Colorectal Cancer/polyps/diverticula/hernias - GI Flashcards
Risk Factors - colorectal cancer
- 75% no known risk factors
- Age – 90% in people 50+ yrs
- IBD
- Personal or FH of CRC or polyps (3x more likely to develop)
- FAP (familial adenomatous polyposis
- Lynch Syndrome
- Lack of exercise
- Low fruit/vegetable intake
- Low-fiber / high fat diet
- Overweight/obesity
- Alcohol
- Tobacco Use
Signs and Symptoms -Colorectal Cancer
- None
- Change in stooling for several days
- Rectal bleeding
- BRBPR, dark tarry stools
- Abd pain, bloating, abd distension
- Palpable mass, hepatomegaly, ascites
- Fatigue, night sweats, loss of appetite, unintentional weight loss
- Iron-deficiency anemia
CRC Screening
- decrease mortality through early diagnosis and treatment of precancerous (adenomatous) and early malignant lesions.
- 60% of deaths could be prevented if all adults >50 had screening
- Identifies pre-cancerous polyps
- Detects cancer at early stage
- 90% of early caught cancer + treatment still alive 5yrs out.
- Normally begins at age 50
- Flex sigmoidoscopy q5 years
- Colonoscopy q10 years
- Double-contrast barium enema q5 years
- CT colonography q5 years
- In FH of polyposis syndrome = begin screening 5 years earlier than age of diagnosis of first-degree relative.
- Annual guaiac –based fecal occult blood test
- Stool DNA
Colonic Polyps
Adenomas – 10% 3 subtypes -Tubular = MC (80%) -Tubulovillous -Villous = highest morbidity/mortality - >1cm with high-grade dysplasia = advanced neoplasm w/ increase carcinoma risk -Nearly all CC come from these -However, only 5% progress to cancer -Develops over 7-10 years
Hyperplastic
- 90%
- Concerning in hyperplastic polyposis syndromes
- Familial Adenomatous Polyposis (FAP)
- Attenuated adenomatous polyposis coli (AAPC)
- Hereditary Nonpolyposis/Lynch Syndrome
- Others
Familial Adenomatous Polyposis (FAP)
- Autosomal dominant in the APC gene
- 75-80% with FH </= age 40
- Increased risk of developing other malignancies
- 100’s – 1000’s of adenomatous polyps
- Develops age 16, asymptomatic
- Untreated leads to CC by age 35-40
Attenuated adenomatous polyposis coli (AAPC)
- Fewer colonic polyps – 30-35
- Develops at later age (36yrs old)`
Hereditary Nonpolyposis/Lynch Syndrome
-Autosomal dominant w/ mutations in DNA mismatch repair proteins
<100 polyps
-70-80% lifetime risk of CRC
-Age of onset = late 20’s-early 30’s
- Symptoms: Abd pain/cramps, bloating, fatigue, loss of appetite, unintentional weight loss
- Signs: change in bowel habits, +FOBT, black tarry stool, iron deficiency
- FH, tumor testing, genetic testing
Associated cancers
- Endometrial (30-40%)
- Ovarian (10-12%)
- Gastric (4-10%)
- Glioblastoma (13%)
CRC Treatment
- Based on staging
- Localized Stage I-III
- Surgical resection (colectomy) with colostomy placement
- Remove primary tumors + clean margins including lymphatic drainage
Common types of chemotherapy: MC – 5-Fluorouracil, others include Xelod, Tegafur, -Oxaliplatin
- Metastatic Disease
- Stage III and some Stage II = 5-fluorouracil + adjuncts
- Short Term: N/V/diarrhea, hair loss, anorexia, fatigue fever, sores, pain, constipation, easy bruising
- Long Term: Lung tissue damage, heart damage, infertility, renal problems, peripheral neuropathy, risk of a second cancer
Treatment Follow-up - CRC
- 85% recurrence within 3 years after resection of primary tumor (Stage II-III)
- Regular surveillance
- Serum CEA every 3 months Stage III or III x 3 years, every 6 months years 4-5
- Annual CT of chest and abdomen x 3 years
- In the absence of high-risk pathology with postoperative colonoscopy, needs colonoscopy in 3 years, then every 5 years
Diverticula
-multiple, mucosal, saclike herniations through weak points in intestinal wall (sites were mesenteric vessels penetrate small bowel)
Diverticulosis
-Cause = unknown
-Risk factors – generally unknown
-Epidemiology
-Equal in men/women/across all races
-Age >50
-Most are asymptomatic (diverticulosis)
-Symptoms = complications (diverticulitis)
-Rectal bleeding (hematochezia, melena, minimal bleeding leads to iron deficiency)
-Abdominal pain, LLQ tenderness (RLQ more common in Asians), guarding
-Fever, elevated WBC?
