Where Are We Now and Where Might We Be Headed in Understanding and Managing Brain Metastases in Colorectal Cancer Patients?

Clinical, Radiologic, and Surgical Features of Brain Metastases in Colorectal Cancer. A Strong Correlation Between Surgical Patterns and Outcome

BACKGROUND

Brain metastases (BMs) from colorectal cancer (CRC) are a small percentage of metastatic patients and surgery is considered the best choice to improve survival. While most research has focused on the risk of CRC spreading to the brain, no studies have examined the characteristics of BMs in relation to surgery and outcome. In this study, we evaluate the clinical and radiologic features of BMs from CRC patients who underwent surgery and analyze their outcomes.

METHODS

The study is a retrospective observational analysis that included a cohort of 31 patients affected by CRC surgically-treated for their related BMs. For all patients, clinical and surgical data (number, site, side, tumor and edema volume, and morphology) were recorded.

RESULTS

Analysis found that synchronous diagnosis and lesion morphology, particularly cystic versus solid, had the most significant impact on survival (6 vs. 22 months, P = 0.04). To compare BMs with cystic morphology to those with solid morphology, a multivariate analysis was conducted. No significant differences were observed between the 2 groups in terms of age, sex, clinical onset, or performance status. The analysis revealed no significant differences in localization with regard to site, tumor and edema volume, biology, or complications rate.

CONCLUSIONS

BMs derived from CRC have a significantly different prognosis depending on whether they present as a solid or cystic pattern. Although solid pattern is more common, cystic BMs in this tumor type are less frequent and are associated with a poorer prognosis, regardless of molecular expression, location, size, and adjuvant treatment.

BRAF V600E-mutant colorectal cancer with CNS metastases treated successfully with encorafenib, binimetinib and cetuximab

This report describes a case of BRAF V600E-mutated colorectal cancer with CNS metastases in which treatment with encorafenib, binimetinib and cetuximab was effective. There is limited information on the ability of encorafenib, binimetinib and cetuximab to enter the CNS.The patient was a 53-year-old man was diagnosed with ascending colon cancer (cT3N3M1c stage IVc). BRAF V600E mutation was confirmed. FOLFOX was started, but CNS metastases soon appeared. Encorafenib, binimetinib and cetuximab were administered and had a favorable effect on the CNS lesions. The patient initially responded well, but his disease progressed 2 months later. Further research is needed to improve management strategies for BRAF V600E-mutated colorectal cancer with CNS metastases.

A case of dMMR/MSI-H/TMB-H colon cancer with brain metastasis treated with PD-1 monoclonal antibody

A 70-year-old man had radical surgery for colon cancer one year before the symptoms of memory loss and decreasing cognitive function. Subsequent magnetic resonance imaging revealed a brain mass, which was surgically resected and confirmed to be metastatic intestinal adenocarcinoma. Immunohistochemistry of the primary tumor and brain metastasis showed mismatch repair deficiency. The patient received adjuvant chemotherapy after surgery. However, the brain metastasis relapsed one month after the last chemotherapy. Genetic testing on the resected colon tumor samples confirmed microsatellite instability-high with a high tumor mutation burden by 77.7 muts/Mb. The patient was subsequently treated with programmed death-1 (PD-1) monoclonal antibody pembrolizumab (keytruda). The brain metastatic lesions were completely shrunk, and a complete clinical response was achieved.

Harnessing immunotherapy for brain metastases: insights into tumor-brain microenvironment interactions and emerging treatment modalities

Brain metastases signify a deleterious milestone in the progression of several advanced cancers, predominantly originating from lung, breast and melanoma malignancies, with a median survival timeframe nearing six months. Existing therapeutic regimens yield suboptimal outcomes; however, burgeoning insights into the tumor microenvironment, particularly the immunosuppressive milieu engendered by tumor-brain interplay, posit immunotherapy as a promising avenue for ameliorating brain metastases. In this review, we meticulously delineate the research advancements concerning the microenvironment of brain metastases, striving to elucidate the panorama of their onset and evolution. We encapsulate three emergent immunotherapeutic strategies, namely immune checkpoint inhibition, chimeric antigen receptor (CAR) T cell transplantation and glial cell-targeted immunoenhancement. We underscore the imperative of aligning immunotherapy development with in-depth understanding of the tumor microenvironment and engendering innovative delivery platforms. Moreover, the integration with established or avant-garde physical methodologies and localized applications warrants consideration in the prevailing therapeutic schema.

Concomitant radiosurgical and targeted oncological treatment improves the outcome of patients with brain metastases from gastrointestinal cancer

BACKGROUND

So far, only limited studies exist that evaluate patients with brain metastases (BM) from GI cancer and associated primary cancers who were treated by Gamma Knife Radiosurgery (GKRS) and concomitant immunotherapy (IT) or targeted therapy (TT).

