Radiosensitivity of Colon and Rectal Lung Oligometastasis Treated With Stereotactic Ablative Radiotherapy

Management of Oligometastatic Colorectal Cancer

The management of oligometastatic colorectal cancer differs from the treatment of metastatic colorectal cancer, and it is essential that those who treat oligometastatic disease be familiar with the treatment options for these patients. Although definitive treatment is often surgical, there are situations where local therapies such as SBRT or ablative techniques may better serve the patient. Adjuvant therapy should be provided to all patients, and neoadjuvant chemotherapy should be considered as well. The role of immunotherapy is currently limited due to the lack of clinical trials in this area.

Stereotactic Body Radiotherapy for Management of Pulmonary Oligometastases in Stage IV Colorectal Cancer: A Perspective

In pulmonary oligometastases from colorectal cancer (POM-CRC), metastasectomy is the primarily recommended treatment. Stereotactic body radiotherapy (SBRT) has been suggested as a viable alternative therapy. SBRT efficacy for POM-CRC is poorly delineated compared to selected non-CRC primaries. This perspective article aims to critically summarize the existing evidence regarding efficacy of SBRT in terms of overall survival (OS) and local control (LC), and factors modulating this, in the treatment of POM-CRC. Overall, reasonable LC and OS rates were observed. The wide range of expansions in planning target volume margins introduced variation in pretreatment protocols. Dose-fractionation schedules varied according to patient and tumor characteristics, though leverage of BED10 in select studies enabled standardization. An association between SBRT dose and improved OS and LC was observed across multiple studies. Prognostic factors that were associated with improved LC included: fewer oligometastases, absence of extra-pulmonary metastases, primary tumor histology, and smaller gross tumor volume. Differences in SBRT modality and techniques over time further confounded results. Many studies included patients receiving additional systemic therapies; preprotocol and adjuvant chemotherapies were identified as prognostic factors for LC. SBRT compared with metastasectomy showed no differences in short-term OS and LC outcomes. In conclusion, SBRT is an efficacious treatment for POM-CRC, in terms of OS and LC. Heterogeneity in study design, particularly pertaining to dose protocols, patient selection, and additional therapies should be controlled for future randomized studies to further validate SBRT efficacy.

Prognostic differences between oligometastatic and polymetastatic disease after resection in patients with colorectal cancer and hepatic or lung metastases: Retrospective analysis of a large cohort at a single institution

BACKGROUND

Long-term survival data are lacking, and prognostic factors are not well-defined for patients with colorectal cancer and hepatic or lung metastases. This study evaluated the outcomes after resection of oligometastatic hepatic or lung metastases from colorectal cancer and sought to identify prognostic factors.

METHODS

We retrospectively investigated 1,123 patients with colorectal cancer and hepatic or pulmonary metastases who underwent curative surgery between January 1991 and December 2016.

RESULTS

Of the 1,123 patients, 719 had hepatic metastases, 287 had pulmonary metastases, and 117 had both. The 5-year overall survival rate was 52.3% in the hepatic metastases group, 70.4% in the pulmonary metastases group, and 71.4% in the hepatic and pulmonary metastases group (P < .001). In total, 1,045 patients had oligometastases (1-5 metastatic lesions in 1 or 2 organs) and 78 had polymetastases (≥6 metastases in 1 or 2 organs). Prognosis was significantly better in patients with oligometastases than in those with polymetastases. The 5-year overall survival rate was 59.0% in the oligometastases group and 35.3% in the polymetastases group (P < .001); the respective 5-year relapse-free survival rates were 37.5% and 11.6% (P < .001). Multivariable analysis identified predictors of both poor overall survival and relapse-free survival to be a high carcinoembryonic antigen level before the first metastasectomy, largest metastasis measuring ≥2 cm, polymetastases, and synchronous metastases.

CONCLUSION

Prognosis after curative resection was better in patients with oligometastatic colorectal cancer in the liver or lung than in those with polymetastases. Multidisciplinary decision-making strategies, including about surgery, should be based on number of metastases rather than their site.

Stage IV anal canal squamous cell carcinoma with long-term survival: a case report

Background

Currently, no established standard treatment exists for metastatic anal squamous cell carcinoma. We report a case of complete response in a patient with stage IV anal squamous cell carcinoma after undergoing multidisciplinary treatment.

Case presentation

A 62-year-old woman visited a nearby doctor with a chief concern of severe pain associated with a firm mass in the anus. The patient was diagnosed with anal canal squamous cell carcinoma and liver metastases and referred to First Department of Surgery Faculty of Medicine University of Fukui for treatment. The patient received a TNM classification of T4N0M1 and stage IV. Rectal amputation was performed; however, postoperative complications hindered immediate anticancer therapy and the liver metastases exacerbated. Radiofrequency hyperthermia and systemic chemotherapy were performed 3 months postoperatively. A prominent reduction in the liver metastasis was observed. Lung metastases appeared during the course of systemic chemotherapy. Radiotherapy was performed to treat the lung lesion and resolved. Radiotherapy was also performed for liver metastasis. The lesion in the liver showed resolution after 54 months postoperatively, and treatment with the anticancer drug was discontinued. Ten-year follow-up findings suggested complete resolution of the lesion in response to the treatment protocol followed in this case. This long-term survival was achieved through a multidisciplinary treatment.

