Immunotherapy in pancreatic cancer and the importance of tumour testing

Abstract

Advanced pancreatic cancer carries a poor prognosis and has traditionally been treated with chemotherapy. However, immunotherapy has made great strides in a subset of patients depending on mismatch repair/microsatellite status. We present a patient with locally advanced pancreatic cancer treated with neoadjuvant chemotherapy followed by surgery and additional adjuvant chemotherapy whose disease progressed while on adjuvant chemotherapy. Tumour testing showed a mismatch repair mutation and high microsatellite instability, making her eligible for treatment with immunotherapy. Germline genetic testing confirmed the clinical suspicion of Lynch syndrome. She has had isolated sites of progression treated with radiation but overall has been receiving immunotherapy for more than 3 years, highlighting the importance of tumour testing as it may allow for additional treatment options and improved survival.

Keywords: pancreatic cancer; therapeutic indications.

Figure 1

Central hepatic metastasis indicated by the arrow at 2 months (A), 10 months (B) and 35 months (C) after starting pembrolizumab. This lesion has had a sustained response to pembrolizumab. Left lateral hepatic metastasis 2 months (D), 10 months (E) and 35 months (F) after starting pembrolizumab. This lesion was treated with stereotactic body radiotherapy (SBRT) 11 months after starting pembrolizumab and has had a sustained response after SBRT. Fiducial placed for SBRT seen in (F).