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Chapter 4 / Pancreatic Adenocarcinoma 41

PDAC detection based on the available data. Other oncogenes implicated

in PDAC pathogenesis are BRAF, AKT2, and MYB; and (iii) DNA mismatch

repair genes: approximately 4% of PDAC appears related to dysregulation of

DNA mismatch repair genes—MSH2, MLH1, PMS1, PMS2, MSH6/GTBP, and

MSH3. It is postulated that these mutations occur in a cumulative fashion

over the life span of a developing PDAC.

DIAGNOSIS

Clinical Presentation

e nonspecic symptoms associated with early PDAC—anorexia, nau-

sea, and weight loss—typically preclude its diagnosis at an early stage in

most cases. e majority of patients with right-sided PDAC present with

jaundice secondary to obstruction of the intrapancreatic portion of the

common bile duct and subsequently develop dark urine, light-colored

stools, and pruritus. ese tumors can also cause mechanical obstruction

of the duodenal C-loop, leading to weight loss, gastric outlet obstruction

and, ultimately, vomiting. Left-sided tumors generally do not cause jaun-

dice and may present with epigastric/back pain from celiac axis lympho-

vascular inltration or focal, segmental pancreatic duct obstruction or,

sometimes, duodenal obstruction at the ligament of Treitz. More subtle

presentations may be encountered in elderly patients with new-onset DM

or with episodes of acute pancreatitis in the absence of cholelithiasis or

ethanol abuse. e most consistent physical nding in PDAC is jaundice,

seen in up to 87% in head-based tumors but just 13% of distal (usually

body) tumors. Hepatomegaly, palpable gallbladder (Courvoisier sign), and

malnutrition may be observed. Signs of advanced disease include ascites,

cachexia, liver nodularity, left supraclavicular adenopathy (Virchow node),

periumbilical adenopathy (Sister Mary Joseph node), and pelvic drop

metastasis (Blumer shelf).

Laboratory Analysis

Workup usually reveals an elevated total and conjugated serum biliru-

bin, alkaline phosphatase, and γ-glutamyl transferase reective of biliary

obstruction. Transaminases, amylase, and lipase may be normal. In patients

with jaundice, malabsorption of fat-soluble vitamins decreases the hepatic

production of vitamin K–dependent clotting factors and results in the pro-

longation of prothrombin time. is coagulopathy can be normalized by

the administration of parenteral or subcutaneous vitamin K. Normocytic

anemia and hypoalbuminemia may reect the chronic nutritional sequelae

of the neoplastic disease process.

e most extensively studied serum tumor marker in PDAC is the

Lewis blood group–related mucin glycoprotein, CA 19-9. e use of CA 19-9

as a diagnostic or screening marker for PDAC is limited by several factors.

CA 19-9 is only moderately accurate (sensitivity 81%) in identifying PDAC

when using the normal cuto value of 37 units/mL. In addition, up to 15%of

individuals do not secrete CA 19-9 because of their Lewis antigen status.

Moreover, patients with small-diameter or early tumors—who would derive

the greatest survival benet from surgical resection—often have normal CA

19-9 levels. Lastly, elevated CA 19-9 levels can be seen in benign pancre-

atic or biliary disease, and CA 19-9 is spuriously elevated in the setting of

jaundice. Nevertheless, CA 19-9 may complement other diagnostic modali-

ties, such as computed tomography (CT), endoscopic retrograde cholan-

giopancreatography (ERCP), or endoscopic ultrasound (EUS), such that the

combined diagnostic accuracy for PDAC nearly approaches 100%. Severely

elevated preoperative CA 19-9 levels (>1,000 units/mL) suggest advanced

Section I / Pancreas42

or unresectable disease. In such instances, many authorities recommend

staging laparoscopy even when high-delity imaging suggests a resectable

tumor. Finally, CA 19-9 nds its best utility in postoperative surveillance.