Conclusions

The present case suggests that multidisciplinary treatment approach is effective for resolving stage IV anal squamous cell carcinoma, and addition of new anticancer drug therapy may improve the overall prognosis of squamous cell carcinoma.

Local Therapies in Advanced Colorectal Cancer

Curative intent surgical resection of colorectal metastases to the liver and lungs in eligible patients results in improved disease control and prolonged overall survival with the potential for cure in a subset of patients. Additional ablative and local therapies for use in the liver, lungs, and other body sites have been developed with emerging data on the utility and toxicity of these treatments. Future studies should focus on identification of appropriate candidates for treatment and determining the optimal modality and timing of treatment accounting for both patient and disease factors.

The Colorectal Cancer Tumor Microenvironment and Its Impact on Liver and Lung Metastasis

Simple Summary

Colorectal cancer (CRC) is the third most common cancer worldwide. Metastasis to secondary organs, such as the liver and lungs, is a key driver of CRC-related mortality. The tumor microenvironment, which consists of the primary cancer cells, as well as associated support and immune cells, significantly affects the behavior of CRC cells at the primary tumor site, as well as in metastatic lesions. In this paper, we review the role of the individual components of the tumor microenvironment on tumor progression, immune evasion, and metastasis, and we discuss the implications of these components on antitumor therapies.

Abstract

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer-related mortality worldwide. A total of 20% of CRC patients present with distant metastases, most frequently to the liver and lung. In the primary tumor, as well as at each metastatic site, the cellular components of the tumor microenvironment (TME) contribute to tumor engraftment and metastasis. These include immune cells (macrophages, neutrophils, T lymphocytes, and dendritic cells) and stromal cells (cancer-associated fibroblasts and endothelial cells). In this review, we highlight how the TME influences tumor progression and invasion at the primary site and its function in fostering metastatic niches in the liver and lungs. We also discuss emerging clinical strategies to target the CRC TME.

Late metastatic presentation is associated with improved survival and delayed wide-spread progression after ablative stereotactic body radiotherapy for oligometastasis

Background

Stereotactic body radiotherapy (SBRT) is increasingly used to treat oligometastatic disease (OMD), but the effect of metastasis timing on patient outcomes remains uncertain.

Methods

An international database of patients with OMD treated with SBRT was assembled with rigorous quality assurance. Early versus late metastases were defined as those diagnosed ≤24 versus >24 months from the primary tumor. Overall survival (OS), progression‐free survival (PFS), and incidences of wide‐spread progression (WSP) were estimated using multivariable Cox proportional hazard models stratified by primary tumor types.

Results

The database consists of 1033 patients with median follow‐up of 24.1 months (0.3–104.7). Late metastatic presentation (N = 427) was associated with improved OS compared to early metastasis (median survival 53.6 vs. 33.0 months, hazard ratio [HR] 0.59, 95% confidence interval [CI]: 0.47–0.72, p < 0.0001). Patients with non‐small cell lung cancer (NSCLC, N = 255, HR 0.49, 95% CI: 0.33–0.74, p = 0.0005) and colorectal cancer (N = 235, HR 0.50, 95% CI: 0.30–0.84, p = 0.008) had better OS if presenting with late metastasis. Late metastasis correlated with longer PFS (median 17.1 vs. 9.0 months, HR 0.71, 95% CI: 0.61–0.83, p < 0.0001) and lower 2‐year incidence of WSP (26.1% vs. 43.6%, HR 0.60, 95% CI: 0.49–0.74, p < 0.0001). Fewer WSP were observed in patients with NSCLC (HR 0.52, 95% CI: 0.33–0.83, p = 0.006) and kidney cancer (N = 63, HR 0.37, 95% CI: 0.14–0.97, p = 0.044) with late metastases. Across cancer types, greater SBRT target size was a significant predictor for worse OS.

Conclusion

Late metastatic presentation is associated with improved survival and delayed progression in patients with OMD treated with SBRT.

Prognostic value of pretreatment F-18 fluorodeoxyglucose PET/CT in colorectal cancer with unresectable metastasis

PURPOSE

The aim of the study was to assess the prognostic value of pretreatment PET/computed tomography (CT) scans in colorectal cancer (CRC) patients with unresectable metastasis.

