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

Outcomes of De Novo Oligometastatic Breast Cancer Treated With Surgery of Primary and Metastasis Directed Radiotherapy

OBJECTIVES

With sensitive imaging for breast cancer, the question arises whether present-day oncologists treat dOMBC with palliative systemic therapy (ST), which, a few years earlier, would have been treated with curative intent. We retrospectively analyzed outcomes of dOMBC treated with curative intent using a combination of surgery, metastasis-directed radiotherapy (RT), and adjuvant/neoadjuvant ST and have also explored the possible role of total lesional glycolysis of metastases and p53 immunohistochemistry in predicting outcomes.

METHODS

Data were collected from a prospectively maintained database using electronic medical records and Radiation Oncology Information System. In the study, dOMBC was defined as up to 3 metastatic sites, all amenable to treatment with ablative RT and primary and axillary disease amenable to curative surgery. Patients were treated with surgery, ST, and RT.

RESULTS

Patients underwent either breast conservation surgery or modified radical mastectomy. Patients were treated with 6 to 8 cycles of chemotherapy in the neoadjuvant and/or adjuvant setting. Hormone receptor-positive patients received either tamoxifen or aromatase inhibitors. Trastuzumab was offered to Her-2-neu receptor-positive patients. RT included locoregional RT and metastases-directed ablative body RT. The median progression-free survival was 39 months (95% CI: -28.7 to 50.1 mo). Two and 3 year estimated disease-free survival (DFS) was 79% and 60.5%, respectively. The median overall survival was not reached. The estimated 3-year overall survival was 87.3%. Total lesional glycolysis of metastases score and p53 status did not affect DFS.

CONCLUSION

Combination treatment of surgery, metastases-directed ablative RT, and ST may provide prolonged DFS in dOMBC.

Palliative surgery versus non-surgery of the solitary metastatic lesion in De novo metastatic breast cancer: A SEER based study

This study aimed to evaluate whether palliative surgery for metastatic lesion could provide a survival benefit in metastatic breast cancer (MBC) patients with solitary metastasis. De novo MBC patients with solitary distant lesions were enrolled utilizing the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was conducted to form matched pairs of the surgery group and the non-surgery group. The breast cancer-specific survival (BCSS) and overall survival (OS) outcomes between the 2 groups were compared in the following 3 sample models: the entire cohort of MBC (7665 cases); subgroups of patients with different isolated metastatic organs; and subgroups of patients with different molecular subtypes for each isolated metastatic organ. Compared with the Non-surgery group, the surgery group showed better BCSS and OS before PSM (HR = 0.88, 95% CI = 0.79-0.99, P = .04 and HR = 0.85, 95% CI = 0.76-0.95, P = .006, respectively). After PSM, palliative surgery still provided an OS benefit in patients with brain metastasis and lung metastasis (HR = 0.59, 95% CI = 0.37-0.95, P = .01 and HR = 0.64, 95% CI = 0.45-0.90, P = .02, respectively). Likewise, a better BCSS benefit was also found in the subset of patients with brain metastasis (HR = 0.61, 95% CI = 0.38-1.00, P = .01). Further stratification analysis indicated that patients with the luminal A subtype with brain metastasis have a better BCSS (HR = 0.36, 95% CI = 0.16-0.79, P = .04) and OS (HR = 0.37, 95% CI = 0.18-0.75, P = .03) after undergoing palliative surgery than nonsurgical treatment. Our study originality showed that palliative surgery for metastatic lesion could improve survival prognosis in patients with special single-organ metastasis and specific molecular subtypes. More clinical studies are needed to determine whether palliative surgery should be performed in MBC patients.

Survival outcomes for women with a solitary extracranial metastasis from breast cancer

BACKGROUND

Aggressive metastasis directed treatment of extracranial oligometastatic breast cancer with the aim of increasing disease-free survival has emerged as a new potential treatment paradigm, however there is currently a lack of data to assist in identifying the subset of patients who will potentially benefit most. This single-institute retrospective cohort study aimed to evaluate survival outcomes for patients with a solitary extracranial metastasis from breast cancer and to assess for significant prognostic factors.

