Prognostic factors for resection of isolated pulmonary metastases in breast cancer patients: a systematic review and meta-analysis

Oligometastatic Breast Cancer: Seeking the Cure by Redefining Stage IV Disease?

OPINION STATEMENT

Breast cancer represents one of the most common malignancies worldwide. In early stages a combination of treatment strategies are offered with curative intent, whereas the therapeutic aim in metastatic disease is to provide the longest possible survival with an acceptable quality of life. The term "oligometastasis", first described by Hellmann and Weichselbaum in 1995, represents an intermediate state between local and systemic disease, where radical focal treatments to all metastatic lesions might have a curative potential. Due to sufficient lack of data, the proper management of oligometastatic disease remains even until today a highly unmet need. Surgery, radiotherapy or ablation (radiofrequency or cryotherapy) are among the local eradication therapies that could offer long-term outcomes in patients with oligometastatic breast cancer (OMBC). The present review aims to bring the readers up to the latest data regarding the management of OMBC according to the different organs involved by setting a framework of current treatment paradigms. It also brings to the forefront debatable questions requiring multidisciplinary approach and highlights the concerns arising from dealing with this clinically and biologically unique entity in everyday clinical practice.

Isolated Endobronchial Metastasis of Breast Cancer Successfully Managed With Multimodal Treatment

Isolated endobronchial metastases of breast cancers, without other visceral metastatic involvement, are exceptional. We report here an observation of isolated endobronchial metastasis discovered 18 months after complete treatment of breast carcinoma. The endobronchial metastasis was revealed by an incoercible cough and hemoptysis. A bronchoscopy revealed a budding tumor process obstructing the right stem bronchus and a biopsy was performed. The anatomopathological and immunohistochemical analysis confirmed the metastatic nature of the endobronchial tumor. The patient received treatment with palbociclib and aromatase inhibitors. Two years after radiotherapy and under hormone treatment, the patient is in complete remission of her breast cancer and endobronchial metastasis. Emerging research suggests that oligometastatic breast cancer carries a superior prognosis. We believe that patients with oligometastatic breast cancer should be treated with curative intent, including ablative therapy to all sites of disease if it can be safely accomplished. This approach may offer an additional chance for prolonged survival.

Role of Surgery in Metastatic Breast Cancer: Insights from a Narrative Review

Metastatic breast cancer is difficult to cure and has a worse prognosis with higher rates of mortality. Recently, breast surgery is believed to improve the survival rates among these women, but due to limited evidence, definite conclusions cannot be made. Therefore, we undertook this narrative review to synthesize the evidence from existing studies to assess the effectiveness of locoregional surgery and surgery of metastatic sites in improving the outcomes among women diagnosed with metastatic cancer disease along with the summary of current treatment guidelines. We reviewed PubMed and Embase and included both observational studies and randomized controlled trials (RCTs) that were published in English between 2000 and 2021. Outcomes were either survival, quality of life, toxicity related to local treatment assessed by mortality at the end of one month, progression-free survival, and breast cancer-specific survival. The main effect size assessed was hazard ratio with their 95% CIs. After literature search, we found 8 observational studies and 3 RCTs. The findings of the observational studies revealed that breast cancer surgery improves survival from 30% to 50% among women. However, findings from RCTs were mixed for local and distant progression survival. Surgery improved the local progression-free survival but worsened the distant progression-free survival. Besides, there was no effect of breast surgery on quality of life. Regarding the surgery of metastatic site, studies are complex with mixed findings and variation in survival depending upon the type of metastatic site and response to initial systematic therapy and other factors. Based on the existing mixed evidence, it is not possible to make firm and definite conclusions about the effectiveness of breast surgery in improving the survival or quality of life among women with metastatic breast cancer. In future, more RCTs are required with a larger sample size to confirm the findings of observational studies.

Intervention for Hepatic and Pulmonary Metastases in Breast Cancer Patients: Prospective, Multi-institutional Registry Study-IMET, Protocol MF 14-02

BACKGROUND

One fourth of early-stage breast cancer cases become metastatic during the follow-up period. Limited metastasis is a metastatic disease condition in which the number of metastatic sites and the extent of the disease both are limited, and the disease is amenable to metastatic intervention. This prospective study aimed to evaluate intervention for limited metastases in the lung, liver, or both.

