Colorectal cancer treatments

In metastatic colorectal cancer treatment, two agents were approved almost simultaneously, cetuximab and bevacizumab. 

Cancer treatment is a multimodality treatment, i.e., surgery is combined with radiotherapy and antineoplastic chemotherapy. The latter treatment mode is used mainly for cancers which have disseminated. Different forms of cancer differ in their sensitivity to chemotherapy with antineoplastic agents. The most responsive include lymphomas, leukemias, choriocarcinoma and testicular carcinoma, while solid tumors such as colorectal, pancreatic and squamous cell bronchial carcinomas generally show a poor response. The clinical use of antineoplastic agents is characterized by the following principles. 

ADCC. Cetuximab is approved for treatment of metastatic colorectal cancer (CRC) and squamous cell carcinoma of the head and neck (SCCHN). Interestingly, an adverse event, acneiform rash seems to correlate with a better response to cetuximab, while there is no such correlation with expression levels of EGFR assessed by immunohistochemistry. Further side effects are rare infusion reactions and hypomagnesia. Two other anti-EGFR antibodies approved for clinical use are the fully human antibody panitumumab (Vectibix)... 

Surgical intervention is a potential treatment option in patients with complications such as fistulae or abscesses, or in patients with medically refractory disease. Ulcerative colitis is curable with performance of a total colectomy. Patients with UC may opt to have a colectomy to reduce the chance of developing colorectal cancer. Patients with CD may have affected areas of intestine resected. Unfortunately, CD may recur following surgical resection. Repeated surgeries may lead to significant malabsorption of nutrients and drugs consistent with development of short-bowel syndrome. 

However, colorectal cancer and rates of fracture were reduced with combined hormonal treatment. 

In summary, combined estrogen plus progestin should not be used for the prevention of chronic diseases because it increases the risk of CHD, stroke, breast cancer, and venous thromboembolism. However, colorectal cancer and rates of fracture were reduced with combined hormonal treatment. 

Cetuximab is a human/mouse antibody that binds to the epidermal growth factor receptor to block its stimulation. The pharmacokinetics of cetuximab demonstrate a volume of distribution that approximates the vascular space and a terminal half-life of 70 to 100 hours. Cetuximab has shown clinical activity in the treatment of colorectal cancer. An acnelike rash may appear on the face and upper torso 1 to 3 weeks after the start of therapy. Other side effects include hypersensitivity reactions, interstitial lung disease, fever, malaise, diarrhea, abdominal pain, and nausea and vomiting. 

Fluorouracil-based chemotherapy is the standard of care for the adjuvant treatment of colorectal cancer either as a single agent or, more commonly, in combination with other agents. 5-Fluorouracil (5-FU) alone results in a small improvement in survival that can vary based on the method of 5-FU administration. Studies suggest that protracted or continuous intravenous (IV) 5-FU infusion treatment schedules are more effective than bolus therapy.20... 

Finally patients who fail standard treatment for metastatic colorectal cancer should be encouraged to participate in a clinical trial evaluating new treatment approaches for this incurable disease. Table 88-5 lists options for first- and second-line... 

Oxaliplatin (Eloxatin ) is similar to other platinum analogs (e.g., cisplatin) in that it binds to the N-7 position of guanine, which results in cross-linking of DNA and double-stranded DNA breaks.26,40 Oxaliplatin differs from cisplatin in that the DNA damage induced by oxaliplatin may not be as easily recognized by DNA repair genes often seen in colorectal cancer. Oxaliplatin, in combination with 5-FU-based regimens, is indicated for the first- and second-line treatment of metastatic colon cancer, as well as the adjuvant treatment of colon cancer. 

Vanhoefer U, Harstrick A, Achter-rath W et al. Irinotecan in the treatment of colorectal cancer clinical overview. J Clin Oncol 2001 19 1501-1518. 

Avastin (tradename, also known as bevacizumab) is a 149 kDa recombinant humanized monoclonal IgGl antibody first approved for medical use in the USA in 2004, and subsequently in the EU in 2005. It is indicated for first-line treatment of patients with metastatic colorectal cancer, in combination with specified (5-fluorouricil-based) small molecule chemotherapeutic drugs. 

Baseline laboratory tests should include complete blood cell count, prothrombin time, activated partial thromboplastin time, liver and renal function tests, and serum carcinoembryonic antigen (CEA). Serum CEA can serve as a marker for monitoring colorectal cancer response to treatment, but it is too insensitive and nonspecific to be used as a screening test for early-stage colorectal cancer. 

Stage of colorectal cancer should be determined at diagnosis to predict prognosis and to develop treatment options. Stage is based on the size of the primary tumor (T ), presence and extent of lymph node involvement (N0-2) and presence or absence of distant metastases (M). 

Chemotherapy is the primary treatment modality for metastatic colorectal cancer (MCRC). Treatment options are generally similar for metastatic cancer of the colon and rectum. 

Chemotherapy Regimens for the Adjuvant Treatment of Colorectal Cancer... 

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