Colorectal Cancer Treatments
Surgery is usually the first treatment for colon or rectal cancer.
The goal of the surgery is to remove as much of the cancer from the body as possible. The two primary types of surgery are open surgery, where the surgeon makes a long cut in the abdomen to remove the tumor, and laparoscopic surgery, where the surgeon makes small cuts in the abdomen and uses a camera and small tools inserted through these cuts to perform the surgery.
The goals of surgery are to remove as much of the cancer as possible and, if possible, to preserve the anal sphincter (the muscle that controls bowel movements) and good bowel function. If the cancer is small and has not grown beyond the inner layers of the rectum, it may be removed through the anus. If the tumor is larger, you may need a total mesorectal resection (TME), which involves removing the rectum as well as fat, blood vessels, and lymph nodes around it in one piece. If the cancer has spread widely, you may need a larger surgery that involves removing organs such as the bladder, ovaries, cervix or vagina. If it has not spread widely, you may be able to have sphincter-sparing surgery. Your doctor may also recommend that you have chemotherapy and radiation before surgery, to decrease the size of the tumor and reduce the need to remove the anal sphincter.
If your surgeon needs to bypass a significant part of your colon or remove the muscle at the opening of your rectum, you will need an ostomy. This procedure makes a new path for stool and other waste by creating a stoma (opening in your abdomen) and connecting the end of your colon or small intestine to the opening. An ostomy pouch that fastens to your skin over the stoma is used to collect waste. A colostomy bypasses part of the large intestine (colon), and is used more frequently in rectal cancer than in colon cancer. An ileostomy bypasses the entire colon and is made at the end of the small intestine (ileum). Ileostomy output is liquid. Output from a colostomy may be semi-solid or solid depending on where the ostomy is created. Some ostomies are reversible after the surgery heals and some will be permanent.
These drugs work by killing all cells in your body that are growing and dividing rapidly. (That’s why you may lose your hair or develop nail problems or other side effects. Chemotherapy may be given into the vein (intravenously) or by mouth (orally). Either way, the drugs reach almost all parts of the body. Chemotherapy given after surgery is called “adjuvant” treatment. Chemotherapy given before surgery to shrink the tumor is called “neoadjuvant” treatment.
Chemotherapy is typically given in cycles of about two to four weeks. Giving the treatment in cycles gives your body time to recover. Your treatment is likely to include alone or in combination:
- 5-Fluorouracil (5-FU), given via IV along with the vitamin-like drug leucovorin.
- Capecitabine (Xeloda®), an oral drug that converts into 5-FU when it gets to the cancer cells.
- Irinotecan (Camptosar®), given via IV
- Oxaliplatin (Eloxatin®), given via IV
- Trifluridine and tipiracil (Lonsurf®), an oral drug
This treatment regimen gives you chemotherapy and radiation during the same time period. Radiation is given 5 days a week for several weeks. The chemotherapy typically used is 5-FU or capecitabine (Xeoloda). Neoadjuvant chemoradiation is given before surgery to shrink the tumor. It is used for treating locally advanced rectal cancer.
These drugs target mutations found only on the cancer cells.
- EGRF (epidurmal growth factor receptor) Inhibitors: If you have stage IV metastatic colorectal cancer and your tumor has a KRAS mutation then your treatment options are likely to include an EGFR inhibitor, such as cetuximab (Erbitux) or (Vectibix).
- VEGFr (vascular endothelial growth factor receptor) Inhibitors: These drugs, know as angiogenesis inhibitors, block the development of the blood vessels cancer cells use to grow and spread. If you have metastatic colorectal cancer, your treatment options may include bevacizumab (Avastin).