METHODS

The study enrolled luminal A/B and/or human epidermal growth factor receptor 2 (HER2)-neu+ patients with operable lung and/or liver metastases in the follow-up assessment after completion of primary breast cancer treatment and patients with a diagnosis of metastasis after 2014. Demographic, clinical, tumor-specific, and metastasis detection-free interval (MDFI) data were collected. Bone metastasis in addition to lung and liver metastases also was included in the analysis. The patients were divided into two groups according to the method of treatment for metastases: systemic therapy alone (ST) group or intervention (IT) group.

RESULTS

Until June 2020, 200 patients were enrolled in the study. The demographic data were similar between the two groups. The median follow-up time was 77 months (range 55-107 months) in the IT group (n = 119; 59.5%) and 57 months (range 39-84) in the ST-only group (n = 81; 40.5%). The median MDFI was 40 months (range 23-70 months) in the IT group, and 35 months (range 13-61 months) in the ST-only group (p = 0.47). The groups had similar surgeries for the primary tumor and axilla. Most of the patients had liver metastases (49.5%, n = 99), and 42% (n = 84) of the patients had lung metastases. Both lung and liver metastases were found in 8.5% (n = 17) of the patients. The primary tumor was estrogen receptor/progesterone receptor-positive in 75% (n = 150) of the patients, and 32% (n = 64) of the patients had HER2-neu+ tumors. Metastatic-site resection was performed for 32% (n = 64) of the patients, and 27.5% (n = 55) of the patients underwent metastatic ablative interventions. In the Kaplan-Meier survival analysis, the hazard of death (HoD) was 56% lower in the IT group than in the ST-only group (hazard ratio [HR], 0.44; 95% confidence interval [CI] 0.26-0.72; p = 0.001). The HoD was lower in the IT group than in the ST-only group for the patients younger than 55 years (HR, 0.32; 95% CI 0.17-0.62; p = 0.0007). In the multivariable Cox regression model, HoD was significantly lower for the patients who underwent intervention for metastases and had an MDFI longer than 24 months, but their liver metastases doubled the risk of death compared with lung metastases.

CONCLUSION

Metastasis-directed interventions have reduced the risk of death for patients with limited lung/liver metastases who are amenable to interventions after completion of primary cancer treatment. For a select group of patients, such as those with luminal A/B or HER2-neu+ breast cancer who are younger than 55 years with limited metastases to the lung and liver or an MDFI longer than 24 months, surgical or ablative therapy for metastases should be considered and discussed on tumor boards.

Surgical Management of Metastatic Breast Cancer: A Mini Review

Breast cancer with distant metastases is a systemic disease. While systemic therapies are the main treatment strategy, locoregional therapy for metastatic breast cancer (MBC) is generally palliative only. However, recent progress in systemic and local therapies has improved the prognosis of patients with MBC and some may expect long-term survival. More vigorous local therapies for MBC may, therefore, be clinically justified in selected patients. A number of clinical trials and studies have investigated the clinical significance of surgical therapy for primary tumors and distant metastases in patients with MBC. Four prospective randomized trials and multiple retrospective studies have investigated the benefit of surgical resection of primary lesions in patients with MBC, with conflicting results. There have been a number of case-control studies examining the impact of surgical resection of distant metastases, but the benefit of this approach in terms of survival is controversial because selection bias is unavoidable in retrospective studies. The present review discusses the state of the literature relating to local management of the primary breast cancer through surgical resection and surgical management of distant metastatic lesions including pulmonary and liver metastases with future perspectives.

Treatment Strategies for Oligometastatic Breast Cancer

OPINION STATEMENT

Oligometastatic breast cancer, typically defined as the presence of 1-5 metastases, represents an intermediate state between locally advanced and widely metastatic disease. Emerging research suggests that oligometastatic cancer has a unique molecular signature distinct from widely metastatic disease, and that it carries a superior prognosis. Owing to its more limited capacity for widespread progression, oligometastatic disease may benefit from aggressive ablative therapy to known metastases. Options for ablation include surgical excision, radiofrequency ablation, and hypofractionated image-guided radiotherapy (HIGRT). The phase II SABR-COMET trial, which enrolled patients with oligometastatic disease of multiple histologies and randomized them to HIGRT vs. standard of care, found a notable survival advantage in favor of HIGRT. Other data suggest that HIGRT may synergize with immunotherapy by releasing powerful cytokines that increase anti-tumor immune surveillance and by recruiting tumor infiltrating lymphocytes, helping to overcome resistance to therapy. There are many ongoing trials exploring the role of ablative therapy, most notably HIGRT, with or without immunotherapy, for the treatment of oligometastatic breast cancer.We believe that patients with oligometastatic breast cancer should be offered enrollment on prospective clinical trials when possible. Outside the context of a clinical trial, we recommend that select patients with oligometastatic breast cancer be offered treatment with a curative approach, including ablative therapy to all sites of disease if it can be safely accomplished. Currently, selection criteria to consider for ablative therapy include longer disease-free interval from diagnosis to metastasis (>2 years), fewer metastases, and fewer involved organs. Undoubtedly, new data will refine or even upend our understanding of the definition and optimal management of oligometastatic disease.