METHODS

Survival after GKRS was compared to the general and specific Graded Prognostic Assessment (GPA) and Score Index for Radiosurgery (SIR). Further, the influence of age, sex, Karnofsky Performance Status Scale (KPS), extracranial metastases (ECM) status at BM diagnosis, number of BM, the Recursive Partitioning Analysis (RPA) classes, GKRS1 treatment mode and concomitant treatment with IT or TT on the survival after GKRS was analyzed. Moreover, complication rates after concomitant GKRS and mainly TT treatment are reported.

RESULTS

Multivariate Cox regression analysis revealed IT or TT at or after the first Gamma Knife Radiosurgery (GKRS1) treatment as the only significant predictor for overall survival after GKRS1, even after adjusting for sex, KPS group, age group, number of BM at GKRS1, RPA class, ECM status at BM diagnosis and GKRS treatment mode. Concomitant treatment with IT or TT did not increase the rate of adverse radiation effects. There was no significant difference in local BM progression after GKRS between patients who received IT or TT and patients without IT or TT.

CONCLUSION

Good local tumor control rates and low rates of side effects demonstrate the safety and efficacy of GKRS in patients with BM from GI cancers. The concomitant radiosurgical and targeted oncological treatment significantly improves the survival after GKRS without increasing the rate of adverse radiation effects. To provide local tumor control, radiosurgery remains of utmost importance in modern GI BM management.

Immunotherapy as a promising treatment strategy for dmmr colorectal cancer with brain metastasis: a case report

Brain metastasis in colorectal cancer is a rare occurrence with poor prognosis and limited treatment options. This case report presents a unique and previously unreported case of brain metastasis in a patient with dMMR (DNA mismatch repair-deficient) colorectal cancer. The patient, a 70-year-old male, initially presented with abdominal pain and was diagnosed with moderately differentiated adenocarcinoma of the right colon. Following surgical resection and adjuvant chemotherapy, the patient developed cognitive decline and was found to have a metastatic lesion in the left temporal lobe. Immunohistochemical analysis revealed MSH2 positivity and MSH6, MLH1, and PMS2 negativity, indicating dMMR status. Further genetic testing showed wild-type Kras, Nras, and Braf, and high tumor mutational burden (TMB). The patient was subsequently treated with pembrolizumab immunotherapy, resulting in a significant improvement of symptoms and a reduction in the size of brain metastasis. This case highlights the rarity and challenging management of brain metastasis in colorectal cancer, particularly in the context of dMMR tumors. The successful use of immunotherapy in this case provides valuable insights into the potential efficacy of immune-based treatments for dMMR colorectal cancer with brain metastasis, underscoring the need for further research in this field.

Five-Fraction Radiosurgery Using a Biologically Equivalent Dose of a Single Fraction of 24 Gy for a 3-cm Parasagittal Para-Central Sulcus Brain Metastasis From Adenocarcinoma of the Cecum

An isolated single brain metastasis (BM) is an extremely rare manifestation of failure in patients with cecal adenocarcinoma (CAC). Total en bloc resection (while preserving function) of a 3-cm BM involving both the primary motor and sensory cortexes presents a conundrum: achieving long-term local control and safety of such a BM is also challenging for stereotactic radiosurgery (SRS). We describe the case of a 3.1-cm BM from CAC in the left parasagittal para-central sulcus region, which was treated using five-fraction SRS with a biologically effective dose (BED) of 81.6 Gy. In the SRS, the gross tumor volume (GTV, 7.14 cm3) was defined based on computed tomography (CT)/T1/T2 matching (enhancing lesion 11.66 cm3), and 98.7% of the GTV (CT/T2 mass) was covered with 43.6 Gy (58% isodose) using volumetric-modulated arcs. The maximum tumor response was partial (19.7% of the prior GTV) and sustained for 15.2 months, leaving minor neurological symptoms. However, the patient developed neurological worsening at six months, attributed to adverse radiation effects with a CT/T1/T2 mismatch, for which medical management, including the addition of bevacizumab (BEV), was effective for one year. Multi-fraction SRS with a high marginal and internal BED and sequential systemic therapy, including BEV, can be a minimally invasive, efficacious, and durable treatment option for a large CAC-BM involving the central sulcus. Early co-administration of BEV following SRS, dose escalation to the GTV boundary, and more than five fractions of SRS may be considered to improve the efficacy and safety further.

Local Control and Survival Outcomes After Stereotactic Radiosurgery for Brain Metastases From Gastrointestinal Primaries: An International Multicenter Analysis

BACKGROUND

There are limited data regarding outcomes for patients with gastrointestinal (GI) primaries and brain metastases treated with stereotactic radiosurgery (SRS).

OBJECTIVE

To examine clinical outcomes after SRS for patients with brain metastases from GI primaries and evaluate potential prognostic factors.

