Survival Benefit of Surgical Removal of Primary Tumor in Patients With Stage IV Breast Cancer

Surgery of the primary tumor in patients with de novo metastatic breast cancer: a nationwide population-based retrospective cohort study in Belgium

PURPOSE

We aimed to assess the impact of surgery of primary tumor in overall survival (OS) of women with de novo metastatic breast cancer.

METHODS

Nationwide, population-based retrospective cohort study of women diagnosed with de novo metastatic breast cancer in Belgium, between Jan/2010-Dec/2014. Data was obtained from the Belgian Cancer Registry and administrative databases. "Surgery" group was defined by surgery of primary tumor up to nine months after diagnosis. We excluded women who did not receive systemic treatment or did not complete nine months follow-up after diagnosis. All the subsequent analyses reporting on overall survival and the stratified outcome analyses were performed based on this nine-month landmark cohort. OS was estimated using Kaplan-Meier method and compared using adjusted Cox proportional hazards models controlling for confounders with 95% confidence intervals (CI). We performed a stratified analysis according to surgery timing and a propensity score matching analysis.

RESULTS

1985 patients, 534 (26.9%) in the "Surgery" and 1451 (73.1%) in the "No Surgery" group. Patients undergoing surgery were younger (p < 0.001), had better performance status (PS) (p < 0.001), and higher proportion of HER2-positive and triple-negative breast cancer (p = 0.012). Median follow-up was 86.0 months (82.6-88.5). Median OS was 60.1 months (57.1-68.2) in the "Surgery" vs. 41.9 months (39.8-44.2) in the "No Surgery" group (adjusted HR 0.56; 0.49-0.64). OS was similar when surgery was performed upfront or after systemic treatment. Propensity score matching analysis confirmed the same findings.

CONCLUSION

Among patients receiving systemic treatment for de novo metastatic breast cancer and surviving nine months or more, those who received surgery of the primary tumor within nine months of diagnosis have longer subsequent survival than those who did not.

Red blood cell-based vaccines for ameliorating cancer chemoimmunotherapy

Immune checkpoint blockade (ICB) therapy has shown promising antitumor effects, but its immune response rate remains unsatisfactory. In recent years, chemotherapy has been proven to have synergistic effects with ICB therapy because some chemotherapeutic agents can enhance the immunogenicity of tumor cells by inducing immunogenic cell death (ICD). However, it cannot be ignored that chemotherapy often shows limited therapeutic efficacy due to high cytotoxicity, drug resistance, and some other side effects. Herein, we report a strategy to improve cancer immunotherapy by utilizing red blood cell-based vaccines (RBC-vaccines) where chemotherapy-induced tumor antigens (cAgs) are anchored onto red blood cells (RBCs) via the EDC/NHS-mediated amine coupling reaction. In this work, RBC-vaccines administered subcutaneously are primarily devoured by dendritic cells (DCs) and significantly improve the efficacy of αPD-1 (anti-programmed cell death 1) treatment by increasing the infiltration of intratumoral CD8⁺ and CD4⁺ T cells and elevating the intratumoral ratio of CD8⁺ T cells to regulatory T cells in the CT-26 colon cancer model. Finally, based on the rejection of tumor rechallenge in cured mice, the combination therapy of RBC-vaccines and αPD-1 can induce the expansion of memory T cells and thereby establish a long-term antitumor immune response. Taken together, the proposed RBC-vaccines have great potential to improve chemoimmunotherapy. STATEMENT OF SIGNIFICANCE: Immunotherapy, especially immune checkpoint blockade therapy, has made great contributions to the treatment of some advanced cancers. Unfortunately, the great majority of patients with cancer do not benefit from immunotherapy. To enhance the response rate of immunotherapy, we developed red blood cell-based vaccines (RBC-vaccines) against cancers where antigens were harvested from chemotherapy-treated cancer cells and then attached to erythrocytes via covalent surface modification. Such RBC-vaccines could provide a wide variety of tumor antigens and damage-associated molecular patterns without the use of any extra ingredients to trigger a stronger antitumor immune response. More importantly, the combination of RBC-vaccines with PD-1 blockade could significantly improve the efficacy of cancer immunotherapy and induce durable antitumor immunity.

Impact of surgical management of primary tumors in stage IV breast cancer patients: a retrospective observational study based on SEER database

OBJECTIVES

Although primary tumour surgery could prolong survival for patients with stage IV breast cancer, how to select candidates for primary tumour surgery is still a challenging problem for medical oncologists.

DESIGN

This study is a retrospective database study.

SETTING AND PARTICIPANTS

In this study, we aimed at evaluating the primary site surgery effect and select the beneficial subgroups. 13 618 patients with stage IV breast cancer, diagnosed between 2010 and 2015, were collected from SEER*Stat database.

INTERVENTIONS

Based on the local surgery at primary tumour site, patients were categorised into three groups: primary tumour surgery performed group, recommended for primary tumour surgery but refused (RBR) group and surgery not recommended (NR) group.

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause survival and breast cancer-specific survival (BCSS).

RESULTS

Univariate Cox regression analyses showed that, compared with surgery group, patients in non-surgery (RBR and NR) groups tend to be older, T4, N0/NX, triple-negative and visceral metastatic. For both all-cause survival and BCSS, non-surgery, advanced T stage, triple-negative BC (TNBC) and visceral metastases were significant risk factors. Primary tumour surgery showed benefits for both all-cause survival (HR=0.44, 95% CI=0.39-0.49, p<0.0001) and BCSS (HR=0.43, 95% CI=0.38-0.49, p<0.0001). However, after propensity score matching, primary tumour surgery failed to demonstrate significant benefits for TNBC (HR=0.96, 95% CI=0.60-1.53, p=0.851) and patients with visceral metastases (HR=0.90, 95% CI=0.60-1.36, p=0.62).

