Primary Epithelial Hepatic Malignancies: Etiology, Epidemiology, and Outcome after Subtotal and Total Hepatic Resection

Radioembolization for colorectal cancer liver metastases: current role and future opportunities – the medical oncologist’s perspective

SUMMARY 

The liver is the most common and often the only site of metastatic disease in patients with metastatic colorectal cancer. For patients who do not have resectable disease, a number of liver-directed therapies are increasingly being used in routine clinical practice, including yttrium-90 radioembolization. The challenge for the medical oncologist is how best to integrate this promising new option into routine practice in the setting of ever-evolving standard systemic therapy options. Here we review the most recent data on the efficacy and safety of yttrium-90, considerations when selecting patients for treatment and we examine the potential impact of current clinical trials.

Yttrium-90 radioembolization as salvage therapy for colorectal cancer with liver metastases

BACKGROUND

Few patients with metastatic colorectal cancer (mCRC) are candidates for resection of their hepatic disease. Yttrium-90 ((90)Y) radioembolization has promise in the treatment of unresectable mCRC. We conducted a retrospective study to assess the efficacy in patients with refractory mCRC who underwent (90)Y radioembolization.

MATERIALS AND METHODS

Patients with unresectable mCRC with liver metastases treated at The Ohio State University were included in this analysis. Demographic data, carcinoembryonic antigen (CEA) values, observed toxicities, and information on prior therapies were collected. Response was assessed by RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 criteria. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method.

RESULTS

Twenty-four patients (median age, 63 years) were included. Of the patients, 54% had extrahepatic disease; 67% had bilobar involvement. The patients had received a median of 3 prior therapies. No objective responses were observed. Five patients had a CEA response. Median PFS and OS were 3.9 months (95% CI, 2.4-4.8 months) and 8.9 months (95% CI, 4.2-16.7 months), respectively. Patients older than 65 years had improved PFS (4.6 vs. 2.4 months) and OS (14 vs. 5.5 months) vs. younger patients, likely due to receipt of (90)Y treatment earlier in their disease course. The presence of extrahepatic disease and the absence of CEA response appeared negatively predictive of efficacy. Toxicities were expected and manageable.

CONCLUSION

(90)Y radioembolization is active in select patients with refractory mCRC and with liver metastases, and is safe and well tolerated in the elderly. In patients with extensive extrahepatic disease, (90)Y should be used in combination with chemotherapy. CEA may be a predictor of efficacy.

Phase III trial comparing protracted intravenous fluorouracil infusion alone or with yttrium-90 resin microspheres radioembolization for liver-limited metastatic colorectal cancer refractory to standard chemotherapy

PURPOSE

Liver dissemination is a major cause of mortality among patients with advanced colorectal cancer. Hepatic intra-arterial injection of the beta-emitting isotope yttrium-90 ((90)Y) bound to resin microspheres (radioembolization) delivers therapeutic radiation doses to liver metastases with minimal damage to adjacent tissues.

PATIENTS AND METHODS

We conducted a prospective, multicenter, randomized phase III trial in patients with unresectable, chemotherapy-refractory liver-limited metastatic CRC (mCRC) comparing arm A (fluorouracil [FU] protracted intravenous infusion 300 mg/m(2) days 1 through 14 every 3 weeks) and arm B (radioembolization plus intravenous FU 225 mg/m(2) days 1 through 14 then 300 mg/m(2) days 1 through 14 every 3 weeks) until hepatic progression. The primary end point was time to liver progression (TTLP). Cross-over to radioembolization was permitted after progression in arm A.