MATERIALS AND METHODS

We retrospectively reviewed the pretreatment PET/CT images of 82 CRC patients with unresectable metastasis and their medical records. On PET/CT images, maximum standardized uptake value (SUVmax) of primary tumor, highest SUVmax of metastatic tumors and number of metastatic organs were identified. The patients were further divided into single and multiple organ metastases groups according to the extent of disease. Survival analysis was performed with the clinical variables and metabolic parameters from PET/CT.

RESULTS

In a total of 82 patients, the age of patients, highest SUVmax of metastatic tumors and number of metastatic organs were independent prognostic factors for overall survival (OS) (all P < 0.05), whereas the SUVmax of primary tumor was not. On multivariate analysis, only the SUVmax of metastatic tumor was a significant prognostic factor in the single organ metastasis group (P = 0.047), whereas the age and highest SUVmax of metastatic tumors were independent prognostic factors in the multiple organ metastases group (all P < 0.05).

CONCLUSION

The highest SUVmax of metastatic tumors was an independent prognostic factor for OS in CRC patients with unresectable metastasis.

Superior outcomes of nodal metastases compared to visceral sites in oligometastatic colorectal cancer treated with stereotactic ablative radiotherapy

BACKGROUND

Stereotactic ablative radiotherapy (SBRT) is a radical option for oligometastatic colorectal cancer (CRC) patients, but most data relate to visceral metastases.

METHODS

A prospective, multi-centre database of CRC patients treated with SBRT was interrogated. Inclusion criteria were ECOG PS 0-2, ≤3 sites of disease, a disease free interval of >6 months unless synchronous liver metastases. Primary endpoints were local control (LC), progression free survival (PFS) and overall survival (OS).

RESULTS

163 patients (172 metastases) were analysed. The median FU was 16 months (IQR 12.2-22.85). The LC at 1 year was 83.8% (CI 76.4%-91.9%) with a PFS of 55% (CI 47%-64.7%) respectively. LC at 1 year was 90% (CI 83%-99%) for nodal metastases (NM), 75% (63%-90%) for visceral metastases (VM). NM had improved median PFS (9 vs 19 months) [HR 0.6, CI 0.38-0.94, p = 0.032] and median OS (32 months vs not reached) [HR 0.28, CI 0.18-0.7, p = 0.0062] than VM, regardless of whether the NM were located inside or outside the pelvis. On multivariate analysis, NM and ECOG PS 0 were significant good prognostic factors. An exploratory analysis suggests KRAS WT is also a good prognostic factor.

CONCLUSION

Nodal site is an important prognostic determinant of SBRT that should incorporated into patient selection. We hypothesise this may have an immunoediting basis.

Tumor Control and Overall Survival after Stereotactic Body Radiotherapy for Pulmonary Oligometastases from Colorectal Cancer: A Meta-Analysis

Purpose

In pulmonary oligometastases from colorectal cancer (POM-CRC), the primarily recommended local therapy is metastasectomy. Stereotactic body radiotherapy (SBRT) is another local therapy modality that is considered as an alternative option in patients who cannot undergo surgery. The purpose of this meta-analysis is to demonstrate the effects of SBRT on POM-CRC by integrating the relevant studies.

Materials and Methods

The authors explored MEDLINE, EMBASE, Cochrane Library, Web of Science, and SCOPUS, and selected studies including patients treated with SBRT for POM-CRC and availability of local control (LC) or overall survival (OS) rate. In this meta-analysis, the effect of SBRT was presented in the form of the LC and OS rates for 1, 2, 3, and 5 years after SBRT as pooled estimates, and the frequency of pulmonary toxicity of grade 3 or higher after SBRT (PTG3-SBRT).

Results

Fourteen full texts among the searched 4,984 studies were the objects of this meta-analysis. The overall number of POM-CRC patients was 495 as per the integration of 14 studies. The pooled estimate LC rate at 1, 2, 3, and 5 years after SBRT was 81.0%, 71.5%, 56.0%, and 61.8%, and the OS rate was 86.9%, 70.1%, 57.9%, and 43.0%, respectively. The LC and OS rates gradually declined until 3 years after SBRT in a similar pattern. Among the 14 studies, only two studies reported PTG3-SBRT as 2.2% and 10.8%, respectively.

Conclusion

For POM-CRC, SBRT is an ablative therapy with a benefit on LC and OS rates and less adverse effects on the lung.

Surgery versus stereotactic radiotherapy for treatment of pulmonary metastases. A systematic review of literature

It is not clear as to which is the best treatment among surgery and stereotactic radiotherapy (SBRT) for lung oligometastases. A systematic review of literature with a priori selection criteria was conducted on articles on the treatment of pulmonary metastases with surgery or SBRT. Only original articles with a population of patients of more than 50 were selected. After final selection, 61 articles on surgical treatment and 18 on SBRT were included. No difference was encountered in short-term survival between pulmonary metastasectomy and SBRT. In the long-term surgery seems to guarantee better survival rates. Mortality and morbidity after treatment are 0–4.7% and 0–23% for surgery, and 0–2% and 4–31% for SBRT. Surgical metastasectomy remains the treatment of choice for pulmonary oligometastases.

