Primary chemotherapy in operable breast carcinoma comparing CMF (cyclophosphamide, methotrexate, 5-fluorouracil) with an anthracycline-containing regimen: short-term responses translated into long-term outcomes

Evaluation of pathological complete response as surrogate endpoint in neoadjuvant randomised clinical trials of early stage breast cancer: systematic review and meta-analysis

OBJECTIVE

To evaluate pathological complete response as a surrogate endpoint for disease-free survival and overall survival in regulatory neoadjuvant trials of early stage breast cancer.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, and Scopus to 1 December 2020.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Randomised clinical trials that tested neoadjuvant chemotherapy given alone or combined with other treatments, including anti-human epidermal growth factor 2 (anti-HER2) drugs, targeted treatments, antivascular agents, bisphosphonates, and immune checkpoint inhibitors.

DATA EXTRACTION AND SYNTHESIS

Trial level associations between the surrogate endpoint pathological complete response and disease-free survival and overall survival.

METHODS

A weighted regression analysis was performed on log transformed treatment effect estimates (hazard ratio for disease-free survival and overall survival and relative risk for pathological complete response), and the coefficient of determination (R2) was used to quantify the association. The secondary objective was to explore heterogeneity of results in preplanned subgroups analysis, stratifying trials according treatment type in the experimental arm, definition used for pathological complete response (breast and lymph nodes v breast only), and biological features of the disease (HER2 positive or triple negative breast cancer). The surrogate threshold effect was also evaluated, indicating the minimum value of the relative risk for pathological complete response necessary to confidently predict a non-null effect on hazard ratio for disease-free survival or overall survival.

RESULTS

54 randomised clinical trials comprising a total of 32 611 patients were included in the analysis. A weak association was observed between the log(relative risk) for pathological complete response and log(hazard ratio) for both disease-free survival (R2=0.14, 95% confidence interval 0.00 to 0.29) and overall survival (R2 =0.08, 0.00 to 0.22). Similar results were found across all subgroups evaluated, independently of the definition used for pathological complete response, treatment type in the experimental arm, and biological features of the disease. The surrogate threshold effect was 5.19 for disease-free survival but was not estimable for overall survival. Consistent results were confirmed in three sensitivity analyses: excluding small trials (<200 patients enrolled), excluding trials with short median follow-up (<24 months), and replacing the relative risk for pathological complete response with the absolute difference of pathological complete response rates between treatment arms.

CONCLUSION

A lack of surrogacy of pathological complete response was identified at trial level for both disease-free survival and overall survival. The findings suggest that pathological complete response should not be used as primary endpoint in regulatory neoadjuvant trials of early stage breast cancer.

Overview of Dual-Acting Drug Methotrexate in Different Neurological Diseases, Autoimmune Pathologies and Cancers

Methotrexate, a structural analogue of folic acid, is one of the most effective and extensively used drugs for treating many kinds of cancer or severe and resistant forms of autoimmune diseases. In this paper, we take an overview of the present state of knowledge with regards to complex mechanisms of methotrexate action and its applications as immunosuppressive drug or chemotherapeutic agent in oncological combination therapy. In addition, the issue of the potential benefits of methotrexate in the development of neurological disorders in Alzheimer’s disease or myasthenia gravis will be discussed.

A Proposal to Redefine Pathologic Complete Remission as Endpoint following Neoadjuvant Chemotherapy in Early Breast Cancer

Many analyses of the efficacy of neoadjuvant treatment (NAT) for early breast cancer including a meta-analysis derived from 10 randomized trials came to the conclusion that patients who would achieve pathologic complete response (pCR) following NAT would experience significant improvement in disease-free and overall survival (OS). Thus, pCR was proposed as a surrogate endpoint for OS, with pCR representing a robust prognostic marker for survival at an individual level. In the current analysis, we argue that OS following NAT-induced pCR might have reflected the initial prognosis of patients mainly defined - among other factors - by the initial pathological lymph node status while being largely independent on the type of administrated treatment, thus pleading against the pCR surrogacy hypothesis. We therefore propose to redefine pCR as a surrogate endpoint of NAT trials by the involvement of additional biologic parameters.

Pathologic complete response as a potential surrogate for the clinical outcome in patients with breast cancer after neoadjuvant therapy: a meta-regression of 29 randomized prospective studies

PURPOSE

To assess the role of pathologic complete response (pCR) after neoadjuvant therapy as surrogate end point of disease-free survival (DFS) and overall survival (OS) in patients with breast cancer, we performed a trial-based meta-regression of randomized studies comparing different neoadjuvant systemic treatments.