METHODS AND MATERIALS

Medical records of 70 female breast cancer patients with a solitary extracranial metastasis actively managed at the Peter MacCallum Cancer Centre (PMCC) Melbourne Campus between 2000 and 2019 were reviewed. Kaplan-Meier curves were used to estimate overall survival (OS), local progression free survival (LPFS) and distant progression free survival (DPFS).

RESULTS

Median follow-up period was 9.4 years. The study included 40 hormone receptor positive/HER2 negative (HR+HER2-), 14 hormone receptor positive/HER2 positive (HR+HER2+), 3 hormone receptor negative/HER2 positive (HR-HER2+), 9 triple negative (TNBC) and 4 unclassified breast cancer patients. 5-year OS rate for all patients was 46%, LPFS rate was 56% and DPFS was 20%. Tumour receptor group had a statistically significant association with OS and DPFS rates. TNBC patients had significantly poorer OS and DPFS rates in comparison to HR+HER2-patients.

CONCLUSION

Among patients with a solitary extracranial metastasis from breast cancer, TNBC was associated with the poorest OS and DPFS rates. Identification of other significant prognostic factors for oligometastatic breast cancer patients may inform guidelines for metastasis directed treatments.

Relationship Between Metabolic Activity, Cellularity, Histopathological Features of Primary Tumors and Distant Metastatic Potential in Breast Cancer

Objectives

The aim of this study was to evaluate the relationship between the types of distant metastatic spread, histopathological features, and imaging features of primary tumor on positron emission tomography/magnetic resonance imaging (PET/MRI) for primary staging in newly diagnosed breast invasive ductal carcinoma (IDC) patients.

Methods

Data from 289 female patients were retrospectively evaluated. Maximum standardized uptake value, metabolic tumor volume (MTV), total lesion glycolysis (TLG), and minimum apparent diffusion coefficient (ADCmin) values of primary tumors were obtained from PET/MRI. The patients were grouped as non-metastatic, oligometastatic (1-5 metastatic lesions) and multimetastatic (>5 metastatic lesions) disease according to the number of distant metastases, and divided into two groups as isolated bone metastasis (IBM) and mixed/soft tissue metastasis (M-SM) groups according to the sites of metastatic spread.

Results

Metabolic parameters had higher values and ADCmin had lower values in the multimetastatic and oligometastatic groups than in the non-metastatic group. MTV was the only parameter that showed significant difference between the multimetastatic and oligometastatic groups. MTV and TLG were significantly higher in the M-SM group than in the IBM group. 18F-fluorodeoxyglucose PET parameters had significantly higher values in grade 3, hormone receptor negative, human epidermal growth factor receptor 2 positive, triple negative, and highly proliferative (Ki-67 ≥14%) tumors. The prediction models that included imaging parameters to predict the presence of distant metastasis had higher discriminatory powers than the prediction models that included only histopathological parameters.

Conclusion

Primary tumors with higher metabolic-glycolytic activity and higher cellularity were more aggressive and had higher metastatic potential in breast IDC. Compared with histopathological parameters alone, the combination of imaging parameters and histopathological features of primary tumors may help to better understand tumor biology and behavior.

Mind the Gap: Recurrence of Oligometastatic Breast Invasive Ductal Carcinoma in the Sternal Gap of Two Tangential Photon Fields of Bilateral Whole Breast Irradiation a Decade Later

Despite bilateral breast cancer being a rare clinical entity compared to unilateral breast cancer, both share a treatment paradigm of breast-conserving therapy for limited disease and metastasis direct therapy for oligometastatic disease. We present a case of left breast invasive ductal carcinoma in the setting of original bilateral breast cancer, now with oligometastatic recurrence to the soft tissue of the sternum, notably in an area not previously irradiated, over a decade later.

