From the Guidelines
Pancreatic cancer is considered unresectable when imaging studies reveal findings such as distant metastases, extensive vascular involvement, or locally advanced disease that cannot be completely removed surgically, as outlined in the NCCN guidelines 1. The criteria for unresectability include distant metastasis, solid tumor contact with the superior mesenteric artery (SMA) or celiac axis (CA) of more than 180 degrees, and unreconstructible superior mesenteric vein/portal vein (SMV/PV) occlusion due to tumor involvement or bland thrombus. Some key points to consider in determining resectability status are:
- Distant metastases to organs such as the liver, lungs, or peritoneum, indicating stage IV disease
- Extensive vascular involvement, particularly when the tumor encases major blood vessels like the SMA, CA, or hepatic artery by more than 180 degrees
- Unreconstructible SMV/PV occlusion due to tumor involvement or bland thrombus
- Locally advanced disease with extension beyond the pancreas that involves adjacent critical structures or organs that cannot be safely removed
- Regional lymph node involvement outside the field of resection, particularly when distant lymph nodes are affected These criteria are crucial in determining the best course of treatment for patients with pancreatic cancer, as attempting surgery in unresectable cases would not achieve complete tumor removal and would expose patients to significant surgical risks without meaningful survival benefit, as noted in the guidelines 1 and supported by other studies 1.
From the FDA Drug Label
- 4 Pancreatic Cancer Gemcitabine Injection is indicated as first-line treatment for patients with locally advanced (nonresectable Stage II or Stage III) or metastatic (Stage IV) adenocarcinoma of the pancreas. The findings that make pancreatic cancer unresectable are not explicitly stated in the drug label. 2
From the Research
Findings that Make Pancreatic Cancer Unresectable
- Tumor involvement of major peripancreatic vessels, such as the portal and superior mesenteric veins, and the celiac, hepatic, and superior mesenteric arteries, can make pancreatic cancer unresectable 3
- A threshold of tumor involvement of one-half circumference of the vessel is highly specific for unresectable tumor 3
- Tumor size (≥30 mm) and abnormalities in the levels of DUPAN-2 and CA 125 are independent predictors of unresectability 4
- Lymph node metastasis, including distant lymph node metastasis, is a common feature of pancreatic cancer and can make the disease unresectable 5, 6
- Metastasis in lymph nodes along the left side of the superior mesenteric artery (SMA-LNs-lt) is a poor prognostic factor for pancreatic head cancer 6
- Involvement of the superior mesenteric vein (SMV), portal vein (PV), and/or splenic vein (SV) can require en bloc resection with concomitant venous reconstruction, making the surgery more complex 7
Vascular Involvement
- Involvement of the superior mesenteric artery (SMA) can be assessed using a 'posterior approach' to identify a replaced right hepatic artery and to facilitate early identification of SMA involvement 7
- Dissection along the longitudinal axis of the SMA can be performed to fully mobilize the pancreatic head and facilitate venous resection and reconstruction 7
Lymph Node Metastasis
- Lymph node metastasis is a common feature of pancreatic cancer and can occur in distant lymph nodes, including those along the left side of the superior mesenteric artery (SMA-LNs-lt) 5, 6
- The presence of lymph node metastasis, including micrometastasis, is a poor prognostic factor for pancreatic cancer 6