RESULTS

Forty-six patients were randomly assigned and 44 were eligible for analysis (arm A, n = 23; arm B, n = 21). Median follow-up was 24.8 months. Median TTLP was 2.1 and 5.5 months in arms A and B, respectively (hazard ratio [HR] = 0.38; 95% CI, 0.20 to 0.72; P = .003). Median time to tumor progression (TTP) was 2.1 and 4.5 months, respectively (HR = 0.51; 95% CI, 0.28 to 0.94; P = .03). Grade 3 or 4 toxicities were recorded in six patients after FU monotherapy and in one patient after radioembolization plus FU treatment (P = .10). Twenty-five of 44 patients received further treatment after progression, including 10 patients in arm A who received radioembolization. Median overall survival was 7.3 and 10.0 months in arms A and B, respectively (HR = 0.92; 95% CI, 0.47 to 1.78; P = .80).

CONCLUSION

Radioembolization with (90)Y-resin microspheres plus FU is well tolerated and significantly improves TTLP and TTP compared with FU alone. This procedure is a valid therapeutic option for chemotherapy-refractory liver-limited mCRC.

Liver metastases from colorectal cancer: radioembolization with systemic therapy

The majority of patients with advanced colorectal cancer die from hepatic metastases caused by disease progression; therefore, several novel technologies are in clinical development to potentially improve local control of liver disease. Radioembolization is a technique for administering radiotherapy internally to unresectable primary or secondary hepatic malignancies in a single procedure. This technique involves the injection of resin or glass microspheres that contain (90)Y into the arterial supply of the liver. Clinical trials of radioembolization used with concomitant radiosensitizing chemotherapy have shown promising results in patients with metastatic colorectal cancer. Several reports suggest that radioembolization is associated with significant downsizing of liver metastases to permit subsequent surgical resection. In this article, the rationale for combining radioembolization with the cytotoxic and molecularly targeted agents licensed for the systemic treatment of colorectal cancer is outlined. Clinical data from trials of radioembolization with concomitant systemic treatment are reviewed, with an emphasis on the appropriateness of primary end points in large-scale trials and the practical aspects of surgical resection in patients whose tumors are successfully downsized by this chemoradiation approach.

Salvage radioembolization of liver-dominant metastases with a resin-based microsphere: initial outcomes

PURPOSE

The use of radioembolization of hepatic metastases with yttrium-90 ((90)Y) microspheres is increasing. The present report describes the outcomes in a cohort of patients with metastatic liver tumors treated with a resin-based microsphere agent.

MATERIALS AND METHODS

Thirty patients with colon (n = 13), breast (n = 7), and other primary cancers (n = 10) were treated after the failure of first- and second-line therapy. Overall survival (OS), time to progression (TTP), and time to treatment failure (TTTF) were calculated from the first treatment. Response was measured according to Response Evaluation Criteria In Solid Tumors at interval follow-up imaging.

RESULTS

Thirty patients underwent 56 infusions of (90)Y, and 18 remained alive at the end of the study. Fourteen patients (47%) had a partial response or stable disease. OS (604 vs 251 days), TTP (223 vs 87 days), and TTTF (363 vs 87 days) were all significantly longer for patients who had a partial response or stable disease (P < .05). Median OS, TTP, and TTTF for patients with colorectal carcinoma were 357, 112, and 107 days, respectively, versus 638, 118, and 363 days in patients with other metastatic sources. Median survival was not reached for patients with breast carcinoma, and the TTP and TTTF were each 282 days. One patient (3%) experienced grade 3 toxicity (gastrointestinal ulceration).

CONCLUSIONS

(90)Y microsphere therapy produced promising survival rates compared with systemic salvage options, with minimal toxicity.

Geometric shifting of the porta hepatis during posthepatectomy radiotherapy for biliary tract cancer

PURPOSE

To evaluate geometric shifting of the porta hepatis induced by liver regeneration during radiotherapy (RT) after partial hepatectomy for biliary tract cancer.

METHODS AND MATERIALS

Between August 2004 and August 2005, the study enrolled 10 biliary tract cancer patients who underwent hemihepatectomy or more extensive surgery and were scheduled to receive postoperative RT. All patients received 4500 cGy RT in 25 fractions with concurrent 5-fluorouracil. Before RT and in the third and fifth weeks during RT, the liver volume was determined using CT, and geometric location of the porta hepatis was determined using a conventional simulator.