Unravelling oligometastatic disease from the perspective of radiation and medical oncology. Part I: non-small cell lung cancer and breast cancer

Oligometastatic disease (OMD) defines a cancer status that is intermediate between localized and widely spread metastatic disease, and can be treated with curative intent. While diagnostic imaging tools have considerably improved in recent years, unidentified micrometastases can still evade current detection techniques, allowing the disease to progress. The various OMD scenarios are mainly defined by the number of metastases, the biological and molecular tumour profiles, and the timing of the development of metastases. Increasing knowledge has contributed to the earlier and improved detection of OMD, underlining the importance of early disease control. In view of increasing OMD detection rates in current real-world clinical practice and the lack of standardized evidence-based guidelines to treat this cancer status, a board of experts from the Spanish Societies of Radiation Oncology (SEOR) and Medical Oncology (SEOM) organized a series of sessions to update the current state-of-the-art on OMD from a multidisciplinary perspective, and to discuss how results from clinical studies might translate into promising treatment options. This expert review series summarizes what is known and what it is pending clarification in the context of OMD in the scenarios of non-small cell lung cancer and breast cancer (Part I), and prostate cancer and colorectal cancer (Part II), aiming to offer specialists a pragmatic framework to help improve patient management.

Locoregional treatment of de novo stage IV breast cancer in the era of modern oncology

Approximately 6% of metastatic breast cancers arise de novo. While systemic therapy (ST) remains the treatment backbone as for patients with metachronous metastases, locoregional treatment (LRT) of the primary tumor remains a controversial method. The removal of the primary has an established role for palliative purposes, but it is unclear if it could also determine a survival benefit. Retrospective evidence and pre-clinical studies seem to support the removal of the primary as an effective approach to improve survival. On the other hand, most randomized evidence suggests avoiding LRT. Both retrospective and prospective studies suffer several limitations, ranging from selection bias and outdated ST to a small sample of patients. In this review we discuss available data and try to identify subgroups of patients which could benefit the most from LRT of the primary, to facilitate clinical practice decisions, and to hypothesize future studies design on this topic.

Oligometastatic breast cancer to parotid gland with complete response

Breast cancer metastatic to parotid gland is a very rare condition which tend to confer poor prognosis and challenging approaches. Oligometastatic breast cancer is usually defined as advanced breast cancer with less or equal than 5 metastatic lesions. We report a case of oligometastatic HER-2 breast cancer to parotid gland and lymph nodes which presented with left hemifacial swelling with erythema and enlargement of cervical and axillary lymph nodes. After 6 cycles of Docetaxel plus Trastuzumab the patient had complete response that was complemented with posterior surgical removal of primary tumor followed by radiotherapy directed to plastron, left supraclavicular and cervical drainage. The patient is still on Trastuzumab therapy and is free of disease in the last two years. We discuss the presentation and approach of a patient with metastatic breast cancer to parotid gland in the oligometastatic scenario.

Oligometastatic breast cancer and metastasis-directed treatment: an aggressive multimodal approach to reach the cure

Metastatic breast cancer (BC) is considered an incurable disease and is usually treated with palliative intent. However, about 50% of metastatic BCs present with only a few metastatic lesions and are characterized by longer overall survival. These patients, defined as oligometastatic, could benefit from a multimodal approach, which combines systemic therapy with metastasis-directed treatment (stereotactic ablative therapy or surgery). The current definition of oligometastatic seems incomplete since it is based only on imaging findings and does not include biological features, and the majority of relevant data supporting this strategy comes from retrospective or non-randomized studies. However, the chance of reaching long-term complete remission or even a cure has led to the development of randomized trials investigating the impact of combined treatment in oligometastatic BC (OMBC). The SABR-COMET trial, the first randomized study to include BC patients, showed promising results from a combination of stereotactic ablative radiotherapy and systemic therapy. Considering the randomized trial's results, multidisciplinary teams should be set up to select OMBC patients who could achieve long-term survival with aggressive multimodal treatment.

Ways to improve breast cancer patients' management and clinical outcome: The 2020 Assisi Think Tank Meeting

We report on the third Assisi Think Tank Meeting (ATTM) on breast cancer, a brainstorming project which involved European radiation and clinical oncologists who were dedicated to breast cancer research and treatment. Held on February 2020, the ATTM aimed at identifying key clinical questions in current clinical practice and "grey" areas requiring research to improve management and outcomes. Before the meeting, three key topics were selected: 1) managing patients with frailty due to either age and/or multi-morbidity; 2) stereotactic radiation therapy and systemic therapy in the management of oligometastatic disease; 3) contralateral breast tumour prevention in BCRA-mutated patients. Clinical practice in these areas was investigated by means of an online questionnaire. In the lapse period between the survey and the meeting, the working groups reviewed data, on-going studies and the clinical challenges which were then discussed in-depth and subjected to intense brainstorming during the meeting; research protocols were also proposed. Methodology, outcome of discussions, conclusions and study proposals are summarized in the present paper. In conclusion, this report presents an in-depth analysis of the state of the art, grey areas and controversies in breast cancer radiation therapy and discusses how to confront them in the absence of evidence-based data to guide clinical decision-making.

