Long-Term Survival and Cure in Distant Metastatic Breast Cancer

Comprehensive Clinical Characterization of Decade-Long Survivors of Metastatic Breast Cancer

BACKGROUND

Elucidating the clinical features of metastatic breast cancer (MBC) patients with an exceptionally favorable prognosis may offer insights to improve the survival of more typical patients.

METHODS

We collected comprehensive real-world data on clinicopathologic characteristics, treatments, and outcomes of 110 consecutive MBC patients who survived for over ten years from the clinical data warehouse of Samsung Medical Center.

RESULTS

The cohort included 54 hormone receptor (HR)-positive/HER2-negative (HR+/HER2-), 21 HR+/HER2+, 16 HR-/HER2+, and 14 triple-negative breast cancer (TNBC) patients. The median age at MBC diagnosis was 48.5 years. Approximately 70% of patients initially had a single-organ metastasis. The most common site of metastasis was the lung (46.4%), followed by distant lymph nodes (37.3%). During a median follow-up of 14.6 years, the median duration of systemic therapy was 11, 8.4, 7.3, and 0.8 years in the HR+/HER2-, HR+/HER2+, HR-/HER2+, and TNBC subgroups, respectively. Seven HER2+ and ten TNBC patients received systemic treatment for less than two years and remained treatment-free for most of the follow-up period, suggesting a potential chance of cure. The TNBC subtype (p < 0.001) and local treatment with curative intent within 1 year of MBC diagnosis (p = 0.002) were significantly associated with long-term treatment-free survival. The survival of HER2+ MBC and TNBC patients, but not that of HR+/HER2- patients, plateaued approximately 13 years after MBC diagnosis.

CONCLUSIONS

A small subset of patients with HER2+ MBC and metastatic TNBC may be curable with multimodality therapy. Prospective studies integrating clinical and genomic data may identify unique clinicogenomic features of MBC patients who can achieve durable disease control without prolonged chemotherapy.

Overall survival of individuals with metastatic cancer in Sweden: a nationwide study

Aims

Consistent improvements for overall survival (OS) have been reported for individuals with metastatic cancer. Swedish population-based registers allow national coverage and long follow-up time. The aim of this study was to estimate and explore long-term OS of individuals diagnosed with metastatic cancer using Swedish nationwide health registers.

Methods

Individuals with metastatic breast (MBC), non-small cell lung (MNSCLC), ovary (MOC) or colorectal cancer (MCRC) or metastatic malignant melanoma (MMM) were identified in the Swedish national cancer register and national patient registers. Survival was estimated and stratified by available variables. Potential cure fractions were estimated using mixture cure models.

Results

In total, approximately 69,000 individuals were identified. The most common cancers were MCRC (36.2%) and MNSCLC (29.5%). Men were more frequently diagnosed with MNSCLC, MCRC, and MMM compared to women. Except for MOC, about 50% of individuals were 70 years or older at diagnosis. Throughout the study period survival differed across cancers. The longest median OS was observed for individuals with MOC and MBC. At 10 years of follow-up, the survival curves flatten at a survival rate of approximately 10% for all cancers except MNSCLC. The youngest age groups had the longest median OS. Increased survival was also observed for individuals diagnosed in 2015 and 2018 compared to individuals diagnosed during earlier years. The estimated cure fractions were 4% for MBC, 1.5% for MNSCLC, 6.8% for MCRC, 8.6% for MOC and MMM.

Conclusions

Long-term survival has been assessed across all indications except for NSCLC.. The findings may be relevant for healthcare planning to meet the needs of future patients and potential long-term survivors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14255-w.

Selected Patients With Peritoneal Metastases From Breast Cancer May Benefit From Cytoreductive Surgery: The Results of a Multicenter Survey

Background

Even though breast cancer is the most frequent extra-abdominal tumor causing peritoneal metastases, clear clinical guidelines are lacking. Our aim is to establish whether cytoreductive surgery (CRS) could be considered in selected patients with peritoneal metastases from breast cancer (PMBC) to manage abdominal spread and allow patients to resume or complete other medical treatments.

Methods

We considered patients with PMBC treated in 10 referral centers from January 2002 to May 2019. Clinical data included primary cancer characteristics (age, histology, and TNM) and data on metastatic disease (interval between primary BC and PM, molecular subtype, other metastases, and peritoneal spread). Overall survival (OS) was estimated using the Kaplan–Meier method. Univariate and multivariable data for OS were analyzed using the Cox proportional hazards model.

Results

Of the 49 women with PMBC, 20 were treated with curative aim (CRS with or without HIPEC) and 29 were treated with non-curative procedures. The 10-year OS rate was 27%. Patients treated with curative intent had a better OS than patients treated with non-curative procedures (89.2% vs. 6% at 36 months, p < 0.001). Risk factors significantly influencing survival were age at primary BC, interval between BC and PM diagnosis, extra-peritoneal metastases, and molecular subtype.