Increasing CA 19-9 levels after surgical resection typically indicate recur-

rence or disease progression, whereas stable or declining levels postopera-

tively indicate absence of recurrence and improved overall prognosis. CEA

has little to no additive value in securing a diagnosis of PDAC.

Investigational Diagnostic Markers

e limited diagnostic utility of CA 19-9 has prompted a search for novel

tumor biomarkers to facilitate the earlier detection of PDAC. ese can

be classied as (i) serum markers

: CA 242, CEA, TPA, TPS, M2-pyruvate

kinase, Mic-1, IGFBP-1a, haptoglobin, serum amyloid A, etc. and (ii) tissue

markers: K-ras, p53, mucins (MUC1/2/5), microRNAs, p21, SMAD4, Bcl-2,

etc. e rst four listed tissue markers have shown promise in early stud-

ies, but none are superior to CA 19-9 nor widely available for use in clinical

practice.

Diagnostic Imaging

Imaging has assumed a crucial role in the diagnosis and stratication of

PDAC patients to stage-appropriate therapy. e goals of imaging are

identication of the primary tumor, assessment of regional invasion and

vascular or lymph node involvement, evaluation of distant metastasis, and

determination of resectability. Common imaging modalities in PDAC are

the following:

(a) Transabdominal Ultrasonography (TAUS): TAUS has an operator-

dependent sensitivity of 60% to 70% in detecting PDAC, which typically

appears as a hypoechoic mass. is modality has largely been replaced

by axial imaging.

(b) Computed Tomography (CT): Multidetector-row CT (MDCT) with three-

dimensional reconstruction is the preferred noninvasive imaging modal-

ity for the diagnosis and staging of PDAC. MDCT utilizes dual-phase

imaging in the arterial and venous phases of enhancement, acquiring

sub-3-mm slices during one 20-second breath hold. PDAC typically

appears as a hypodense mass—although it can appear isodense—in the

parenchyma and is best seen on the portal venous phase of enhance-

ment. MDCT also provides a comprehensive view of tumor abutment or

encasement of the major peripancreatic vascular structures (celiac axis,

superior mesenteric artery [SMA] and superior mesenteric vein [SMV],

splenic artery, and portal vein [PV]) as well as peripancreatic lymphade-

nopathy and hepatic or omental metastasis. Finally, it provides the best

spatial road map for the anatomic relationships between the primary

tumor and the local vasculature.

in MRI technology have improved its ability to diagnose and stage

pancreatic cancer. A majority of PDACs have low-signal intensity on

T1-weighted fat-suppressed images. Upon dynamic imaging after gado-

linium contrast injection, PDAC enhances relatively less than surround-

ing parenchyma and reveals progressive enhancement on subsequent

phases. MR cholangiopancreatography (MRCP) can optimally assess

the biliary and pancreatic ductal anatomy as well as the postresection

pancreatic remnant. Although some authorities consider MRI com-

parable to MDCT in detecting PDAC, obtaining both studies oers no

signicant advantage in assessing patients with radiographically resect-

able disease. MRCP is more useful for evaluating cystic masses of the

pancreas.

Chapter 4 / Pancreatic Adenocarcinoma 43

(d)

Positron Emission Tomography (PET): In this functional imaging tech-

nique, a positron-emitting tracer—uorine-18—is labeled to uorode-

oxyglucose (FDG), which is rapidly taken up by tumor cells. Although

unenhanced PET/CT has a limited role in the local staging of PDAC

due to its poor depiction of primary tumor and its relationship to adja-

cent vasculature, intravenous contrast-enhanced PET/CT has been

shown to have improved accuracy for PDAC detection in recent stud-

ies. However, since FDG also localizes at sites of inammation and

infection, PET imaging is largely used as an adjunct modality to detect

disseminated disease. Furthermore, its reimbursement is currently

limited for PDAC, as opposed to its acceptance for other established

solid malignancies.

