Pancreatic/colorectal cancer Flashcards
Pancreatic Cancer
general
4th leading cause of death in the United States
High-risk groups:
African Americans and individuals of Jewish ancestry
7% have a family history of pancreatic cancer in a first-degree relative
Categories:
Endocrine pancreatic cancer
Develop from cells in the endocrine gland of the pancreas
Exocrine pancreatic cancer (95%)
Develop from ductal or acinar cells of the pancreas
Cystic neoplasms
Can be mistaken for benign cysts which are common
Exocrine Pancreatic Cancer
general
Adenocarcinoma
Most common neoplasm of the pancreas
60% arise in the head
20% arise in the body or tail
20% involve the entire pancreas
Types:
Ductal carcinoma (90%)
Acinar cell carcinoma (~5%)
Squamous cell carcinoma – rare
Adenosquamous cell carcinoma - rare-Aggressive cancer with poor prognosis
Colloid carcinoma
Adenocarcinoma pancreatic cancer
RF
Smoking (thought to cause 30%)
Chronic pancreatitis (>20 years)
High alcohol consumption
Obesity
Type II diabetes mellitus *
Metformin use and possibly aspirin use may reduce the risk of pancreatic cancer slightly
Insulin use and glucagon-like peptide-1-based therapy may increase the risk
Inherited genetic syndrome (5-10%)
Multiple endocrine neoplasia 1
Hereditary breast and ovarian cancer syndrome (BRCA1 & BRCA2 mutations)
Familial pancreatic carcinoma
Hereditary pancreatitis (PSS1 mutation)
Peutz-Jeghers syndrome
Lynch syndrome
Non-polyposis colorectal cancer
Increased risk for other cancers at a young age
said dont need to memeorize list
pancreatic cancer
Sx
nonspecific and GI
Symptoms are similar to chronic pancreatitis
Nonspecific symptoms
Poor appetite
Weight loss
Gastrointestinal symptoms
Abdominal pain
Severe, belt-shaped epigastric pain or left upper quadrant pain
Radiates to the back (worse at night)
Nausea/vomiting
Jaundice
Obstruction of extrahepatic bile ducts (tumors in the pancreatic head)
Malabsorption
Pale, greasy stools that float in the toilet (diarrhea)
Impaired glucose tolerance
Pancreatic Cancer
PE findings
Signs
Courvoisier sign- Enlarged, nontender gallbladder (poor prognosis)
Sister Mary Joseph’s sign-Hard, palpable nodule bulging into the umbilicus- Metastasis of a malignant cancer in the abdomen or pelvis
Hypercoagulability
Trousseau syndrome (10%)- Recurring, migratory thrombophlebitis
Red, tender extremities
Splenic vein thrombosis
Sister Mary Joseph’s sign – umbilical nodule
pancreatic cancer
Lab findings
By the time of diagnosis, 90% of patients have locally advanced tumors that involve retroperitoneal structures, spread to lymph nodes, or metastasized to the liver or lung
Labs
CBC with differential
CMP
↑ alkaline phosphatase and ↑ bilirubin with bile duct obstruction or liver metastasis
Lipase and amylase
Normal or minimally elevated###
CA 19-9, CEA, and CA 125 (tumor markers)
Used to monitor cancer progression in diagnosed patients, as well as treatment efficacy
Not sensitive or specific enough to be used for population screening
Pancreatic cancer
imaging studies
Imaging
Abdominal ultrasound
First test performed if jaundice is the presenting symptom
CT scan of the abdomen and pelvis with contrast
Indications:
Initial symptoms are abdominal pain and weight loss
If ultrasound reveals a pancreatic mass
Alternative test MRI/MRCP (magnetic resonance imaging/magnetic resonance cholangiopancreatography)
Endoscopic ultrasound (EUS)
Used when other diagnostic tests are inconclusive or to perform fine needle aspiration
FYI…thrombosis of unknown origin may be caused by an undiagnosed malignancy
(common due to pancreatic cancer, pulmonary cancer, or prostatic cancer – 3Ps)
pancreatic cancer
whipple procedure
indications
Procedure of choice
Resection of the pancreatic head, distal stomach, duodenum, gallbladder, and common bile duct
Indicated for cancers strictly limited to the head of the pancreas, periampullary area, and duodenum
pancreatic cancer