Oligometastatic Breast Cancer: How to Manage It?

Breast cancer (BC) is the most frequent cancer among women and represents the second leading cause of cancer-specific death. A subset of patients with metastatic breast cancer (MBC) presents limited disease, termed 'oligometastatic' breast cancer (OMBC). The oligometastatic disease can be managed with different treatment strategies to achieve long-term remission and eventually cure. Several approaches are possible to cure the oligometastatic disease: locoregional treatments of the primary tumor and of all the metastatic sites, such as surgery and radiotherapy; systemic treatment, including target-therapy or immunotherapy, according to the biological status of the primary tumor and/or of the metastases; or the combination of these approaches. Encouraging results involve local ablative options, but these trials are limited by being retrospective and affected by selection bias. Systemic therapy, e.g., the use of CDK4/6 inhibitors for hormone receptor-positive (HR+)/HER-2 negative BC, leads to an increase of progression-free survival (PFS) and overall survival (OS) in all the subgroups, with favorable toxicity. Regardless of the lack of substantial data, this subset of patients could be treated with curative intent; the appropriate candidates could be mostly young women, for whom a multidisciplinary aggressive approach appears suitable. We provide a global perspective on the current treatment paradigms of OMBC.

Multimodal and palliative treatment of patients with pulmonary metastases

Pulmonary metastasectomy has become an important part of the multimodality treatment. Surgical practice is based on observational studies published during the last decades, since no randomized clinical trials exist on the topic. However, the overall survival can be improved after pulmonary metastasectomy in carefully selected patients. The objective of resection of pulmonary metastases is to remove all tumor while preserving as much normal pulmonary parenchyma as possible and reduce invasiveness. Contrary, nonsurgical local treatment options for pulmonary metastases include thermal ablation techniques and stereotactic ablative body radiation. Thermal ablation techniques include microwave, cryotherapy and radiofrequency ablation. The present review article gives an overview on the topic and should help thoracic surgeons to make the right decisions in their daily practice.

Pulmonary metastasectomy for pulmonary metastasis of breast cancer has a limited prognostic impact: a multi-institutional retrospective analysis

Background

Pulmonary metastasectomy (PM) for breast cancer-derived pulmonary metastasis is controversial. This study aimed to assess the prognostic factors and implication of PM for metastatic breast cancer using a multi-institutional database.

Methods

Clinical data of 253 females with pulmonary metastasis of breast cancer who underwent PM between 1982 and 2017 were analyzed retrospectively.

Results

The median patient age was 56 years. The median follow-up period was 5.4 years, and the median disease-free interval (DFI) was 4.8 years. The 5- and 10-year survival rates after PM were 64.9% and 50.4%, respectively, and the median overall survival was 10.1 years. Univariate analysis revealed that the period of PM before 2000, a DFI <36 months, lobectomy/pneumonectomy, large tumor size, and lymph node metastasis were predictive of a worse overall survival. In the multivariate analysis, a DFI <36 months, large tumor size, and lymph node metastasis remained significantly related to overall survival. The 5- and 10-year cancer-specific survival rates after PM were 66.9% and 54.7%, respectively, and the median cancer-specific survival was 13.1 years. Univariate analyses revealed that the period of PM before 2000, DFI <36 months, lobectomy/pneumonectomy, large tumor size, lymph node metastasis, and incomplete resection were predictive of a worse cancer-specific survival. Multivariate analysis confirmed that a DFI <36 months, large tumor size and incomplete resection were significantly related to cancer-specific survival.

Conclusions

As PM has limited efficacy in breast cancer, it should be considered an optional treatment for pulmonary metastasis of breast cancer.