CONCLUSION

Surgery was associated with prolonged survival in stage IV breast cancers, but not in patients with TNBC and visceral metastases.

Impact of Postoperative Radiotherapy on Survival of Patients With de novo Stage IV Breast Cancer: A Population-Based Study From the SEER Database

Purpose: In our study, we aimed to evaluate the role of postoperative radiotherapy for patents with de novo stage IV breast cancer. Patients and Methods: Patients diagnosed with stage IV breast cancer from 2010 to 2016 were selected from the Surveillance, Epidemiology, and End Result (SEER) database. Those patients who received both chemotherapy and surgery and lived longer than 6 months were divided into radiotherapy and non-radiotherapy groups. Kaplan-Meier analysis and multivariate Cox proportional hazards models were used to estimate the survival outcomes before and after being 1:1 propensity score matched (PSM). Subgroup analyses stratified by age, subtype, status of distant metastasis, and surgery type were also performed. Results: Among 1,935 patients, 52% (1006) underwent radiotherapy while the non-radiotherapy group contained 48% (929). After PSM, a total of 1,520 patients in two groups of 760 patients were enrolled in this analysis. Kaplan-Meier and the multivariate survival analysis demonstrated that the radiotherapy group presented with a better prognosis compared to the non-radiotherapy group (after PSM, BCSS: Hazard Ratio, 0.697; 95% confidence interval, 0.59-0.823; P < 0.001; OS: Hazard Ratio, 0.707; 95% confidence interval, 0.601-0.831; P < 0.001). Further subgroup analyses showed the Luminal subtype (HR+/HER2-), triple-negative breast cancer (TNBC), and bone-only metastasis patients presented with the most promising survival in the radiotherapy group. Conclusions: Postoperative radiotherapy is associated with a significant survival advantages in BCSS and OS. It can be an optimal supplementary treatment for stage IV patients after surgery, especially for Luminal subtype, TNBC, and patients with a low metastatic burden.

Locoregional therapy of the primary tumour in de novo stage IV breast cancer in 216 066 patients: A meta-analysis

Patients presenting with de novo stage IV metastatic breast cancer have a complex disease which is normally treated with palliative intent and systemic therapy. However, there is mounting evidence that resection of the primary tumour and/or localised radiotherapy (locoregional therapy; LRT) could be associated with overall survival improvements. We aimed to conduct a meta-analysis to inform decision making. Using the PubMed, Cochrane and Ovid SP databases, a literature review and meta-analysis were conducted to assess the effect of LRT on overall survival. Studies were analysed for the impact of LRT on survival. All forms of LRT resulted in a significant 31.8% reduction in mortality (N = 42; HR = 0.6823 (95% CI 0.6365; 0.7314)). Surgical resection resulted in a significant 36.2% reduction in mortality (N = 37; HR = 0.6379 (95% CI 0.5974; 0.6811)). The prospective trials reported a 19.23% reduction in mortality which was not statistically significant (N = 3, HR = 0.8077 (95% CI 0.5704; 1.1438). 216 066 patients were included. This is the largest meta-analysis regarding this question to date. Our meta-analysis shows that LRT of the primary tumour seems to improve overall survival in de novo stage IV disease. Therefore, this therapeutic option should be considered in selected patients after a careful multidisciplinary discussion.

The Impact of Locoregional Treatment on Survival in Patients With Metastatic Breast Cancer: A National Cancer Database Analysis

BACKGROUND

Although systemic therapy is the standard treatment for metastatic breast cancer, the value of locoregional treatment (LRT) of the primary tumor and its impact on survival is controversial. This study evaluates survival outcomes in patients with metastatic breast cancer after receiving LRT (surgery and/or radiation therapy) of the primary tumor.

MATERIALS AND METHODS

The National Cancer Database was used to identify 16,128 qualifying cases of metastatic breast cancer who received systemic therapy with or without LRT from 2004 to 2013. Treatment modality was divided into surgery (Sx), radiation therapy (RT), surgery followed by RT (Sx + RT), and no LRT. The median survival and 3-year actuarial survival rates (OS) were analyzed for each treatment group. On multivariate analyses, adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were computed using Cox regression modeling to adjust for patient and clinicopathologic characteristics.

RESULTS

Overall, the median follow-up was 28.3 months, and the median survival for all patients was 37.2 months. With 9761 deaths reported, the estimated 3-year OS was 51.3%. The Sx + RT group (n = 2166) had the highest 3-year OS of 69.4%, followed by the Sx group (n = 4293) with 57.6%, the no LRT group (n = 8955) with 44.3%, and the RT group (n = 714) with 41.5% (P < .0001). On multivariate analysis, compared with the no LRT group, a decreased HR was noted in patients receiving Sx (adjusted HR, 0.68; 95% CI, 0.65-0.71; P < .0001) and Sx + RT (adjusted HR, 0.46; 95% CI, 0.43-0.49; P < .0001).

CONCLUSION

LRT, especially surgery followed by RT, in addition to systemic therapy, was associated with improved survival in patients with metastatic breast cancer.