A pooled analysis of gemcitabine plus docetaxel versus capecitabine plus docetaxel in metastatic breast cancer

Capecitabine for hormone receptor-positive versus hormone receptor-negative breast cancer

BACKGROUND

Retrospective analyses suggest that capecitabine may carry superior activity in hormone receptor-positive relative to hormone receptor-negative metastatic breast cancer. This review examined the veracity of that finding and explored whether this differential activity extends to early breast cancer.

OBJECTIVES

To assess effects of chemotherapy regimens containing capecitabine compared with regimens not containing capecitabine for women with hormone receptor-positive versus hormone receptor-negative breast cancer across the three major treatment scenarios: neoadjuvant, adjuvant, metastatic.

SEARCH METHODS

On 4 June 2019, we searched the Cochrane Breast Cancer Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 5) in the Cochrane Library; MEDLINE; Embase; the World Health Organization International Clinical Trials Registry Platform; and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials looking at chemotherapy regimens containing capecitabine alone or in combination with other agents versus a control or similar regimen without capecitabine for treatment of breast cancer at any stage. The primary outcome measure for metastatic and adjuvant trials was overall survival (OS), and for neoadjuvant studies pathological complete response (pCR).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias and certainty of evidence using the GRADE approach. Hazard ratios (HRs) were derived for time-to-event outcomes, and odds ratios (ORs) for dichotomous outcomes, and meta-analysis was performed using a fixed-effect model.

MAIN RESULTS

We included 26 studies with outcome data by hormone receptor: 12 metastatic studies (n = 4325), 6 neoadjuvant trials (n = 3152), and 8 adjuvant studies (n = 13,457). Capecitabine treatment was added in several different ways across studies. These could be classified as capecitabine alone compared to another treatment, capecitabine substituted for part of the control chemotherapy, and capecitabine added to control chemotherapy. In the metastatic setting, the effect of capecitabine was heterogenous between hormone receptor-positive and -negative tumours. For OS, no difference between capecitabine-containing and non-capecitabine-containing regimens was observed for all participants taken together (HR 1.01, 95% confidence interval (CI) 0.98 to 1.05; 12 studies, 4325 participants; high-certainty evidence), for those with hormone receptor-positive disease (HR 0.93, 95% CI 0.84 to 1.04; 7 studies, 1834 participants; high-certainty evidence), and for those with hormone receptor-negative disease (HR 1.00, 95% CI 0.88 to 1.13; 8 studies, 1577 participants; high-certainty evidence). For progression-free survival (PFS), a small improvement was seen for all people (HR 0.89, 95% CI 0.82 to 0.96; 12 studies, 4325 participants; moderate-certainty evidence). This was largely accounted for by a moderate improvement in PFS for inclusion of capecitabine in hormone receptor-positive cancers (HR 0.82, 95% CI 0.73 to 0.91; 7 studies, 1594 participants; moderate-certainty evidence) compared to no difference in PFS for hormone receptor-negative cancers (HR 0.96, 95% CI 0.83 to 1.10; 7 studies, 1122 participants; moderate-certainty evidence). Quality of life was assessed in five studies; in general there did not seem to be differences in global health scores between the two treatment groups at around two years' follow-up. Neoadjuvant studies were highly variable in design, having been undertaken to test various experimental regimens using pathological complete response (pCR) as a surrogate for disease-free survival (DFS) and OS. Across all patients, capecitabine-containing regimens resulted in little difference in pCR in comparison to non-capecitabine-containing regimens (odds ratio (OR) 1.12, 95% CI 0.94 to 1.33; 6 studies, 3152 participants; high-certainty evidence). By subtype, no difference in pCR was observed for either hormone receptor-positive (OR 1.22, 95% CI 0.76 to 1.95; 4 studies, 964 participants; moderate-certainty evidence) or hormone receptor-negative tumours (OR 1.28, 95% CI 0.61 to 2.66; 4 studies, 646 participants; moderate-certainty evidence). Four studies with 2460 people reported longer-term outcomes: these investigators detected no difference in either DFS (HR 1.02, 95% CI 0.86 to 1.21; high-certainty evidence) or OS (HR 0.97, 95% CI 0.77 to 1.23; high-certainty evidence). In the adjuvant setting, a modest improvement in OS was observed across all participants (HR 0.89, 95% CI 0.81 to 0.98; 8 studies, 13,547 participants; moderate-certainty evidence), and no difference in OS was seen in hormone receptor-positive cancers (HR 0.86, 95% CI 0.68 to 1.09; 3 studies, 3683 participants), whereas OS improved in hormone receptor-negative cancers (HR 0.72, 95% CI 0.59 to 0.89; 5 studies, 3432 participants). No difference in DFS or relapse-free survival (RFS) was observed across all participants (HR 0.93, 95% CI 0.86 to 1.01; 8 studies, 13,457 participants; moderate-certainty evidence). As was observed for OS, no difference in DFS/RFS was seen in hormone receptor-positive cancers (HR 1.03, 95% CI 0.91 to 1.17; 5 studies, 5604 participants; moderate-certainty evidence), and improvements in DFS/RFS with inclusion of capecitabine were observed for hormone receptor-negative cancers (HR 0.74, 95% CI 0.64 to 0.86; 7 studies, 3307 participants; moderate-certainty evidence). Adverse effects were reported across all three scenarios. When grade 3 or 4 febrile neutropenia was considered, no difference was seen for capecitabine compared to non-capecitabine regimens in neoadjuvant studies (OR 1.31, 95% CI 0.97 to 1.77; 4 studies, 2890 participants; moderate-certainty evidence), and a marked reduction was seen for capecitabine in adjuvant studies (OR 0.55, 95% CI 0.47 to 0.64; 5 studies, 8086 participants; moderate-certainty evidence). There was an increase in diarrhoea and hand-foot syndrome in neoadjuvant (diarrhoea: OR 1.95, 95% CI 1.32 to 2.89; 3 studies, 2686 participants; hand-foot syndrome: OR 6.77, 95% CI 4.89 to 9.38; 5 studies, 3021 participants; both moderate-certainty evidence) and adjuvant trials (diarrhoea: OR 2.46, 95% CI 2.01 to 3.01; hand-foot syndrome: OR 13.60, 95% CI 10.65 to 17.37; 8 studies, 11,207 participants; moderate-certainty evidence for both outcomes).