RESULTS

The liver volume increase during RT was 246.6 +/- 118.2 cm(3). The overall actual shifting length of the porta hepatis was 9.8 +/- 2.5 mm, with right and left hepatectomy causing a 10.1 +/- 1.7 mm shift to the right or 9.2 +/- 4.3 mm shift to the left, respectively. The actual shifting length of the porta hepatis was proportional to the increase in liver volume during RT (r = 0.742, p = 0.014).

CONCLUSION

The results of this study have demonstrated that the porta hepatis can be shifted by liver regeneration after partial hepatectomy. We recommend an additional RT margin or adaptive RT (repeat planning at several intervals during the treatment course) to avoid exclusion of the porta hepatis from the RT target volume after partial hepatectomy for biliary tract cancer.

Resin 90Y-microsphere brachytherapy for unresectable colorectal liver metastases: modern USA experience

PURPOSE

Salvage therapy for patients with unresectable colorectal liver metastases that were refractory to oxaliplatin and irinotecan was performed via radioactive microspheres. High doses of radiation were delivered to tumors from permanently implanted 90Y microspheres, delivered through the hepatic arterial vessels.

METHODS AND MATERIALS

Patients from 7 institutions were selected for treatment after screening-defined vascular access to all the tumors, and imaging-confirmed microspheres would be implanted only in the liver tumors. All patients were followed with laboratory and imaging studies at regular intervals until death. Toxicities, both acute and late, were recorded, and actuarial survival determined.

RESULTS

A total of 208 patients were treated from April 2002 to April 2005. Median follow-up of the 129 men and 79 women is 13 months (range, 1-42 months). Median survival is 10.5 months for responders but only 4.5 months in nonresponders. No treatment-related procedure deaths or radiation-related venoocclusive liver failures were found. Computed tomography partial response was 35%; positron emission tomography response of 91% and reduction in carcinoembryonic antigen of 70% were achieved.

CONCLUSIONS

In this group of heavily pretreated patients, radioactive microspheres produced an encouraging median survival, with acceptable toxicity, and a significant objective response rate, which suggests that further investigation of this approach is warranted.

Hepatic hemorrhage caused by percutaneous tumor ablation: radiofrequency ablation versus cryoablation in a porcine model

PURPOSE

To determine the extent of hepatic hemorrhage caused by percutaneous cryoablation performed with a small-diameter cryoablation probe compared with that caused by percutaneous radiofrequency (RF) ablation in a porcine model.

MATERIALS AND METHODS

The study was pre-approved by the institutional research animal care and use committee, and husbandry and experiments complied with National Institutes of Health standards for care and use of laboratory animals. Percutaneous hepatic ablation was performed in 18 domestic pigs (mean weight, 45 kg) by using a 17-gauge (1.5-mm-diameter) RF electrode (n = 6), a cluster of three RF electrodes (n = 6), or a 13-gauge (2.4 mm-diameter) cryoprobe (n = 6). Ablation was performed in four sites per liver. Total blood loss, minimum lesion diameter, maximum lesion diameter, and lesion volume were determined for each group and compared by using analysis of variance.

RESULTS

Mean blood loss was 11.11 mL +/- 11.47 (standard deviation), 105.29 mL +/- 175.58, and 28.06 mL +/- 30.97 with the single RF electrode, RF electrode cluster, and cryoablation probe, respectively. Mean minimum and maximum lesion diameters were largest with the RF electrode cluster (2.40 and 3.98 cm, respectively), followed by the cryoablation probe (2.38 and 3.94 cm) and single RF electrode (1.49 and 2.63 cm). Mean minimum and maximum lesion diameters were significantly different between the single RF electrode and the RF electrode cluster, as well as between the single RF electrode and the cryoablation probe (P < .001). Mean lesion volume was largest for the RF electrode cluster (24.03 cm3), followed by those for the cryoablation probe (17.46 cm3) and single RF electrode (9.05 cm3) (single RF electrode vs cryoablation probe, P < .05). Lesion volumes were not significantly different with the RF electrode cluster versus the single RF electrode (P = .052) or with the RF electrode cluster versus the cryoablation probe (P = .381).