Patients with metastatic cancer with a limited number of deposits may benefit from surgical removal or irradiation of tumor nodules in addiction to chemotherapy. Surgical resection has been demonstrated to improve survival and, in some cases, can be curative. Stereotactic radiotherapy is emerging as a less invasive alternative to surgery, but settings and implications of the two treatments are profoundly different. The two techniques show similar results in the short-term, with lower complications rates for radiotherapy, while in the long-term surgery seems to guarantee higher survival rates.

Dose-time fractionation schedules of preoperative radiotherapy and timing to surgery for rectal cancer

Chemoradiotherapy (CRT) is extensively used prior to surgery for rectal cancer to provide significantly better local control, but the radiotherapy (RT), as the other component of CRT, has been subject to less interest than the drug component in recent years. With considerable developments in RT, the use of advanced techniques, such as intensity-modulated radiotherapy (IMRT) in rectal cancer, is garnering more attention nowadays. The radiation dose can be better conformed to the target volumes with possibilities for synchronous integrated boost without increased complications in normal tissue. Hopefully, both local recurrence and toxicities can be further reduced. Although those seem to be of interest, many issues remain unresolved. There is no international consensus regarding the radiation schedule for preoperative RT for rectal cancer. Moreover, an enormous disparity exists regarding the RT delivery. With the advent of IMRT, variations will likely increase. Moreover, time to surgery is also quite variable, as it depends upon the indication for RT/CRT in the clinical practices. In this review, we discuss the options and problems related to both the dose-time fractionation schedule and time to surgery; furthermore, it addresses the research questions that need answering in the future.

A systematic review and meta-analysis of stereotactic body radiation therapy for colorectal pulmonary metastases

Background

There is growing evidence to support the hypothesis that radical treatment of pulmonary oligometastatic disease with stereotactic body radiation therapy (SBRT) can improve oncological outcomes. However, some reports suggest colorectal cancer (CRC) pulmonary metastases are associated with radioresistance. The present systematic review aimed to assess the local control (LC), overall survival (OS), and progression-free survival (PFS) of patients with CRC pulmonary metastases treated by SBRT. Secondary outcomes included assessment of peri-procedural complications and identification of prognostic factors on LC.

Methods

Electronic databases were systematically searched from their dates of inception using predefined criteria. Summative statistical analysis was performed for patients with CRC pulmonary metastases, and comparative meta-analysis was performed for patients with CRC versus non-CRC pulmonary metastases.

Results

Using predefined criteria, 18 relevant studies were identified from the existing literature. LC for CRC pulmonary metastases treated by SBRT at 1-, 2-, and 3-year were estimated to be 81%, 66%, and 60%, respectively. OS and PFS at 3-year were 52% and 13%, respectively. Patients with CRC pulmonary metastases were associated with significantly lower LC compared to non-CRC pulmonary metastases [HR, 2.93; 95% confidence interval (CI), 1.93-4.45; P<0.00001], but higher OS (HR, 0.61; 95% CI, 0.45-0.82; P=0.001). There were no reported periprocedural mortalities and low incidences of periprocedural morbidities.

Conclusions

These findings may have implications for patient and treatment selection, dose fractionation, and support the hypothesis that CRC pulmonary metastases may require higher biological effective doses while respecting normal tissue constraints when treated with SBRT.

A meta-analysis of stereotactic radiotherapy for pulmonary oligometastases from colorectal cancer

BACKGROUND

For patients with colon cancer with lung metastasis, conventional radiotherapy is commonly used, which mainly acts on the double-stranded DNA inside the tumor cells. However, many foreign studies have found that increasing the dose of radiotherapy cannot improve the prognosis of patients, and because of its side effects on normal tissues, the commonly used dose of radiotherapy is usually between 60 and 70 Gy. However, the local control of lung tumors using this dose is not good. With the rapid development of science and technology, stereotactic body radiotherapy (SBRT) technology has been widely used in patients with non-small cell lung cancer, and SBRT is also used in patients with colon cancer and lung metastasis. However, some studies have found that because there are more hypoxic cells in colon cancer tissues than in other tissues, and hypoxic cells are relatively insensitive to radiation, the efficacy of SBRT in patients with lung metastasis from colon cancer is worse than that in patients with lung metastasis from other sites. However, this conclusion is controversial. There is no definite conclusion about the optimal dose of radiotherapy. Some studies have found that increasing the dose of radiotherapy can improve the prognosis of patients with colon cancer and lung metastasis. However, this conclusion is controversial. On the basis of many studies both in China and other countries, this study made a meta-analysis on the efficacy of SBRT in the treatment of colon cancer with lung metastasis and non-colon cancer with lung metastasis, as well as a comparison of the efficacy of different radiation doses in the treatment of colon cancer with lung metastasis, in order to provide evidence-based medicine-related evidence.

