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Colorectal cancer is ranked ___ in the US for mena nd women in incidence and _____for overall death rates.
Peak age is _____years or older. The most common lesions are _______.
Causes of colorectal cancer include:
- diet high in fat and low in fiber
- smoking & alcohol
- minimal physical activity
- familial polyposis(an inherited condition in which numerous polyps form mainly in the epithelium of the large intestine.)Depending on the genotype:familial polyposis is treated with removal of either the colon or both the colon and rectum in order to prevent cancer.
- chronic ulcerative colitis
Radiation therapy is most commonly used as an adjuvant in RECTAL cancer. RT dose is______ for large field and _____boost. Total dose of ______.
Intraoperative Radiatin Therapy (IORT) is ____________of electrons in a single fraction.
45 Gy, 540-1400 cGy boost, 50-59Gy
IORT electrons: 10-20 Gy
Symptoms of colorectal cancer include:
- #1-BLOOD IN STOOLrectal bleeeding(hematochezia)
- change in bowel habits
- pencil stools
- tenesmus(the feeling of constantly needing to pass stools even if the bowels are already empty.)
- N & V
Colorectal cancer is detected via:
- physical exam
- radiographic and endoscopic studies
- digital exam &proctosimoidoscopy to determine the sie, mobility, location from the anal verge, and rectal wall inolvement.
Once colorectal cancer has been detected, the extent of the disease, including the pathology and any metastasis can be evaluated with:
- Chest X-Ray
- Lab studies including CEA(carcinoembryonic antigen) tumor markers
- *Note, the more fixed the massis to surrounding stuctures or tissues, the worse the prognosis
_____% of all colorectal lesions are _____. Staging is done by the TNM or _____classification(levels A,B, C). Staging goes by the penetration through the layers of the bowel wall.
90-95%, Adenocarcinoma, Dukes
- Dukes Staging Classification for tumors
- A - tumor has not penetrated through the bowel wall
- B - tumor penetrated through bowel wall
- C- through bowel wall and lymph nodes
- D - metastasized to distance sitess
- Stage O-Tis
- Stage 1-tumor invades the submucosa or the muscularis propria/no nodes/no mets
- Stage IIA-tumor invades through the muscularis propria into the subserosa/no nodes/no mets
- Stage IIB-Tumor directly invades other organs or sturcture and/or perforates visceral peritoneum/no nodes/no mets
- Stage IIIA- tumor invades submucosa or muscularis propria/1-3 regional node sites/no distant mets
- Stage IIIB- tumor invades through the muscularis propria into the subserosa and/or tumor directly invades other organs or sturcture and/or perforates visceral peritoneum/1-3 regional node sites/no distant mets
- Stage IIIC- Any T/4 + regional node sites/ no distant mets
- Stage IV- any T/any N/ distant metastasis
The treatment choice for colorectal cancer is ______. A ____ ___ ___involves removal of the tumor plus margin and immediatly adjacent lymph nodes. The bowel is the reanastomosed and a ________is not necessary.This procedure is used for colon cancers and select rectal cancers(upper 2/3 of the rectum-6-12cm from the verge). A ____is used for patients with cancer in the lower third(Distal 5 cm)of the rectum who require surgery and does not save the the sphincter and therefor and bag is needed permanently.
- low anterior resection (LAR)
- abdominoperineal resection (APR)
Colorectal cancer spreads via _______ ___________(penetrates the bowel wall, not longitudinally like esophageal) with no skip mets.If the tumor has penetrated the submucosal layer than spread is through lymphatics which happens in an _______ fashion. The lymph node spread in order is:(5 lymph node sites). Spread through the blood is to the _____,______,____, and _______. Spread also by PERITONEAL SEEDING.
- direct extension, orderly
- parirectal, internal ileac, common ileacs, paraaortic, scv
- LIVER, lung, bone, ovaries, adrenal
Hematogenous spread of colorectal cancer is to :
- LIVER(#1 place)
Lymph node spread of colorectal cancer is in the following order: (5 sites)
- internal iliac
- common iliacs
*Memory Aid: People In C
The #1 place for colorectal mets is the _______.
RECTAL FIELD DESIGNS:
BOTTOM:bottom of _____ _______ or ______cm below gross tumor
Lateral:_____cm lateral to _____ ____ and______
TOP AND BOTTOM: _______________
ANTERIOR:Anterior edge of the ________ ______
POSTERIOR:____cm behind the _____ _________
- BOTTOM:bottom of the obturator foramina or 3-5 cm below gross tumor
- LATERAL:2cm lateral to pelvic brim and inlet
- TOP & BOTTOM: Same as AP/PA
- ANTERIOR: Anterior edge of the femoral head
- POSTERIOR: 2cm behind the bony sacrum
- Pre- or Post-op and in conjunction with chemotherapyFields are designed to encompass primary tumor volumeand
- pelvic lymph nodes, shrinking to treat primary tumor to a higher dose.A
- 3-field or 4-field technique is used. AP, PA, RT and LT Lateral.
Patients with rectal cancer usually have hematachezia commonly known as ______.
Cancer of the large bowel is usually diagnosed via findings of the physical exam and ______ and _______ studies.
- radiographic, endoscopic
- (barium enema, colonoscopy, flexible sigmoidoscopy, proctosigmiodoscopy, endorectalultrosound)
Approximately _____% of colorectal patients have nodes positive at the time of diagnosis.
What is the dose limiting structure or organ at risk in the pelvis?
the small intestines(45Gy)
For simulation the patient is placed in a prone or supine position, the bladder is empty of full(in order to take the small intestines out of the field), women have ____ _____, ______ for the bowels, wire _____ and ___ ______
- (Prone allows gluteal fold to decrease)
- Women have vaginal marker
- Contrast for bowels
- scar and anal verge
Radiation dose for external beam is _______ cGy with _____ cGy boost.
Intraoperative Radiation Therapy (IORT) dose is _____cGy of electrons in a single fraction.
4500 cGy to large field,540-1440 cGy boost
Acute side effects to radiation therapy include small bowel toxicities:
Other acute side effects include:_____, and _______.
- Small bowel toxicities (<4500 cGy)
- Abdominal cramps and
- Bloody or mucus
- proctitis(Acute radiation proctitis — symptoms occur in the first few weeks after therapy. These symptoms include diarrhea and the urgent need to defecate, often with inability to do so (tenesmus). Acute radiation proctitis usually resolves without treatment after several months, but symptoms may improve with butyrate enemas. This acute phase is due to direct damage of the lining (epithelium) of the colon.)
- Moist dequamation
- Leukopenia and thrombocytopenia
Chronic side effects of radiation therapy include:
- Persistent diarrhea
- Increased bowel frequency
- Urinary incontinence
- Bladder atrophy
- Enteritis, adhesions and obstructions of the small bowel
How is radiation therapy used for colorectal cancer?
- Pre- or Post-op and in conjunction with chemotherapy
- Fields are designed to encompass primary tumor volume
- and pelvic lymph nodes, shrinking to treat primary tumor to a higher dose.A 3-field or 4-field technique is used. AP, PA, RT and LT Lateral.
Chemotherapy for colorectal cancer is used with Radiation Therapy in pre- and post-op setting includes:
5-FU and gemcitabine
5-FU, leucovorin, FOLFOX, FOLFIRI,Erbitux
5 year survival rate for colorectal cancer is _____%.
* Regular use of ant-inflammatory drugs and post-menopausal hormones have been shown to decrease the risk of colon cancer
Not recommended as a preventative measure though