Rectal Cancer

https://emedicine.medscape.com/article/281237-overview

Rectal cancer is a disease in which cancer cells form in the tissues of the rectum; colorectal cancer occurs in the colon or rectum. Adenocarcinomas comprise the vast majority (98%) of colon and rectal cancers; more rare rectal cancers include lymphoma (1.3%), carcinoid (0.4%), and sarcoma (0.3%).

The incidence and epidemiology, etiology, pathogenesis, and screening recommendations are common to both colon cancer and rectal cancer. The image below depicts the staging and workup of rectal cancer.

Diagnostics. Staging and workup of rectal cancer patients.

Signs and symptoms

Bleeding is the most common symptom of rectal cancer, occurring in 60% of patients. However, many rectal cancers produce no symptoms and are discovered during digital or proctoscopic screening examinations.

Other signs and symptoms of rectal cancer may include the following:

• Change in bowel habits (43%): Often in the form of diarrhea; the caliber of the stool may change; there may be a feeling of incomplete evacuation and tenesmus

• Occult bleeding (26%): Detected via a fecal occult blood test (FOBT)

• Abdominal pain (20%): May be colicky and accompanied by bloating

• Back pain: Usually a late sign caused by a tumor invading or compressing nerve trunks

• Urinary symptoms: May occur if a tumor invades or compresses the bladder or prostate

• Malaise (9%)

• Pelvic pain (5%): Late symptom, usually indicating nerve trunk involvement

• Emergencies such as peritonitis from perforation (3%) or jaundice, which may occur with liver metastases (< 1%)

See Clinical Presentation for more detail.

Diagnosis

Perform physical examination with specific attention to the size and location of the rectal tumor in addition to possible metastatic lesions, including enlarged lymph nodes or hepatomegaly. In addition, evaluate the remainder of the colon.

Examination includes the use of the following:

• Digital rectal examination (DRE): The average finger can reach approximately 8 cm above the dentate line; rectal tumors can be assessed for size, ulceration, and presence of any pararectal lymph nodes, as well as fixation to surrounding structures (eg, sphincters, prostate, vagina, coccyx and sacrum); sphincter function can be assessed

• Rigid proctoscopy: This examination helps to identify the exact location of the tumor in relation to the sphincter mechanism

Laboratory tests

Routine laboratory studies in patients with suspected rectal cancer include the following:

• Complete blood count

• Serum chemistries

• Liver and renal function tests

• Carcinoembryonic antigen (CEA) test

• Histologic examination of tissue specimens

Screening tests may include the following:

• Guaiac-based FOBT

• Stool DNA screening (SDNA)

• Fecal immunochemical test (FIT)

• Rigid proctoscopy

• Flexible sigmoidoscopy (FSIG)

• Combined glucose-based FOBT and flexible sigmoidoscopy

• Double-contrast barium enema (DCBE)

• Computed tomography (CT) colonography

• Fiberoptic flexible colonoscopy (FFC)

Imaging studies

If metastatic (local or systemic) rectal cancer is suspected, the following radiologic studies may be obtained:

• CT scanning of the chest, abdomen, and pelvis

• Endorectal ultrasonography

• Endorectal or pelvic magnetic resonance imaging (MRI)

• Positron emission tomography (PET) scanning: Not routinely indicated

See Workup for more detail.

Management

A multidisciplinary approach that includes colorectal surgery/surgical oncology, medical oncology, and radiation oncology is required for optimal treatment of patients with rectal cancer. Surgical technique, use of radiotherapy, and method of administering chemotherapy are important factors. 

Strong considerations should be given to the intent of surgery, possible functional outcome, and preservation of anal continence and genitourinary functions. The first step involves achievement of cure, because the risk of pelvic recurrence is high in patients with rectal cancer, and locally recurrent rectal cancer has a poor prognosis.

Surgery

Radical resection of the rectum is the mainstay of therapy. The timing of surgical resection is dependent on the size, location, extent, and grade of the rectal carcinoma. Operative management of rectal cancer may include the following:

• Transanal excision: For early-stage cancers in a select group of patients

• Transanal endoscopic microsurgery: Form of local excision that uses a special operating proctoscope that distends the rectum with insufflated carbon dioxide and allows the passage of dissecting instruments

• Endocavity radiotherapy: Delivered under sedation via a special proctoscope in the operating room

• Sphincter-sparing procedures: Low anterior resection, coloanal anastomosis, abdominal perineal resection

Adjuvant medical management

Adjuvant medical therapy may include the following:

• Adjuvant radiation therapy

• Intraoperative radiation therapy

• Adjuvant chemotherapy

• Adjuvant chemoradiation therapy

• Radioembolization

Pharmacotherapy

The National Comprehensive Cancer Network guidelines recommend the use of as many chemotherapy drugs as possible to maximize the effect of adjuvant therapies for colon and rectal cancer.

