Para-aortic Lymph Node Metastasis in Resectable Pancreatic Cancer

Lymph node metastases are a strong prognostic predictor for pancreatic cancer. Para-aortic lymph nodes (PALN) (No. 16 nodes) are the final nodes for periampullary cancers before the cancer cells enter the systemic lymphatic circulation. Some consider these nodes to be regional lymph nodes and dissect them as a part of a routine lymphadenectomy for pancreatic cancer. Others argue that metastases to these nodes represent systemic disease and recommend that radical surgery including extended lymphadenectomy should be abandoned. There is no consensus whether to abort the resection if metastases in PALN are discovered pre- or perioperatively. Use of adjuvant and neoadjuvant chemotherapy may further affect the impact of lymph node metastases, including PALN.

The aim of this study is to define the incidence and clinical consequences of PALN metastasis in patients submitted to a tentative curative resection for carcinoma of the head of the pancreas by systematically resecting paraaortic lymph nodes.

Primary outcome

1\) To determine incidence of PALN metastasis in patients submitted to a tentative curative resection

Secondary outcomes

1. To determine prognosis of patients with PALN metastasis after a curative resection 2. To determine incidence of metastasis in reginal lymph nodes in patients submitted to a tentative curative resection. 3. To determine prognosis of patients with metastasis in regional lymph nodes in patients submitted to a tentative curative resection. 4. To address the question of how to optimize the frozen section analyses of PALN as related to the final pathology report.

PALN are resected separately and analyzed both as cryo sections and by routine histochemistry.

Prevalence of PALN differ markedly from 5% to 30%. Given the descriptive primary endpoint, no rigorous power calculation can be made. Assuming a prevalence of 17% (as reported in a recent series from Stockholm), a hazard ratio for survival ranging from 1,04 to 3,00 and and a drop out of 17%. Complete data is needed for 90 patients but the trial aim to include 300.

Resection of PALN is becoming routine at most participating centers in the trial. Therefore, the trial will not alter care for the participating patients in any major way. Rather the trial aims to systematically asses how this altered practice affect patient outcome.

• To determine prognosis of patients with PALN metastasis (lgll station 16) after a curative resection [Time frame: 6 years]
• To determine incidence of metastasis in lgll station 8, 9 and 12 in patients submitted to a tentative curative resection. [Time frame: 5 years]
• To determine prognosis of patients with metastasis in lgll station 8, 9 and 12 in patients submitted to a tentative curative resection. [Time frame: 6 years]
• To address the question of how to optimize the frozen section analyses (lgll station 16) as related to the final pathology report? [Time frame: 5 years]