Oligometastatic Breast Cancer: How to Manage It?

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.

HR+/HER2- Advanced Breast Cancer Treatment in the First-Line Setting: Expert Review

The approval of CDK4/6 inhibitors has dramatically improved care for the treatment of HR+/HER2- advanced breast cancer, but navigating the rapidly-expanding treatment evidence base is challenging. In this narrative review, we provide best-practice recommendations for the first-line treatment of HR+/HER2- advanced breast cancer in Canada based on relevant literature, clinical guidelines, and our own clinical experience. Due to statistically significant improvements in overall survival and progression-free survival, ribociclib + aromatase inhibitor is our preferred first-line treatment for de novo advanced disease or relapse ≥12 months after completion of adjuvant endocrine therapy and ribociclib or abemaciclib + fulvestrant is our preferred first-line treatment for patients experiencing early relapse. Abemaciclib or palbociclib may be used when alternatives to ribociclib are needed, and endocrine therapy can be used alone in the case of contraindication to CDK4/6 inhibitors or limited life expectancy. Considerations for special populations-including frail and fit elderly patients, as well as those with visceral disease, brain metastases, and oligometastatic disease-are also explored. For monitoring, we recommend an approach across CDK4/6 inhibitors. For mutational testing, we recommend routinely performing ER/PR/HER2 testing to confirm the subtype of advanced disease at the time of progression and to consider ESR1 and PIK3CA testing for select patients. Where possible, engage a multidisciplinary care team to apply evidence in a patient-centric manner.

Conditional cause-specific survival after chemotherapy and local treatment for primary stage IV breast cancer: A population-based study

Background

Conditional survival (CS) represents the probability of surviving for additional years after the patient has survived for several years, dynamically describing the survival rate of the patient with the varying time of survival. The aim of this study was to evaluate the conditional cause-specific survival (CCSS) after chemotherapy and local treatment for metastatic breast cancer, and to identify the prognostic factors affecting the CCSS.

Methods

Patients diagnosed with primary stage IV breast cancer in the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015 were included. CS is defined as the probability of additional survival for y years after the patient had survived x years with the calculation formula CCSS (x | y) = CSS (x + y)/CSS (x), where CSS(x) indicates the patient’s cause-specific survival rate at the time of x years. Cox proportional hazard models were used to evaluate predictors of CCSS.

Results

A total of 3,194 patients were included. The 5-year CSS was 39%, whereas the 5-year CCSS increased to 46%, 57%, 71%, and 85% after the diagnosis of 1, 2, 3, and 4 years. For patients with adverse clinical pathological features, CCSS had more pronounced increase with survival time and is more different from the CSS at diagnosis. No matter at the time of diagnosis or 1 year or 3 years after diagnosis, HER2 status, local treatment, and multisite metastasis were independent prognostic factors that affect the long-term survival of patients (all P < 0.05).

Conclusion

The 5-year CCSS of patients with stage IV breast cancer was extended as the survival years increased. HER2 status, multisite metastasis, and local treatment were independent prognostic factors even 3 years after diagnosis.

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.

Stereotactic Body Radiation Therapy in Patients with Oligometastatic Disease: Clinical State of the Art and Perspectives

Stereotactic body radiation therapy (SBRT) is a form of radiation therapy (RT) in which a small number of high doses of radiation are delivered to a target volume using highly sophisticated equipment. Stereotactic body radiation therapy is crucial in two cancer stages: early primary cancer and oligometastatic disease, with the goal of inducing complete cancer remission in both. This treatment method is commonly used to treat a variety of disease types. Over the years, a growing body of clinical evidence on the use of SBRT for the treatment of primary and metastatic tumors has accumulated, with efficacy and safety demonstrated in randomized clinical trials. This article will review the technical and clinical aspects of SBRT according to disease type and clinical indication.

Radiotherapy and radiosensitization in breast cancer: Molecular targets and clinical applications

Relatively poor survival outcomes are observed in advanced or metastatic breast cancer, where local control of the primary or metastatic disease may be achieved by surgical resection, local ablative and radiation therapies. Radioresistance, poses a major challenge in achieving durable oncologic outcomes, mandating development of novel management strategies. Although multimodality approaches that combine radiotherapy with chemotherapy, or systemic agents, are utilized for radiosensitization and treatment of various malignancies, this approach has not yet found its clinical application in breast cancer. Some agents for breast cancer treatment can serve as radiosensitizers, creating an opportunity to enhance effects of radiation while providing systemic disease control. Hence, combination of radiotherapy with radiosensitizing agents have the potential to improve oncologic outcomes in advanced or metastatic breast cancer. This review discusses molecular targets for radiosensitization and novel systemic agents that have potential for clinical use as radiosensitizers in breast cancer.