AIM

To compare the efficacy of stereotactic radiotherapy for colon cancer with lung metastasis and non-colon cancer with lung metastasis (Study 1), and to compare the efficacy of different doses of radiotherapy for colon cancer with lung metastasis (Study 2).

Methods

The controlled trials including cases with pulmonary oligometastases from colon cancer published from January 2008 to December 2018 were searched according to the method of the Cochrane Collaboration, and meta-analysis was carried out by using RevMan5.3 software.

Results

Fourteen studies were included, of which nine were included in Study 1, involving 486 patients with colon cancer and 938 with non-colon cancer, and five were included in Study 2, involving 157 patients treated with high doses and 185 treated with low doses. Meta-analysis indicated that the clinical efficacy of stereotactic radiotherapy for pulmonary oligometastases from colorectal was significantly lower than that for pulmonary oligometastases from other cancers, and that the efficacy of high doses was significantly better than that of low doses (P < 0.05).

Conclusion

SBRT has worse efficacy for pulmonary oligometastases from colorectal than for those from other cancer, and better efficacy for pulmonary oligometastases from colon cancer can be achieved by dose escalation.

Stereotactic Radiotherapy for Pulmonary Oligometastases From Colorectal Cancer: A Systematic Review and Meta-Analysis

PURPOSE

The purpose of this study was to determine whether pulmonary oligometastases from colorectal cancer have greater radioresistance than that of pulmonary oligometastases from other cancers and whether good local control can be achieved by dose escalation in stereotactic body radiotherapy.

MATERIALS AND METHODS

This systematic review and meta-analysis were conducted according to the preferred reporting items for systematic reviews and meta-analyses statement and methods. Studies were obtained from a database search of PubMed, Web of Science, and Google Scholar for publications using search terms designed to identify studies on "oligometastases," "lung," "stereotactic radiotherapy," and "colorectal cancer." For meta-analysis 1, studies that showed the number of local failures after stereotactic body radiotherapy for pulmonary metastases from colorectal carcinoma and other cancers were included. For meta-analysis2, studies in which a comparison was made of local control rates of pulmonary metastases from colorectal carcinoma by stereotactic body radiotherapy with a higher dose and that with a lower dose were included. A meta-analysis was performed using Mantel-Haenszel statics with the fixed or random-effect model by Review Manager 5.3.

RESULTS

Eighteen retrospective studies with 1920 patients with pulmonary oligometastases were used in meta-analysis 1. The local control rate in patients with pulmonary oligometastases from colorectal cancer was significantly lower than that in patients with pulmonary oligometastases from other cancers (odds ratio = 3.10, P < .00001). Next, 8 retrospective studies with 478 patients were included in meta-analysis 2 for dose escalation. Better local control was achieved by a higher prescription dose than by a lower prescription dose (odds ratio = 0.16, P < .00001).

CONCLUSION

Our meta-analysis indicated that local control of pulmonary oligometastases from colorectal cancer by stereotactic body radiotherapy was significantly worse than that of pulmonary metastases from other cancers; however, our results also indicated that good local control of pulmonary oligometastases from colorectal cancer can be achieved by dose escalation.

Predictive factors for survival of oligometastatic colorectal cancer treated with Stereotactic body radiation therapy

BACKGROUND AND PURPOSE

Colorectal cancer (CRC) represents one of the major leading causes of death from cancer. Aim of the present study was to analyze outcome of oligometastatic CRC patients treated with stereotactic body radiation therapy (SBRT), and to evaluate predictive factors of survival.

MATERIALS AND METHODS

We included patients with maximum 5 metastases. Previous/concomitant systemic treatments were allowed. End points of the present study were the outcome in terms of Local control of treated metastases (LC), progression free survival (PFS), and overall survival (OS).

RESULTS

437 metastases were treated in 270 patients. Lung was site of metastases in 48.5% of cases, followed by liver (36.4%). Systemic treatment was administered before SBRT in 199 patients (73.7%). Median follow-up time was 23 months (3-98.7). Rates of LC at 1, 3 and 5 years were 95%, 73% and 73%, respectively. Time from diagnosis of metastases to SBRT was the only factor predictive of LC (HR 1.62, p = 0.023). Median PFS was 8.6 months. Rates of OS at 1, 3 and 5 years were 88.5%, 56.6%, and 37.2%, respectively. Lesion greater than 30 mm (HR 1.82, p = 0.030), presence of non-lung metastases (HR 1.67, p = 0.020), the use of systemic treatment before SBRT (HR 1.82, p = 0.023), and progression of treated metastases (HR 1.80, p = 0.007), were all predictive of worse OS.