Conclusions

The improved outcome in selected cases after a multidisciplinary approach including surgery should lead researchers to regard PMBC patients with greater attention despite their scarce epidemiological impact. Our collective efforts give new information, suggest room for improvement, and point to further research for a hitherto poorly studied aspect of metastatic BC.

Oligometastatic breast cancer: Are we there yet?

Patients with metastatic breast cancer are usually considered incurable. Recent advances have resulted in significant improvements in survival for patients with metastatic breast cancer. Due to the lack of randomised trials and heterogeneous disease biology, treatment decisions for patients with oligometastatic breast cancer vary widely. Some patients are treated similar to those with widespread disease while others are treated more aggressively. We conducted a review of the evidence for treatment options in oligometastatic breast cancer and consulted ClinicalTrials.gov to explore currently accruing or studies in development aimed at investigating oligometastatic disease in breast cancer. Surgery to the primary tumour in patients with metastatic breast cancer has failed to show any advantage over systemic therapy. However, there may be a benefit in women with controlled systemic disease who are hormone receptor positive with bone-predominant metastasis. Stereotactic radiotherapy has gained increased interest in this setting due to its excellent efficacy and lower rates of associated toxicity. A significant challenge remains in identifying the patient population who would benefit from such an approach, and to do so, we need to understand the distinct biology of oligometastatic breast cancer. Unique miRNA expression and low levels of tumour infiltrating lymphocytes in the immune micro-environment have been described in tumour tissues in patients with oligometastatic breast cancer. There is ongoing research aimed to better characterise these tumours, thus, allowing the selection of patients who would truly benefit from multi-modality treatment in an attempt for long-term survival and cure.

Epidemiology of De Novo Metastatic Breast Cancer

Most cases of metastatic breast cancer (MBC) arise as a recurrence of a previously treated early breast cancer. Distinct from recurrent MBC is de novo MBC (dnMBC), which describes patients who present with distant sites of disease at initial diagnosis and is reviewed here. dnMBC represents approximately 3% to 6% of new breast cancer diagnoses in high-income countries. This incidence has not declined despite decades of widespread use of population-based mammography screening. Overrepresentation of both biologically aggressive tumors and patients negatively impacted by social determinants of health are characteristics of dnMBC. Survival has generally been superior for patients with dnMBC compared with those with recurrent MBC, although it is similar to that for patients with recurrent MBC with long disease-free intervals. Subgroups of patients with dnMBC who experience prolonged survival include those with human epidermal growth factor receptor-2-positive disease or hormone receptor-positive bone-only disease. Opportunities to decrease dnMBC presentation may include novel screening modalities suited for biologically aggressive breast tumors and improved access to health care. Recognizing that there will remain some women diagnosed with dnMBC, refining our ability to identify those likely to be long-term survivors could allow for appropriate escalation or de-escalation of care. Finally, evaluation of tumor genomics in robust sample sizes has the potential to advance our knowledge of the biology of dnMBC as an entity distinct from recurrent MBC.

Immunotherapies and Metastatic Cancers: Understanding Utility and Predictivity of Human Immune Cell Engrafted Mice in Preclinical Drug Development

Metastases cause high mortality in several cancers and immunotherapies are expected to be effective in the prevention and treatment of metastatic disease. However, only a minority of patients benefit from immunotherapies. This creates a need for novel therapies that are efficacious regardless of the cancer types and metastatic environments they are growing in. Preclinical immuno-oncology models for studying metastases have long been limited to syngeneic or carcinogenesis-inducible models that have murine cancer and immune cells. However, the translational power of these models has been questioned. Interactions between tumor and immune cells are often species-specific and regulated by different cytokines in mice and humans. For increased translational power, mice engrafted with functional parts of human immune system have been developed. These humanized mice are utilized to advance understanding the role of immune cells in the metastatic process, but increasingly also to study the efficacy and safety of novel immunotherapies. From these aspects, this review will discuss the role of immune cells in the metastatic process and the utility of humanized mouse models in immuno-oncology research for metastatic cancers, covering several models from the perspective of efficacy and safety of immunotherapies.

