Leptomeningeal disease in pancreas ductal adenocarcinoma: A manifestation of longevity

Clinical and molecular characteristics of patients with brain metastasis secondary to pancreatic ductal adenocarcinoma

BACKGROUND

The prognosis for patients with pancreatic ductal adenocarcinoma (PDAC) is poor. Secondary brain metastasis (Br-M) occurs in less than 1% of patients. Clinical characteristics and molecular alterations have not been characterized in this rare patients' subset.

MATERIALS AND METHODS

The Foundry software platform was used to retrospectively query electronic health records for patients with Br-M secondary to PDAC from 2005 to 2023; clinical, molecular, and overall survival (OS) data were analyzed.

RESULTS

Br-M was diagnosed in 44 patients with PDAC. Median follow-up was 78 months; median OS from initial PDAC diagnosis was 47 months. Median duration from PDAC diagnosis to Br-M detection was 24 months; median OS from Br-M diagnosis was 3 months. At Br-M diagnosis, 82% (n = 36) of patients had elevated CA19-9. Lung was the most common preexisting metastatic location (71%) with Br-M, followed by liver (66%). Br-M were most frequently observed in the frontal lobe (34%, n = 15), cerebellar region (23%, n = 10), and leptomeninges (18%, n = 8). KRAS mutations were detected in 94.1% (n = 16) of patients who had molecular data available (n = 17) with KRASG12V being the most frequent subtype 47% (n = 8); KRASG12D in 29% (n = 5); KRASG12R in 18% (n = 3). Patients who underwent Br-M surgical resection (n = 5) had median OS of 8.6 months, while median OS following stereotactic radiosurgery only (n = 11) or whole-brain radiation only (n = 20) was 3.3 and 2.8 months, respectively.

CONCLUSION

Br-M is a late PDAC complication, resulting in an extremely poor prognosis especially in leptomeningeal disease. KRAS was mutated in 94.1% of the patients and the KRASG12V subtype was prevalent.

A Unique Case of a Patient With Pancreatic Cancer Developing Leptomeningeal Metastases While on Gemcitabine and Nab-Paclitaxel

Brain metastases and leptomeningeal disease are rare with pancreatic cancer. Leptomeningeal disease is a catastrophic complication to have as patients deteriorate rapidly. Patients can present with symptoms of cranial nerve neuropathies, headache, nausea, and focal neurological deficits. We present a patient with metastatic pancreatic cancer who was treated initially with FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) which resulted in marked clinical and radiologic improvement. However, he started to develop severe peripheral neuropathy and was switched to maintenance gemcitabine and nab-paclitaxel. On this regimen, his systemic disease was well controlled but he developed leptomeningeal carcinomatosis. To our knowledge, this is the first case of leptomeningeal metastases developing in a patient with pancreatic adenocarcinoma while on treatment with gemcitabine and nab-paclitaxel after cessation of FOLFIRINOX. We should maintain high clinical suspicion for leptomeningeal disease in pancreatic cancer, especially when systemic disease is well controlled, as the chemotherapeutic agents may not be crossing the blood-brain barrier effectively contributing to high morbidity and mortality.

A Rare Case of Brain Metastases in an Elderly Patient With Primary Pancreatic Cancer

Pancreatic adenocarcinoma is an extremely aggressive cancer with a low survival rate. Common sites for metastases include the liver and lungs, while brain metastases are considered extremely rare, especially in elderly patients. We present an elderly female patient who developed brain metastases 51 months after the initial diagnosis of pancreatic cancer and was treated with gross tumor resection, chemotherapy, and stereotactic radiosurgery. The treatment completely resolved her neurological symptoms but did not result in improved survival for this patient. The patient developed generalized tonic-clonic seizures, was diagnosed with leptomeningeal carcinomatosis, and died 5.5 months after tumor resection. The literature on pancreatic cancer with brain metastases is scarce, with limited guidelines for treatment strategies in this patient population. Adding this case report to the existing literature may provide additional guidance to clinicians managing patients with similar presentations.

Leptomeningeal disease in BRIP1-mutated pancreatic adenocarcinoma

Leptomeningeal disease is rare in pancreatic cancer and prognosis remains poor. Mutation profiles are now directing therapy to improve survival. We describe a case of leptomeningeal and brain metastasis in BRCA1 interacting protein 1, or BRIP1-mutated pancreatic adenocarcinoma with progression through several lines of chemotherapy and immunotherapy. A woman in her late 50s presented with metastatic pancreatic adenocarcinoma on liver biopsy. She achieved complete response after modified FOLFIRINOX and started a poly (ADP-ribose) polymerase (PARP) inhibitor for a BRIP1 mutation. She had recurrence at 9 months and started pembrolizumab (programmed cell death protein 1, or PD-1receptor antibody) for tumour mutational burden of 10 muts/Mb. At 10 months, she presented with lower extremity weakness and back pain. MRI revealed leptomeningeal metastases from T11 to cauda equina roots and right occipital metastasis. Cerebrospinal fluid studies revealed elevated pressure (290 mm H2O) and protein (73 mg/dL) with negative cytology. Leptomeningeal carcinomatosis was diagnosed. She began palliative radiation but died at 11 months from initial diagnosis.