(e) Endoscopic Ultrasound (EUS): EUS has gained popularity in recent years

as a minimally invasive modality for the local staging of PDAC. Its par-

ticular benet is realized in the clarication of small (< 2 cm) lesions in

the setting of negative or equivocal CT ndings, evaluation of malignant

lymphadenopathy, detection of vascular involvement, and the ability to

obtain a tissue diagnosis when combined with ne needle aspiration

(FNA). Combined with FNA, EUS has a sensitivity of 93% and 88% for

T- and N-stage disease, respectively. However, unless protocol-based

neoadjuvant therapy is planned or the patient is a poor operative can-

didate, a tissue diagnosis is not required in acceptable-risk patients with

resectable lesions on noninvasive axial imaging (CT or MRI). Moreover,

EUS is invasive, is operator dependent, and cannot assess liver or distant

metastasis, thereby limiting its utility.

(f) Endoscopic Retrograde Cholangiopancreatography: Although its sen-

sitivity for the diagnosis of PDAC approaches 90%, the routine use of

diagnostic ERCP for suspected PDAC is unsupported. With the current

advances in CT/MRI technology, diagnostic ERCP should be reserved for

select groups of patients: (i) those with obstructive jaundice but with-

out a detectable mass on CT or MRI; (ii) symptomatic but nonjaundiced

patients with equivocal ndings on CT or MRI; and (iii) suspected pan-

creatic cancer in the setting of chronic pancreatitis. Even in these circum-

stances, many authorities advocate for noninvasive alternatives, such as

MRCP. Nevertheless, ERCP is often utilized prior to surgical consultation

for relief of jaundice.

Clinicopathologic Staging

e American Joint Committee on Cancer (AJCC) staging for pancreatic

cancer is based on the TNM classication, incorporating extent of primary

tumor (T), presence of regional lymph node involvement (N), and presence

of distant metastasis (M) (Table 4.1).

MANAGEMENT

Preoperative Considerations

Assessing Surgical Resectability

Although the TNM classication is used for pathologic staging and

clinical description, the crucial step for the surgeon in the preoperative

workup of PDAC patients is to determine operability—an option available

to fewer than a quarter of all patients at diagnosis. PDAC of the pancreatic

head, neck, or uncinate process is stratied into the following: (a) resect-

able, dened as no radiographic evidence of extrapancreatic disease, a

patent SMV–PV conuence, and no evidence of tumor extension to the

celiac axis or SMA; (b) borderline resectable, dened as nonmetastatic

tumor with SMA abutment (≤180 degrees), abutment or encasement of

Section I / Pancreas44

the gastroduodenal artery (GDA) up to or around a short, reconstructable

segment of the common hepatic artery (CHA), or complete occlusion of

the SMV–PV conuence, with suitable, uninvolved vein above and below

to allow venous reconstruction (as a general rule, tumors encasing up to

2 cm of the SMV and/or PV for up to a 180-degree circumference are con-

sidered technically possible); (c) locally advanced, dened as encasement

(>180 degrees) of the celiac axis or SMA or occlusion of SMV–PV conu-

ence without an option for venous resection and reconstruction; and

(d) metastatic, dened as distant metastatic spread to the liver, perito-

neum, or rarely the lung. It is important to realize that, for this disease,

operability≠resectability. Up to 85% (but certainly not 100%) of radiograph-

ically amenable lesions are resectable intraoperatively, whereas fewer than

20% of locally advanced lesions are ultimately amenable to resection.

Role of Diagnostic Laparoscopy

e use of diagnostic laparoscopy in PDAC staging remains controversial.