Impact of mRNA-Assessed Molecular Subtype Conversion, Intact and Apoptotic Circulating Tumor Cells on Survival of Metastatic Breast Cancer Patients: Proof of Principle

Breast cancers (BC) can mutate, allowing metastatic tumors (MT) to sometimes differ to primary tumors (PT) in gene expression. Despite contemporary metastatic breast cancer (MBC) therapy, subtype conversion seems prognostically disadvantageous. We strived to determine the influence of mRNA-assessed intrinsic subtype stability comparing PT and MT biopsies and circulating tumor cell (CTC)-based liquid biopsies on progression free survival (PFS) and overall survival (OS). Additional analyzed prognostic factors were PT subtype, MT subtype and hormone receptor loss. Kaplan-Meier curves and the log rank tests were used to compare PFSs and OSs. The proportions of luminal B and triple negative subtype MTs were increased compared to those observed in PTs. Fifteen patients were found to have tumors that underwent intrinsic subtype conversion and their OS was significantly decreased (p = 0.038). No such difference was observed when it comes to PFS. The majority of these tumors switched to a more aggressive intrinsic subtype. No significant differences in PFSs or OSs were observed between subtype converters with triple negative PTs compared to those with luminal subtype PTs. The same is true of subtype stable patients. Total CTC, iCTC and aCTC counts decreased with therapy, but there were no significant differences between subtype converters and subtype stable patients. Our data confirm a poorer overall survival of the intrinsic subtype converters and emphasize the importance of acquiring biopsies and re-biopsies of all available metastatic lesions alongside with CTC-based liquid biopsies for earlier recognition of patients with poorer prognosis and in need of altered individualized therapy regimens.

Recommendations for cancer screening would be different if we measured endpoints that are valid, reliable, specific, and important to patients

BACKGROUND

Despite enthusiasm for cancer screening, systematic reviews consistently fail to show that screening reduces all-cause mortality. This narrative review explores conceptual issues, and inconsistencies between evidence and opinion about screening.

REVIEW

We examined the interpretation of screening studies in relation to three intellectual traditions: (1) The relationship between prevention and cure; (2) Confirmation bias and the challenge of incorporating new data: less care may produce better outcomes than more care; (3) The answers to three structured questions about efficacy, effectiveness, and value of treatments proposed by Sir Archie Cochrane and Sir Austin Bradford Hill.

SYNTHESIS

When considering extensions of life expectancy or all-cause mortality, systematic reviews typically show cancer screening to have only small effects and often non-significant effects on all-cause mortality. Early diagnosis does not assure application of an intervention that alters the pathway toward demise. The interpretation of screening results is also affected by several known biases. Investigators and advocates are encumbered by an over focus on studies designed to determine if a treatment can work under ideal circumstances. To advance the field, we need a greater emphasis on evaluations that ask 'Does the treatment work under real-world conditions?', and 'Is the treatment worth it?' in terms of outcomes that are meaningful to patients.

Cut-Off Analysis of CTC Change under Systemic Therapy for Defining Early Therapy Response in Metastatic Breast Cancer

Detection of circulating tumor cells (CTC) can distinguish between aggressive and indolent metastatic disease in breast cancer patients and is thus considered an independent, negative prognostic factor. A clear decline in CTCs is observed in patients who respond to systemic therapy. Nevertheless, CTCs can decrease in patients experiencing disease progression during systemic therapy, too. This study aims to determine the differences between CTC decline in patients responding to therapy and those in whom disease is progressing. Therefore, CTC values were compared at the start and after one cycle of a new line of systemic therapy. In all, 108 initially CTC-positive patients (with ≥5 intact CTCs in 7.5 mL blood) were enrolled in this study and intact and apoptotic CTCs were measured via the CellSearch^® system. A cut-off analysis was performed using Youden’s J statistics to differentiate between CTC change in the two groups. Here, 64 (59.3%) patients showed stable disease or partial response vs. 44 (40.7%) presenting disease progression. Median overall survival was 23 (range: 4–92) vs. 7 (2–43) months (p < 0.001). Median intact CTC count at enrollment was 15.0 (5–2760) vs. 30.5 (5–200000) cells (p = 0.39) and 2.5 (0–420) vs. 8.5 (0–15000) cells after one cycle of systemic therapy (p = 0.001). Median apoptotic CTC count at enrollment was 10.5 (0–1500) vs. 9 (0–800) cells (p = 0.475) and 1 (0–200) vs. 3 (0–250) cells after one cycle of systemic therapy (p = 0.01). A 50% reduction in baseline apoptotic CTC count represents the optimal cut-off to differentiate between therapy response and disease progression. An apoptotic CTC reduction of ≤10% is 74% specific for early disease progression.

Breast Cancer With Brain Metastases: Perspective From a Long-Term Survivor

The purpose of this essay is to inform others that it is possible to survive breast cancer with brain metastases. The second author is the subject patient and a long-term survivor of systemic metastatic breast cancer with numerous brain metastases (corresponding to 8% survivor group). We credit her survival to a combination of (1) medicine as practiced by an excellent oncologist with whom we developed a partnership to manage the patient’s health, (2) our informed exploration of the available scientific knowledge including a review of scientific research articles that go beyond conventional care, and (3) the patient’s supplementation with numerous repurposed drugs and other substances reported to have antitumor properties. Alongside her conventional treatment (the medical standard of care), it seems likely that this supplementation has been a key factor in the patient’s long-term survival. We also point out that the lack of follow-up magnetic resonance imaging brain scans for early detection of brain metastases poses substantial risks for patients with HER2+ metastatic breast cancer in non–central nervous system locations. Thus, we suggest that research be conducted on such early detection for possible inclusion in the recommendations for the medical standard of care. Finally, medical doctors and also patients with backgrounds in biological science may wish to consider potential options and advantages of repurposed drugs and other substances reported in scientific publications when the medical standard of care has limited options for advanced cancer and other severe chronic health conditions. However, any efforts along this line by patients should be in collaboration with their medical doctors.