CONCLUSION

Mean blood loss from percutaneous cryoablation in this model was between that for RF ablation with the single electrode and that for RF ablation with the electrode cluster.

Selective approach to major hepatic resection for hepatocellular carcinoma in chronic liver disease

For large HCCs, partial liver resection remains the best therapeutic option for cure because neither liver transplantation nor percutaneous treatments are indicated. In specialized centers, a better selection of at-risk patients and technical procedures, including the use of intermittent inflow occlusion and the anterior approach, have contributed to improve dramatically the outcome of major liver resection for HCC in CLD. In addition, portal vein embolization has become an important tool to hypertrophy the future liver remnant before major liver resection in cirrhotic patients with apparently normal liver function.

Surgery and ablative therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, responsible for an estimated one million deaths annually. The incidence in the United States has steadily increased over the past two decades. Although HCC has historically had a dismal prognosis, it is now being detected earlier as a result of improved radiologic imaging and surveillance. This affords the opportunity to treat patients with curative intent, and may improve survival. Partial hepatectomy and transplantation each provide potentially curative therapy for selected patients with HCC. Transplantation is indicated when there is severe underlying liver dysfunction. Local ablative therapy, such as ethanol injection, hepatic artery embolization, and radiofrequency ablation, offer palliation for patients when surgery is not feasible. The rational application of the myriad of therapies to a patient with HCC is designed to maximize both quality of life and survival.

Ultrasound monitoring of temperature change during radiofrequency ablation: preliminary in-vivo results

Radiofrequency (RF) ablation is an interstitial focal ablative therapy that can be used in a percutaneous fashion and permits in situ destruction of hepatic tumors. However, local tumor recurrence rates after RF ablative therapy are as high as 34% to 55%, which may be due in part to the inability to monitor accurately temperature profiles in the tissue being ablated, and to visualize the subsequent zone of necrosis (thermal lesion) formed. The goal of the work described in this paper was to investigate methods for the real-time and in vivo monitoring of the spatial distribution of heating and temperature elevation to achieve better control of the degree of tissue damage during RF ablation therapy. Temperature estimates are obtained using a cross-correlation algorithm applied to RF ultrasound (US) echo signal data acquired at discrete intervals during heating. These temperature maps were used to display the initial temperature rise and to continuously update a thermal map of the treated region. Temperature monitoring is currently performed using thermosensors on the prongs (tines) of the RF ablation probe. However, monitoring the spatial distribution of heating is necessary to control the degree of tissue damage produced.

CT versus sonography for monitoring radiofrequency ablation in a porcine liver

OBJECTIVE

The objective of this study was to compare CT and sonography for monitoring radiofrequency (RF) lesions in porcine livers.

SUBJECTS AND METHODS

RF lesions (n = 12) were created in three pig livers by applying 13 min of current to a multielectrode RF probe with a target temperature of 95 degrees C. Helical unenhanced CT and corresponding axial sonography were performed before ablation, at 2 min, 8 min, and immediately after ablation. Contrast-enhanced CT was performed after ablation. CT scans and sonograms were evaluated by blinded observers for conspicuity of the RF lesion, edge detection (visibility of liver-lesion interface), and artifacts. Hounsfield units were recorded at every time interval, and radiologic-pathologic correlation for lesion size and configuration was performed.

