The effect of metastasectomy: fact or fiction?

Reoperative Pulmonary Metastasectomy: Outcomes and Indications

Recurrent pulmonary metastasis after initial pulmonary metastasectomy is common and poses a clinical dilemma. Reoperative pulmonary metastasectomy is an option that in select patients has been shown to be safe and technically feasible resulting in encouraging survival results from non-randomized retrospective studies. As with metastasectomy in general, there is ongoing debate if observed benefit of repeat pulmonary resection is a result of surgery or a reflection of selection bias. This review summarizes available evidence regarding reoperative pulmonary metastasectomy, discusses selection bias, and outlines future directions in the context of our evolving understanding of the oligometastatic state.

Surgical and Interventional Management of Lung Metastasis: Surgical Assessment, Resection, Ablation, Percutaneous Interventions

The lungs are the second most common site of metastases for colorectal cancer after the liver. Pulmonary metastases can be identified at the time of diagnosis of the primary tumor, or metachronously. About 20% of patients with colorectal cancer will develop pulmonary metastases. The best options for treatment include a multidisciplinary treatment approach consisting of surgical resection whenever possible, and chemotherapy. Surgical options most often include minimally invasive segmentectomy or wedge resection, while patients unable to have surgery may benefit from radio frequency ablation or radiation treatment. Prognosis is dependent on preoperative carcinoembryonic antigen level, number, and location of metastatic lesions, and resectability of primary tumor. Overall, pulmonary metastases are best treated by complete resection whenever possible.

Pulmonary Metastasectomy for Adrenocortical Carcinoma-Not If, but When

BACKGROUND

Adrenocortical carcinoma (ACC) commonly metastasizes to the lungs, and pulmonary metastasectomy (PM) is utilized due to limited systemic options.

METHODS

All ACC patients with initially only lung metastases (LM) from a single institution constituted this observational case series. Kaplan-Meier and Cox proportional hazard analyses evaluated the association with potential prognostic factors and outcomes. Overall survival (OS) was calculated from the date of the PM or, in those patients who did not undergo surgery, from the development of LM.

RESULTS

A total of 75 ACC patients over a 45-year period met the criteria; 52 underwent PM, and 23 did not. The patients undergoing PM had a median OS of 3.1 years (95% CI: 2.4, 4.7 years) with the 5- and 10-year OS being 35.5% and 32.8%, respectively. The total resected LM did not impact the OS nor the DFS. The patients who developed LM after 11 months from the initial ACC resection had an improved OS (4.2 years; 95% CI: 3.2, NR; p = 0.0096) compared to those developing metastases earlier (2.4 years; 95% CI: 1.6, 2.8). Patients who underwent PM within 11 months of adrenalectomy demonstrated a reduced OS (2.2 years; 95% CI: 1.0, 2.7) compared to those after 11 months (3.6 years, 95% CI: 2.6, NR; p = 0.0045). PM may provide benefit to those patients with LM at presentation (HR: 0.5; p = 0.2827), with the time to first PM as a time-varying covariate.

CONCLUSIONS

PM appears to have a role in ACC patients. The number of nodules should not be an exclusion factor. Patients developing LM within a year of primary tumor resection may benefit from waiting before further surgeries, which may provide additional insight into who may benefit from PM.

Survival outcomes of lung metastases from colorectal cancer treated with pulmonary metastasectomy or modern systemic chemotherapy: a single institution experience

BACKGROUND

Although pulmonary metastasectomy is an accepted treatment strategy for resectable lung metastases (LM) from colorectal cancer (CRC), its survival benefits are controversial. In contrast, recent advancements in chemotherapy have significantly improved metastatic CRC prognosis. This study aimed to evaluate survival outcome of LM from CRC in the age of newly developed chemotherapy.

METHODS

We retrospectively reviewed 50 patients who underwent complete resection and 22 patients who received chemotherapy as definitive treatment for LM from resected CRC at our hospital. The present study was limited to patients who started treatment for isolated LM after molecular targeted drugs became available in Japan.

RESULTS

Overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS) rates after pulmonary resection were 64.5%, 66.4%, and 32.6% at five years, respectively. OS and CSS rates of chemotherapy patients were 26.8% and 28.3% at five years, with a median progression-free survival time of 10.0 months. When compared the characteristics of surgical and chemotherapy patients, patients with pN factors of CRC (p = 0.013), smaller size (p < 0.001), larger number (p < 0.001), and bilateral (p < 0.001) LM received chemotherapy. Univariate analysis showed that multiple LM and rectal lesions were poor prognostic factors for OS (p = 0.012) and DFS (p = 0.017) in surgical patients, and rectal lesions were a poor prognostic factor for OS (p = 0.013) in chemotherapy patients.

CONCLUSIONS

Pulmonary metastasectomy showed a favorable survival in patients with LM from CRC. Despite the high recurrence rate after metastasectomy and recent advances in chemotherapy, surgical resection could still be considered as a valid option among multidisciplinary treatments.

TRIAL REGISTRATION

The research plan was approved by the Institutional Review Board of Shinko Hospital (No. 2142) on February 7, 2022.

