Stereotactic body radiation therapy is associated with improved overall survival compared to chemoradiation or radioembolization in the treatment of unresectable intrahepatic cholangiocarcinoma

A Practical Guide for the Systemic Treatment of Biliary Tract Cancer in Canada

Biliary tract cancers (BTC) are rare and aggressive tumors with poor prognosis. Radical surgery offers the best chance for cure; however, most patients present with unresectable disease, and among those receiving curative-intent surgery, recurrence rates remain high. While other locoregional therapies for unresectable disease may be considered, only select patients may be eligible. Consequently, systemic therapy plays a significant role in the treatment of BTC. In the adjuvant setting, capecitabine is recommended following curative-intent resection. In the neoadjuvant setting, systemic therapy has mostly been explored for downstaging in borderline resectable tumours, although evidence for its routine use is lacking. For advanced unresectable or metastatic disease, gemcitabine-cisplatin plus durvalumab has become the standard of care, while the addition of pembrolizumab to gemcitabine-cisplatin has also recently demonstrated improved survival compared to chemotherapy alone. Following progression on gemcitabine-cisplatin, several chemotherapy combinations and biomarker-driven targeted agents have been explored. However, the optimum regimen remains unclear, and access to targeted agents remains challenging in Canada. Overall, this article serves as a practical guide for the systemic treatment of BTC in Canada, providing valuable insights into the current and future treatment landscape for this challenging disease.

Locoregional Therapy for Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) has a poor prognosis, and surgical resection (SR) offers the only potential for cure. Unfortunately, only a small proportion of patients are eligible for resection due to locally advanced or metastatic disease. Locoregional therapies (LRT) are often used in unresectable liver-only or liver-dominant ICC. This review explores the role of these therapies in the treatment of ICC, including radiofrequency ablation (RFA), microwave ablation (MWA), transarterial chemoembolization (TACE), transarterial radioembolization (TARE), external beam radiotherapy (EBRT), stereotactic body radiotherapy (SBRT), hepatic arterial infusion (HAI) of chemotherapy, irreversible electroporation (IE), and brachytherapy. A search of the current literature was performed to examine types of LRT currently used in the treatment of ICC. We examined patient selection, technique, and outcomes of each type. Overall, LRTs are well-tolerated in the treatment of ICC and are effective in improving overall survival (OS) in this patient population. Further studies are needed to reduce bias from heterogenous patient populations and small sample sizes, as well as to determine whether certain LRTs are superior to others and to examine optimal treatment selection.

Actual over 3-year survival after stereotactic body radiation therapy in patients with unresectable intrahepatic cholangiocarcinoma

PURPOSE

As a non-invasive treatment, stereotactic body radiation therapy (SBRT) has been an emerging and effective option for patients with unresectable intrahepatic cholangiocarcinoma (ICC). The Cyber Knife has an SBRT system, which can realize real-time tracking of tumors during treatment. It can protect the surrounding normal liver tissue while the tumor gets the therapeutic dose. The purpose of this study was to evaluate the factors affecting the local control rate for patients after SBRT treatment, and to predict the factors affecting survival rates, then to report the 3-year actual survival rates after treatment and identify the influencing factors of 3-year survival rate.

MATERIALS AND METHODS

We conducted a long-term follow-up of 43 patients with unresectable intrahepatic cholangiocarcinoma who underwent Cyber Knife in our hospital from January 2016 to December 2018. Regular medical check-ups were performed every 2-3 months after SBRT to evaluated the effect of treatment.

RESULTS

The median follow-up time was 15 months (4-78 months), and the median progression-free survival (PFS) was 6 months (95% CI, 2.788-9.212) and the median overall survival (OS) was 12 months (95% CI, 3.434-20.566), respectively. Based on modified Response Evaluation and Criteria in Solid Tumor (mRECIST), response rate (RR) and disease control rate (DCR) of SBRT in unresectable ICC were 55.2% and 86%. The 1-, 2- and 3-years OS rate were 51.2%, 32.6% and 23.3%. Multivariate analysis based on competing risk survival analysis identified that patients with multiple nodules, large diameter, high level of CA199 and CEA, poor ECOG performance status had worse overall survival (p < 0.05). Patients who survived ≥3 years had significantly lower levels of CEA, CA199, smaller tumor diameters and lower number of lesions (p < 0.05).