AUTHORS' CONCLUSIONS

In summary, a moderate PFS benefit by including capecitabine was seen only in hormone receptor-positive cancers in metastatic studies. No benefit of capecitabine for pCR was noted overall or in hormone receptor subgroups when included in neoadjuvant therapy. In contrast, the addition of capecitabine in the adjuvant setting led to improved outcomes for OS and DFS in hormone receptor-negative cancer. Future studies should stratify by hormone receptor and triple-negative breast cancer (TNBC) status to clarify the differential effects of capecitabine in these subgroups across all treatment scenarios, to optimally guide capecitabine inclusion.

Invasive breast cancer over four decades reveals persisting poor metastatic outcomes in treatment resistant subgroup - the "ATRESS" phenomenon

BACKGROUND

Major advances in breast cancer treatment have led to a reducuction in mortality. However, there are still women who are not cured. We hypothesize there is a sub-group of women with treatment-resistant cancers causing early death.

METHODS

Between 1975 and 2006, 5392 women with invasive breast cancer underwent surgery at Guy's Hospital, London. Data on patient demographics, tumour characteristics, treatment regimens, local recurrence, secondary metastasis, and death were prospectively recorded. We considered four time periods (1975-1982, 1983-1990, 1991-1998, 1999-2006). Risks and time to event analysis were performed with Cox proportional hazards model and Kaplan-Meier estimation.

RESULTS

Unadjusted hazard ratios for developing metastasis and overall mortality relative to the 1975-1982 cohort decreased steadily to 0.23 and 0.63, respectively in 1999-2006. However, metastasis-free interval shortened, with the proportion of women developing metastasis ≤5 years increasing from 73.9% to 83.0%. Furthermore, median post-metastatic survival decreased from 1.49 years to 0.94 years. Applying our risk criteria identified the presence of ±200 patients in each cohort who developed metastasis early and died within a much shorter time frame.

CONCLUSIONS

Advances in treatment have decreased the risk of metastasis and improved survival in women with invasive breast cancer over the last 40 years. Despite this, a subpopulation with shorter metastasis-free and post-metastatic survival who are unresponsive to available treatment remains. This may be due to the ATRESS phenomenon (adjuvant therapy-related shortening of survival) secondary to preselection inherent in adjuvant therapy, successful treatment of less malignant tumour cells and treatment-induced resistance in the remaining tumour clones.