MRI-guided Radiotherapy (MRgRT) for treatment of Oligometastases: Review of clinical applications and challenges

PURPOSE

Early clinical results on the application of magnetic resonance imaging (MRI) coupled with a linear accelerator to deliver MR-guided radiation therapy (MRgRT) have demonstrated feasibility for safe delivery of stereotactic body radiotherapy (SBRT) in treatment of oligometastatic disease. Here we set out to review the clinical evidence and challenges associated with MRgRT in this setting.

METHODS AND MATERIALS

We performed a systematic review of the literature pertaining to clinical experiences and trials on the use of MRgRT primarily for the treatment of oligometastatic cancers. We reviewed the opportunities and challenges associated with the use of MRgRT.

RESULTS

Benefits of MRgRT pertaining to superior soft-tissue contrast, real-time imaging and gating, and online adaptive radiotherapy facilitate safe and effective dose escalation to oligometastatic tumors while simultaneously sparing surrounding healthy tissues. Challenges concerning further need for clinical evidence and technical considerations related to planning, delivery, quality assurance (QA) of hypofractionated doses, and safety in the MRI environment must be considered.

CONCLUSIONS

The promising early indications of safety and effectiveness of MRgRT for SBRT-based treatment of oligometastatic disease in multiple treatment locations should lead to further clinical evidence to demonstrate the benefit of this technology.

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.

Oligometastasis in breast cancer—current status and treatment options from a radiation oncology perspective

Evidence from a few small randomized trials and retrospective cohorts mostly including various tumor entities indicates a prolongation of disease free survival (DFS) and overall survival (OS) from local ablative therapies in oligometastatic disease (OMD). However, it is still unclear which patients benefit most from this approach. We give an overview of the several aspects of stereotactic body radiotherapy (SBRT) in extracranial OMD in breast cancer from a radiation oncology perspective. A PubMed search referring to this was conducted. An attempt was made to relate the therapeutic efficacy of SBRT to various prognostic factors. Data from approximately 500 breast cancer patients treated with SBRT for OMD in mostly in small cohort studies have been published, consistently indicating high local tumor control rates and favorable progression-free (PFS) and overall survival (OS). Predictors for a good prognosis after SBRT are favorable biological subtype (hormone receptor positive, HER2 negative), solitary metastasis, bone-only metastasis, and long metastasis-free interval. However, definitive proof that SBRT in OMD breast cancer prolongs DFS or OS is lacking, since, with the exception of one small randomized trial (n = 22 in the SBRT arm), none of the cohort studies had an adequate control group. Further studies are needed to prove the benefit of SBRT in OMD breast cancer and to define adequate selection criteria. Currently, the use of local ablative SBRT should always be discussed in a multidisciplinary tumor board.

The Role of the CDK4/6 Inhibitor Ribociclib in Locally Advanced and Oligometastatic Hormone Receptor Positive, Her2 Negative, Advanced Breast Cancer: Case Series and Review of the Literature

The recent addition of cyclin-dependent kinase 4 (CDK4) and CDK6 inhibitors to endocrine therapy has remarkably improved the outcome of patients affected with hormone receptor positive (HR+), human epidermal grow factor receptor 2 negative (HER2 -) advanced breast cancer (ABC). Ribociclib showed to be effective across most subgroups, regardless of the number and the site of metastasis. Up to 10% of patients with ABC, reported an oligometastatic condition, recently defined as a slow-volume metastatic disease with limited number and size of metastatic lesions (up to 5 and not necessarily in the same organ), potentially amenable for local treatment, aimed at achieving a complete remission status. Despite the wide use of CDK4/6 inhibitors in HR+, HER2-, ABC treatment, data regarding both locally advanced, inoperable disease and oligometastatic conditions are still poor. We reported a review and case series of HR+, HER2-, ABC patients treated with ribociclib as first-line therapy, for a locally advanced and oligometastatic conditions, reporting an impressive response and good safety profile.

