Colorectal Cancer

Is your treatment what more than 1,100 Oncologists recommend?

The information provided below is meant to help you understand the role of your colorectal cancer biology treatment decisions, as well as the role of other tools used in determining your ability to receive chemotherapy or targeted therapy (precision medicine).

Excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in the United States, with 95,270 colon cancers and 39,220 rectal cancers estimated to occur in 2016 just in the United States (CA Cancer J Clin 2016; 66(1):7-30). The chance of developing colorectal cancer from birth to death is 1 in 21 for men and 1 in 23 for women in the United States. Despite these seemingly high numbers of new patients being diagnosed each year, mortality is declining due to the combined benefit of early detection and more effective treatments. In many cases, screening with colonoscopy prevents colorectal cancer by finding and removing precancerous polyps before they turn into cancer.

The 5-year survival for people with stage I colon cancer is approximately 92%, followed by stage II with 63% to 87%s survival, and stage III with 53% to 89%. Stage IV, or metastatic colorectal cancer or cancer that has spread to other parts of the body, has a 5-year survival rate of about 11%. The 5-year relative survival for people with rectal cancer are similar, 87%, 49%-80%, 58%-71%, and 12%, for stage I, II, III, and IV, respectively.

Risk Factors

Approximately 80% of the cases are caused by increasing age, sedentary lifestyle, low fiber diet, diets rich in red and processed meat, excessive alcohol intake, inflammatory bowel conditions (ulcerative colitis) and radiation exposure. The remainder 20% are caused by genetic causes, including familial adenomatous polyposis (FAP) and hereditary non-polyposis colon cancer (HNPCC). People with FAP inherit the APC gene mutation causing the development of numerous polyps and potentially cancer, and require regular screening with colonoscopy with removal of polyps or surgery prior to the development of cancer. People with HNPCC (Lynch syndrome) can develop not only cancer at a young age, but also other cancers (ovarian, pancreas, breast, biliary, endometrial, gastric, genitourinary and small bowel). Testing for HNPCC is recommended, especially in people over 70 years of age with colon cancer because it can affect the treatment choice.

Treatment

There are three different approaches to treating colorectal cancer. Depending on the type and stage of your cancer you can receive either one or a combination of the following treatments:

• Surgery
• Radiation
• Chemotherapy with or without targeted therapy (precision medicine)

Surgery

Surgery is usually a main component of the treatment for colorectal cancer and it can be done before or after radiation and chemotherapy. There are several types of surgery for colorectal cancer, and which type is best for you will depend on the stage or extent of the cancer and the goal of the surgery. Types of surgeries include: (removal of the polyps) and local excision of the tumor, colectomy (removal part of the colon), and diverting colostomy. You will need to discuss your individual case with your oncologic surgeon.

Radiation

Radiation therapy, or radiotherapy are commonly used in the treatment of colorectal cancer. The radiation oncologist will determine whether you will need to receive radiation for your cancer, as this depends on the cancer stage, your age and overall health status.

Chemotherapy/Targeted Therapy

This website is designed to address this part of your treatment and offer you personalized information about your treatment options that will yield the best survival and quality of life.

There are multiple factors to affect your cancer treatment options, and they are as follows:

1) Cancer Stage

Cancer staging describes the extent or spread of cancer at the time of diagnosis. The stage is determined via radiological testing (CT scan, bone scan or PET/CT) and carcinoembryonic antigen (CEA). The stages are as follows:

Stage 0 (carcinoma in situ): abnormal cells are found in the innermost layer of the colon wall that may become cancer
Stage I: tumor invades the inner lining of the colon up to the third layer and no lymph node involved with cancer
Stage II: tumor invades through the muscle wall of the colon and no lymph node involved with cancer
Stage III: tumor spreads outside of the colon and lymph nodes involved with cancer
Stage IV or advanced: tumor spreads to other parts of the body

2) Cancer characteristics

Vascular endothelial growth factor (VEGF) is a protein normally made by tumor cells and it is responsible for increasing the blood flow to the tumor in order to facilitate the growth of the tumor.

Epidermal growth factor receptor (EGFR) is a protein on the surface of cancer cells in high amounts and helps them grow. EGFR is generally present in 49-82% of colorectal cancer.

KRAS mutation is a mutated gene that can be found in 35-40% of metastatic colon cancer patients. Having this mutation will inform your physician that certain therapies, such as precision medicines, will not be beneficial.

BRAF mutation – Similar to Kras mutations, BRAF mutations places the patient at risk of having a poor treatment response and potentially worse outcomes. This mutation is present in 5% to 10% of all colorectal cancers.

The chemotherapy treatment for colorectal cancer usually comprises of two or more drugs. The drugs most often used include: 5-Fluorouracil (5-FU), Capecitabine (Xeloda), Irinotecan (Camptosar), Oxaliplatin (Eloxatin). The most common drug combinations include:

• FOLFOX:  Leucovorin calcium, Fluorouracil, oxaliplatin
• CapeOX: oxaliplatin, capecitabine
• FOLFIRI: irinotecan, fluorouracil, leucovorin
• FOLFOXIRI: irinotecan, oxaliplatin, fluorouracil, leucovorin

Targeted therapies (precision medicines) are often added in colorectal cancer therapy. These precision medicines include:

• Anti-VEGF: Targeted drugs (precision medicine) that targets VEGF such as bevacizumab, ramucirumab, and ziv-aflibercept, block this protein path from stimulating new blood vessels formation to stop cancer growth
• Targeted drugs (precision medicine) that target EGFR include: cetuximab and panitumumab. These drugs will not work in patients who have the KRAS and BRAF gene mutations
• Kinase inhibitors, such as regorafenib, inhibit receptor tyrosine kinases(RTK), via targeting blood vessels and thus stopping the growth of the cancer cells

Finally, chemotherapy and targeted therapies can result in unpleasant side effects such as hair loss, numbness of fingers or toes, cardiac toxicity, nausea, vomiting, diarrhea, abnormal liver function or low white blood cell count that could cause infection, and fatigue.  However, advances in the oncology field have led to numerous supportive measures, such as white blood cell growth support (i.e. Neulasta) or anti-nausea medications (such as Zofran, Emend), that help to control most side effects when used as prescribed.

The best time to use this service (based on more than 1,100 cancer experts) is after you have learned the details of your cancer and treatment plan from your treating physicians, and would like to clarify and confirm that your treatment is the best option for your cancer. This questionnaire is used mainly for drug treatment in medical oncology.