Although the combination of laparoscopy with laparoscopic ultrasound can

improve the accuracy of determining peritoneal and/or hepatic dissemina-

tion to almost 98%, we do not recommend the routine application of diagnos-

tic laparoscopy in PDAC due to its questionable cost-eectiveness as well as

the impressive accuracy of modern high-delity axial imaging. Moreover, even

in potentially unresectable disease, laparoscopy is unnecessary if the patient

were to benet most from surgical palliation (see below). Alternatively, a

more selective use of diagnostic laparoscopy is justied in those patients with

a high risk of occult metastatic disease in whom nonsurgical palliation would

Tumor (T)

Tx: Primary tumor cannot be assessed

T0: No evidence of primary tumor

Tis: Carcinoma in situ

T1: Tumor limited to the pancreas, 2 cm or less in greatest dimension

T2: Tumor limited to the pancreas, more than 2 cm in greatest dimension

T3: Tumor extends beyond the pancreas but without involvement of the celiac

axis or the superior mesenteric artery

T4: Tumor involves the celiac axis or the superior mesenteric artery

(unresectable primary tumor)

Regional Lymph Nodes (N)

Nx: Regional lymph nodes cannot be assessed

N0: No regional lymph node metastasis

N1: Regional lymph node metastasis

Distant Metastasis (M)

Mx: Distant metastasis cannot be assessed

M0: No distant metastasis

M1: Distant metastasis

Stage T N M 5-Year Survival (%)

IA T1 N0 M0 20–30

IB T2 N0 M0 20–30

IIA T3 N0 M0 10–25

IIB T1, T2, T3 N1 M0 10–15

III T4 Any N M0 0–5

IV Any T Any N M1 —

AJCC Staging of Pancreatic Ductal Adenocarcinoma

(seventh edition)

TABLE

4.1

Chapter 4 / Pancreatic Adenocarcinoma 45

be durable. is scenario includes the following: (a) lesions in the pancreatic

body or tail; (b) larger (>

cm) primary tumors; (c) equivocal radiographic

ndings suggestive of occult metastasis such as low-volume ascites, perito-

neal carcinomatosis, or small hepatic lesions not amenable to percutaneous

biopsy; and (d) markedly elevated CA 19-9 or hypoalbuminemia suggestive

of advanced disease. In addition, diagnostic laparoscopy may be considered

in certain cases of borderline resectable and/or locally advanced disease—

understanding that evidence of metastatic spread might alter whether radia-

tion therapy would be used in conjunction with chemotherapy.

Role of Preoperative Biliary Drainage for Obstructive Jaundice

In the past, a majority of patients with resectable PDAC who presented

with obstructive jaundice underwent either endoscopic or percutaneous

transhepatic preoperative biliary drainage (PBD) before surgical referral.

Recently, however, the routine use of PBD in resectable PDAC has been dis-

couraged in the light of convincing evidence that PBD increases the rate of

postoperative complications and oers little benet compared with early

surgery for resectable tumors. In a recent randomized multicenter trial, van

der Gaag et al. showed that PBD was associated with signicantly higher

rates of serious perioperative complications compared with early surgery,

while mortality and length of hospital stay did not dier signicantly

between the groups. However, the role of biliary drainage as temporary

palliation in patients with borderline resectable tumors undergoing neo-

adjuvant therapy is clinically relevant. In such situations, authorities advo-

cate the use of self-expandable metal stents over plastic stents given their

improved durability should the tumor be ultimately deemed unresectable.

Role of Neoadjuvant Therapy for PDAC

ere is growing enthusiasm for the use of neoadjuvant chemoradiation

in PDAC that relies on the following theoretical principles: (a) increased

ecacy of chemoradiation in well-oxygenated tissue not devascularized by

surgery; (b) potential for downstaging, thereby improving R0 resection and

decreasing locoregional recurrence rates; and (c) identifying patients with

rapidly progressive disease who might not derive a survival advantage from

surgery. Several groups have utilized neoadjuvant regimens involving gem-

citabine, 5-FU, or paclitaxel plus radiation for resectable PDAC. Current

data suggest that while neoadjuvant chemotherapy is well tolerated and

does not delay surgical intervention, there is no clear survival benet to this

strategy compared with standard postoperative adjuvant therapy. A 2009

AHPBA-SSO-SSAT consensus panel indicated that neoadjuvant therapy for

resectable PDAC should be considered investigational and oered within

the context of clinical trials or multidisciplinary treatment programs.