RESULTS

Mean size of RF lesions was 3. 03 +/- 0.9 cm. On CT, RF lesions had consistently lower attenuation values than surrounding liver (22.2 H lower than liver at 8 min, p < 0.0001). Echogenicity was variable with sonography (hypoechoic = 59%, hyperechoic = 25%, isoechoic = 16%). Unenhanced CT significantly improved conspicuity, edge detection of RF lesions, and decreased artifacts compared with sonography (p < 0.05). Contrast-enhanced CT improved RF lesion detection, border discrimination, and artifacts compared with sonography (p < 0.05). Unenhanced CT had the best correlation to pathologic size (r = 0.74), followed by contrast-enhanced CT (r = 0.72) and sonography (r = 0.56). Contrast-enhanced CT best correlated with lesion shape, but slightly overestimated size because of areas of ischemia peripheral to the RF lesion.

CONCLUSION

In this animal model, unenhanced CT was an effective way to monitor RF ablation compared with sonography because of increased lesion discrimination, reproducible decreased attenuation during ablation, and improved correlation to pathologic size.

Surgical treatment of malignant liver tumours

Surgical resection is the mainstay of treatment for malignant liver tumours and offers the only chance of cure. Advances in radiological imaging, surgical technique and peri-operative management have enabled liver resection to be performed safely. Partial hepatectomy is indicated for the treatment of hepatocellular carcinoma and hepatic metastases from colorectal cancer. In addition, it may be utilized for selected patients with liver metastases from other primary tumours. Total hepatectomy with transplantation may be of benefit in some patients with unresectable neuroendocrine metastases or small hepatocellular carcinomas. The role of cryosurgery has not been precisely defined, and it needs to be compared with other palliative therapies such as ethanol injection and hepatic artery embolization.

The effects of hepatic cryosurgery on tumor growth in the liver

BACKGROUND

The effects of hepatic cryosurgery on residual hepatic tumor growth, and on tumor immunity, have not been determined.

MATERIALS AND METHODS

Two experiments were performed. In both, animals (n = 10 per group) had solitary left lobe hepatomas established, and underwent left lobectomy, cryoablation, or control laparotomy. Experiment I: immediately after tumor treatment, intraportal challenge of hepatoma cells was performed to evaluate for the effects of treatment on residual hepatic tumor growth. Experiment II: animals were challenged 14 days after tumor treatment, and splenocyte cytotoxicity assays were performed to evaluate for tumor immunity. Hepatic tumor nodules were counted 3 weeks after challenge in both experiments.

RESULTS

In animals challenged immediately after tumor treatment, the mean number of liver nodules at 3 weeks was similar between control and cryoablation groups (65 +/- 13 vs 115 +/- 38, P = 0.17). Animals that had undergone resection, however, had a significant increase in the mean number of nodules as compared to cryoablation (278 +/- 74 vs 115 +/- 38, P = 0. 04) and control (278 +/- 74 vs 65 +/- 13, P = 0.002) animals. In addition, only resection animals had elevation in serum levels of the growth factor FGF-basic, 48 h after treatment (mean = 30 +/- 14 pg/ml). In animals challenged 14 days following treatment, all groups had similar numbers of nodules (resection vs cryoablation, P = 0.8). Splenocyte cytotoxicity was not increased after cryosurgical treatment.

CONCLUSIONS

Unlike partial hepatectomy, cryoablation of hepatomas in rats does not accelerate residual tumor growth in the liver or result in production of the growth factor FGF-basic. We did not find evidence for the development of tumor immunity following cryosurgery.

Cryosurgery on the Treatment of Hepatic Tumors

BACKGROUND: Primary and metastatic tumors in the liver are difficult to treat. When surgical resection is not feasible, cryotherapy is one of the several alternative approaches. METHODS: The data on outcomes from hepatic resections are reviewed, and the rationale and techniques of performing cryosurgery for unresectable hepatic cancers are described. The literature is reviewed and combined with the experiences of the authors on cryosurgery for management of hepatic tumors. RESULTS: The indications and techniques for performing cryosurgery are now well established. The procedure is relatively safe, and long-term survival rates of over 20% may be achieved. CONCLUSIONS: While cryotherapy is effective for localized tumors in the liver, additional adjuvant approaches are required to control disease in the untreated liver. Endoscopic techniques may minimize patient morbidity.