Surgical Resection of Pulmonary Metastases from Melanoma in Oligometastatic Patients: Results from a Multicentric Study in the Era of Immunoncology and Targeted Therapy

In the last decade, the emergence of effective systemic therapies (ESTs) in the form of both targeted and immuno-based therapies has revolutionized the treatment of patients with advanced stage III and stage IV melanoma. Even though lungs represent the most frequent site of melanoma metastases, only limited data are available on the role of surgery in isolated pulmonary metastases from malignant melanoma (PmMM) in the era of ESTs. The aim of this study is to describe the outcomes of patients who underwent metastasectomy of PmMM in the era of ESTs, in order to identify prognostic factors affecting survival and to provide a framework for more informed patient selection of treatmeant with lung surgery in the future. Clinical data of 183 patients who underwent metastasectomy of PmMM between June 2008 and June 2021 were collected among four Italian Thoracic Centers. The main clinical, surgical and oncological variables reviewed were: sex, comorbidities, previous oncological history, melanoma histotypes and primary site, date of primary cancer surgical treatment, melanoma growth phase, Breslow thickness, mutation pattern disease, stage at diagnosis, metastatic sites, DFI (Disease Free Interval), characteristics of lung metastases (number, side, dimension, type of resection), adjuvant therapy after lung metastasectomy, site of recurrence, disease-free survival (DFS) and cancer-specific survival (CSS; defined as the time interval between the first melanoma resection or lung metastasectomy and death from cancer). All patients underwent surgical resection of the primary melanoma before lung metastasectomy. Twenty-six (14.2%) patients already had a synchronous lung metastasis at the time of primary melanoma diagnosis. A wedge resection was performed in 95.6% of cases to radically remove the pulmonary localizations, while an anatomical resection was necessary in the remaining cases. The incidence of major post-operative complications was null, while only 21 patients (11.5%) developed minor complications (mainly air leakage followed by atrial fibrillation). The mean in-hospital stay was 4.46 ± 2.8 days. Thirty- and sixty-day mortality were null. After lung surgery, 89.6% of the population underwent adjuvant treatments (47.0% immunotherapy, 42.6% targeted therapy). During a mean FUP of 107.2 ± 82.3 months, 69 (37.7%) patients died from melanoma disease, 11 (6.0%) from other causes. Seventy-three patients (39.9%) developed a recurrence of disease. Twenty-four (13.1%) patients developed extrapulmonary metastases after pulmonary metastasectomy. The CSS from melanoma resection was: 85% at 5 years, 71% at 10 years, 54% at 15 years, 42% at 20 years and 2% at 25 years. The 5- and 10-year CSS from lung metastasectomy were 71% and 26%, respectively. Prognostic factors negatively affecting CSS from lung metastasectomy at multivariable analysis were: melanoma vertical growth (p = 0.018), previous metastatic sites other than lung (p < 0.001) and DFI < 24 months (p = 0.007). Our results support the evidence that surgical indication confirms its important role in stage IV melanoma with resectable pulmonary metastases, and selected patients can still benefit from pulmonary metastasectomy in terms of overall cancer specific survival. Furthermore, the novel systemic therapies may contribute to prolonged survival after systemic recurrence following pulmonary metastasectomy. Patients with long DFI, radial growth melanoma phase and no site of metastatization other than lung seem to be the best candidate cases for lung metastasectomy; however, to drive stronger conclusions, further studies evaluating the role of metastasectomy in patients with iPmMM are needed.

Treatment and survival of patients with metachronous colorectal lung metastases

INTRODUCTION

The lungs are the second most common site for metachronous metastases in colorectal cancer. No treatment algorithm is established, and the role of adjuvant chemotherapy is unclear. This study aimed to map pulmonary recurrences in a modern multimodal treated population, and to evaluate survival depending on management.

METHODS

Retrospective study based on the COLOFOL-trial population of 2442 patients, radically resected for colorectal cancer stage II-III. All recurrences within 5 years were identified and medical records were scrutinized.

RESULTS

Of 165 (6.8%) patients developing lung metastases as first recurrence, 89 (54%) were confined to the lungs. Potentially curative treatment was possible in 62 (37%) cases, of which 33 with surgery only and 29 with surgery and chemotherapy combined. The 5-year overall survival (5-year OS) for all lung recurrences was 28%. In patients treated with chemotherapy only the 5-year OS was 7.5%, compared with 55% in patients treated with surgery, and 72% when surgery was combined with chemotherapy. Hazard ratio for mortality was 2.9 (95% confidence interval 1.40-6.10) for chemotherapy only compared to surgery.

CONCLUSION

A high proportion of metachronous lung metastases after colorectal surgery were possible to resect, yielding good survival. The combination of surgery and chemotherapy might be advantageous for survival.

Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) randomised controlled trial: a systematic review of published responses

OBJECTIVES

The objective of this review was to assess the nature and tone of the published responses to the Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) randomized controlled trial.

METHODS

Published articles that cited the PulMiCC trial were identified from Clarivate Web of Science (©. Duplicates and self-citations were excluded and relevant text extracted. Four independent researchers rated the extracts independently using agreed scales for the representativeness of trial data and the textual tone. The ratings were aggregated and summarized. Two PulMiCC authors carried out a thematic analysis of the extracts.

RESULTS

Sixty-four citations were identified and relevant text was extracted and examined. The consensus rating for data inclusion was a median of 0.25 out of 6 (range 0 to 5.25, IQR 0-1.5) and for textual tone the median rating was 1.87 out of 6 (range 0 to 5.75, IQR 1-3.5). The majority of citations did not provide adequate representation of the PulMiCC data and the overall the textual tone was dismissive. Although some were supportive, many discounted the findings because the trial closed early and was underpowered to show non-inferiority. Two misinterpreted the authors' conclusions but there was acceptance that five-year survival was much higher than widely assumed.