However, there may be an emerging role for neoadjuvant strategies in

borderline resectable tumors. Investigators from the University of Virginia

demonstrated that 46% of patients with borderline resectable PDAC under-

went surgical resection after completing neoadjuvant capecitabine-based

chemoradiation. is group had favorable overall survival (OS)—median

23 months—similar to that of a historical cohort of patients with resectable

PDAC. In a recent report from the M.D. Anderson Cancer Center, 66% of

borderline resectable PDAC patients underwent resection after neoadju-

vant therapy (chemoradiation alone or gemcitabine-based chemotherapy

followed by chemoradiation), of which an R0 resection was achieved in

95%. Median OS in this cohort was up to 33 months following their uniquely

highly standardized protocol. ese data solidify the role for induction

therapy in borderline resectable PDAC, with attempted resection oered to

patients without evidence of cancer progression on presurgical restaging

Section I / Pancreas46

studies. Several challenges remain: (a) adherence to and application of the

consensus denition of “borderline resectable” tumors across institutions;

(b) what the most eective neoadjuvant modality is (chemotherapy alone,

chemoradiation, or a combination); and (c) need for a multi-institutional

trial to validate these optimistic early reports. As is the case for resectable

tumors, it remains a fact that there has been no direct clinical comparison

of the two techniques that would clearly advocate one over the other.

Surgical Resection and Related Controversies

Resection of PDAC can be broadly categorized into two types: (i) pancreati-

coduodenectomy for tumors situated in the head, neck, or uncinate process

or (ii) distal pancreatectomy for tumors of the body and tail. While techni-

cal details of these operations can be found in Chapter 7 by Pilgrim et al.,

a discussion of the global conduct of these operations and select lingering

controversies in the operative management of PDAC follows.

Pancreaticoduodenectomy (Whipple Procedure)

e preliminary steps of a PD or Whipple procedure involve assessment of

resectability. e liver, peritoneal surfaces, celiac axis–level lymph nodes,

and remainder of the abdomen are inspected for metastatic disease. As

noted earlier, this assessment may be performed laparoscopically in select

circumstances. A Kocher maneuver is performed to assess for retroperito-

neal, SMV, SMA, or celiac takeo involvement. e SMV is identied in the

plane anterior to the third portion of the duodenum between the transverse

mesocolon and the uncinate process by opening the lesser sac through the

gastrocolic omentum. e porta hepatis is examined by mobilizing the gall-

bladder and tracing the cystic duct to its junction with the common hepatic

duct. Once the tumor is considered resectable on both of these fronts, early

division of the extrahepatic biliary tree allows caudal retraction of the distal

common bile duct and visualization of the anterior aspect of the PV. In a

pylorus-preserving PD, division of bowel occurs 2 cm distal to the pylorus

and 20 cm distal to the ligament of Treitz. e divided proximal jejunum is

delivered posterior to the superior mesenteric vessels to facilitate dissec-

tion of the pancreas o the right lateral aspect of the SMV. Vein resection

may be required and ranges from primary repair to patch reconstruction

to interposition grafting. e pancreatic neck overlying the SMV–PV is

divided, and the pancreatic head is meticulously dissected o the right

lateral aspects of the SMV–PV. Dissection of the retroperitoneal “meso-

pancreas” ensues with the aim of removing the tissue up to the adventitial

layer of the SMA along the right side of its course. Reconstruction involves

a pancreaticoenteric anastomosis—most commonly pancreaticojejunos-

tomy (PJ)—in an end-to-end or end-to-side fashion using either a duct-to-

mucosa or invagination technique. Alternatively, a pancreaticogastrostomy

(PG) can be used. e biliary–enteric anastomosis is typically performed in

an end-to-side fashion approximately 10 cm distal to the PJ on the pancre-

aticobiliary limb of the jejunum. e duodenojejunostomy (DJ) is placed, in

a majority of cases, in an antecolic orientation 50 to 60 cm downstream to

the biliary–enteric anastomosis. Enteric feeding tubes (gastrostomy or jeju-

nostomy) can be used selectively in those patients who the surgeon expects

may not thrive postoperatively.

