Future options with capecitabine (Xeloda) in (neo)adjuvant treatment of breast cancer

Pharmacokinetic and bioequivalence study of two capecitabine tablets in Chinese patients with solid tumor cancer

Capecitabine (CAP) is one of the fluoropyrimidine deoxynucleoside carbamates, which can be converted to 5-fluorouracil (5-FU) by thymine deoxynucleoside phosphorylase (dThdPase) to exert antitumor effects. The purpose of this study is to compare the pharmacokinetics (PK), bioequivalence (BE), and safety of two CAP tablets in Chinese patients with solid tumor cancer. The results showed that the geometric mean ratios (GMRs) of Cmax, AUC0-t and AUC0-∞ of CAP T/R reagent were 90.26%, 95.27%, and 95.07, respectively. The values and 90% confidence intervals (CI) of AUC0-t, AUC0-∞, and Cmax all fall within the range of 80.00-125.00%. In addition, a total of 22 subjects in this study had 30 adverse events, with an incidence of 45.83%, and there were no serious adverse events and adverse events that led to withdrawal from the trial.

Changes in 18F-FDG tumor metabolism after a first course of neoadjuvant chemotherapy in breast cancer: influence of tumor subtypes

BACKGROUND

The aim of this study is to evaluate the impact of the different breast cancer subtypes on the tumor (18)F-FDG uptake at baseline and on its changes after the first course of neoadjuvant chemotherapy (NAC).

PATIENTS AND METHODS

One hundred and fifteen women with newly diagnosed, large or locally advanced breast cancer undergoing NAC were included. Estrogen receptor (ER), progesterone receptor (PR) and HER2 status were used to define three major tumor subtypes: triple negative (TN) (ER-/PR-/HER2-), luminal (ER+ and/or PR+; HER2-) and HER2 positive (HER2+). Using Fluorine-18 fluorodeoxyglucose positron emission tomography, the tumoral standard uptake value (SUV) maximal index was measured at baseline and just before the second course of NAC.

RESULTS

TN tumors presented the highest baseline SUV (11.3 ± 8.5; P < 0.0001). The decrease of SUV after the first course of NAC (ΔSUV) was significantly higher in TN and HER2-positive subtypes (-45% ± 25% and -57% ± 30%, respectively) than in luminal one (-19% ± 35%; P < 0.0001). ΔSUV was a predictive factor of the pathological complete response only in HER2-positive tumors (cut-off = -75%; P < 0.03) with an accuracy of 76%.

CONCLUSION

The baseline (18)F-FDG tumoral uptake but also its early response to NAC is different according to the immunohistological subtypes of breast cancer.

Capecitabine in Combination with Novel Targeted Agents in the Management of Metastatic Breast Cancer: Underlying Rationale and Results of Clinical Trials

At present there is no established standard of care for metastatic breast cancer and prognosis remains poor, although the use of newer chemotherapeutic regimens has led to modest improvements in survival. Capecitabine, an oral prodrug of 5-fluorouracil, is a promising addition to these approaches, having already shown single-agent activity against metastatic breast cancer. Following a pivotal trial demonstrating that capecitabine confers increased survival when used in combination with docetaxel, it is being investigated intensively in combined regimens using other standard chemotherapeutic agents, as well as with novel molecularly targeted therapies. Among the novel agents, the most intensively studied in combination with capecitabine is trastuzumab. Despite preclinical data suggesting that these two agents might not show additive effects, clinical trials have been very encouraging for both heavily pretreated patients and for patients receiving first-line therapy in the metastatic setting. This work is being further extended in an ongoing trial in the neoadjuvant setting. An initial trial in combination with bevacizumab, enrolling heavily pretreated patients, was less successful, but following the example of the E2100 trial, this combination is being re-examined in less heavily treated patients. In addition, this review discusses ongoing trials with an array of newer molecularly targeted agents. Significant improvement in time to progression has already been demonstrated in the combination of lapatinib and capecitabine compared with capecitabine monotherapy; for the most part, however, these trials are still in early stages.