Pilot study of docetaxel combined with lobaplatin or gemcitabine for recurrent and metastatic breast cancer

BACKGROUND

This study evaluated the efficacy and safety of docetaxel combined with lobaplatin, relative to docetaxel combined with gemcitabine, for treating patients with recurrent metastatic breast cancer (rMBC).

METHODS

Patients with rMBC received ≥2 cycles (21 days each) of either docetaxel and lobaplatin (DL; n = 21), or docetaxel and gemcitabine (DG; n = 22). On day 1 of each cycle, all patients were given 75 mg/m intravenous docetaxel. Patients in DL and DG were also given, respectively, 35 mg/m intravenous lobaplatin (day 2) or 1000 mg/m intravenous gemcitabine (days 1, 8).

RESULTS

Five (11.6%) and 16 (37.2%) patients achieved complete remission and partial response, respectively; rates of response and disease control were 48.8%. The response rates of the groups were comparable (47.6%, 50.0%). The median survival times after relapse and metastasis of the DL group (18 months) were significantly less than that of the DG group (25 months). Median progression-free survivals after relapse and metastasis were similar (12 cf. 14 months). The main toxic side reaction was grade 2, with no treatment-related deaths. Rates of the following were comparable between DG and DL: grade 3 or 4 white blood cells (23.8%, 31.8%) and digestive tract toxicity (4.8%, 4.5%); neutropenia (28.6%, 22.7%); anemia (4.8%, nil); and thrombocytopenia (19.0%, 13.6%). Other toxicities included hepatic toxicity, myalgia, infection, and fatigue.

CONCLUSIONS

Both the DL and DG regimens were associated with encouraging benefits, while treatment-related toxicity was manageable. Therefore, these regimens are effective options for treatment of rMBC.

TRIAL REGISTRATION

This clinical trial study was approved by the Ethics Committee of Guizhou Cancer Hospital, and has been registered in the China Clinical Trial Center (December 8, 2014, No. ChiCTR-IPR-14005633).

Gemcitabine-based chemotherapy as a viable option for treatment of advanced breast cancer patients: a meta-analysis and literature review

This meta-analysis was designed to compare the efficacy and safety of gemcitabine-based regimens for the treatment advanced breast cancer (ABC). Altogether 15 studies involving 8195 ABC patients were retrieved for analysis. Compared with non-gemcitabine-based chemotherapies, patients receiving gemcitabine-based therapy exhibited better overall survival (OS), progression free survival (PFS), and objective response rate (ORR) (HR = 1.12, 95% CI 1.05 to 1.19; HR = 1.16, 95% CI 1.03 to 1.30; HR = 1.14, 95% CI 1.04 to 1.24). Grade 3/4 hematologic toxicity was significantly high but manageable in gemcitabine-based groups. Subgroup analysis revealed that patients with first-line gemcitabine-based chemotherapy had better OS (HR = 1.19, 95% CI 1.07 to 1.32), PFS (HR = 1.17, 95% CI 1.08 to 1.27), and ORR (RR = 1.16, 95% CI 1.02 to 1.32). In addition, additional gemcitabine chemotherapy also showed better OS (HR = 1.17, 95% CI 1.06 to 1.30), PFS (HR = 1.20, 95% CI 1.11 to 1.30) and ORR (RR = 1.23, 95% CI 1.06 to 1.42) than gemcitabine replacement therapy. Furthermore, patients receiving gemcitabine-taxanes-based regimens had better OS (HR = 1.17, 95% CI 1.06 to 1.28), PFS (HR = 1.12, 95% CI 1.04 to 1.20) and ORR (RR = 1.17, 95% CI 1.01 to 1.35) than patients with non-gemcitabine-taxanes-based chemotherapy. These findings indicate that gemcitabine combination regimens could serve as a promising regimen for ABC patients, though increased hematologic toxicity should be considered with caution.