Temporality and Patterns of Metastatic Recurrence in Node-Positive Breast Cancer Following Trimodality Therapy: Opportunity for Improved Oligometastases Detection and Salvage Local Therapy

OBJECTIVES

There is evidence that detection and treatment of oligometastases (≤5 lesions) may improve survival in breast cancer patients. However, there are no current national guidelines for screening of early, asymptomatic metastases. This study examined the patterns and timing of recurrence with respect to survival in node-positive breast cancer (NPBC) patients at higher risk for developing metastases.

METHODS

A single-institution retrospective review of NPBC patients treated with trimodality therapy was performed to collect patient and disease characteristics, recurrence location, method of detection, and survival outcome. Univariate and multivariate analyses were done to identify factors associated with recurrence.

RESULTS

Ninety-four NPBC patients treated at a safety-net hospital between 2008 and 2019 were identified. Twenty-one developed recurrence and were divided into oligometastatic (OM) (n=10) or diffusely metastatic (DM) (n=11) subgroups. Median recurrence-free survival in OM and DM was 18 and 36 months, respectively. Median overall survival (OS) for OM was not reached. Median OS for DM was 57 months. Four patients with OM progressed to diffuse disease in a median period of 17 months; median survival thereafter was 57 months. All patients with recurrence had distant metastases on initial detection, with the most common site being bone (14). Recurrence was most frequently detected by computed tomography (CT) (13), with the majority of disease located within the thorax region.

CONCLUSIONS

All NPBC patients had distant metastasis at time of recurrence. Patients with OM had shorter interval to recurrence yet longer OS compared with DM. This study highlights improved surveillance imaging for timely detection of OM breast cancer that may yet be amenable to aggressive local salvage therapy to prevent progression to diffuse disease.

Distribution Characteristics and Prognostic Value of Immune Infiltration in Oligometastatic Breast Cancer

BACKGROUND

To assess the distribution characteristics and the prognostic value of immune infiltration in female oligometastatic breast cancer patients.

METHODS

We retrospectively analyzed the clinicopathological data of oligometastatic breast cancer (OMBC) patients diagnosed between June 2000 and January 2020. Immune markers were quantified by immunohistochemistry on FFPE tissues in paired normal breast tissues, primary breast cancers and oligometastatic lesions. Survival analyses were performed using the Kaplan-Meier curves and Cox-proportional hazards model.

RESULTS

A total of 95 female OMBC patients visited Sun Yat-sen University Cancer Center between June 2000 and January 2020, and 33 of them had matched normal breast tissues, primary cancers and oligometastatic lesions and were reviewed in immune infiltration analysis. CD8 of primary tumors had a higher expression than that in matched normal tissues. The expressions of CD8 and FOXP3 were higher in the primary sites than that in the oligometastatic lesions. CD3, CD4 and CD8 were significantly lower in the intratumoral regions than that in the peritumoral regions both in primary and oligometastatic lesions. Notably, the high percentage of CD3 in the intratumoral oligometastatic lesions predicted the longer PFS and OS, and higher CD4 in the same lesions also predicted a better OS. There was obviously positive correlation between CD4/CD3 and Ki-67 in primary cancers and negative correlation between CD4/CD3 and ER in oligometastatic sites.

CONCLUSION

We explored immune distribution and evolution in time and space in OMBC to provide new understandings for biological behaviors of this disease and further divided patients in different prognosis.

Breast cancer patients with isolated bone metastases and oligometastatic bone disease show different survival outcomes

In this study, we planned to investigate the clinical course of patients with breast cancer with oligometastatic bone disease (OMBD). The patients were grouped according to the characteristics and the sites of metastases. Group I included 928 patients without metastasis. Group II, the OMBD group, included 68 patients. Group III, the widespread metastasis group, comprised 185 patients with multiple bone metastases and/or solid organ metastases. The mean overall survival of the groups was 16.7 ± 0.3 years in group 1, and 7.8 ± 0.8 and 5.9 ± 0.4 years in groups 2 and 3, respectively (p < 0.001 for the comparison of all three groups together; p < 0.001 for group 1 vs. 2 and 3) and (p = 0.037 for group 2 vs. group 3). In the subgroup survival analysis of patients in group 2 (OMBD), the mean and median survival was 5.5 ± 0.8 and 4.0 ± 0.8 years vs. 9.2 ± 0.98 and 9.0 ± 1.05 years in patients with more than one bone metastasis and single bone metastasis, respectively (p = 0.019). OMBD seems to be a different disease than breast cancer with isolated bone metastases. The high risk of developing OMBD, especially following locoregional recurrence, increases the importance of locoregional therapy in large T and N stage tumors.

