Colorectal and Anal Cancers

Colorectal and Anal Cancers

Multiple Choice

A 71-year-old woman presents to the emergency department with abdominal distention, nausea, vomiting, and obstipation. She is otherwise hemodynamically stable. A computed tomography scan of the abdomen and pelvis reveals a mass in the sigmoid colon with proximal diffuse colonic distention to 12 cm, suspicious for colon cancer, with no evidence of lymphadenopathy or intra-abdominal lesions. Resuscitation is initiated, and the surgical team is consulted. The patient undergoes surgery without complication and is discharged to home. Pathology reveals invasive adenocarcinoma invading to the pericolorectal tissues, with 3/15 lymph nodes positive for invasive adenocarcinoma. What should be recommended for adjuvant therapy?

• Radiation only

• Fluorouracil, leucovorin, and oxaliplatin

• Surveillance only

• Doxorubicin (Adriamycin), paclitaxel, and cyclophosphamide

Fluorouracil, leucovorin, and oxaliplatin

Fluorouracil, leucovorin, and oxaliplatin (FOLFOX) is the preferred regimen for adjuvant chemotherapy for colon cancers in patients who have T3 or greater disease, any nodal metastases, or any distant metastases.

Patients who have T3 or greater disease, any nodal metastases, or any distant metastases should undergo adjuvant chemotherapy if they are candidates based on health status and patient preference. Doxorubicin (Adriamycin), paclitaxel, and cyclophosphamide (ACT) is the preferred regimen for treatment of breast cancer.

Multiple Choice

A 67-year-old man undergoes a left hemicolectomy for a stage II descending colon adenocarcinoma. Following routine colon cancer resection, what are appropriate follow-up measures for this patient?

• Clinical examination and carcinoembryonic antigen level every 3 to 6 months, PET/CT of the chest/abdomen/pelvis every 6 to 12 months, and colonoscopy at 12 months

• Clinical examination and computed tomography of the chest/abdomen/pelvis every 3 to 6 months only

• Clinical examination and carcinoembryonic antigen level every 3 to 6 months, computed tomography of the chest/abdomen/pelvis every 6 to 12 months, and colonoscopy at 12 months

• Clinical examination and carcinoembryonic antigen level, computed tomography of the chest/abdomen/pelvis, and colonoscopy every 3 to 6 months

Clinical examination and carcinoembryonic antigen level every 3 to 6 months, computed tomography of the chest/abdomen/pelvis every 6 to 12 months, and colonoscopy at 12 months

Periodic examination and screening studies are key recommendations for evaluating for colon cancer recurrence, although practices vary among surgeons. The exact timing of when each of these should be performed is also variable. These are the recommendations from the National Comprehensive Cancer Network (NCCN) Clinical Care Guidelines for Colon Cancer. 

Multiple Choice

A 60-year-old man with T2N1M0 anal squamous cell carcinoma completes therapy with a modified Nigro regimen (5-fluorouracil, mitomycin C, and pelvic radiation therapy). He is seen every 8 weeks for physical examination. At 6 months after treatment, a persistent 2-cm lesion is noticeable. What is the next best step in management?

• Fulguration of residual lesion

• Wide local excision

• Low anterior resection

• Biopsy

Biopsy

Following treatment with chemoradiotherapy, patients should undergo a surveillance examination of the anal canal 8 to 12 weeks after completion of treatment and at 6- to 8-week intervals until resolution of suspicious findings. Patients who have persistent disease can be followed up to 6 months for assessment of complete remission. After complete remission is achieved, surveillance can occur every 3 to 6 months for the next 5 years. Patients who have persistent disease at 6 months or demonstrate signs of progression earlier than 6 months should undergo repeat biopsy to confirm cancer. Restaging with positron emission tomography–computed tomography is also appropriate. Patients with isolated local disease should be considered for salvage abdominoperineal resection. This is associated with 5-year locoregional control in 30% to 77% of patients, with an overall survival at 5 years of 30% to 60%.

Multiple Choice

A patient comes to your office after a colonoscopy performed for rectal bleeding leads to a diagnosis of rectal cancer. The findings of the colonoscopy show a nonobstructing 2.5-cm polypoid mass 8 cm from the rectal verge. A biopsy reveals adenocarcinoma. He is wondering what the difference is between local staging with endorectal ultrasonography (ERUS) versus pelvic MRI. What should you tell him?

• Pelvic MRI is more accurate for superficial cancers regarding T staging.

• Pelvic MRI has the ability to define the extent of involvement of the mesorectal fascia, whereas ERUS does not.

• ERUS is more sensitive and specific for the presence of advanced nodal disease.

• ERUS has the ability to define the extent of involvement of the mesorectal fascia, whereas pelvic MRI does not.

• Both modalities are interchangeable and equal in terms of their strengths in local staging.

Pelvic MRI has the ability to define the extent of involvement of the mesorectal fascia, whereas ERUS does not.

Pelvic MRI images the entire pelvis, and information regarding the mesorectal fascia and any involvement of the circumferential radial margin by larger tumors can be obtained. ERUS is more accurate in excluding nodal involvement rather than diagnosing it because of its limited visualization. The advantage of ERUS is its overall accuracy of 84% in defining the T stage (which is better than CT or MRI); however, this number decreases as the T stage gets higher. It is very accurate for T0 or T1 lesions.