Adjuvant chemotherapy and radiation therapy(2) with Symptomatic treatment(3)
Adjuvant chemotherapy and radiation therapy
Initiated following Whipple procedure
Initiated for patients with localized, but unresectable tumors → noncurative
Symptomatic treatment
Analgesics (opioids)
Procedures to maintain biliary patency
Pancreatic enzyme supplementation
pancreatic cancer
prognosis
Patients undergoing resection
Medial survival: ~18 months
Carcinoma of the body or tail of the pancreas
Poor prognosis
80-85% present with advanced unresectable disease
5-year survival rate: 2-5%
Metastatic disease
5-year survival rate: ~3%
Colorectal Cancer (CRC)
general
3rd most common cancer (among both men and women)
2nd most common cause of death due to cancer in the United States
Most common cancer of the GI tract
Incidence and mortality rates have been declining
>50% of the cases occur in the rectum and sigmoid colon
95% are adenocarcinomas
Most colorectal cancers (CRCs) arise from polyp
CRC
etiology
Colorectal polyps
Abnormal tissue outgrowths arising from the colonic mucosa and extending into the lumen
Most common lesions from which CRC arises
CRC
Sessile vs Pedunculated polyps
Morphology
Sessile: polyp without a stalk, with growth adjacent to the mass
Pedunculated: polyp with a stalk
30% of the population has polyps by the age of 50
CRC
RF
Age ≥ 45 (94% of new CRC cases)- new screening age!
Hereditary syndromes:
Familial adenomatous polyposis (FAP)
Peutz-Jeghers syndrome (PJS)
Family history of CRC
Colon pathologies:
Risk increases with the duration of the disorder
Inflammatory bowel disease (IBD)
Large adenomatous polyps or previous CRC
Other medical conditions:
Cystic fibrosis
Abdominopelvic radiation
Conditions with increasedinsulinor insulin-like growth factor (diabetes,acromegaly,obesity)
Lifestyle and social factors:
Smoking and alcohol consumption (> 4 drinks/day)
Diet (increased fat, red and processed meat, low fiber)
CRC
patho
Most CRCs begin with adenomatous polyposis coli (APC) gene inactivation(gene mutation)
Multiple genetic hits are required for CRC progression (10–15 years to develop)
Proto-oncogene mutations → loss of cancer suppression genes
Overexpression of COX-2- inflammation
CRC spreads by direct extension through the bowel wall, hematogenous metastasis, regional lymph node metastasis, and perineural spread
CRC
S/Sx
Often asymptomatic
CRC detected on screening colonoscopy
Symptomatic:
Dependent on location
Systemic features: weakness, anemia, weight loss
Iron deficiency anemia in an elderly patient indicates colon cancer until proven otherwise
Right-sided carcinomas
general
Includes tumors of the cecum, ascending and transverse colon
Obstructive symptoms are uncommon:
Stool in the area is still liquid
Lumen is larger (than left side)
Lesions can grow, ulcerate, and lead to occult blood loss:
Iron deficiency anemia: fatigue, angina, palpitations
Melena
Tumors sometimes grow large enough to be palpable through the abdominal wall
anemia more common here
obstruction uncommon
Left-sided carcinomas
Includes tumors of the descending colon, sigmoid colon, and the rectum
Cancerous lesions can impede passage of stool, causing:
Abdominal cramping or colicky pain
Changes in bowel habits (constipation alternating with loose stools)
Blood-streaked stools or hematochezia
Decreased stool caliber due to obstruction
Pencil thin stools may be a sign of narrowing or obstruction due to colon cancer
Rectal cancers
S/Sx
Palpable ulcerating mass on rectal exam
Tenesmus
Sensation of incomplete evacuation
Rectal bleeding with defecation
Rectal pain
Obstruction
FYI…rectal bleeding, even with obvious hemorrhoids or known diverticular disease, coexisting cancer must be ruled out
CRC
Metastasis
CRCs metastasize by direct extension or via hematogenous and lymphatic route
Sites of metastasis:
Liver - 1st site for intestinal (colon) tumors
Abdominal distention, jaundice, ascites, hepatomegaly