Distal Pancreatectomy

Fewer resections are performed for tumors of the body and tail of the pan-

creas due to a higher incidence of advanced disease at initial presenta-

tion. Resection of these tumors is achieved with a distal pancreatectomy

accompanied by, in a vast majority of cases, splenectomy. As with PD, initial

Chapter 4 / Pancreatic Adenocarcinoma 47

exploration is geared to rule out hepatic or peritoneal metastasis, and lapa-

roscopy has a higher yield than with proximal tumors. If metastasis is not

present, the lesser sac is entered and involvement of the SMV is adjudicated.

If resection is attempted, the spleen and distal pancreas are mobilized in a

retrograde fashion. e pancreas is then transected to the left of the SMV–

PV trunk and the main pancreatic duct ligated. is is usually performed

with a stapling device, although suturing the duct is acceptable—evidence

does not support any particular technique. However, due to limitations in

the posterior extent of resection and the ability to achieve a complete N1

nodal dissection with the classic distal pancreatosplenectomy, Strasberg

et al. proposed the radical antegrade modular pancreatosplenectomy

(RAMPS) procedure in 2003. is approach, which relies on medial to lateral

dissection, improves visibility, enables an N1 nodal dissection, enhances the

ability to achieve microscopically negative tangential margins, and permits

adjustment of the depth of the posterior extent of resection coupled with

early rather than late control of the vasculature. Long-term results revealed

R0 resection rates of up to 81%, negative tangential margins in 89%, and

median survival of 26 months.

Surgical Palliation

PDAC patients found to have unresectable disease at laparotomy, or those

with tumor-related symptoms poorly alleviated by nonoperative methods,

are appropriate candidates for surgical palliation. It involves biliary bypass,

gastroenteric bypass, chemical splanchnicectomy, or combinations thereof.

Hepatico- or choledochojejunostomy, using a Roux-en-Y conduit, is the pre-

ferred method of biliary bypass and results in a decreased risk of recurrent

jaundice compared with choledochoduodenostomy or cholecystojejunos-

tomy. Some patients undergoing biliary bypass alone ultimately require

gastroenteric bypass for eventual duodenal obstruction. A prospective trial

evaluating the role of prophylactic gastrojejunostomy (GJ) in unresectable

PDAC found that 19% of patients randomized to no GJ developed late gas-

tric outlet obstruction requiring intervention compared with 0% in the GJ

group (p<0.01), although mean OS between the groups was similar. Finally,

chemical splanchnicectomy—injection of 50% alcohol at the celiac nerve

plexus—signicantly reduces mean pain scores in patients with unresect-

able right-sided PDAC. is should be reserved for unresectable patients

who present with signicant pain prior to laparotomy.

Controversies in Pancreatic Resection for PDAC

(a) Role for Extended Lymphadenectomy: Four randomized trials have

attempted to answer if there is benet to extended lymph node dissec-

tion in PDAC. e data, substantiated by numerous strong meta-analyses,

suggest that extended lymphadenectomy increases the morbidity without

signicantly improving median or 5-year survival.

(b) Classical Versus Pylorus-Preserving PD : Most surgeons prefer the pylorus-

preserving PD because it reduces operative time and blood loss, retains

the entire gastric reservoir, and does not compromise oncologic out-

comes (negative margin rate or OS) compared with the classical variant.

Furthermore, no appreciable dierence is observed in gastric physiology

or nutrition postoperatively.

resection and reconstruction after PD for PDAC are nonstandardized.

Several single-center experiences suggest that, in the absence of other

contraindications for resection, a controlled venous resection and

reconstruction when the tumor cannot be separated from the SMV, PV

or SMV–PV conuence is safe and feasible. Recently, however, a large

Section I / Pancreas48

retrospective analysis of the ACS NSQIP database revealed that vascu-

lar resection after PD is associated with a signicantly higher overall

morbidity and 30-day postoperative mortality. Arterial resection is not

advised with the exception of a short segment of hepatic artery for those

tumors invading the GDA takeo. Most experienced pancreatic surgeons

avoid concomitant arterial and venous resection.