METHODS

The systematic literature search included electronic databases and proceedings of oncologic meetings. Endocrine therapy trials were excluded. Treatment effects on DFS and OS were expressed as hazard ratios (HRs), and treatment effects on pCR were expressed as odds ratios (ORs). A weighted regression analysis was performed on log-transformed treatment effect estimates to test the association between treatment effects on the surrogate outcome and treatment effects on the clinical outcome.

RESULTS

Twenty-nine trials, 59 arms, and 30 comparisons, for a total of 14,641 patients, were included in the analysis. Using the complete set of data, the regression of either the log(HR) for DFS or the log(HR) for OS on the log(OR) for pCR demonstrated only weak associations (R(2) = 0.08; 95% CI, 0 to 0.47; and R(2) = 0.09; 95% CI, 0.01 to 0.41, respectively). Better associations were found in an exploratory analysis assessing a subset of trials comparing intensified/dose-dense chemotherapy versus standard-dose regimens (DFS: R(2) = 0.79; 95% CI, 0.26 to 0.95; P = .003; and OS: R(2) = 0.57; 95% CI, 0.19 to 0.93; P = .03).

CONCLUSION

This meta-regression analysis of 29 heterogeneous neoadjuvant trials does not support the use of pCR as a surrogate end point for DFS and OS in patients with breast cancer. However, pCR may potentially meet the criteria of surrogacy with specific systemic therapies.

Mitochondrial DNA content as a potential marker to predict response to anthracycline in breast cancer patients

Mutations and reduced mitochondrial DNA (mtDNA) content are commonly observed in breast cancer, yet their functional significance is not clear. This study aimed to determine whether the mtDNA content in breast cancer plays an important role in modulating the response to anthracycline treatment in vivo and in vitro. The mtDNA content in tumor cells was analyzed using quantitative polymerase chain reaction in 60 Taiwanese breast cancer patients to correlate with their survival. In addition, human breast cancer MDA-MB-231 cells were treated with ethidium bromide to decrease mtDNA copy number. Cell survival was determined by trypan blue exclusion assay and intracellular reactive oxygen species (ROS) were determined by flow cytometry. After an anthracycline-based regimen, the disease-free survival of patients with higher mtDNA content breast cancer was significantly lower than that of patients with lower mtDNA content breast cancer (p = 0.03). Moreover, the MDA-MB-231 cells with low copies of mtDNA had higher sensitivity to doxorubicin treatment and increased ROS production when compared with higher mtDNA parental cells. Our results suggest that the level of mtDNA copy number in breast cancer may be a potential biomarker for prediction of the response to anthracycline-containing regimens in breast cancer patients.

Weight gain and recovery of pre-cancer weight after breast cancer treatments: evidence from the women's healthy eating and living (WHEL) study

PURPOSE

To examine predictors of weight gain following breast cancer diagnosis and subsequent return to pre-cancer weight.

OBJECTIVES

To determine (1) the associations of anti-neoplastic chemotherapy and/or, Tamoxifen((R)) therapy on weight change following breast cancer diagnosis, (2) whether chemotherapy modified the effect of specific demographic and tumor characteristics on weight gain, (3) the proportion and characteristics of women who gained significant weight on chemotherapy and returned to their pre-cancer weight during follow-up.

SUBJECTS AND METHODS

Participants were 3088 breast cancer survivors, aged 27-74 years. Weight was measured at baseline and years 1 through 6; pre-cancer weight was self-reported. Cancer stage and treatment modalities were obtained by medical record review; demographic and physical activity data were obtained from questionnaires. Weight gain of >/=5% body weight following cancer diagnosis was considered significant.

RESULTS

Chemotherapy was significantly associated with weight gain (OR = 1.65, 95% CI = 1.12, 2.43) and Tamoxifen((R)) was not (OR = 1.03, 95% CI = 0.71, 1.51). Tamoxifen((R)) did not modify the effect of either chemotherapy or its different regimens on weight gain. Both types (anthracycline: OR = 1.63, p-value = 0.01, non-anthracycline: OR = 1.79, p = 0.003) and all regimens of chemotherapy (AC: OR = 1.55, p-value = 0.01, CAF: OR = 1.83, p = 0.003, CMF: OR = 1.76, p = 0.004) were associated with weight gain but the associations were not different from one another. Only 10% of participants returned to their pre-cancer diagnosis weight at the follow-up visits; the degree of initial gain (p for trend <0.0001) predicted that return.

CONCLUSION

Chemotherapy was associated with clinically meaningful weight gain, and a return to initial weight following weight gain was unlikely.