CONCLUSIONS

Published comments reveal a widespread reluctance to consider seriously the results of a carefully conducted randomized trial. This may be because the results challenge accepted practice because of 'motivated reasoning'. But there is a widespread misunderstanding of the fact that though PulMiCC with 93 patients was underpowered to test non-inferiority, it still provides reliable evidence to undermine the widespread belief in a major survival benefit from metastasectomy.

Role of surgical resection and its alternative local therapy for pulmonary metastasis of colorectal cancer

We reviewed surgical and alternative treatments for pulmonary metastasis of colorectal cancer, focusing on recent reports. The standard treatment for pulmonary metastasis of colorectal cancer is pulmonary resection, if resectable, despite the fact that the metastasis is hematogenous to distant organs. Guidelines in several countries, including Japan, have described pulmonary resection as a useful option because of the favorable long-term prognosis reported in various studies pertaining to pulmonary resection. The indications for pulmonary resection have been reviewed in several studies; additionally, the number of metastases, pretreatment carcinoembryonic antigen value, and disease-free interval from the primary resection to pulmonary recurrence have been proposed. However, no consensus has been reached to date. Contrastingly, recent advances in chemotherapy have remarkably improved the outcome of distant metastases, indicating that it is time to reconsider the significance of local treatment, including pulmonary resection. In addition to surgical resection, minimally invasive therapies, such as stereotactic body radiation therapy and radiofrequency ablation have been developed as local treatments for pulmonary metastases, and their long-term results have been reported. Prospective controlled trials and large-scale data analyses are needed to determine the best local treatment for pulmonary metastases and to find the appropriate indication for each treatment.

Pulmonary metastasectomy: limits to credibility

Lung metastases are a common site of spread for many malignant tumours. Pulmonary metastasectomy has been practiced for many years for sarcomas and is now becoming increasingly frequently advocated for patients with many other tumours, especially colorectal cancer. In this article we argue that this procedure is one framed by therapeutic opportunity and not supported by strong evidence. It is potentially harmful and may not be effective. Our argument is based on several important issues: (I) the vagueness of the concept of "oligometastases" and its biological implausibility; (II) the flaws in the often-cited observational evidence, especially selection bias; (III) the lack of any reliable randomised trial evidence of improved survival but evidence of harm; (IV) the failure of strategies to detect metastases earlier to influence overall survival. The introduction of stereotactic radiotherapy and image-guided thermal ablation have made the urge to treat lung metastases stronger but without any good evidence to justify their use. We acknowledge the problems of carrying out randomised trials when there is a clear lack of equipoise in the clinical teams involved but believe that there is an ethical need to do so. Many patients are probably being given false hope of cure or prolonged survival but are at risk of harm from pulmonary metastasectomy or ablation. It is possible that a few patients may benefit but without better evidence we do not know which, if any, do.

Results of redo pulmonary metastasectomy

Repeat surgical resection (redo) for pulmonary metastases is a questionable, albeit intriguing topic. We performed an extensive review of the literature, to specifically analyze results of redo pulmonary metastasectomies. We reviewed a total of 3,523 papers. Among these, 2,019 were excluded for redundancy and 1,105 because they were not completely retrievable. Out of 399 eligible papers, 183 had missing information or missing abstract, while 96 lacked data on survival. A total of 120 papers dated from 1991 onwards were finally included. Data regarding mortality, major morbidity, prognostic factors and long-term survivals of the first redo pulmonary metastasectomies were retrieved and analyzed. Homogeneity of data was affected by the lack of guidelines for redo pulmonary metastasectomy and the risks of bias when comparing different studies has to be considered. According to the histology sub-types, redo metastasectomies papers were grouped as: colorectal (n=42), sarcomas (n=36), others (n=20) and all histologies (n=22); the total number of patients was 3,015. Data about chemotherapy were reported in half of the papers, whereas targeted or immunotherapy in 9. None of these associated therapies, except chemotherapy in two records, did significantly modify outcomes. Disease-free interval before the redo procedure was the prevailing prognostic factor and nearly all papers showed a significant correlation between patients’ comorbidities and prognosis. No perioperative mortality was reported, while perioperative major morbidity was overall quite low. Where available, overall survival after the first redo metastasectomy ranged from 10 to 72 months, with a 5-years survival of approximately 50%. The site of first recurrence after the redo procedure was mainly lung. Despite the data retrievable from literature are heterogeneous and confounding, we can state that redo lung metastasectomy is worthwhile when the lesions are resectable and the perioperative risk is low. At present, there are no “non-surgical” therapeutic options to replace redo pulmonary metastasectomies.

Pulmonary Metastasectomy in Colorectal Cancer: updated analysis of 93 randomized patients - control survival is much better than previously assumed

AIM

Lung metastases from colorectal cancer are resected in selected patients in the belief that this confers a significant survival advantage. It is generally assumed that the 5-year survival of these patients would be near zero without metastasectomy. We tested the clinical effectiveness of this practice in Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC), a randomized, controlled noninferiority trial.

METHOD

Multidisciplinary teams in 14 hospitals recruited patients with resectable lung metastases into a two-arm trial. Randomization was remote and stratified according to site, with minimization for age, sex, primary cancer stage, interval since primary resection, prior liver involvement, number of metastases and carcinoembryonic antigen level. The trial management group was blind to patient allocation until after intention-to-treat analysis.