(d) Margin Status: Current margin nomenclature is poorly dened and the

value of intraoperative frozen section analysis has not been studied

extensively. Controversy exists over the proper techniques for speci-

men analysis by pathologists. Achieving an R0 resection and a negative

SMA/uncinate margin correlates most strongly with positive long-term

outcomes. Patients with R1 resections should be strongly considered for

adjuvant multimodal therapy.

(e) Minimally Invasive PD: Although minimally invasive distal pancreatic

resections are being increasingly employed for cancer, minimally invasive

PD (MIPD) for PDAC continues to lack widespread acceptance because

matched comparative trials and long-term outcomes comparing MIPD

to the open approach are lacking. Recently, comparisons between the two

suggest that MIPD is associated with reduced length of stay and blood

loss without compromising standard oncologic principles. Although

long-term follow-up is lacking, short-term results suggest equivalent, but

not better, rates of recurrence and survival when highly skilled specialists

apply MIPD techniques.

Postoperative Considerations

Postoperative Complications

e overall complication rate after PDAC resection, especially PD, con-

tinues to approach 40%. e most common immediate complications are

postoperative pancreatic stula (approximately 15%), delayed gastric emp-

tying (approximately 5%), hemorrhage (approximately 5%), and wound

infection (approximately 20%). Long-term eects of parenchymal resection

may manifest in pancreatic insuciency. ese include diabetes and steat-

orrhea—both of which occur in approximately 25% of all patients.

(a) Postoperative Pancreatic Fistula (POPF): A gradation of POPF—A (bio-

chemical, with no clinical impact) through C (rendering a life-threatening,

major deviation from clinical recovery)—was developed by a consensus

panel (ISGPF) in 2005. ere is no unequivocal evidence to suggest that

anastomotic route (PJ vs. PG), anastomotic technique (duct-to-mucosa

vs. invagination vs. single-layer end-to-side PJ), pancreatic duct stenting,

or use of long-acting somatostatin analogs alters the incidence of POPF

formation.

(b) Delayed Gastric Emptying (DGE): e severity of DGE after pylorus-

preserving PD—grades A through C—relates to the need for nasogas-

tric decompression, volume of gastric euent, and inability to tolerate

oral intake postoperatively. e pathogenesis of DGE remains unclear,

although putative mechanisms include antral ischemia, absence of duo-

denal motilin, gastric atony from a vagotomized stomach, and gastric

dysrhythmia secondary to POPF or edema from uid overload. ere

is convincing randomized evidence that (i) an antecolic compared

with a retrocolic reconstruction and (ii) postoperative administration

of erythromycin (motilin agonist) signicantly reduce the incidence of

DGE after pylorus-preserving PD.

Postoperative Adjuvant Therapy

Adjuvant therapy, supported by a large body of evidence, is a critical part of

the postoperative management of PDAC. e Gastrointestinal Tumor Study

Chapter 4 / Pancreatic Adenocarcinoma 49

Group (GISTG, 1985) originally showed that 5-FU–based chemoradiation

followed by maintenance chemotherapy had a signicant median OS ben-

et compared with observation alone (20 months vs. 11 months, p=0.03).

Despite limited accrual, the GITSG trial was the rst to show a potential ben-

et for adjuvant therapy after resection of pancreatic cancer. e European

Organization for Research and Treatment of Cancer (EORTC, 1999) study

was similar and randomized resected patients to concurrent chemoradia-

tion without subsequent chemotherapy versus observation alone. Median

OS was not signicantly dierent (24.5 months vs. 19 months, p= 0.208).

e European Study Group for Pancreatic Cancer (ESPAC-1, 2004) study

was conducted with a 2×2 factorial design. e four arms included sur-

gery alone, 5-FU–based chemotherapy alone, 5-FU–based chemoradiation

alone, and both modalities. Patients receiving chemotherapy (chemother-

apy alone or chemoradiation followed by chemotherapy) had a signicantly

improved median OS compared with the no-chemotherapy arm (chemo-

radiation alone or surgery alone; 19.7 months vs. 14 months, p=0.0005).