METHODS

The International Radiosurgery Research Foundation centers were queried for patients with brain metastases from GI primaries managed with SRS. Primary outcomes were local control (LC) and overall survival (OS). Kaplan-Meier analysis was used for univariate analysis (UVA) of prognostic factors. Factors significant on UVA were evaluated with a Cox multivariate analysis proportional hazards model. Logistic regressions were used to examine correlations with RN.

RESULTS

We identified 263 eligible patients with 543 brain metastases. Common primary sites were rectal (31.2%), colon (31.2%), and esophagus (25.5%) with a median age of 61.6 years (range: 37-91.4 years) and a median Karnofsky performance status (KPS) of 90% (range: 40%-100%). One-year and 2-year LC rates were 83.5% (95% CI: 78.9%-87.1%) and 73.0% (95% CI: 66.4%-78.5%), respectively. On UVA, age >65 years ( P = .001), dose <20 Gy ( P = .006) for single-fraction plans, KPS <90% ( P < .001), and planning target volume ≥2cc ( P = .007) were associated with inferior LC. All factors other than dose were significant on multivariate analysis ( P ≤ .002). One-year and 2-year OS rates were 68.0% (95% CI: 61.5%-73.6%) and 31.2% (95% CI: 24.6%-37.9%), respectively. Age > 65 years ( P = .006), KPS <90% ( P = .005), and extracranial metastases ( P = .05) were associated with inferior OS.

CONCLUSION

SRS resulted in comparable LC with common primaries. Age and KPS were associated with both LC and OS with planning target volume and extracranial metastases correlating with LC and OS, respectively. These factors should be considered in GI cancer patient selection for SRS.

Clinical features and prognostic factors of brain metastases from colorectal cancer: a single center experience

PURPOSE

The study aimed to investigate the clinical characteristics, prognostic factors, survival times, and therapy outcomes of brain metastases (BM) from colorectal cancer (CRC).

METHODS

The clinical characteristics of 25 patients with BM from CRC were retrospectively analyzed. The time of the occurrence of BM after diagnosis of CRC was recorded. Meanwhile, the time from the occurrence of lung, bone, liver, and other extracranial metastases to the occurrence of BM was also recorded. We evaluate the time factors affecting the length of the occurrence of BM and the potential prognostic factors after BM diagnosis. The influences of patients undergoing surgery-based comprehensive treatment, radiotherapy-based comprehensive treatment, and co-medication were also assessed.

RESULTS

In patients with BM from CRC, lung metastases (13/25) occurred at a higher frequency than liver metastases (8/25) and bone metastases (6/25). The median time to the development of BM was much shorter (3.7 vs. 25.3 months, p = 0.027), with the brain being the origin site for the metastasis. The median overall survival reached 9.9 months. The interval between diagnosis of BM and bone, liver, and lung metastasis remains 3, 6.5, and 11 months, respectively. The brain lesions of patients with BM alone had higher rates in supratentorial (88.9%), while those with extracranial metastasis had a 62.5% incidence of infratentorial metastasis. The difference was statistically significant (p < 0.05). The time of occurrence of BM in patients aged 67 years and younger was 16.1 and 30.1 months, respectively. The differences between them were statistically significant (p = 0.043). The BM time for left- and right-sided colon cancer were 26.5 and 7.8 months, representing a statistically significant difference (p = 0.015). The time to onset of BM for patients with and without the resection of primary lesions was 25.4 and 4.5 months. Statistically significant differences are shown (p = 0.007). Univariate analysis demonstrated that the prognosis of patients was related to the KPS score, the number of BM, the treatment methods, and the occurrence of lung metastasis (p < 0.05). The multivariate analysis revealed that the treatment modality and lung metastasis were independent prognostic factors for CRC patients with BM. Right-sided CRC patients with BM have a poor prognosis (8.1 vs. 10.2 months, p = 0.31). Although median survival time was not significantly different between patients with and without bevacizumab combination therapy, bevacizumab therapy is associated with a better survival time (9.9 vs. 7.1 months, p = 0.27).

CONCLUSION

Patients with left-sided CRC, especially those with lung metastases, are prone to brain metastases, and patients with brain metastases as the first metastatic site have a higher rate of supratentorial metastases. Young patients with right hemicolon cancer and patients who have not undergone primary lesion resection have a shorter time for the occurrence of BM. Patients with colorectal lung metastases, especially those young with right-sided CRC, require close imaging surveillance of BM. The prognosis of CRC patients with BM and lung metastases is poor, and comprehensive treatment based on surgery could significantly prolong patients' survival time.