RESULTS

From 2010 to 2016, 93 participants were randomized. These patients were 35-86 years of age and had between one and six lung metastases at a median of 2.7 years after colorectal cancer resection; 29% had prior liver metastasectomy. The patient groups were well matched and the characteristics of these groups were similar to those of observational studies. The median survival after metastasectomy was 3.5 (95% CI: 3.1-6.6) years compared with 3.8 (95% CI: 3.1-4.6) years for controls. The estimated unadjusted hazard ratio for death within 5 years, comparing the metastasectomy group with the control group, was 0.93 (95% CI: 0.56-1.56). Use of chemotherapy or local ablation was infrequent and similar in each group.

CONCLUSION

Patients in the control group (who did not undergo lung metastasectomy) have better survival than is assumed. Survival in the metastasectomy group is comparable with the many single-arm follow-up studies. The groups were well matched with features similar to those reported in case series.

Pulmonary Metastasectomy versus Continued Active Monitoring in Colorectal Cancer (PulMiCC): a multicentre randomised clinical trial

BACKGROUND

Lung metastasectomy in the treatment of advanced colorectal cancer has been widely adopted without good evidence of survival or palliative benefit. We aimed to test its effectiveness in a randomised controlled trial (RCT).

METHODS

Multidisciplinary teams in 13 hospitals recruited participants with potentially resectable lung metastases to a multicentre, two-arm RCT comparing active monitoring with or without metastasectomy. Other local or systemic treatments were decided by the local team. Randomisation was remote and stratified by site with minimisation for age, sex, primary cancer stage, interval since primary resection, prior liver involvement, the number of metastases, and carcinoembryonic antigen level. The central Trial Management Group were blind to patient allocation until completion of the analysis. Analysis was on intention to treat with a margin for non-inferiority of 10%.

RESULTS

Between December 2010 and December 2016, 65 participants were randomised. Characteristics were well-matched in the two arms and similar to those in reported studies: age 35 to 86 years (interquartile range (IQR) 60 to 74); primary resection IQR 16 to 35 months previously; stage at resection T1, 2 or 3 in 3, 8 and 46; N1 or N2 in 31 and 26; unknown in 8. Lung metastases 1 to 5 (median 2); 16/65 had previous liver metastases; carcinoembryonic antigen normal in 55/65. There were no other interventions in the first 6 months, no crossovers from control to treatment, and no treatment-related deaths or major adverse events. The Hazard ratio for death within 5 years, comparing metastasectomy with control, was 0.82 (95%CI 0.43, 1.56).

CONCLUSIONS

Because of poor and worsening recruitment, the study was stopped. The small number of participants in the trial (N = 65) precludes a conclusive answer to the research question given the large overlap in the confidence intervals in the proportions still alive at all time points. A widely held belief is that the 5-year absolute survival benefit with metastasectomy is about 35%: 40% after metastasectomy compared to < 5% in controls. The estimated survival in this study was 38% (23-62%) for metastasectomy patients and 29% (16-52%) in the well-matched controls. That is the new and important finding of this RCT.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT01106261. Registered on 19 April 2010.

[Oligometastases and oligoprogressions: Concepts and natural history]

The oligometastatic paradigm refers to an intermediate biologic state of cancer with restricted metastatic capacity. Its phenotype is characterized by a limited number of metastases and a slow tumor growth. Various clinical and pre-clinical studies associated this state to alterations of the biological mechanisms involved in metastatic diffusion. Eventually, this transitional state leads to a wide metastatic dissemination. However, there is a period during which the patient could benefit from local ablative treatment. Depending on several prognostic factors and the treatment provided, long survival or even healing can sometimes be achieved. The selection of patients eligible for such a curative strategy may be adapted following clinical, radiological or biological markers. Recent improvement of therapeutic and imaging are changing the clinical definition of oligometastatic cancer, which should be adapted to evidence from recent clinical and preclinical data.

An overview on clinical, pathological and molecular features of lung metastases from colorectal cancer

Introduction: Lung metastases occur in 10-20% of patients with colorectal cancer (CRC). Most of them are treated with palliative intent and have a poor prognosis. Pulmonary metastasectomy may be a curative option for carefully selected patients with 5-year survival rates ranging from 25% to 60%. However, up to 70% of patients develop recurrence after pulmonary metastasectomy. Therefore, the identification of prognostic factors is essential in CRC patients with resectable lung metastases. Areas covered: This review aims at summarizing the actual body of knowledge available on lung metastases from CRC focusing on their clinical, pathological and molecular profile. Moreover, we provide an update on experts' attitudes towards lung metastasectomy, adjuvant or perioperative chemotherapy. Expert opinion: Traditional clinical prognosticators such as the total number of pulmonary metastases, carcinoembryonic antigen (CEA) serum levels before surgery, and presence of lymph node metastases cannot provide reliable criteria to predict survival after lung metastasectomy. Indeed, research efforts have been directed in recent years toward studying the biological characteristics of lung lesions to better define prognosis and response to treatment, and ultimately shed new light on their proper local and systemic management.

Oligometastatic breast cancer

Metastatic breast cancer (MBC) is considered as incurable. The group of patients with oligometastatic disease (a few metastatic lesions and organs involved) apparently have better prognosis. It is claimed that, these patients could be treated with curative intent, and multidisciplinary aggressive approach should be considered. Despite the lack of strong data it is increasingly accepted in clinical practice. Currently, the appropriate candidate would be young woman with good performance status, low tumour burden with long disease-free interval. Because for them with already favorable nature of their disease, aggressive treatment has greater chances to improve survivals. Local ablative treatment (radiotherapy/surgery) has a crucial role in this setting. Available mainly from retrospective in nature long-term results are encouraging but need confirmation in prospective randomized studies. In this review, I discuss the definition of oligometastatic disease, its nature, currently available data and ongoing prospective randomized trials dedicated to oligometastatic breast cancer patients.