Interestingly, patients who received radiation (chemoradiation alone or

chemoradiation followed by chemotherapy) had worse median OS com-

pared with those not receiving radiation (chemotherapy alone and surgery

alone; 15.9 months vs. 17.9 months, p=0.05).

With gemcitabine emerging as a viable alternative to 5-FU chemo-

therapy, the CONKO-001 study demonstrated that resected patients receiv-

ing adjuvant gemcitabine had signicantly improved median OS compared

with observation alone (22.8 months vs. 20.2 months, p=0.005). e ESPAC-3

trial, a head-to-head comparison between adjuvant gemcitabine versus 5-FU

alone, found a nonsignicant dierence in median OS (23.6 months vs. 23.0

months). Of note, there was a greater incidence of high-grade, treatment-

related toxicities in the 5-FU arm. e Radiation erapy Oncology Group

(RTOG-9704), which compared adjuvant gemcitabine+5-FU–based chemo-

radiation and 5-FU+5-FU–based chemoradiation, found a nonstatistically

signicant survival benet with gemcitabine (20.5 months vs. 16.9 months,

p=0.09). Although both 5-FU and gemcitabine have been validated as via-

ble adjuvant options, gemcitabine has largely replaced 5-FU in the Unites

States due its greater tolerability and improved quality-of-life outcomes.

The Debate Surrounding Adjuvant Radiotherapy

Although the benet of adjuvant chemotherapy is unequivocally agreed

upon, the concurrent use of radiation therapy remains contentious. In the

United States, the use of adjuvant chemoradiation is still largely standard

practice. Proponents for this approach cite the survival benet seen in the

GISTG trial and the design aws underlying the conclusions of the ESPAC-1

trial. In Europe, adjuvant chemotherapy alone is preferred, presumably

from dierent interpretations of the same data presented above.

Future Directions in Adjuvant Therapy

Adjuvant trials with erlotinib, FOLFIRINOX, maintenance capecitabine, and

a therapeutic vaccine GI-4000 are underway and are described elsewhere.

OUTCOMES AND FOLLOW-UP

Historically, after PDAC resection, the perioperative mortality rate was 20%

to 40% and 5-year survival approximately 3%. ese statistics have changed

dramatically, with current operative mortality rates having declined to well

under 5% and 5-year survival regularly eclipsing 20% in recent studies from

high-volume pancreatic surgery centers. is improvement is likely multi-

factorial and is related to advances in preoperative imaging, improvements

in surgical technique and perioperative care, and availability of broader

Section I / Pancreas50

adjuvant therapy options. Recently, a contemporary analysis of 424 PDAC

resections from the University of Pennsylvania and Beth Israel Deaconess

Medical Center demonstrated median, 1-year, and 5-year survivals of

21.3 months, 76%, and 23%, respectively. e 30-day mortality was only

0.7%. Seventy-six percent of patients received adjuvant therapy. Patients

with major complications (Clavien grade IIIb–IV) survived similarly to

those without complications. In general, predictors of survival include

patients with R0/N0/M0 characteristics, tumor diameters less than 3 cm,

negative resection margins, and well or moderate tumor dierentiation and

those who receive adjuvant chemoradiation.

CONCLUSION

Overall, the prognosis of PDAC continues to be disappointing. However,

survival in resectable PDAC has increased dramatically over the last few

decades, in part due to signicant improvements in surgical expertise and

adjuvant multimodal therapy. Correspondingly, the therapeutic boundaries

in PDAC care are being pushed with respect to expanding indications for

PDAC resection and aggressive neoadjuvant strategies in borderline resect-

able tumors. Continuing renement in our surgical techniques, combined

with emerging chemo- and radiotherapeutic options, provides cautious

optimism for the future of this often frustrating disease.