Lungs - 1st site for distal rectal tumors
Cough, dyspnea (may be from pleural effusion), hemoptysis
Colorectal Cancer Screening
Average-risk patients
Begins at age 45 years
Continues until 75 years
76-85 years: decision to screen should be individualized
Screening options:
Colonoscopy every 10 years *
Fecal occult blood test annually
Fecal immunochemical tests (FIT) preferred *
Flexible sigmoidoscopy every 5 years (every 10 years if combined with FIT)
CT colonoscopy every 5 years
Fecal DNA testing combined with FIT every 3 years
Family history - 1st degree relative with colorectal cancer diagnosed prior to age 60
Colonoscopy every 5 years
Begins at age 40, or 10 years before the age the relative was diagnosed (whichever comes first)
CRC
High-sensitivity guaiac-basedfecal occult blood test(HSgFOBT)
Identifies hemoglobin in stool
Positive test: guaiac reagent turns paper blue (peroxidase reaction)
Restrictions:
Eliminate red meat (3 days before test)
Limitvitamin Cto < 250 mg a day (3 days before test)
Nonsteroidal anti-inflammatory drug (NSAID) intake may affect the test
3 consecutive stool samples needed
CRC
Fecal Immunochemical Test (FIT)
Tests for hemoglobin in the stool
More sensitive and specific than older guaiac-based tests
No medication or diet restrictions prior to the test
Only 1 sample needed
Positive test can result from nonmalignant disorders (ulcers, diverticulosis)
Negative test does not rule out cancer because cancers do not bleed continuously
Fecal DNA testing
Detects DNA mutations and methylation markers shed from a colonic tumor
Test is typically combined with FIT
Test available by prescription
No dietary or medication restrictions
A full stool sample is required
Positive fecal DNA-FIT test should have a follow-up colonoscopy within 6 months
10% of patients have a normal colonoscopy
CRC
Colonoscopy
Gold standard
Visualization of lesion(s) and tissue sampling (biopsy or lesion removal) can be performed
Requires medication adjustment (NSAIDs,aspirin, anticoagulant)
Requires bowel preparation
CRC
Sigmoidoscopy
Endoscope reaches up to the splenic flexure
Allows visualization of only the leftcolon(so right-sided lesions are missed)
Allows removal of lesions, but lesions > 1 cm usually done in subsequent colonoscopy
Requires medication adjustment (NSAIDs,aspirin, anticoagulant)
Performed in-office without sedation
CRC
Computed tomography (CT) colonography
Virtual colonoscopyby generating 2D and 3D images
Requires bowel preparation, but sedation not required
The bowel is distended by introducing air or carbon dioxide via therectum
Can be used in incomplete colonoscopy (obstruction, tortuous colon) or as an initial diagnostic test
Less sensitive and highly interpreter-dependent
Does not allow for the biopsy of lesions
CRC
Air contrastbarium enema
May showapple core lesion (descending colon) = apple core sign
CRC
monitoring success of treatment/recurrance
Required testing:
CT scan of the abdomen and pelvis
CXR
Routine labs: CBC, CMP
Carcinoembryonic antigen(CEA):
Tumormarker for CRC (Present in 70% of patients)
Neither sensitive nor specific and therefore cannot be used for screening
Elevated preoperatively (CEA> 5 ng/mL has worse prognosis) and low after resection, it can be used for monitoring for recurrence
What would non-normalization of CEA levels after surgical resection mean? Mets
CRC
CRC
Treatment & Follow-up
Surgical resection
Wide resection
Indicated for patients without metastatic disease
Chemotherapy and radiation therapy
Improves survival by 10-30% in patients with positive lymph nodes
Surveillance colonoscopy
First performed 1 year after surgery
Second performed 3 years later if no polyp(s) or tumor(s) are found
Continued at 5-year intervals
CRC
Prognosis
Dependent on staging
5-year survival rate:
Cancer limited to the mucosa - 90%
Extension through the bowel wall – 70-80%
Positive lymph nodes – 30-50%
Metastatic disease - < 20%