The impact of effective systemic therapies on surgery for stage IV melanoma

INTRODUCTION

The outcomes of patients with metastatic melanoma have significantly improved with the introduction of effective systemic therapies (ESTs). The role of surgery in the context of ESTs for stage IV melanoma is evolving. We sought to characterise the changing patterns of surgery and oncological outcomes in patients with stage IV melanoma treated before and after the establishment of ESTs.

METHODS

Patients undergoing surgical resection of stage IV melanoma were identified from our institutional database from 2003 to 2015. Patients were grouped into two cohorts, those referred before EST (2003-2007) and after EST (2011-2015). Clinicopathological variables, patterns of surgery and oncological outcomes in the two groups were compared.

RESULTS

A total of 138 patients underwent surgery for stage IV melanoma (n = 69 in each cohort). We observed no significant difference in the ratio of operations/patients performed. However, the pattern of operations altered, with a significant decrease in in-transit excisions (0.9% vs. 19.4%, p < 0.001) and an increase in abdominal metastasectomies (21.1% vs. 4.2%, p < 0.001), in the after-EST cohort. Novel indications for surgical intervention were noted in the after-EST cohort, with a significant increase in potentially curative operations for residual oligometastatic disease (15.9% vs. 4.3%, p = 0.045). Survival after surgery was prolonged in the after-EST cohort (median 16 months vs. 6 months, p < 0.001), with the stage at initial metastasectomy (stage 4a, hazard ratio [HR] 0.45 (0.28-0.73), p = 0.001) and treatment with immune checkpoint inhibitors (HR 0.38 (0.25-0.60), p < 0.001) associated with prolonged survival.

DISCUSSION

Surgery remains important in the management of stage IV melanoma, with evolving indications and patterns of intervention after the introduction of ESTs. The combination of judicious surgery and EST may improve oncological outcomes.

Prognostic factors after pulmonary metastasectomy of colorectal cancers: a single-center experience

Background

Surgical resection has been widely admitted as the treatment of choice for pulmonary metastases of colorectal cancer (CRC). Nevertheless, this practice is not supported by high level of evidence and patients' eligibility remains controversial. Aim of this study was to evaluate long terms results and factors influencing survival after lung metastasectomy of CRC.

Methods

A single-center retrospective analysis of patients with pathologically proven colorectal metastasis, operated from 2004 to 2013, was performed. Patients were treated with a multidisciplinary approach and selected for surgery if complete resection was considered feasible.

Results

Three hundred and six patients were considered for analysis. Mean number of lesions at CT scan was 2.6±2.3. Ratios of each largest resection type at first side surgery were: segmentectomy 20.6%, lobectomy 12.9%, bilobectomy 1.2%, pneumonectomy 1.2% and sub-lobar resection 64.1%, respectively. No in-hospital death occurred. At pathology, mean number of resected metastasis was 2.6±2.3, ranging from 1 to 12. Resection was complete in 92.5% of patients. Nodal involvement was proven in 40 (12.9%) patients. The initially planned complete resection could not be achieved in 23 (7.5%) cases. Mean follow-up was 3.06±2.36 years. Kaplan-Meier analysis revealed that recurrence-free survival (RFS) was 76.3% [95% confidence interval (95% CI), 71-80.7%], 38.9% (95% CI, 33-44.7%), 28.3% (95% CI, 22.5-34.4%) and 22.7% (95% CI, 16.5-29.5%) at 1, 3, 5 and 7 years, respectively. Overall survival (OS) estimates were 77.8% (95% CI, 72.7-82.7%), 59.0% (95% CI, 51.2-66.4%), and 56.9% (95% CI, 48.4-65.0%) at 3, 5 and 7 years, respectively. Multivariate analysis, including pT parameter of the primary tumor, number of lesions, one-sided versus bilateral lung disease, and body mass index (BMI) (all significant at univariate analysis), showed that bilateral disease (P<0.001) and pT4 primary (P=0.005) were independent pejorative predictors of OS, whereas BMI ≥25 was protective (P=0.028).

Conclusions

Bilateralism and primary tumor local extension influence the prognosis of patients surgically treated for pulmonary colorectal metastases. Specifically designed randomized trials are necessary.

Stereotactic Body Radiotherapy for Oligometastasis: Opportunities for Biology to Guide Clinical Management

Oligometastasis refers to a state of limited metastatic disease burden, in which surgical or ablative treatment to all known visible metastases holds promise to extend survival or even effect cure. Stereotactic body radiotherapy is a form of radiation treatment capable of delivering a high biologically effective dose of radiation in a highly conformal manner, with a favorable toxicity profile. Enthusiasm for oligometastasis ablation, however, should be counterbalanced against the limited supporting evidence. It remains unknown to what extent (if any) ablation influences survival or quality of life. Rising clinical equipoise necessitates the completion of randomized controlled trials to assess this, several of which are underway. However, a lack of clear identification criteria or biomarkers to define the oligometastatic state hampers optimal patient selection.This narrative review explores the evolutionary origins of oligometastasis, the steps of the metastatic process at which oligometastases may arise, and the biomolecular mediators of this state. It discusses clinical outcomes with treatment of oligometastases, ongoing trials, and areas of basic and translational research that may lead to novel biomarkers. These efforts should provide a clearer, biomolecular definition of oligometastatic disease and aid in the accurate selection of patients for ablative therapies.