CONCLUSIONS

Stereotactic body radiation therapy represents an effective approach in the management of oligometastatic CRC. Control of treated oligometastases seems to be a strong positive predictive factor for both PFS and OS.

Integration of stereotactic radiotherapy in the treatment of metastatic colorectal cancer patients: a real practice study with long-term outcome and prognostic factors

Background

There are very few clinical or prognostic studies on the role of SRT (Stereotactic Radiation Therapy) in the continuum of care of metastatic colorectal cancer (mCRC) patients.

Patients and methods

Patients affected by oligo-mCRC were treated with SRT before or after front-line standard treatments. SRT was delivered according to a risk-adapted protocol. Total body CT (Computed Tomography) scan was done before therapy and every three months thereafter. The radiologic responses to therapy were evaluated by RECIST (Response Evaluation Criteria In Solid Tumors). FDG-PET (FluoroDeoxyGlucose - Positron Emission Tomography) was done before and after SRT; metabolic responses were evaluated by using the EORTC (European Organization for Research and Treatment of Cancer) criteria. The Kaplan-Meier product limit method was applied to graph Overall Survival (OS) and Progression-Free Survival (PFS).

Results

Forty-seven patients were included. Twenty-one patients had disease limited to lungs, 9 to lung and liver, 7 only to liver, 10 to multiple sites. The median prescription SRT dose was 60 Gy per organ in 3 fractions (median biological effective dose of 180 Gy). The reduction of delta SUVmax (maximum Standardized Uptake Value) correlated with the local control (p<0.001) and two-years survival (p=0.003). At univariate analysis, localization of primary tumor, site of metastases, KRAS (Kirsten RAt Sarcoma) oncogene mutational status, response to first-line chemotherapy, response to SRT and number of treated lesions predicted both PFS and OS.

Discussion

This real practice experience suggests that further studies are needed to analyze the promising role of SRT in the multidisciplinary management of mCRC.

A matched-pair analysis of stereotactic body radiotherapy (SBRT) for oligometastatic lung tumors from colorectal cancer versus early stage non-small cell lung cancer

BACKGROUND

The use of stereotactic body radiotherapy (SBRT) for early-stage primary non-small cell lung cancer (NSCLC) reported excellent local control rates. But the optimal SBRT dose for oligometastatic lung tumors (OLTs) from colorectal cancer (CRC) has not yet been determined. This study aimed to evaluate whether SBRT to a dose of 48-60 Gy in 4-5 fractions could result in similar local outcomes for OLTs from CRC as compared to early-stage NSCLC, and to examine potential dose-response relationships for OLTs from CRC.

METHODS

OLTs from CRC and primary NSCLCs treated with SBRT to 48-60 Gy in 4-5 fractions at a single institution were evaluated, and a matched-pair analysis was performed. Local recurrence-free survival (LRFS) was estimated by the Kaplan-Meier method. Univariate Cox regression was performed to identify significant predictors.

RESULTS

There were 72 lung lesions in 61 patients (24 OLTs from CRC in 15 patients and 48 NSCLCs in 46 patients) were analyzed with a median follow-up of 30 months. LRFS for OLTs from CRC was significantly worse than that of NSCLC when treated with 48-60 Gy/4-5 fx (p = 0.006). The 1, 3 and 5-year LRFS of OLTs from CRC vs NSCLC were 80.6% vs. 100%, 68.6% vs. 97.2%, and 68.6% vs. 81.0%, respectively. On univariate analysis, OLTs from CRC treated with higher dose (BED₁₀ = 132 Gy) exhibited significantly better local recurrence-free survival than those treated to lower doses (BED₁₀ ≤ 105.6 Gy) (p = 0.0022). The 1 and 3-year LRFS rates for OLTs treated to a higher dose (BED₁₀ = 132 Gy) were 88.9% and 81.5%, vs 33.3%, and not achieved for lower doses (BED₁₀ ≤ 105.6 Gy).

CONCLUSION

The LRFS of OLTs from CRC after SBRT of 48-60 Gy/4-5 fx was significantly worse than that of primary NSCLC. Lower dose SBRT appeared to have inferior control for OLTs of CRC in this cohort. Further studies with larger sample sizes are needed.

Presentation, diagnosis and treatment of colorectal cancer

Colorectal (bowel) cancer remains a common disease, particularly in developed countries. If diagnosed early, it has a high five-year survival rate, yet the disease remains a significant cause of mortality. This article aims to improve nurses' understanding of the signs and symptoms of colorectal cancer, and the role of all nurses in supporting early diagnosis and providing follow-up care. It also discusses the available treatment options for colorectal cancer, enabling nurses to offer informed care to patients, who in turn, can make informed decisions about their treatment.

