Introduction

Localized pancreatic ductal adenocarcinoma (PDAC) was once considered a uniquely surgical problem. Staging of PDAC was routinely accomplished in the operating room; patients found to have technically removable tumors upon exploration underwent pancreatectomy, and those who were not found to have removable tumors underwent palliative bypass operations. Radical resections involving wide clearance of soft tissues and the mesenteric vasculature¹ and/or total pancreatectomy² were often advocated as a means to control local recurrence and distant progression. Perioperative mortality was common,³ and adjuvant therapy was not routine.⁴ Although longterm survival was distinctly rare, it was never observed in the absence of a potentially curative pancreatectomy.⁵ Therefore, despite generally discouraging results, surgery became accepted as the only potentially curative therapy for patients with an otherwise uniformly fatal disease.

Although PDAC remains a considerable clinical problem, the perioperative management of patients with localized disease has changed significantly over the past 35 years. Advances in multidisciplinary treatment programs that emphasize highquality pretreatment staging, meticulous surgical care, and perioperative adjuvant therapies have collectively provided a basis for optimism; now, as many as one-quarter of patients who receive combination therapy with chemotherapy with or without chemoradiation and pancreatectomy can expect to live 5 years or longer.⁶ However, among the treatments administered as part of these multimodality programs, surgery remains the only one that is potentially curative on its own. Therefore, although localized PDAC is no longer considered a uniquely surgical condition, resection of the primary pancreatic tumor and regional lymph nodes remains as important today as it was 35 years ago.

Staging

In the 1970s and 1980s, accurate pretreatment staging of PDAC was impossible because only low-resolution cross-sectional imaging technologies were available at that time. Discrimination between localized and disseminated disease and between resectable and nonresectable primary tumors was therefore largely made in the operating room at exploratory surgery. Cross-sectional imaging has now improved to the point at which the primary tumor’s anatomy and relationship to the mesenteric vasculature can be determined radiographically with great precision, and metastatic disease can be safely ruled out in the majority of patients. Furthermore, studies correlating radiographic findings to surgical outcomes have led to the establishment of objective staging designations that reflect the surgeon’s likelihood of achieving a margin-negative resection.

Pretreatment staging with computed tomography or magnetic resonance imaging is now used to help optimize and individualize the treatment of patients with localized PDAC (Table I-1 and Fig. I-1).⁷,⁸,⁹,¹⁰ Locally advanced disease is represented radiographically as the cancer’s extensive involvement of the mesenteric vasculature. Complete resection of the primary cancer to microscopically clear margins (R0 resection) is rarely feasible for patients with this stage of disease, and attempts to use neoadjuvant therapy to reduce the size or anatomic extent of such cancers and thus improve the surgeon’s ability to remove them have been unsuccessful.¹¹ Therefore, patients with locally advanced cancers are typically treated with chemotherapy
and/or chemoradiation. At the other end of the spectrum, potentially resectable cancers on computed tomography scans appear to be separate from the mesenteric vasculature or approximate the vessels only minimally, and such tumors can routinely be resected safely to negative margins, so surgery is generally recommended as the initial therapeutic approach.¹² Finally, borderline resectable tumors radiographically appear to approximate the mesenteric vasculature to a limited degree. Patients with these tumors are at high risk for at least microscopically incomplete (R1) resection.¹⁰

TABLE I-1 Staging Designations Used for Patients with Localized Pancreatic Cancer

	Staging Designation
Vessel	Potentially Resectable	Borderline Resectable	Locally Advanced
SMV-PV	No interface or interface between the tumor and vessel measuring <180° of the circumference of the vessel wall	Interface between the tumor and vessel measuring ≥180° of the circumference of the vessel wall and/or reconstructible occlusion	Unreconstructable occlusion of the vessel by the tumor
SMA	No interface	Interface between the tumor and vessel measuring <180° of the circumference of the vessel wall	Interface between the tumor and vessel measuring ≥180° of the circumference of the vessel wall
CHA	No interface	Reconstructible, short-segment interface between the tumor and vessel of any degree	Unreconstructable interface between the tumor and vessel
Celiac trunk	No interface	Interface between the tumor and vessel measuring <180° of the circumference of the vessel wall	Interface between the tumor and vessel measuring ≥180° of the circumference of the vessel wall
CHA, common hepatic artery; SMA, superior mesenteric artery; SMV-PV, superior mesenteric vein-portal vein.
From Katz MH, Marsh R, Herman JM, et al. Borderline resectable pancreatic cancer: need for standard ization and methods for optimal clinical trial design. Ann Surg Oncol 2013;20(8):2787-2795, with permission.