Suppression of PTEN/AKT signaling decreases the expression of TUBB3 and TOP2A with subsequent inhibition of cell growth and induction of apoptosis in human breast cancer MCF-7 cells via ATP and caspase-3 signaling pathways

The aim of the present study was to evaluate the effects of PTEN/AKT signaling on TUBB3 and TOP2A expression and on the subsequent cell growth of human breast cancer MCF-7 cells. We found that the disease-free survival (DFS) and overall survival (OS) of breast cancer patients with TUBB3‑positive tumors were lower than these rates in the patients with TUBB3-negative tumors. Meanwhile, DFS and OS of breast cancer patients with TOP2A-positive tumors were also lower than these rates in patients with TOP2A-negative tumors. Suppression of PTEN reduced the protein expression of TUBB3 and TOP2A in MCF-7 cells. Suppression of PTEN also reduced cell proliferation and induced apoptosis and caspase-3 activity in MCF-7 cells. Moreover, an increase in ATP also reduced TUBB3 and TOP2A protein expression, reduced cell proliferation and induced apoptosis and caspase-3 activity in the MCF-7 cells following suppression of PTEN. Suppression of phosphorylation-AKT (p-AKT) reduced the protein expression of TUBB3 and TOP2A in the MCF-7 cells. Suppression of p-AKT also reduced cell proliferation and induced apoptosis and caspase-3 activity in the MCF-7 cells. Then, ATP also reduced TUBB3 and TOP2A protein expression, reduced cell proliferation and induced apoptosis and caspase-3 activity in MCF-7 cells following suppression of p-AKT. These results suggest that PTEN/AKT signaling affects the expression of TUBB3 and TOP2A reducing cell growth and inducing apoptosis of human breast cancer MCF-7 cells through ATP and caspase-3 signaling pathways. TUBB3 and TOP2A may be promising prognostic markers for the efficacy of adjuvant cisplatin-based chemotherapy.

Clinical outcomes among HR+/HER2- metastatic breast cancer patients with multiple metastatic sites: a chart review study in the US

Background

Hormone receptor-positive, human epidermal growth factor receptor-2-negative (HR+/HER2−) is the most common type of metastatic breast cancer (mBC). While mBC patients generally have poor prognosis with limited progression-free survival (PFS) and overall survival (OS), those with multiple metastatic sites may have even worse clinical outcomes due to multiple organ involvement. This study aimed to compare clinical outcomes including PFS, time on treatment (TOT), and OS between HR+/HER2− mBC patients with multiple metastases versus those with a single metastasis in a real-world clinical setting.

Methods

This was a retrospective chart review study of postmenopausal HR+/HER2− mBC women who had failed a non-steroidal aromatase inhibitor in the adjuvant or metastatic setting and initiated a new treatment for mBC between 07/01/2012 and 04/15/2013. Patients were classified to one of two study groups (multiple metastases or single metastasis) based on the number of non-lymph-node metastases at the initiation of the new treatment. PFS, TOT and OS were compared between the two groups using Kaplan–Meier analyses and multivariable Cox proportional hazard models adjusting for patient disease and treatment characteristics. Separate Cox models were conducted including models with an interaction term between line of therapy and study group to assess the impact of multiple metastases on clinical outcomes across different lines of therapy.

Results

A total of 699 patient charts were collected, including 291 patients with multiple metastases and 408 single metastasis patients. Worse performance status and a higher proportion of prior chemotherapy for mBC were observed among patients with multiple metastases. Overall, patients with multiple metastases had significantly shorter PFS [adjusted hazard ratio (HR) = 1.55, 95 % confidence interval (CI) 1.21–1.98], TOT (adjusted HR = 1.33, 95 % CI 1.05–1.67), and OS (adjusted HR = 1.77, 95 % CI 1.15–2.74) than single metastasis patients. Similar outcomes were observed in each line of therapy.

Conclusions

Among HR+/HER2− mBC patients, patients with multiple metastases had significantly shorter PFS, TOT, and OS than single metastasis patients, highlighting the substantial clinical burden and unmet need for more efficacious treatments for the former group of patients.

Adjuvant Therapy Reduces Rate of Dissemination but Shortens Survival Thereafter

In the subgroup of patients who suffer from metastases despite adjuvant therapy, survival after dissemination is shortened. This is partially due to an adjuvant chemotherapy-induced resistance to previous treatment and may be similar after hormonal therapy and immunotherapy.

In reply

Many factors contribute to patient survival in metastatic breast cancer and other late-stage cancers. It is doubtful that adjuvant therapy causes a worse survival outcome. This being said, should resistance develop following adjuvant therapy, the patient needs to be offered a first-line solution that is free of cross-resistance.