Rationale for combining chemotherapy and hormonal therapy in breast cancer

Vaccines in Breast Cancer: Challenges and Breakthroughs

Breast cancer is a problem for women's health globally. Early detection techniques come in a variety of forms ranging from local to systemic and from non-invasive to invasive. The treatment of cancer has always been challenging despite the availability of a wide range of therapeutics. This is either due to the variable behaviour and heterogeneity of the proliferating cells and/or the individual's response towards the treatment applied. However, advancements in cancer biology and scientific technology have changed the course of the cancer treatment approach. This current review briefly encompasses the diagnostics, the latest and most recent breakthrough strategies and challenges, and the limitations in fighting breast cancer, emphasising the development of breast cancer vaccines. It also includes the filed/granted patents referring to the same aspects.

Concurrent and sequential initiation of ovarian function suppression with chemotherapy in premenopausal women with endocrine-responsive early breast cancer: an exploratory analysis of TEXT and SOFT

BACKGROUND

Recent breast cancer treatment guidelines recommend that higher-risk premenopausal patients should receive ovarian function suppression (OFS) as part of adjuvant endocrine therapy. If chemotherapy is also given, it is uncertain whether to select concurrent or sequential OFS initiation.

DESIGN AND METHODS

We analyzed 1872 patients enrolled in the randomized phase III TEXT and SOFT trials who received adjuvant chemotherapy for hormone receptor-positive, HER2-negative breast cancer and upon randomization to an OFS-containing adjuvant endocrine therapy, initiated gonadotropin-releasing-hormone-agonist triptorelin. Breast cancer-free interval (BCFI) was compared between patients who received OFS concurrently with chemotherapy in TEXT (n = 1242) versus sequentially post-chemotherapy in SOFT (n = 630). Because timing of trial enrollment relative to adjuvant chemotherapy differed, we implemented landmark analysis re-defining BCFI beginning 1 year after final dose of chemotherapy (median, 15.5 and 8.1 months from enrollment to landmark in TEXT and SOFT, respectively). As a non-randomized treatment comparison, we implemented comparative-effectiveness propensity score methodology with weighted Cox modeling.

RESULTS

Distributions of several clinico-pathologic characteristics differed between groups. Patients who were premenopausal post-chemotherapy in SOFT were younger on average. The median duration of adjuvant chemotherapy was 18 weeks in both groups. There were 231 (12%) BC events after post-landmark median follow-up of about 5 years. Concurrent use of triptorelin with chemotherapy was not associated with a significant difference in post-landmark BCFI compared with sequential triptorelin post-chemotherapy, either in the overall population (HR = 1.11, 95% CI 0.72-1.72; P = 0.72; 4-year BCFI 89% in both groups), or in the subgroup of 692 women <40 years at diagnosis (HR = 1.13, 95% CI 0.69-1.84) who are less likely to develop chemotherapy-induced amenorrhea.

CONCLUSION

Based on comparative-effectiveness modeling of TEXT and SOFT after about 5 years median follow-up, with limited statistical power especially for the subgroup <40 years, neither detrimental nor beneficial effect of concurrent administration of OFS with chemotherapy on the efficacy of adjuvant therapy that includes chemotherapy was detected.

CLINICALTRIALS.GOV

NCT00066690 and NCT00066703.

Concurrent vs sequential adjuvant chemotherapy and hormone therapy in breast cancer: a multicenter randomized phase III trial

BACKGROUND

The most appropriate timing of chemotherapy and hormone therapy administration is a critical issue in early breast cancer patients. The purpose of our study was to compare the efficacy of concurrent vs sequential administration of adjuvant chemotherapy and tamoxifen.

METHODS

Women with node-positive primary breast cancer were randomly assigned to receive tamoxifen (20 mg/d for 5 years) during (concurrent arm) or after (sequential arm) adjuvant chemotherapy. Chemotherapy consisted of alternating regimens of cyclophosphamide, epidoxorubicin, and 5-fluorouracil and cyclophosphamide, methotrexate, and 5-fluorouracil every 21 days for a total of 12 cycles. The primary endpoint was overall survival (OS), and secondary endpoints were toxic effects and disease-free survival (DFS). No provision for interim analyses was made in the original study protocol. Survival curves were estimated by the Kaplan-Meier method. Multivariable Cox regression models, adjusted for age, menopausal status, tumor stage, and lymph node and hormone receptor status, were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). All statistical tests were two-sided.

RESULTS

From 1985 to 1992, 431 patients were randomly assigned and studied according to the intention-to-treat principle. After a maximum of 15.4 years of follow-up (median 12.3 years), the estimated actuarial 10-year OS was equivalent for the two study arms (concurrent arm: 111 patients, 66%, 95% CI = 59% to 72%; sequential arm: 114 patients, 65%, 95% CI = 59% to 72%, P = .86). No differences in DFS and toxic effects were evident. Four interim analyses were performed, but no alpha error adjustment was necessary because of the largely negative results of this final analysis (sequential vs concurrent arm: HR of death = 1.06, 95% CI = 0.78 to 1.44, P = .76; HR of relapse = 1.16, 95% CI = 0.88 to 1.52, P = .36).

CONCLUSIONS

No statistically significant differences in OS, DFS, and toxic effects between concurrent and sequential adjuvant chemo- and hormone therapies were observed. Our study does not support the superiority of one schedule of chemo- and hormone-therapy administration over the other. However, because of the limited statistical power of the study, these results must be considered with caution.

Modalities of chemotherapy and endocrine therapy for growth inhibition of androgen-stimulated mouse carcinoma (Shionogi carcinoma 115)

Effects of chemotherapy and endocrine therapy applied individually or in combination on growth of an androgen-stimulated mouse tumor, Shionogi carcinoma 115 (SC 115), were examined. In the present study cyclophosphamide and castration were used as chemo- and endocrine therapy, respectively, and simultaneous combination of these two treatments was found to be the most effective in inhibiting tumor growth. When comparing the effect of castration alone with that of injection of cyclophosphamide alone, the former retarded the tumor growth more efficiently, but relapse occurred in both instances. Injection of cyclophosphamide to the relapsed tumor after castration caused a marked effect when compared with the effect of the drug on the untreated or the chemotherapy-relapsed tumors. Castration caused a retardation of growth in the chemotherapy-relapsed tumor, but the survival period was shorter than that observed in the mice that received castration followed by injection of cyclophosphamide. From these results, it was concluded that castration followed by chemotherapy was the preferred order among sequential treatments for the SC 115; however, the optimal treatment was produced by simultaneous combination of chemotherapy plus castration.