Oligometastatic Breast Cancer: Is This a Curable Entity? A Contemporary Review of the Literature

PURPOSE OF REVIEW

Oligometastatic breast cancer (OMBC) remains a poorly understood entity for which no standard of care exists at this time. This review will focus on our biologic understanding of OMBC and provide an update on current treatment strategies.

RECENT FINDINGS

The introduction of micro RNA expression profiling has advanced our understanding of the biologic underpinnings of OMBC. Although most of the data regarding treatment have come from retrospective studies, there are now prospective randomized trials reporting progression-free survival and overall survival improvements with stereotactic ablative radiotherapy (SABR). Ongoing studies designed to evaluate addition of SABR as well as other novel agents will further develop this field and provide new treatment options. A "cure" for OMBC remains elusive. With further basic research coupled with novel prospective trials, patients will hopefully enjoy increased progression-free survival and overall survival, and ideally a delay to more toxic systemic therapy.

[The role of systemic therapy of lung metastases with lymph node involvement]

Modern systemic therapy with chemotherapy, targeted therapy and immunotherapy has led to a significant improvement in the overall survival in many tumor diseases over the past 15 years. Thus, the surgical treatment of lung metastases and lymph node metastases is not only valuable to achieve a cure for selected tumors but it can and must be used to eliminate tumor growth peaks in the case of a circumscribed progression. These can be an expression of tumor heterogeneity that cannot be achieved by systemic therapy. Depending on the dynamics and extent of the metastasis, the therapeutic approach must be individually decided in the tumor board.

[Progress in Surgery for Pulmonary Metastases]

Lung is the most common metastatic site for tumors other than the liver. Pulmonary metastasectomy is also one of the common operations in thoracic surgery. However, the effect of pulmonary metastasectomy is controversial. As far as the current experience is concerned, patients with pulmonary metastases with long disease free interval, low-grade malignant tumor and complete excision have the greatest benefit from metastasectomy. This review is about the progress of surgical treatment of pulmonary metastases.
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Interdisciplinary Screening, Diagnosis, Therapy and Follow-up of Breast Cancer. Guideline of the DGGG and the DKG (S3-Level, AWMF Registry Number 032/045OL, December 2017) - Part 2 with Recommendations for the Therapy of Primary, Recurrent and Advanced Breast Cancer

Purpose The aim of this official guideline coordinated and published by the German Society for Gynecology and Obstetrics (DGGG) and the German Cancer Society (DKG) was to optimize the screening, diagnosis, therapy and follow-up care of breast cancer. Method The process of updating the S3 guideline published in 2012 was based on the adaptation of identified source guidelines. They were combined with reviews of evidence compiled using PICO (Patients/Interventions/Control/Outcome) questions and with the results of a systematic search of literature databases followed by the selection and evaluation of the identified literature. The interdisciplinary working groups took the identified materials as their starting point and used them to develop suggestions for recommendations and statements, which were then modified and graded in a structured consensus process procedure. Recommendations Part 2 of this short version of the guideline presents recommendations for the therapy of primary, recurrent and metastatic breast cancer. Loco-regional therapies are de-escalated in the current guideline. In addition to reducing the safety margins for surgical procedures, the guideline also recommends reducing the radicality of axillary surgery. The choice and extent of systemic therapy depends on the respective tumor biology. New substances are becoming available, particularly to treat metastatic breast cancer.

Long-Term Survival and Prognostic Factors of Pulmonary Metastasectomy in Liver Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Lung is the most common extrahepatic metastatic organ of liver cancer. Surgical resection is a common local treatment for pulmonary metastasis. But the long-term prognosis of pulmonary metastasectomy varies greatly due to the small sample size and different results of previous studies. Therefore, we conducted this meta-analysis to evaluate the combined 5-year overall survival (OS) rate and prognostic factors after pulmonary metastasectomy in liver cancer.

METHODS

Key words such as liver cancer pulmonary metastasis and metastasectomy were retrieved firstly in PubMed, Cochrane Library, Embase and Chinese Wanfang databases. Eligible studies were identified by manual searches. Each included study should report 5-year OS rate and/or prognostic factors of pulmonary metastasectomy. Newcastle-Ottawa Scale was used for quality assessment, and heterogeneity was estimated by I². We calculated the combined 5-year survival rates and determined the prognostic factors for OS by the hazard ratios (HR) and number of events.