Investigation of the Definition of De Novo Oligometastatic Nasopharyngeal Carcinoma: A Retrospective Study

Background

The prognosis of metastatic nasopharyngeal carcinoma (mNPC) is highly heterogeneous. As a special stage of distant metastasis of mNPC, quite a few oligometastatic NPC (omNPC) patients can still achieve a long-term survival after treatment. However, there is no uniform standard for the definition of omNPC until now.

Methods

We retrospectively analyzed the survival data of 191 patients with de novo mNPC at the Affiliated Cancer Hospital and Institute of Guangzhou Medical University between 2010 and 2017 and specifically analyzed the clinical outcomes associated with the number of metastatic organs/lesions and tried to find a cohort with relatively better prognosis to define as omNPC.

Results

The median overall survival (OS) of the entire group of patients was 21.5 months (95% CI 15.0–28.0), and the 1-year, 2-year, and 3-year OS rates were 72.2%, 46.1%, and 34.3%, respectively. Multiple-organ metastases (P < 0.001) and >5 metastatic lesions (P < 0.001) were adverse influencing factors of prognosis, and the number of metastatic lesions (P < 0.001) was the independent factor influencing the prognosis of de novo mNPC. The overall survival (OS) and progression-free survival (PFS) of patients with ≤5 metastatic lesions were significantly better than those of patients with >5 metastatic lesions.

Conclusion

Patients with ≤5 metastatic lesions presented a better survival, and this criterion may be a definition standard for the de novo omNPC.

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.

Breast cancer

Breast cancer is still the most common cancer worldwide. But the way breast cancer is viewed has changed drastically since its molecular hallmarks were extensively characterised, now including immunohistochemical markers (eg, ER, PR, HER2 [ERBB2], and proliferation marker protein Ki-67 [MKI67]), genomic markers (eg, BRCA1, BRCA2, and PIK3CA), and immunomarkers (eg, tumour-infiltrating lymphocytes and PD-L1). New biomarker combinations are the basis for increasingly complex diagnostic algorithms. Neoadjuvant combination therapy, often including targeted agents, is a standard of care (especially in HER2-positive and triple-negative breast cancer), and the basis for de-escalation of surgery in the breast and axilla and for risk-adapted post-neoadjuvant strategies. Radiotherapy remains an important cornerstone of breast cancer therapy, but de-escalation schemes have become the standard of care. ER-positive tumours are treated with 5-10 years of endocrine therapy and chemotherapy, based on an individual risk assessment. For metastatic breast cancer, standard therapy options include targeted approaches such as CDK4 and CDK6 inhibitors, PI3K inhibitors, PARP inhibitors, and anti-PD-L1 immunotherapy, depending on tumour type and molecular profile. This range of treatment options reflects the complexity of breast cancer therapy today.

Can we cure oligometastatic disease? A practical point of view

PURPOSE OF REVIEW

To critically analyze the available evidence on oligometastatic breast cancer and to suggest therapeutic approaches for optimal management of these patients.

RECENT FINDINGS

Unlike metastatic breast cancer, which remains incurable, patients with a limited number and extent of metastatic lesions, that is, oligometastatic disease, might achieve disease control and long-term survival when radical therapy of the primary tumor, if present, and metastatic disease is added to standard systemic therapy. However, the lack of a clear definition, variety of presentations, and the absence of biomarkers makes oligometastatic breast cancer a poorly understood clinical entity for which there is no standard treatment.

