INTRODUCTION
Pancreatic ductal adenocarcinoma (PDAC) carries one of the poorest overall prognosis of all human malignancies. The 5-year survival in patients with PDAC, for all stages, remains as low as 6–7%. The low survival rate is attributed to several factors, of which the two most important are aggressive tumor biology and late stage at which most patients are diagnosed. Only 10–20% of patients are eligible for resection at presentation, 30–40% are unresectable/locally advanced, and 50–60% are metastatic. Pancreatic cancer without distant metastasis can be divided into three categories: resectable, borderline resectable, and locally advanced. In absence of metastatic disease, the most important factor for improving survival and possibly offer cure is to achieve a margin-negative resection. Even after potential curative resection, most patients develop recurrences eventually, and 5-year survival of completely resected patients is only up to 25%. The aggressive tumor biology and its inherent resistance to chemotherapy and radiotherapy contributes to early recurrence and metastasis.
SURGICAL ADVANCES
Pancreatic cancer surgery has evolved over the past few decades and remains the cornerstone of treatment of resectable and borderline resectable tumors. Advances in modern imaging give precise information on disease extension and vascular involvement that aids in surgical planning in order to achieve a margin-negative resection.
SURGICAL TECHNIQUES
Surgical techniques for pancreatic cancer include pancreaticoduodenectomy, distal pancreatectomy with splenectomy, and total pancreatectomy. Standard lymphadenectomy for pancreatoduodenectomy should include removal of lymph node stations 5, 6, 8a, 12b1, 12b2, 12c, 13a, 13b, 14a, 14b, 17a, and 17b. Involvement of superior mesenteric vein (SMV)/portal vein(PV) was previously considered as a contraindication for resection. However, curative resection along with SMV/PV with vascular reconstruction has now become a standard practice in specialized high-volume centers. To improve margin-negative resections, specially in borderline resectable tumors with proximity to vascular structures, SMA first approach was proposed as a new modification of standard pancreatico-duodenectomy. In a systematic review, SMA first approach was shown to be associated with better perioperative outcomes, such as blood loss, transfusion requirements, pancreatic fistula, delayed gastric emptying, and reduced local and metastatic recurrence rates. In case of arterial involvement, there is no good evidence at present to justify arterial resections for right-sided pancreatic tumors. However, the modified Appleby procedure, which includes en bloc removal of celiac axis with or without arterial reconstruction, when used in appropriately selected patients, offers margin negative resection with survival benefit for locally advanced pancreatic body and tail tumors and should be performed in high-volume centers. Most evidence does not support advantage of more extended resections such as removal of the para-aortic lymph nodes and nerve plexus and multivisceral resections routinely. Such extended resections are associated with compromised quality of life because of associated higher perioperative morbidity and intractable diarrhea. However, in highly selected patients, with preserved performance status and stable or nonprogressive disease on neoadjuvant treatment, such extended resections can provide survival advantage over palliative treatments. Radical surgery in the presence of oligometastatic disease has also been reported to prolong survival in highly selected patients.