RESULTS

Seventeen cohort studies with a total of 513 patients were included in this meta-analysis. The combined 5-year survival rates after pulmonary metastasectomy were 33% [95% confidence interval (95% CI) 29-37%]. The poor prognostic factors were disease-free interval (DFI) < 12 months (HR = 2.421 95% CI 1.384 4.236) and existence of cirrhosis (HR = 1.936 95% CI 1.031 3.636).

CONCLUSION

The 5-year OS rate of patients with pulmonary metastasectomy after resection of primary liver cancer is 33%. DFI < 12 months and existence of cirrhosis are probably poor prognostic factors.

Cure in metastatic breast cancer

Oligometastatic disease characterizes a distinct subgroup of metastatic breast cancer patients that might benefit from different treatment strategies to achieve long-lasting remission and potentially cure. Those long-lasting remissions are reported after locoregional treatment of the primary tumor and all metastatic sites in several case series; however, unlike other tumor entities, prospective data are lacking. Furthermore, tumor eradication by excellent systemic anticancer therapy with novel chemotherapies and targeted agents can lead to long-term survival. In addition, reactivation of the host immune defense by immuno-oncologic drugs can achieve long-lasting tumor control. So far, unfortunately, checkpoint inhibitors as monotherapy have led to responses only in a small percentage of patients with metastatic breast cancer. This short review summarizes available data on long-lasting remissions and potential cure in metastatic breast cancers. It describes and discusses data on locoregional treatment, chemo-, antibody- and immunotherapy and tries to select individual patients for whom a multidisciplinary treatment approach with curative intention might be an option to achieve long-term survival.

Significance of lung biopsy for the definitive diagnosis of lung nodules in breast cancer patients

The aim of the present study was to evaluate the significance of lung biopsy for the modification of the treatment strategy in breast cancer patients who develop lung nodules during follow-up after breast surgery. Of 53 consecutive patients who underwent lung biopsies in two institutions (Hiroshima University Hospital and Hiroshima Prefectural Hospital, Hiroshima, Japan) between 1997 and 2014, 45 underwent lung surgery and 8 underwent percutaneous or transbronchial tumor biopsy for lung nodules developing after curative surgery for breast cancer. The indications for lung biopsy included lung nodules for which a definitive diagnosis was difficult to achieve, and those for which the treatment strategy depended on the pathological diagnosis. The lung nodules were pathologically diagnosed as primary breast cancer metastases to the lungs in 25 (47%), primary malignant lung tumors in 21 (40%) and benign disease in 7 (13%) patients. Among the 25 metastatic patients confirmed by lung biopsy, phenotype discordance was observed in 6 patients (24%). A total of 3 patients with lung metastasis proven to have estrogen or progesterone receptor upregulation by lung biopsy received endocrine therapy. Univariate analysis revealed that patients with metastatic breast cancer confirmed by lung biopsy were significantly younger and had more locally advanced primary cancers diagnosed via clinical and pathological assessment compared with patients with other diseases. Therefore, mastectomy and axillary lymph node dissection were performed more frequently in the metastasis group compared with the others group. Multivariate analysis revealed that mastectomy (P<0.001) and axillary dissection (P<0.001) were independent factors predicting that the lung nodules would be metastases from breast cancer. Lung biopsy in breast cancer patients who developed lung nodules during the follow-up period after breast cancer surgery was crucial for making a definitive diagnosis and modifying the treatment strategy, which may improve the prognosis of breast cancer patients.

Lung Metastasectomy for Pulmonary Metastatic Breast Carcinoma

Breast carcinoma with pulmonary metastasis can be treated locally or systemically. Following primary tumour resection patients with isolated, completely resectable pulmonary nodules and definite functional operability can be offered lung metastasis resection. Following metastasectomy a median survival of 32 to 96.6 months can be achieved with corresponding five-year survival rates between 30.8 and 54.4%. The procedure is associated with a mortality rate of 0 to 3%. The most important independent prognostic factor for long-term survival is complete resection of all lung lesions. The configuration and pattern of metastasis as well as disease-free interval, hormone and HER2/neu receptor status also appear to influence prognosis, but are of lesser importance. Intrapulmonary recurrence of metastases may, after careful selection on a case-by-case basis, also be treated operatively. In some cases this is associated with a favourable long-term prognosis. Pulmonary metastasectomy should be the treatment of choice for selected patients with metastatic breast carcinoma.