Increased efficacy of stereotactic ablative radiation therapy after bevacizumab in lung oligometastases from colon cancer

Aim:

Metastases from colorectal cancer are poorly responsive to stereotactic ablative radiation therapy (SABR) due to intratumoral hypoxia. Intratumoral oxygenation is improved by administration of angiogenesis inhibitors. Thus, there could be a clinical synergistic effect of SABR with bevacizumab on metastases from colorectal cancer. The aim of this study was to evaluate the feasibility and efficacy of SABR after bevacizumab in lung oligometastases from colon cancer.

Methods:

The data of patients with lung metastases from colon cancer who underwent SABR were retrospectively evaluated according to the following inclusion criteria: number of metastases ≤3; lung oligometastases from colon cancer in patients who underwent SABR; patients receiving previous chemotherapy alone or in combination with bevacizumab; Karnofsky performance status >80; life expectancy >6 months; at least 6 months’ follow-up after SABR; presence of KRAS mutation. The results were compared with those of a similar cohort of patients with irradiated lung lesions from colorectal cancer in whom bevacizumab was not previously administered.

Results:

A total of 40 lung metastases were analyzed. The complete response rate after SABR was higher in patients who had received bevacizumab than in those who had not (p = 0.04). Additionally, in the bevacizumab group, a higher rate of post-SABR complete response was observed in case of oligopersistent versus oligorecurrent metastases (p = 0.001).

Conclusions:

In the setting of lung oligometastases from colon cancer the present study attested the higher efficacy of SABR after bevacizumab administration. Further studies in this field of research are strongly advocated.

Radiosensitivity of Lung Metastases by Primary Histology and Implications for Stereotactic Body Radiation Therapy Using the Genomically Adjusted Radiation Dose

INTRODUCTION

We assessed the radiosensitivity of lung metastases on the basis of primary histologic type by using a validated gene signature and model lung metastases for the gnomically adjusted radiation dose (GARD).

METHODS

Tissue samples were identified from our prospective observational protocol. The radiosensitivity index (RSI) 10-gene assay was run on samples and calculated alongside the GARD by using the previously published algorithms. A cohort of 105 patients with 137 lung metastases treated with stereotactic body radiation therapy (SBRT) at our institution was used for clinical correlation.

RESULTS

A total of 138 unique metastatic lung lesions from our institution's tissue biorepository were identified for inclusion. There were significant differences in the RSI of lung metastases on the basis of histology. In order of decreasing radioresistance, the median RSIs for the various histologic types of cancer were endometrial adenocarcinoma (0.49), soft-tissue sarcoma (0.47), melanoma (0.44), rectal adenocarcinoma (0.43), renal cell carcinoma (0.33), head and neck squamous cell cancer (0.33), colon adenocarcinoma (0.32), and breast adenocarcinoma (0.29) (p = 0.002). We modeled the GARD for these samples and identified the biologically effective dose necessary to optimize local control. The 12- and 24-month Kaplan-Meier rates of local control for radioresistant versus radiosensitive histologic types from our clinical correlation cohort after lung SBRT were 92%/87% and 100%, respectively (p = 0.02).

CONCLUSIONS

In this analysis, we have noted significant differences in radiosensitivity on the basis of primary histologic type of lung metastases and have modeled the biologically effective dose necessary to optimize local control. This study suggests that primary histologic type may be an additional factor to consider in selection of SBRT dose to the lung and that dose personalization may be feasible.

Impact of Right-sided Primary Tumor Location Among Patients With Oligometastatic Colorectal Cancer Treated With Stereotactic Body Radiotherapy

INTRODUCTION

Among patients with colorectal cancer, those with right-sided primary tumors have worse outcomes in both the primary and metastatic setting. Patients with oligometastatic colorectal cancer (OMCC) have improved prognosis relative to those with diffusely metastatic disease. We aimed to assess if the trend toward worse outcomes with right-sided tumors remained in the oligometastatic setting.

PATIENTS AND METHODS

We analyzed 31 patients treated at a single institution with stereotactic body radiotherapy for OMCC from 2011 to 2014 to assess the impact that primary tumor location had on overall survival (OS) and progression-free survival (PFS).

RESULTS

Overall, patient local control was fair (66% at 2 y); however, distant control was only 37.4% at 2 years. The median OS was 2.4 years; the median PFS was 6.5 months. Patients with right-sided primary tumors had numerically worse median OS than those with left-sided or rectal primary tumors (1.4 vs. 3.7 y, P=0.09). Median PFS was significantly worse among those with right-sided primaries (2.9 vs. 10.8 mo, P=0.05). This held on multivariate analysis.

CONCLUSIONS

These results affirm that patients with OMCC have extended OS periods and that stereotactic body radiotherapy offers strong local control in these settings. We show that even in the oligometastatic setting those with right-sided primary tumors have worse outcomes relative to those with left-sided or rectal primary tumors. This suggests more aggressive treatment may be needed for those with oligometastatic right-sided colorectal cancer.