Stereotactic ablative body radiotherapy (SAbR) for oligometastatic cancer

The metastatic state of most solid cancers traditionally has been regarded as an incurable dissemination of disease, with treatment focused on delaying progression rather than eliminating all tumour burden. In this setting, local therapies including surgery and radiotherapy are directed at quality of life end points and not at improvement in survival. However, improvements in imaging and systemic therapy have highlighted populations of patients with lower burden of metastatic disease, termed "oligometastatic," who may present an exception. This condition is hypothesized to bridge the gap between incurable metastatic disease and locoregional disease, where miliary spread either has not occurred or remains eradicable. Consequently, elimination of such low-burden residual disease may "cure" some patients or delay further progression. Accordingly, use of local therapies with the intent of improving survival in oligometastatic disease has increased. Technological advances in radiation delivery with stereotactic ablative body radiotherapy (SAbR) in particular have provided a non-invasive and low-morbidity option. While observational studies have provided interesting preliminary data, significant work remains necessary to prove the merits of this treatment paradigm. This review discusses the data for the oligometastatic state and its treatment with SAbR, as well as challenges to its investigation.

The expanding role of stereotactic body radiation therapy in oligometastatic solid tumors: What do we know and where are we going?

The spectrum hypothesis posits that there are distinct clinical states of metastatic progression. Early data suggest that aggressive treatment of more biologically indolent metastatic disease, characterized by metastases limited in number and destination organ, may offer an opportunity to alter the disease course, potentially allowing for longer survival, delay of systemic therapy, or even cure. The development of stereotactic body radiation therapy (SBRT) has opened new avenues for the treatment of oligometastatic disease. Early data support the use of SBRT for treating oligometastases in a number of organs, with promising rates of treated metastasis control and overall survival. Ongoing investigation is required to definitively establish benefit, determine the appropriate treatment regimen, refine patient selection, and incorporate SBRT with systemic therapies.

New Strategies in Stereotactic Radiotherapy for Oligometastases

Patients with metastatic solid tumors are usually treated with palliative intent. Systemic therapy and palliative radiation are often used, with the goals of prolonging survival or maintaining quality of life, but not of cure. In contrast to this paradigm, the theory of oligometastasis suggests that some patients who have a small number of metastases may be amenable to cure if all lesions can be eradicated. Aggressive treatment of patients with oligometastases, using either surgery or radiotherapy, has become more common in the past decade, yet in most situations, no randomized evidence is available to support such an approach. Stereotactic ablative radiotherapy (SABR) is a novel treatment for oligometastases, delivering large doses of radiotherapy in only a few treatments, with excellent rates of local control, and appears to be an excellent noninvasive alternative to surgical resection of metastases. This article reviews recent biologic and clinical data that support the existence of the oligometastatic state and discusses gaps in this evidence base. The emerging role for SABR in the management of this challenging patient population is discussed with a focus on ongoing clinical trials in an attempt to improve overall survival, delay progression, or induce immunologic anticancer effects through the abscopal effect.

Ablative Approaches for Pulmonary Metastases

Pulmonary metastases are common in patients with cancer for which surgery is considered a standard approach in appropriately selected patients. A number of patients are not candidates for surgery due to a medical comorbidities or the extent of surgery required. For these patients, noninvasive or minimally invasive approaches to ablate pulmonary metastases are potential treatment strategies. This article summarizes the rationale and outcomes for non-surgical treatment approaches, including radiotherapy, radiofrequency and microwave ablation, for pulmonary metastases.

Clinical and molecular markers of long-term survival after oligometastasis-directed stereotactic body radiotherapy (SBRT)

BACKGROUND

The selection of patients for oligometastasis-directed ablative therapy remains a challenge. The authors report on clinical and molecular predictors of survival from a stereotactic body radiotherapy (SBRT) dose-escalation trial for oligometastases.

METHODS

Patients who had from 1 to 5 metastases, a life expectancy of >3 months, and a Karnofsky performance status of >60 received escalating SBRT doses to all known cancer sites. Time to progression, progression-free survival, and overall survival (OS) were calculated at the completion of SBRT, and clinical predictors of OS were modeled. Primary tumor microRNA expression was analyzed to identify molecular predictors of OS.

RESULTS

Sixty-one evaluable patients were enrolled from 2004 to 2009. The median follow-up was 2.3 years for all patients (range, 0.2-9.3 years) and 6.8 years for survivors (range, 2.0-9.3 years). The median, 2-year, and 5-year estimated OS were 2.4 years, 57%, and 32%, respectively. The rate of progression after SBRT was associated with an increased risk of death (hazard ratio [HR], 1.44; 95% confidence interval [CI], 1.24-1.82). The time from initial cancer diagnosis to metastasis (HR, 0.98; 95% CI, 0.98-0.99), the time from metastasis to SBRT (HR, 0.98; 95% CI, 0.98-0.99), and breast cancer histology (HR, 0.12; 95% CI, 0.07-0.37) were significant predictors of OS. In an exploratory analysis, a candidate classifier using expression levels of 3 microRNAs (miR-23b, miR-449a, and miR-449b) predicted survival among 17 patients who had primary tumor microRNA expression data available.

CONCLUSIONS

A subset of oligometastatic patients achieves long-term survival after metastasis-directed SBRT. Clinical features and primary tumor microRNA expression profiling, if validated in an independent dataset, may help select oligometastatic patients most likely to benefit from metastasis-directed therapy. Cancer 2016;122:2242-50. © 2016 American Cancer Society.

Is Surgery Warranted for Oligometastatic Disease?

