Devita, Hellman, and Rosenberg's Cancer

LWBK1006-20 LWW-Govindan-Review December 12, 2011 19:4

248 DeVita, Hellman, and Rosenberg’s CANCER: Principles and Practice of Oncology Review

segmental resection of pancreas with PanINs in the resected tissue, pan-

creatic cancer can develop in the pancreatic remnant. The strongest evi-

dence that PanINs are precancerous lesions is the stepwise progression of

genetic mutational events that correlates with the stepwise progression of

worsening PanINs culminating in adenocarcinoma. PanIN-1 lesions show

a predominance of K-ras mutations and overexpression of HER-2/neu. In

PanIN-2 lesions, p16 mutations are the typical mutational event, and in

PanIN-3 lesions, p53, DPC4, and BRCA2 mutations predominate. The

mutational pattern of PanIN-3 lesions is equivalent to mutations found in

pancreatic adenocarcinoma. These events are the basis of a current pro-

gression model for pancreatic cancer in which point mutation of K-ras

and overexpression of HER-2/neu are initiating early events, p16 inac-

tivation is an intermediate event, and p53, DPCA, BRCA2 inactivation

follow just before invasion outside of the duct. Approximately 90% of

all cases have p16 mutations, 75% have p53 mutations, and 55% have

DPC4 mutations. It is estimated that 10% to 20% of pancreatic cancers

are hereditary or have a familial link. Of patients with available data

in the United States who were diagnosed with pancreatic cancer from

1996 to 2002, 8% presented with local disease, 31% presented with

regional disease, and 61% had distant metastases. Therefore, the major-

ity of patients are metastatic at diagnosis. Five-year survival from all stages

of disease is 5%. Pancreatic cancer tends to occur later in life. Only 10%

of patients in Europe present before the age of 50 years, whereas those

aged 50 to 54 years experience an incidence of 9.8 per 100,000, and

those aged 70 to 74 years experience an incidence of 57 per 100,000. The

median age of diagnosis with pancreatic cancer in the United States is

72 years.

Answer 20.2.3. The answer is C.

The patient has a stage III, T4N1M0 pancreatic cancer. As per the sixth

edition of the American Joint Committee on Cancer staging system, this

represents unresectable disease. The T-stage designation classifies T1 to

T3 tumors as potentially resectable and T4 tumors as locally advanced

(unresectable). Tumors with any involvement of the superior mesenteric

or celiac arteries are classified as T4; however, tumors that involve the

superior mesenteric, splenic, or portal veins are classified as T3 because

these veins can be resected and reconstructed provided that they are

patent.

Answer 20.2.4. The answer is A.

Laparoscopy and multiphase CT have evolved concurrently as methods

to evaluate a pancreatic mass. Both have emerged as highly effective in

evaluating the tumors, but CT as a noninvasive modality supplants the use

of routine laparoscopy. Currently, routine use of laparoscopy is not war-

ranted. The cornerstone of diagnostic evaluation of a pancreatic tumor

is the multiphase CT scan, coordinating intravenous contrast adminis-

tration with subsequent rapid thin-cut CT through the pancreas during

arterial, portal venous, and parenchymal phases of enhancement. With