-Labs – WBC, UA, electrolytes
-Imaging: abd xray (flat/upright), CT is gold standard
Treatment
-Inpatient vs outpatient
-2 antibiotics (metronidazole + levaquin or amoxicillin-clavulanate/TMP-SMX+ metronidazole)
-Surgery consult for repeat attacks
Hernia
-Cause = unknown
-Risk factors – generally unknown
-Epidemiology
-Equal in men/women/across all races
-Age >50
May be:
-Reducible: pop back in
-Incarcerated (irreducible) - cant get in
-Strangulated: incarcerated hernia with vascular compromise, may lead to bowel gangrene
Treatment
-Attempt reduction of recently incarcerated hernias
-If strangulation: NPO, NG tube, IV fluids, broad-spectrum antibx., immediate surgery
Types of hernias
- Umbilical
- Ventra wall/incisional
- Femoral
- Inguinal
Umbilical
- Congenital
- Weakness or opening in the muscle deep to the umbilicus
- Caused by incomplete closing of the umbilical ring
- Small protrusion through the umbilicus
- Worsened by coughing, crying, straining, stooling
- Soft, reduces easily, occasionally stays protruded
- May resolve on own
- Up to 80% resolve on own
- Surgery later age 5-6
Incisional/Ventral Hernia
-Associated with prior surgery due to weakened scar tissue
-More likely in obese patients and pregnant women
-Other risk factors: Surgery, Persistent straining/lifting, Severe vomiting or coughing
-Soft, usually non-tender bulge
-Can be worse with increase abdominal pressure (straining/lifting)
-May or may not reduce
Diagnosis
-Made on H&P
-Hard to image since better seen when supine
Treatment
-Avoid worsening activities, support bands, surgery consult
Inguinal Hernia
3 types
- Direct
- Indirect
- Femoral
- Common surgery referral
- 75% hernias are inguinal
- Inguinal: 25% lifetime risk in males vs. 2% in female
- 2/3 indirect vs. 1/3 direct inguinal
- Femoral – most common in females
- Surgery
- Incarceration – non-reducible, stuck
- Strangulation
- Incarcerated hernia w/ compromised blood flow leading to gangrene
- Painful, N/V, surgical emergency
Indirect Hernia
-Most Common
-Passage of intestine through the internal inguinal ring down the inguinal canal
-Into the scrotum because it follows the spermatic cord
-Can be congenital
Risk Factors
-Repeated lifting, straining, climbing
-H/of prior hernia repair
Presenting Symptoms
-Bulge
-Pain – aching, pulling, sharp pain
-Worse with increased groin pressure
-Surgery
-Recurrence likely especially in trade workers
Direct Inguinal Hernia
- Passage of intestine through the external inguinal ring through Hesselbach’s Triangle
- Lateral boundary: inferior epigastric artery
- Medial boundary: rectus muscle
- Inferior boundary: inguinal ligament
- Rarely enters scrotum
- Surgery
- Recurrence likely especially in trade workers
Femoral Hernia
-Least common
-Passage through the femoral ring
-Can involve fat or pre-peritoneal tissue
-Caused by intra-abdominal pressure
-Obesity
-Pregnancy
-Bulge – quite obvious at times
-Worse with straining or supine position
Diagnosis and Treatment
-H&P
-Imaging
-Surgery Consult
Intussusception
-Due to imbalances in the force of the intestinal walls
-Invagination and telescoping
Stats
-1:2000 live births
-2/3 occur in age sloughing infarcted mucosa -> “currant jelly stools” (sloughed mucosa, blood, mucus) -> gangrene
Presenting symptoms
-Classic Triad in 1/3 patient
-Abdominal pain, vomiting, blood in stool (”currant jelly stools”)
-Pain (colicky, severe, intermittent), drawing up legs to abdomen and kicking legs in the area, calm in between attacks
-Lethargy – can be only sign
-Palpable abdominal mass
-Preceding URI
-PE: chubby, cycling episodes every 15-30 mins, peritonitis (if gangrene), pale
Diagnosis
-CONTRAST ENEMA (quick & therapeutic)
leukocytosis, vitals, flat/upright abdominal xrays, US
-Surgery – if suspect gangrene or perforation
Tx: Nonsurgical
-Air enema vs. barium enema
-Fluid resuscitation
TX: Surgery
-Prognosis based on timing of intervention
-Early detection/treatment = 1% mortality rate
-Untreated = uniformly fatal in 2-5 days
Toxic Megacolon
- Acute toxic colitis with dilation of the colon
- Radiographic evidence of >6cm in transverse colon, loss of haustra in UC
- Any 3 of the following : Fever >101.5, tachycardia >120bpm, leukocytosis
- 1 of the following: dehydration, AMS, electrolyte abnormality, hypotension
- Worst complication is perforation
TMC - Causes
- Inflammatory: UC, Crohns, Pseudomembranous colitis
- Infection: Salmonella, Shigella, Campylobacter, Yersinia, C. dif, CMV, rotavirus
- Other: chemo, radiation, ischemic
- Rapid tapering/abrupt DC of steroids, sulfasalazine, 5-aminosalicycic acid
- Medications negatively impacting motility: anticholinergics, anti-diarrheals, antidepressants, opiods
Prognosis
- No perforation = 4% mortality rate
- Perforation = 20% mortality rate
- Best prognosis with surgery (need ostomy)
-Many present w/ TMC during firsts IBD flare
TMC –Physical Exam
-Symptoms of colitis: diarrhea, abd pain, rectal bleeding, tenesmus, vomiting, fever
-History: recent travel, abx use, chemo, immunosuppression
Ill, toxic (high fever, abdom pain, tachycardia,dehydration)
-Perforation: peritonitis (rebound, rigidity)
TMC - Diagnosis
Labs
-CBC (leukocytosis with left shift, anemia)
-Electrolyte disturbances
-ESR and CRP elevated
Imaging
-Serial plain abdominal xrays
-CT scan – if TM is suspected – may find perforation
TMC- Treatmet
- Reduce distention to prevent perforation
- Bowel rest, NG tube for decompression
- All narcotics, antidiarrheals, anticholinergic meds stopped
- Correct fluid/electrolyte disturbances
- Treat toxemia
- Broad-spectrum IV antibiotics
- IV steroids
- Repeat abdominal plain films
- Cyclosporine
- Colectomy/proctolectomy