The development of metastases after curative treatment can be seen as a failure. A common justification for the removal of metastases is that the knowledge that they are there may cause psychological distress, a real symptom that may be relieved by their removal. Although it is a commonly used justification for metastasectomy, the authors are unaware of any studies confirming or quantifying the health gain. This article strongly challenges the belief in clinical effectiveness and demonstrates that it is supported neither by a sound biological rationale nor by any good evidence. Reasons are suggested why this unfounded belief has become so prevalent.

Thoracoscopic Management of Pulmonary Metastases

In appropriately selected patients, resection of pulmonary metastases from various primary tumors can lead to improved survival. Metastasectomy has traditionally been performed by open thoracotomy; however, thoracoscopic resection offers the important benefits of a less invasive approach with more expeditious recovery. Concerns regarding missed lesions during thoracoscopy have not been realized in analyses of survival and may be offset by a policy of repeat metastasectomy for pulmonary recurrences. Despite the relative paucity of prospective trials, the preponderance of data supports the use of video-assisted thoracic surgery for pulmonary metastasectomy, which represents our preferred strategy for these patients.

Multi-reoperations for lung metastases

In this study, we investigated role and results of multi-reoperations for lung metastases. From 1986 to 2010, 113 consecutive patients (61 men and 52 women; mean age: 53.2 ± 12.8 years) underwent repeated lung metastasectomy with curative intent in our institution. Two procedures were performed in 113 patients, three in 54, four in 31, five in eight and six in three. There was no perioperative mortality. Cumulative 5-year survival was 65% and this was significantly higher than the value recorded for patients undergoing only one metastasectomy (42%; p = 0.021). Size, number of resections and probability of recurrence increased by number of operation whereas disease free interval reduced. At any metastasectomy both short disease-free interval and multiple metastases resulted in the most significant negative prognosticators. In conclusion, redo metastasectomy is worthwhile for the initial procedures, afterwards both disease-free and overall survivals decrease and surgery lose its efficacy.

The role of stereotactic radiotherapy in the treatment of oligometastases

"Oligometastasis" describes a limited number of metastases arising typically from solid tumors whose behavior suggests an "intermediate" malignant state since it may potentially have a more favorable prognosis. Historically, selected patients with oligometastases often underwent surgical resection since anecdotal evidence suggested it could improve progression-free or overall survival. No prospective randomized trial evidence to date supports survival benefits from surgery. Short courses of highly focused, very high dose radiotherapy (stereotactic radiosurgery; stereotactic body radiotherapy) have emerged as a surgical surrogate to manage oligometastates. For solitary brain metastases, randomized study evidence supports stereotactic radiosurgery as part of their management because of overall survival benefits. Modeled after stereotactic radiosurgery, stereotactic body radiotherapy for extracranial metastases is becoming increasingly common given its efficacy and low toxicity, is an active area of clinical research, and is the subject of this review.

Finding the evidence for pulmonary metastasectomy in colorectal cancer: the PulMicc trial

ABSTRACT 

The PulMiCC trial is a randomized controlled trial testing the effect on survival of pulmonary metastasectomy in patients with colorectal cancer. In stage 1 of the trial patients with treated primary colorectal cancer metastatic to the lungs are invited to consent for protocol-based evaluation of their suitability for metastasectomy. The evaluation is as in current practice and includes PET/CT. A decision for or against metastasectomy may be based on the opinion of the clinicians and the preference of the patient. If there is uncertainty the patient is invited to consent to have the treatment arm assigned by randomization in stage 2 of PulMiCC. More than 300 patients have entered stage 1 and more than 70 are in stage 2.

History and present status of pulmonary metastasectomy in colorectal cancer

Clinical practice with respect to metastatic colorectal cancer differs from the other two most common cancers, breast and lung, in that routine surveillance is recommended with the specific intent of detecting liver and lung metastases and undertaking liver and lung resections for their removal. We trace the history of this approach to colorectal cancer by reviewing evidence for effectiveness from the 1950s to the present day. Our sources included published citation network analyses, the documented proposal for randomised trials, large systematic reviews, and meta-analysis of observational studies. The present consensus position has been adopted on the basis of a large number of observational studies but the randomised trials proposed in the 1980s and 1990s were either not done, or having been done, were not reported. Clinical opinion is the mainstay of current practice but in the absence of randomised trials there remains a possibility of selection bias. Randomised controlled trials (RCTs) are now routine before adoption of a new practice but RCTs are harder to run in evaluation of already established practice. One such trial is recruiting and shows that controlled trial are possible.

The oligometastatic state - separating truth from wishful thinking

The oligometastatic paradigm implies that patients who develop a small number of metastatic lesions might achieve long-term survival if all these lesions are ablated with surgery or stereotactic radiotherapy. Clinical data indicate that the number of patients with oligometastatic disease receiving aggressive treatment is increasing rapidly. We examine the key evidence supporting or refuting the existence of an oligometastatic state. Numerous single-arm studies suggest that long-term survival is 'better-than-expected' after ablative treatment. However, the few studies with adequate controls raise the possibility that this long-term survival might not be due to the treatments themselves, but rather to the selection of patients based on favourable inclusion criteria. Furthermore, ablative treatments carry a risk of harming healthy tissue, yet the risk-benefit ratio cannot be quantified if the benefits are unmeasured. If the strategy of treating oligometastases is to gain widespread acceptance as routine clinical practice, there should be stronger evidence supporting its efficacy.