The Lack of Evidence for an Association between Cancer Biomarker Conversion Patterns and CTC-Status in Patients with Metastatic Breast Cancer

Circulating tumor cell (CTC) detection is a prognostic factor in the metastatic breast cancer (MBC) setting. Discrepancies in primary (PT) and metastatic tumor (MT) genetic profiles are also of prognostic importance. Our study aimed to compare the CTC statuses and prognoses between those with subtype stable MBCs and MBCs with specific biomarker conversions. The study enrolled 261 MBC patients, treated at the National Center for Tumor Diseases, Heidelberg, Germany in a five-year period. All underwent PT and MT biopsies and subsequent CTC enumeration before the initiation of systemic therapy. ER and HER2 statuses of the PTs and MTs were determined and progression free survivals (PFSs) and overall survivals (OSs) were recorded. We compared CTC statuses, CTC counts, PFSs and OSs between subgroups of patients with different receptor change patterns. Patients who had tumors that converted to triple negative MTs had the shortest median OSs, while HER2 expression was not associated with a shorter median OS. No significant differences in PFSs and OSs have been demonstrated by Kaplan-Meier curve comparisons in any of the subgroup analyses. CTC counts were similar in all subgroups. CTCs were comparably less frequently detected in patients with a stable HER2 expression. Similar proportions of CTC positives were observed in all other subtype change pattern subgroups, barring the aforementioned HER2 stable subgroup. The detection of CTCs was of no appreciable prognostic value in different receptor change pattern subgroups in our cohort.

Factors Affecting Decisions Regarding Terminal Care Locations of Patients With Metastatic Breast Cancer

BACKGROUND

Metastatic breast cancer (MBC) is generally incurable, but patients can survive longer than those with other cancer types. Treatment strategies for MBC are complex, and it is difficult to establish evidence of efficacy since symptoms and patient backgrounds vary markedly. Some patients struggle to decide where to receive end-of-life care, despite palliative care intervention, and some die in unexpected places. With the aim of ascertaining the best way to intervene on behalf of patients with end-stage breast cancer, we retrospectively examined interventions provided by our palliative care team. We investigated factors influencing the decision-making processes of patients with MBC regarding end-of-life care locations and where patients actually died.

METHODS

Clinical records of 44 patients with MBC, all Japanese women, who received palliative care interventions at our hospital, were retrospectively investigated. We examined factors, such as age, possibly impacting decision-making processes regarding the final location and actual place of death.

RESULTS

Thirty-five (80%) patients were able to decide where to receive end-of-life care, while the others were not. For these 35 patients, desired locations were the palliative care unit (77%), home palliative care (14%), and the hospital (9%). Age and recurrence-free survival (RFS) were factors influencing patients' decision-making processes (P = .030 and .044, respectively). Of the 35 patients, 25 (71%) were able to receive end-of-life care at their desired locations.

CONCLUSIONS

Young patients and those with short RFS struggled with making decisions regarding where to receive end-of-life care. Such patients might benefit from prompt introduction of advanced care planning.

Advances in the Characterization of Circulating Tumor Cells in Metastatic Breast Cancer: Single Cell Analyses and Interactions, and Patient-Derived Models for Drug Testing

Metastasis is the major cause of breast cancer death worldwide. In metastatic breast cancer, circulating tumor cells (CTCs) can be captured from patient blood samples sequentially over time and thereby serve as surrogates to assess the biology of surviving cancer cells that may still persist in solitary or multiple metastatic sites following treatment. CTCs may thus function as potential real-time decision-making guides for selecting appropriate therapies during the course of disease or for the development and testing of new treatments. The heterogeneous nature of CTCs warrants the use of single cell platforms to better inform our understanding of these cancer cells. Current techniques for single cell analyses and techniques for investigating interactions between cancer and immune cells are discussed. In addition, methodologies for growing patient-derived CTCs in vitro or propagating them in vivo to facilitate CTC drug testing are reviewed. We advocate the use of CTCs in appropriate microenvironments to appraise the effectiveness of cancer chemotherapies, immunotherapies, and for the development of new cancer treatments, fundamental to personalizing and improving the clinical management of metastatic breast cancer.