CONCLUSION

The SBRT might be a candidate option for patients who unable to perform surgery. The rate of 3-year survival after SBRT for unresectable ICC can be expected with 23.3%.

Stereotactic radiotherapy for intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive malignancy with an increasing incidence worldwide and poor prognosis, despite several advances and continuous efforts to develop effective treatments. Complete surgical resection is the mainstay of treatment and offers a potentially curative option, but is only possible in less than a third of patients, owing to advanced disease. Chemotherapy is a well-established treatment in the adjuvant and palliative setting, however, confers limited benefit. Conventional radiotherapy is challenging due to local toxicity. With recent advances in stereotactic ablative radiotherapy (SABR), it is now possible to focus ablative beams of radiotherapy precisely aimed at tumours to minimise damage to surrounding viscera. This review details the history, technical background and application of SABR to iCCA, with directions for future research suggested.

Ablative liver radiotherapy for unresected intrahepatic cholangiocarcinoma: Patterns of care and survival in the United States

BACKGROUND

Single-institution studies have shown the oncologic benefit of ablative liver radiotherapy (A-RT) for patients with unresectable intrahepatic cholangiocarcinoma (ICC). However, adoption of A-RT across the United States and its associated outcomes are unknown.

METHODS

We queried the National Cancer Data Base for nonsurgically managed patients with ICC diagnosed between 2004 and 2018. Patients were labeled A-RT for receipt of biologically effective doses (BED10 ) ≥ 80.5 Gy and conventional RT (Conv-RT) for lower doses. Associations with A-RT use and overall survival were identified using logistic and Cox regressions, respectively.

RESULTS

Of 27,571 patients, the most common treatments were chemotherapy without liver RT (45%), no chemotherapy or liver RT (42%), and liver RT ± chemotherapy (13%). Use of liver RT remained constant over time. Of 1112 patients receiving liver RT with known doses, RT was 73% Conv-RT (median BED10 , 53 Gy; median, 20 fractions) and 27% A-RT (median BED10 , 100 Gy; median, 5 fractions). Use of A-RT increased from 5% in 2004 to 48% in 2018 (Ptrend < .001). With a median follow-up of 52.3 months, median survival estimates for Conv-RT and A-RT were 12.8 and 23.7 months (P < .001), respectively. On multivariable analysis, stage III and IV disease correlated with a higher risk of death, whereas chemotherapy and A-RT correlated with a lower risk.

CONCLUSIONS

Although A-RT has been increasingly used, use of liver RT as a whole in the United States remained constant despite growing evidence supporting its use, suggesting continued unmet need. A-RT is associated with longer survival versus Conv-RT.

LAY SUMMARY

Bile duct cancer is a rare, deadly disease that often presents at advanced stages. Single-institution retrospective studies have demonstrated that use of high-dose radiotherapy may be associated with longer survival, but larger studies have not been conducted. We used a large, national cancer registry of patients diagnosed between 2004 and 2018 to show that liver radiotherapy use remains low in the United States, despite growing evidence that patients who receive it live longer. Furthermore, we showed that patients who received high-dose radiotherapy lived longer than those who received lower doses. Greater awareness of the benefits of liver radiotherapy is needed to improve patient outcomes.

Space-Making Particle Therapy for Unresectable Hilar Cholangiocarcinoma

INTRODUCTION

Although the primary treatment option for hilar cholangiocarcinoma (HC) has been surgical resection, most patients present with unresectable advanced tumors at the time of diagnosis. Particle therapy (PT) holds great potential for HC, even though the anatomical proximity to the gastrointestinal tract prevents delivering a radical dose to the tumor. Space-making PT (SMPT), consisting of spacer placement surgery and subsequent PT, has been developed to minimize complications and maximize the therapeutic benefit of dose escalation for HC. This study aimed to conduct a dosimetric evaluation and examine the effectiveness of SMPT for the treatment of HC.

METHODS

Between 2007 and 2018, 12 patients with unresectable HC treated with SMPT were enrolled. The treatment outcomes and effectiveness of spacer placement surgery were evaluated through analyses of pre- and post-surgical parameters of dose-volume histograms.

