Immuno-genomic-radiomics to predict response of biliary tract cancer to camrelizumab plus GEMOX in a single-arm phase II trial

Background & Aims

Immunotherapy is an option for the treatment of advanced biliary tract cancer (BTC), although it has a low response rate. In this post hoc analysis, we investigated the predictive value of an immuno-genomic-radiomics (IGR) analysis for patients with BTC treated with camrelizumab plus gemcitabine and oxaliplatin (GEMOX) therapy.

Methods

Thirty-two patients with BTC treated with camrelizumab plus GEMOX were prospectively enrolled. The relationship between high-throughput computed tomography (CT) radiomics features with immuno-genomic expression was tested and scaled with a full correlation matrix analysis. Odds ratio (OR) of IGR expression for objective response to camrelizumab plus GEMOX was tested with logistic regression analysis. Association of IGR expression with progression-free survival (PFS) and overall survival (OS) was analysed with a Cox proportional hazard regression.

Results

CT radiomics correlated with CD8⁺ T cells (r = -0.72-0.71, p = 0.004-0.047), tumour mutation burden (TMB) (r = 0.59, p = 0.039), and ARID1A mutation (r = -0.58-0.57, p = 0.020-0.034). There was no significant correlation between radiomics and programmed cell death protein ligand 1 expression (p >0.96). Among all IGR biomarkers, only four radiomics features were independent predictors of objective response (OR = 0.09-3.81; p = 0.011-0.044). Combining independent radiomics features into an objective response prediction model achieved an area under the curve of 0.869. In a Cox analysis, radiomics signature [hazard ratio (HR) = 6.90, p <0.001], ARID1A (HR = 3.31, p = 0.013), and blood TMB (HR = 1.13, p = 0.023) were independent predictors of PFS. Radiomics signature (HR = 6.58, p <0.001) and CD8⁺ T cells (HR = 0.22, p = 0.004) were independent predictors of OS. Prognostic models integrating these features achieved concordance indexes of 0.677 and 0.681 for PFS and OS, respectively.

Conclusions

Radiomics could act as a non-invasive immuno-genomic surrogate of BTC, which could further aid in response prediction for patients with BTC treated with immunotherapy. However, multicenter and larger sample studies are required to validate these results.

Impact and implications

Immunotherapy is an alternative for the treatment of advanced BTC, whereas tumour response is heterogeneous. In a post hoc analysis of the single-arm phase II clinical trial (NCT03486678), we found that CT radiomics features were associated with the tumour microenvironment and that IGR expression was a promising marker for tumour response and long-term survival.

Clinical trial number

Post hoc analysis of NCT03486678.

[Intra and extra hepatic cholangiocarcinomas radiation therapy]

Cholangiocarcinomas are digestive tumors whose incidence remains low and have poor prognosis. The benefits of adjuvant radiochemotherapy and radiotherapy have never been demonstrated in any phase III randomized controlled trial. Chemotherapy with capecitabine 6 months is the standard of care in adjuvant setting. Radiochemotherapy is validated in R1 patients. It is not recommended in neoadjuvant situations given the lack of evidence. Chemotherapy and radiochemotherapy are validated in adjuvant or locally advanced diseases. Stereotactic radiation therapy offers an interesting perspective, at the cost of significant digestive toxicities, requiring evaluation in randomized trials.

Curative Resection After Gemcitabine, Cisplatin and S-1 Chemotherapy for Initially Unresectable Biliary Duct Cancer: A Case Report

A 68-year-old woman was diagnosed with unresectable upper bile duct cancer with suspected invasion of the right hepatic artery and para-aortic lymph node metastasis (T4N3M0, stage IVb). She underwent plastic stent placement for obstructive jaundice and enrolled in our phase I study for unresectable biliary tract cancer consisting of cisplatin (25 mg/m(2) i.v. for 120 min) followed by gemcitabine (1,000 mg/m(2) i.v. for 30 min) on days 1 and 8, and oral S-1 on alternate days. After 8 courses of neoadjuvant chemotherapy without adverse effects, computed tomography showed near-complete disappearance of the tumor of the upper bile duct and of swollen lymph nodes. She then underwent sub-total stomach-preserving pancreatico duodenectomy and lymph node dissection. The pathological stage was pT1N0M0, stage I. The patient made a satisfactory recovery, was discharged 29 days after operation, and remains free of disease at 3 months after the operation under adjuvant chemotherapy using S-1.