SUMMARY

Improvements in systemic therapies along with radical treatment of the primary tumor and metastatic lesions, together with optimization in the use of imaging tools, may help to increase the percentage of patients with metastatic breast cancer who achieve no-evidence-of-disease status or, at least, chronification of the disease. However, the fundamental question remains: which patients may benefit the most from a radical therapeutic approach? In this article, we propose strategies for the appropriate selection and comprehensive management of these patients.

Solitary Pancreatic Head Metastasis from Ductal Carcinoma of Breast: A Case Report

Liver, bones, and brain are common sites for breast cancer metastasis. We report here a rare scenario of metastasis to pancreatic head from breast cancer after a disease free interval of 7 years. A 60-year old breast cancer survivor noticed upper abdominal pain for 2 weeks, and her investigations revealed a pancreatic head mass lesion. Computed tomography imaging revealed a solitary pancreatic mass lesion with portal cavernoma formation and a guided biopsy yielded adenocarcinoma on histopathological examination. Immunohistochemistry processing demonstrated estrogen receptor, cytokeratin 7, and GATA 3 positivity which confirmed it to be a metastasis. Therapy was initiated with palbociclib and exemestane. Later, everolimus was started in view of failure of hormonal therapy. The patient is still alive 21 months after diagnosing the recurrence.

Prognostic factors in patients with oligometastatic breast cancer - A systematic review

AIM

Oligometastatic breast cancer (OMBC) is a disease-entity with potential for long-term remission in selected patients. Those with truly limited metastatic load (rather than occult widespread metastatic disease) may benefit from multimodality treatment including local ablative therapy of distant metastases. In this systematic review, we studied factors associated with long-term survival in patients with OMBC.

METHODS

Eligible studies included patients with OMBC who received a combination of local and systemic therapy as multimodal approach and reported overall survival (OS) or progression-free survival (PFS), or both. The Quality in Prognosis Studies (QUIPS) tool was used to assess the quality of each included study. Independent prognostic factors for OS and/or PFS are summarized.

RESULTS

Of 1271 screened abstracts, 317 papers were full-text screened and twenty studies were included. Eleven of twenty studies were classified as acceptable quality. Definition of OMBC varied between studies and mostly incorporated the number and/or location of metastases. The 5-year OS ranged between 30 and 79% and 5-year PFS ranged between 25 and 57%. Twelve studies evaluated prognostic factors for OS and/or PFS in multivariable models. A solitary metastasis, >24 months interval between primary tumor and OMBC, no or limited involved axillary lymph nodes at primary diagnosis, and hormone-receptor positivity were associated with better outcome. HER2-positivity was associated with worse outcome, but only few patients received anti-HER2 therapy.

CONCLUSIONS

OMBC patients with a solitary distant metastasis and >24 months disease-free interval have the best OS and may be optimal candidates to consider a multidisciplinary approach.

Clinical features and prognostic factors for extracranial oligometastatic breast cancer in China

Evidence of an oligometastatic state in metastatic breast cancer (MBC) is relatively limited. The aim of our study was to investigate the clinical features and prognostic factors for extracranial oligometastatic breast cancer and to identify the best treatment approaches in this select population. Fifty postoperative inpatients diagnosed with extracranial oligometastatic breast cancer at the National Cancer Center in China between 2009 and 2014 were consecutively enrolled. Oligometastatic breast cancer was defined as MBC with three or fewer metastatic lesions confined to one organ; de novo Stage IV disease and local-regional recurrence were excluded. The median progression-free survival (PFS) and overall survival (OS) times were 15.2 and 78.9 months, respectively, and the 2-year PFS and 5-year OS rates were 40% and 58%, respectively. First-line treatment approach with standard systemic treatment + surgical resection for all metastatic lesions was an independent prognostic factor for prolonged PFS (hazard ratio = 0.32; 95% confidence interval [CI], 0.14-0.73; P = .006) and OS (hazard ratio = 0.35; 95% CI, 0.14-0.86; P = .022). Subgroup analysis showed that patients with a disease-free interval (DFI) ≥24 months, one metastatic lesion or the hormone receptor (HR) + subtype were more likely to get benefit from resection. Patients with oligometastatic breast cancer have a relatively good prognosis. Surgical resection for metastatic lesions could significantly improve PFS and OS. Further prospective research is warranted to confirm the results and to develop biomarkers for better patient selection.