Flattening filter-free technique in volumetric modulated arc therapy for lung stereotactic body radiotherapy: A clinical comparison with the flattening filter technique

The present study sought to evaluate the impact of the flattening filter-free (FFF) technique in volumetric modulated arc therapy for lung stereotactic body radiotherapy. Its clinical safety and availability were compared with the flattening filter (FF) method. The cases of 65 patients who underwent lung volumetric modulated arc therapy-stereotactic body radiotherapy (VMAT-SBRT) using FF or FFF techniques were reviewed. A total of 55 Gy/4 fractions (fr) was prescribed for peripheral lesions or 56 Gy/7 fr for central lesions. The total monitor units (MU), treatment time, dose to tumors, dose to organs at risk, tumor control (local control rate, overall survival, progression-free survival) and adverse events between cases treated with FF and cases treated with the FFF technique were compared. A total of 35 patients were treated with conventional FF techniques prior to November 2014 and 30 patients were treated with FFF techniques after this date. It was revealed that the beam-on time was significantly shortened by the FFF technique (P<0.01). Other factors were similar for FFF and FF plans in respect to conformity (P=0.95), homogeneity (P=0.20) and other dosimetric values, including total MU and planning target volume/internal target volume coverage. The median follow-up period was 18 months (range, 2-35). One-year local control rates were 97.1 and 90.0% in the FF group and FFF groups, respectively (P=0.33). Grade 3 pneumonitis was observed in 5.8% of FF patients and 3.4% of FFF patients (P=1.00). No other adverse events ≥grade 3 were observed. The results of the study suggest that VMAT-SBRT using the FFF technique shortens the treatment time for lung SBRT while maintaining a high local control rate with low toxicity.

Stereotactic body radiation therapy for liver oligo-recurrence and oligo-progression from various tumors

Purpose

To evaluate the outcomes of stereotactic body radiation therapy (SBRT) for patients with liver oligo-recurrence and oligo-progression from various primary tumors.

Materials and Methods

Between 2002 and 2013, 72 patients with liver oligo-recurrence (oligo-metastasis with a controlled primary tumor) and oligo-progression (contradictory progression of a few sites of disease despite an overall tumor burden response to therapy) underwent SBRT. Of these, 9 and 8 patients with uncontrollable distant metastases and patients immediate loss to follow-up, respectively, were excluded. The total planning target volume was used to select the SBRT dose (median, 48 Gy; range, 30 to 60 Gy, 3–4 fractions). Toxicity was evaluated using the Common Toxicity Criteria for Adverse Events v4.0.

Results

We evaluated 55 patients (77 lesions) treated with SBRT for liver metastases. All patients had controlled primary lesions, and 28 patients had stable lesions at another site (oligo-progression). The most common primary site was the colon (36 patients), followed by the stomach (6 patients) and other sites (13 patients). The 2-year local control and progression-free survival rates were 68% and 22%, respectively. The 2- and 5-year overall survival rates were 56% and 20%, respectively. The most common adverse events were grade 1–2 fatigue, nausea, and vomiting; no grade ≥3 toxicities were observed. Univariate analysis revealed that oligo-progression associated with poor survival.

Conclusion

SBRT for liver oligo-recurrence and oligo-progression appears safe, with similar local control rates. For liver oligo-progression, criteria are needed to select patients in whom improved overall survival can be expected through SBRT.

Radiobiological parameters of liver and lung metastases derived from tumor control data of 3719 metastases

BACKGROUND AND PURPOSE

The radiobiological parameters for liver and lung metastases treated with stereotactic body radiation therapy (SBRT) are poorly defined. This project aimed at estimating these parameters from published tumor control probability (TCP) data, and separately for metastases with colorectal cancer (CRC) and non-CRC histology.

MATERIALS AND METHODS

A total of 62 studies with 89 different treatment prescriptions for a total of 3719 metastases were analyzed in a Bayesian framework using four different radiobiological models: The LQ, mLQ, LQ-L and the regrowth model which accounts for tumor regrowth after SBRT.

RESULTS

Depending on the particular model, α/β ratios in the range 13-23Gy for pulmonary metastases and 16-28Gy for hepatic metastases were estimated. For CRC metastases the estimated α/β ratio was 43.1±4.7Gy compared to 21.6±7.8Gy for non-CRC metastases. Typical isocenter dose prescriptions of 3×12Gy, 3×14.5Gy and 3×17Gy applied within 5days were predicted sufficient to control 90% of lung, liver and CRC metastases after 1yr, respectively.

CONCLUSIONS

α/β ratios for liver and lung metastases are higher than the usually assumed 10Gy. Differences between CRC and non-CRC histology were found. Future studies confirming these findings in individual patient data are needed.