The following agents may be used in the management of rectal cancer:

• Antineoplastic agents (eg, fluorouracil, vincristine, leucovorin, irinotecan, oxaliplatin, cetuximab, bevacizumab, panitumumab)

• Vaccines (eg, quadrivalent human papillomavirus [HPV] vaccine)

BOTOX under eyes!

“Did you know Botox can help eliminate dark circles under the eyes? Now no one has to know you’ve been tired since 2012.”

— Dr. Dale

Diet, Exercise Tied to Reduced Death Risk in Colon Cancer

https://www.medscape.com/viewarticle/895371

Good diet and exercise habits may improve survival rates for people who have colon cancer, according to results of an observational study published April 12 in JAMA Oncology.

Patients with stage III colon cancer and a lifestyle considered highly consistent with the American Cancer Society (ACS) guidelines on diet and exercise had a 42% lower relative risk for death compared with patients who did not, said Erin L. Van Blarigan, ScD, from the University of California, San Francisco, and colleagues.

In an accompanying editorial, Michael J Fisch, MD, MPH, and coauthors urged physicians to heed the lesson about the applicability of the ACS Nutrition and Physical Activity Guidelines for people already facing colon cancer.

"If you were skeptical about emphasizing nutrition and physical activity for colorectal cancer survivors based on the nature of the end points previously examined or the size of demonstrated effects, or the fact that most of the similar studies were conducted among patients with breast cancer, these data should soften those concerns," write Fisch, who works for Anthem's AIM Specialty Health, Chicago, Illinois, and coauthors.

The editorialists also say that the new study will allow physicians who previously gave vague advice about diet and exercise to be more precise, and recommend five to six servings of fruits and vegetables per day and 150 minutes of exercise per week.

The editorialists describe the findings as a "cancer control gem that came out of the ashes of" an earlier failed trial.

That trial was the Cancer and Leukemia Group B (CALGB) 89803 study, a chemotherapy trial among patients with colon cancer involving irinotecan and started about 20 years ago. However, a lifestyle survey was administered in the clinic during and after chemotherapy as part of this study. After exclusions, there were 992 patients eligible for analysis by Van Blarigan and colleagues for an observational study.

Over a 7-year median follow-up, there were 335 recurrences and 299 deaths, including 43 deaths without recurrence. Compared with patients with a poor ACS guidelines score (0 to 1; n = 262; 26%), patients with an excellent score (5 to 6; n = 91; 9%) had a 42% lower relative risk for death during the study period (hazard ratio [HR], 0.58; P = .01 for trend) and improved disease-free survival (HR, 0.69; P = .03 for trend).

High adherence to the ACS guidelines (score of 5 to 6) was also associated with a 9.0% absolute reduction in the risk for death at 5 years compared with a score of 0 to 4, reported the study authors.

The editorialists described that mortality difference as "striking."

There may be no harm in recommending that patients who have stage III colon cancer adopt the ACS lifestyle recommendations, while acknowledging that this may be difficult for them, Van Blarigan said in an JAMA podcast interview.

"There's no reason to put it off, but they may not feel up to it if they are currently undergoing treatment," she said.

There's a demand for this kind of detailed information about lifestyle recommendations for people who have been treated for colon cancer, said senior study author, Jeffrey A. Meyerhardt, MD, MPH, from the Dana-Farber Cancer Institute in Boston, Massachusetts, in the same podcast.

"That's a question that patients ask a lot about…'What should I eat? Should I exercise?'" he said.

More Study Details

To compare outcomes based on lifestyle choices, the study authors assigned an ACS guidelines score for each included patient based on a combination of factors: body mass index; physical activity; and intake of vegetables, fruits, whole grains, and red and processed meats. As noted above, scores ranged from 0 to 6, with higher numbers indicating healthier behaviors.

The researchers also examined the connections between these factors and death after colon cancer on their own.

They reported that patients with a body mass index (BMI) of 25.0 to 29.9 had lower risk for death than patients with a BMI of 30 or higher. Compared with patients who abstain from alcohol, heavy drinkers had a non–statistically significant increased risk for death, while patients consuming low to moderate amounts of alcohol had a non–statistically significant decreased risk for death, the authors said.

Consuming five or more servings of vegetables and fruits per day appeared to be helpful, but the findings on red and processed meat ran contrary to what might be expected, the authors said. Low intake of red and processed meat after colon cancer was associated with an increased risk for death.

"Higher protein intake may be beneficial for cancer survivors," Van Blarigan and study colleagues write. "Thus, it is possible that red meat is inversely associated with colon cancer mortality, despite being positively associated with colon cancer incidence."

The authors noted the limitations of their study. They couldn't conclude, for example, that the associations are independent of a patient's prediagnosis lifestyle or that changing behaviors after cancer diagnosis can achieve these results. They also pointed out that the study population was predominantly white and may not be representative of all patients with colon cancer.

The National Cancer Institute funded this study. The study authors and editorialists have disclosed no relevant financial relationships.

JAMA Oncol. Published online April 12, 2018. Abstract