supplementation with standard of care chemotherapy. * To determine the safety and tolerability of the combination of vitamin D supplementation with standard of care chemotherapy. * To estimate the change in vitamin D receptor (VDR) expression from pre- and post-neoadjuvant treatment breast tumor tissue samples of vitamin D deficient patients. * To estimate the change in vitamin D receptor (VDR) expression from pre- to post-neoadjuvant treatment breast tumor tissue samples in a sample of 5 vitamin D sufficient patients. * To estimate the changes in the fecal microbiome of vitamin D deficient patients from pre- to post-neoadjuvant treatment. * To estimate the changes in the fecal microbiome in a sample of 5 vitamin D sufficient patients from pre- to post-neoadjuvant treatment. Patients will be followed for a minimum of 30 days after the last study intervention is administered for adverse events monitoring. Patients will be followed for 30 days after removal from study or until death, whichever occurs first. Patients removed from study for unacceptable adverse events will be followed until resolution or stabilization of the adverse event.

Arms & interventions

• DrugStandard of Care Neoadjuvant Chemotherapy (NAC)

  Participants will receive standard of care neoadjuvant chemotherapy with doxorubicin (60 mg/m2) and cyclophosphamide (600 mg/m2) for 4 cycles and paclitaxel (80 mg/m2) weekly for 12 cycles. Doxorubicin and cyclophosphamide (AC) may be administered on a classical every 3 week or dose dense every 2-week (with growth factor support) schedule at the treating physician's discretion. Routine incorporation of carboplatin is not required, however use of carboplatin (AUC 1.5 to 2 weekly or AUC 6 on week 1, 4, 7, and 10) with paclitaxel is allowed at the treating investigator's discretion. Upon completion of neoadjuvant chemotherapy, all patients will undergo definitive surgery with either breast conservation or mastectomy with axillary lymph node staging. Type of surgery will be determined by the treating physician.

• Dietary SupplementVitamin D3

  Participants with deficient levels of vitamin D will receive vitamin D supplementation at the initiation of chemotherapy with 50,000 IU of oral vitamin D3 (cholecalciferol) once a week to be continued for 20 weeks during neoadjuvant chemotherapy.

• OtherDrug Diary

  Participants that will receive Vitamin D will be asked to fill out a drug diary on a daily basis. Compliance and feasibility will be assessed through a drug diary and pill counts at set time points.

Outcome measures

Eligibility criteria