Primary Colorectal Tumor Location and Predictors for Metastasis to the Brain

Introduction Although rectal cancer is thought to have a higher rate of metastasis to the brain compared with colon cancer, there is limited and contradictory data on the subject. This study aims to determine the prevalence of brain metastasis for colon and rectal cancers (CRC), and to explore associations and predictors of brain metastasis (BM). Methods The 2010-2016 National Cancer Database (NCDB) was queried for patients with stage IV CRC. Patients with missing data on site of metastasis and primary tumor location were excluded. Chi-square test was used for categorical data and multivariate logistic regression analysis was performed to evaluate the predictors of BM. Results Of 108,540 stage IV CRC patients, the prevalence of BM was 1.21% from the right colon, 1.29% from the left colon, and 1.59% from the rectal adenocarcinoma (p<0.001). The presence of lung, bone, and liver metastases were the strongest predictors for BM. Bone and lung metastases increased the odds for BM by 3.87 (95% CI: 3.36-4.46) and 3.38 (95% CI: 3.01-3.80), respectively while the presence of liver metastasis decreased odds for BM by 55% (OR: 0.45; 95% CI: 0.40-0.50). On multivariate analysis, primary tumor location was not predictive of BM. Discussion This study helps to characterize the prevalence and associations of BM from CRC using the NCDB. The correlation between BM and bone and lung metastases, along with negative association of liver metastasis further supports the hypothesis of systemic transmission of tumor cells. Further identification of predictors and correlations with BM may help guide surveillance among patients with advanced CRC.

Single-fraction SRS and multiple-fraction SRT for brain metastases from colorectal cancer

Objective

Brain metastasis from colorectal cancer (CRC) is rare. Although stereotactic radiotherapy (SRT) and stereotactic radiosurgery (SRS) are effective treatments for brain metastasis, reports on brain metastasis of CRC are limited. This study compared the efficacy of SRT and SRS for the treatment of brain metastases from CRC and analysed the related factors to reveal the specificity CRC-derived brain metastasis.

Methods

A retrospective analysis of 116 patients with brain metastases from colorectal cancer was performed and included 56 patients in the SRT group and 60 patients in the SRS group. The clinical characteristics of the two groups were analysed, and the local tumour control rate, overall survival time and radiation-induced brain injury were compared between the two groups.

Results

The objective response rates of the SRT and SRS groups were 76.8% and 66.7%, respectively, while the local control rates at 6 months were 87.5% and 81.6%, respectively, and no significant differences were observed between the groups (P=0.295). The median overall survival time was 10.3 months for all patients and was 10.9 months in the SRT group and 9.8 months in the SRS group, with no significant difference between the groups (P=0.123). A multivariate analysis showed that the main factors of poor prognosis were low GPA score (P=0.002), KRAS mutation (P=0.035), extracranial metastasis (P=0.005) and no bevacizumab treatment (P=0.001). No significant difference was observed in the incidence of acute and late radiation-induced injury between the two groups.

Conclusion

Both SRT and SRS are effective methods for the treatment of CRC-derived brain metastases. The simultaneous use of bevacizumab may be one of the most important factors that affects the survival of these patients.

Primary Tumor Resection Provides Survival Benefits for Patients with Synchronous Brain Metastases from Colorectal Cancer

Background: Brain metastases (BMs), particularly synchronous brain metastases, in colorectal cancer (CRC) patients are uncommon. The survival benefit of primary tumor resection (PTR) in patients with metastatic colorectal cancer is controversial. Whether PTR can bring survival benefits to patients with BMs of CRC has not been reported. Methods: From 2010 to 2016, 581 CRC patients with BMs from the Surveillance, Epidemiology, and End Results (SEER) database were divided into PTR and non-PTR groups. The log-rank test was used to compare the survival distributions. The Kaplan-Meier method was used to estimate survival. By controlling additional prognostic factors, a Cox proportional multivariate regression analysis was used to estimate the survival benefit of PTR. Results: The median overall survival for CRC patients with synchronous BMs was 3 months, with a 1-year survival rate of 27.2% and a 2-year survival rate of 12.8%. The PTR group contained 171 patients (29.4%), whereas the non-PTR group had 410 patients (70.6%). Patients who underwent PTR had a 1-year survival rate of 40.2% compared to 21.7% in those who did not (p < 0.0001). Cox proportional analysis showed that patients ≥60 years (hazard ratio [HR] 1.718, 95% confidence interval [CI] 1.423−2.075, p < 0.0001) had a shorter OS than patients < 60 years of age. OS was better in CEA-negative than in CEA-positive patients (HR 0.652, 95% CI 0.472−0.899, p = 0.009). Patients in whom the primary tumor was removed had considerably improved prognoses (HR 0.654, 95% CI 0.531−0.805, p < 0.0001). Subgroup analysis revealed that the PTR group achieved a survival advantage except for patients with CEA negative. Conclusions: Patients with synchronous BMs from CRC may benefit from primary tumor resection (PTR). Age, CEA level, and PTR were independent prognostic risk factors for CRC patients with synchronous BMs.