RESULTS

All patients completed the planned SMPT protocol. The median survival time was 29.6 months, and the 1- and 3-year overall survival rates were 82.5% and 45.8%, respectively. The mean V95% value (volume irradiated with 95% of the planned treatment dose) of the gross tumor volume and clinical target volume after spacer placement surgery improved to 98.5% and 96.6% from preoperative values of 85.6% and 78.1%, respectively (p = 0.0196 and p = 0.0053, respectively). Grade 3 or higher adverse events after SMPT were seen in 6 patients.

DISCUSSION/CONCLUSION

SMPT led to improvements in dosimetric parameters and showed good feasibility and excellent outcomes. SMPT can be a promising novel alternative for unresectable HC.

Benchmarking Outcomes after Ablative Radiotherapy for Molecularly Characterized Intrahepatic Cholangiocarcinoma

We have previously shown that ablative radiotherapy (A-RT) with a biologically effective dose (BED10) ≥ 80.5 Gy for patients with unresectable intrahepatic cholangiocarcinoma (ICC) is associated with longer survival. Despite recent large-scale sequencing efforts in ICC, outcomes following RT based on genetic alterations have not been described. We reviewed records of 156 consecutive patients treated with A-RT for unresectable ICC from 2008 to 2020. For 114 patients (73%), next-generation sequencing provided molecular profiles. The overall survival (OS), local control (LC), and distant metastasis-free survival (DMFS) were estimated using the Kaplan-Meier method. Univariate and multivariable Cox analyses were used to determine the associations with the outcomes. The median tumor size was 7.3 (range: 2.2-18.2) cm. The portal vein thrombus (PVT) was present in 10%. The RT median BED10 was 98 Gy (range: 81-144 Gy). The median (95% confidence interval) follow-up was 58 (42-104) months from diagnosis and 39 (33-74) months from RT. The median OS was 32 (29-35) months after diagnosis and 20 (16-24) months after RT. The one-year OS, LC, and intrahepatic DMFS were 73% (65-80%), 81% (73-87%), and 34% (26-42%). The most common mutations were in IDH1 (25%), TP53 (22%), ARID1A (19%), and FGFR2 (13%). Upon multivariable analysis, the factors associated with death included worse performance status, larger tumor, metastatic disease, higher CA 19-9, PVT, satellitosis, and IDH1 and PIK3CA mutations. TP53 mutation was associated with local failure. Further investigation into the prognostic value of individual mutations and combinations thereof is warranted.

Cholangiocarcinoma Therapeutics: An Update

BACKGROUND

Cholangiocarcinoma (CCA) is the second most common hepatobiliary cancer and associated with a poor prognosis. Only one-third of CCA cases are diagnosed at operable stages. However, a high rate of relapse has been observed postoperatively. Besides screening for operable individuals, efficacious therapeutic for recurrent and advanced CCA is urgently needed. The treatment outcome of available therapeutics is important to clarify clinical indication and facilitate the development of treatment strategies.

OBJECTIVE

This review aims to compare the treatment outcome of different therapeutics based on both overall survival and progression-free survival.

METHODS

Over one hundred peer-reviewed articles were examined. We compared the treatment outcome between different treatment methods, including tumor resection with or without postoperative systematic therapy, chemotherapies including FOFLOX, and targeted therapies, such as IDH1, K-RAS, and FGFR inhibitors. Notably, the scientific basis and outcome of available treatment methods were compared with the standard first-line therapy.

RESULTS

CCAs at early stages should firstly undergo tumor resection surgery, followed by postoperative treatment with Capecitabine. Chemotherapy can be considered as a preoperative option for unresectable CCAs. Inoperable CCAs with genetic aberrances like FGFR alterations, IDH1, and KRAS mutations should be considered with targeted therapies. Fluoropyrimidine prodrug (S-1)/Gemcitabine/Cisplatin and nab-Paclitaxel/Gemcitabine/Cisplatin show favorable outcome which hints at the triplet regimen to be superior to Gemcitabine/Cisplatin on CCA. The triplet chemotherapeutic should be tested further compared to Gemcitabine/Cisplatin among CCAs without genetic alterations. Gemcitabine plus S-1 was recently suggested as the convenient and equivalent standard first-line for advanced/recurrent biliary tract cancer.

