Although colon cancer is the fourth most commonly diagnosed cancer in the U.S., roughly two-thirds of patients are diagnosed before their disease has spread, when the prognosis is generally good. These patients undergo surgery and, sometimes,额外的治疗通常化疗。
Up to 30 percent of colon cancers, however, have already spread (metastasized) by the time the patient is diagnosed.
治疗for metastatic colon cancer
Patients withmetastatic colon cancer (stage 4)get intensive chemotherapy, saysPaul Oberstein, M.D.在纽约大学朗格尼的珀尔马特癌症中心胃肠肿瘤医学项目主任。在这种情况下，化疗不提供治疗，但确实减轻症状，帮助患者活得更长。
“We usually start with a combination of chemotherapy and a targeted therapy, which is determined based on tumor characteristics,” Dr. Oberstein says. “The mutations in the tumor matter very much when it comes to what targeted therapy to give.”
Dr. Oberstein says the location of the tumor—whether it’s on the left or the right side of your colon—also drives decisions about which targeted therapy to give. Your overall health also matters. If you’re on medications for other diseases, for example, some targeted therapies may interact with these drugs.
在一般情况下，奥伯博士说，大多数转移性结肠癌患者得到化疗的结合，并有针对性的代理。“这将控制病情，他们会在一段时间保持稳定，平均为6至15个月。在某些时候，他们要么不能耐受化疗，或肿瘤生长，尽管化疗，患者在治疗的进步。”
If your tumor continues to grow, your oncologist will try another combination of drugs, which should give you several additional months of disease control. This is second-line therapy. When second-line therapy subsequently fails to control your cancer, you’ll get another combination of drugs (third-line therapy).
“Putting that all together, patients with metastatic colon cancer get multiple lines of chemotherapy and live with their disease for an average of two to three years with the current therapies that we have,” says Dr. Oberstein. “The duration depends to a large extent on the mutations within the tumors (certain mutations predict doing worse or better) and a lot to the health of the patient and how they tolerate chemotherapy.”
较新的治疗方案：靶向治疗和免疫治疗
Some tumors have specific molecules that help cancer cells grow, multiply quickly, and spread outside the colon.靶向治疗are drugs or substances developed specifically to disrupt these molecules so that cancer cells can’t grow or survive. For example, anti-VEGF (vascular endothelial growth factor) targeted drugs limit a tumor’s ability to grow new blood vessels, which bring the tumor nutrients it needs to grow.
Unlike chemotherapy, which kills all fast-growing cells, targeted therapy interrupts the处理by which tumor cells grow and spread. When given in conjunction with chemotherapy, some targeted therapies help chemotherapy be more effective. To date, the U.S. Food and Drug Administration (FDA) has approved six targeted therapies for metastatic colon cancer. Not all targeted therapies work in all patients, so treatment is tailored to the unique features of your tumor.
“We’re taking a deep dive into these tumors, looking at the genetics of tumors and using the information to guide therapies,” says塞缪尔J. Klempner，M.D。, a gastrointestinal oncologist at The Angeles Clinic and Research Institute, a Cedars-Sinai affiliate, and assistant professor of Medicine at Cedars-Sinai.
One molecular group of interest is BRAF mutant colon cancers, Dr. Klempner says. “BRAF is a protein. If you mutate it in certain areas, it’s like flipping a switch on all the time. It’s a signal for the tumor cell to grow.”
对于BRAF突变靶向治疗是小分子抑制剂，经常丸剂，其中获得所述肿瘤细胞内，并关闭开关。“FDA最近批准在结直肠癌执导BRAF联合治疗方案，” Klempner博士说。“这是重要的，因为它有利于一组谁不响应以及传统化疗的患者，并且是一般不差的一组。这是不错的东西提供这些病人。”
Immunotherapy，另一方面，刺激免疫系统来对抗癌症。检查点抑制剂，例如，破坏癌细胞免疫系统的能力，以隐藏。这些疗法正在在其他类型的癌症成功地使用，并已开始在结肠癌中使用为好。
For example, about five percent of stage 4 colon cancer patients have specific tumor characteristics calledmicrosatellite high，Klempner博士解释说。“肿瘤有错误在机械，在DNA修复错误。所以免疫系统被灌注到承认他们这些类型的肿瘤中积累成千上万的突变。当你给免疫治疗，患者往往有较高的响应率。通常情况下，反应持续了一年多和药物耐受性良好。”FDA已批准用于转移性结肠癌3个免疫疗法。
Dr. Klempner says these are good examples of learning what makes tumors tick by studying them in the lab and then developing targeted drugs that translate into improved outcomes for patients. Pathologists now routinely test tumor biopsies to see if patients might be candidates for targeted therapy or immunotherapy.
Bottom line
这些疗法仅适用于患者的一小部分。此外，他们是昂贵和毒副作用是化疗的副作用不同。例如，不进行治疗，在有人经受免疫治疗咳嗽或腹泻可能（分别肺或结肠，发炎）变成肺炎或结肠炎。告诉你的肿瘤科医生立即如果您遇到的副作用，同时服用这些药物。
如果你被诊断为转移性结肠癌，问你的肿瘤医生，如果你有资格获得临床试验这是评估潜在的新疗法。