Role of segmentectomy for pulmonary metastases

Pulmonary metastasectomy has not been proven by randomized trials to be more effective than non-operative management, but currently has a well-accepted role for certain primary cancers, in particular colorectal cancer and sarcoma. One of the principal tenets for pulmonary metastasectomy is that all lesions are resected. A major technical difference compared to surgical management of primary lung cancer is that management of metastatic disease frequently requires the resection of multiple and possibly bilateral lesions. In addition, surgeons and patients must often consider repeat surgery for management of metachronous lesions that develop some time after a previous resection, given the nature of metastatic cancer. Therefore, surgeons must ensure complete resection of lesions with negative margins but also must be cognizant of minimizing resection of functional lung tissue as much as possible, in order to ensure that both current and future lesions can be resected while leaving patients with adequate pulmonary function. Segmentectomy is generally infrequently utilized for pulmonary metastasectomy, but has a role for lesions for which a wedge resection is technically not possible but a lobectomy is not required. Segmentectomy can be an important tool in achieving the dual goals of complete resection and impacting pulmonary function as little as possible. Using minimally invasive techniques with thoracoscopy to perform segmentectomy is associated with less short-term morbidity than thoracotomy. Although the use of minimally invasive techniques limits manual palpation and therefore potential resection of small lesions not identified by pre-resection imaging, the current literature does not suggest that these procedures should be done via thoracotomy.

Descriptive analysis of and overall survival after surgical treatment of lung metastases

OBJECTIVE:

To describe demographic characteristics, surgical results, postoperative complications, and overall survival rates in surgically treated patients with lung metastases.

METHODS:

This was a retrospective analysis of 119 patients who underwent a total of 154 lung metastasis resections between 1997 and 2011.

RESULTS:

Among the 119 patients, 68 (57.1%) were male and 108 (90.8%) were White. The median age was 52 years (range, 15-75 years). In this sample, 63 patients (52.9%) presented with comorbidities, the most common being systemic arterial hypertension (69.8%) and diabetes (19.0%). Primary colorectal tumors (47.9%) and musculoskeletal tumors (21.8%) were the main sites of origin of the metastases. Approximately 24% of the patients underwent more than one resection of the lesions, and 71% had adjuvant treatment prior to metastasectomy. The rate of lung metastasis recurrence was 19.3%, and the median disease-free interval was 23 months. The main surgical access used was thoracotomy (78%), and the most common approach was wedge resection with segmentectomy (51%). The rate of postoperative complications was 22%, and perioperative mortality was 1.9%. The overall survival rates at 12, 36, 60, and 120 months were 96%, 77%, 56%, and 39%, respectively. A Cox analysis confirmed that complications within the first 30 postoperative days were associated with poor prognosis (hazard ratio = 1.81; 95% CI: 1.09-3.06; p = 0.02).

CONCLUSIONS:

Surgical treatment of lung metastases is safe and effective, with good overall survival, especially in patients with fewer metastases.

Pulmonary metastasectomy: what is the practice and where is the evidence for effectiveness?

Pulmonary metastasectomy is a commonly performed operation and is tending to increase as part of a concept of personalised treatment for advanced cancer. There have been no randomised trials; belief in effectiveness of metastasectomy is based on registry data and surgical follow-up studies. These retrospective series are comprised predominately of solitary or few metastases with primary resection to metastasectomy intervals longer than 2-3 years. Five-year survival rates of 30-50% are recorded, but as case selection is based on favourable prognostic features, an apparent association between metastasectomy and survival cannot be interpreted as causation. Cancers for which lung metastasectomy is used are considered in four pathological groups. In non-seminomatous germ cell tumour, for which chemotherapy is highly effective, excision of residual pulmonary disease guides future treatment and in particular allows an informed decisions as to further chemotherapy. Sarcoma metastasises predominately to lung and pulmonary metastasectomy for both bone and soft tissues sarcoma is routinely considered as a treatment option but without randomised data. The commonest circumstance for lung and liver metastasectomy is colorectal cancer. Repeated resections and ablations are commonplace but without evidence of effectiveness for either. For melanoma, results are particularly poor, but lung metastases are resected when no other treatment options are available. In this review, the available evidence is considered and the conclusion reached is that in the absence of randomised trials there is uncertainty about effectiveness. A randomised controlled trial, Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC), is in progress and randomised trials in sarcoma seem warranted.

Pulmonary Metastasectomy for Colorectal Cancer: Recent Reports Prompt a Review of the Available Evidence

Pulmonary metastasectomy for colorectal cancer is commonplace surgery, but the practice has grown on the basis of follow-up studies. These studies base their conclusion on the effectiveness of metastasectomy on the survival rates at 5 years of very highly selected patients. Three publications in the last year, a registry study, a meta-analysis and a randomised controlled trial of monitoring and early detection of cancer recurrence, prompted a review of the evidence. A critical examination of the evidence suggests that much of the apparent benefit may be due to selection of patients most likely to survive on the basis of well-known prognostic features, explicitly stated in the clinical record. Clinicians also assess their patients over time and do not offer surgery to those with faster progression. Such clinical judgements are of their nature often subtle and undocumented and thus cannot be retrieved from the clinical record. Although some patients may have long survival following pulmonary metastasectomy, and indeed their survival might be believed to be due to resection of pulmonary metastases, how many patients must be operated on to find these survivors? What is the number 'needed to treat'? It may be that of the patients having metastasectomy, for the greater proportion it does not materially alter their survival. A randomised controlled trial to resolve this uncertainty is in progress. The Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) trial is recruiting in Britain and Europe.