CONCLUSION

This review provides a comparative outcome between novel targeted therapies and currently available therapeutics.

Twenty Years of Radiation Therapy of Unresectable Intrahepatic Cholangiocarinoma: Internal or External? A Systematic Review and Meta-Analysis

PURPOSE

Both external beam radiation therapy (EBRT) and selective-internal radiation therapy (SIRT) are implemented to treat unresectable intrahepatic cholangiocarcinoma (iCCA). The present study aimed to evaluate the efficacy of EBRT and SIRT in managing iCCA through a systematic review and meta-analysis.

METHODS

PubMed and Cochrane database were queried to search for studies published from January 2000 toJune 2020 without language restrictions. Median survival time, overall survival, and radiological response were extracted. Secondary outcomes such as complication rates, predictors of survival, and downstage to surgery were pooled. Patient-level survival data were obtained to generate Kaplan-Meier survival graph. Pooled outcomes were analyzed with a random-effect model.

RESULTS

Twenty-nine and 20 studies including 732 and 443 patients from the SIRT and EBRT groups were included in the present study. From initial radiation treatment, the median survival time for patients who underwent SIRT and EBRT were 12.0 (95% confidence interval [CI]: 10.8-14.6) and 13.6 (95% CI: 11.1-16.0) months, respectively. As first-line therapy, the median survival time was 36.1 (95% CI: 20.6-39.5) months for SIRT and 11.0 (95% CI: 9.3-13.6) months for EBRT. Both radiation modalities were effective in downstaging initially unresectable iCCA to surgery (SIRT: 30.5%; EBRT: 18.3%). Patients in the SIRT group encountered more post-embolization abdominal pain (6.9 vs. 2.2%), ulcer (1.0 vs. 0.5%), nausea (1.6 vs. 0.7%), anorexia (5.9 vs. 0%), thrombocytopenia (7.3 vs. 6.0%), hyperbilirubinemia (5.2 vs. 2.1%), and hypoalbuminemia (13.2 vs. 3.3%), whereas EBRT was associated with higher rates of anemia (0.6 vs. 7.5%) and neutropenia (6.5 vs. 11.0%).

CONCLUSIONS

Both EBRT and SIRT were safe and effective in treating unresectable iCCA. However, available evidence was highly heterogeneous regarding patient population, limiting fair comparison between 2 radiation modalities. Future high-quality comparative studies are warranted.

Stereotactic radiotherapy in intrahepatic cholangiocarcinoma: A systematic review

Among biliary tract cancers, intrahepatic cholangiocarcinoma (ICC) has different characteristics compared with those in other sites. Current guidelines suggest several treatment options for ICC, including stereotactic body radiation therapy (SBRT). However, the role of SBRT in locally advanced ICC is unclear. The aim of the present study was to present a systematic review on the efficacy and safety of SBRT in ICC. A systematic review based on the PRISMA methodology was performed. Only papers reporting outcomes in terms of overall survival (OS) after SBRT in inoperable patients with ICC were included. Secondary aims were local control (LC), progression-free survival (PFS) and treatment-related toxicity. Six papers (145 patients) were included in the present analysis. SBRT was frequently used as a salvage treatment, since 28.6-66.7% of patients received previous systemic or local treatments. The median SBRT dose was 45 Gy delivered in 3-5 fractions. The median follow-up was 16 months, and median OS time was 14 months (range, 10-48 months). In one of the included studies, SBRT was significantly superior in terms of OS compared with both chemoradiation and trans-arterial-radio-embolization. The 1-year LC rate was 85% in one study, and 1-year PFS rates were 50 and 68% in two studies, respectively. Toxicity was generally not reported in detail or was reported including other sites of biliary cancers. Overall, limited evidence was available on the efficacy of SBRT in ICC, which should be further investigated in prospective studies with a larger number of patients. However, based on the available data, SBRT seems to produce similar results compared with other ICC treatments, with the advantage of being a very short and non-invasive therapy. Therefore, SBRT should be considered in selected patients with ICC.