How much does adding herbal medicine improve colorectal cancer survival? — a 46% lower risk of death confirmed by research

Across the papers in our ongoing "Cancer" series, the type of cancer studied differs, yet they all arrive at the same conclusion. This colorectal cancer study likewise shows the same result: patients who added herbal medicine to standard treatment had a markedly lower risk of death than those who did not.

How much can herbal medicine help survival in colorectal cancer?

Colorectal cancer (colorectal cancer) is a leading cause of cancer death worldwide. When found early the 5-year survival rate exceeds 65%, but for stage IV with distant metastasis it falls to just 9–12%. Standard treatments such as surgery, chemotherapy, and radiation follow, but along the way they bring burdens such as digestive trouble, bowel dysfunction, and fatigue.

Published in 2020 in the international journal Evidence-Based Complementary and Alternative Medicine, this study analyzed 535 patients newly diagnosed with colorectal cancer between 2004 and 2014. Among them, 147 patients who took herbal medicine for 30 or more days within the first year after diagnosis were compared with 388 who did not. Unlike studies using insurance-claims data alone, it drew on hospital medical records containing cancer stage, surgery, chemotherapy, and radiation information; and by starting follow-up 3 months after diagnosis it corrected for so-called immortal time bias^* — both strengths of this study.

After adjusting together for multiple factors (age, sex, stage, comorbidities, surgery, chemotherapy, radiation), patients who added herbal medicine had a 46% lower risk of death than those who did not (hazard ratio 0.54, 95% confidence interval 0.38–0.77). Their 1-, 3-, and 5-year survival rates were 92%, 75%, and 63% — higher at every time point than the non-users' 80%, 62%, and 54% — and the two survival curves diverged significantly (log-rank P=0.006).

The benefit was clearer in advanced colorectal cancer

The study also broke the results down by stage. In advanced stage III (P=0.027) and IV (P=0.003), the survival of the herbal medicine group was significantly higher — a point worth noting.

In the advanced stages, where the risk of recurrence and metastasis rises and survival drops sharply, the strength of herbal medicine becomes clearly apparent.

Which herbal medicines were used?

A variety of formulas were used; among them, the ones that significantly lowered the risk of death were Gui Pi Tang, Ping Wei San, and Ban Xia Xie Xin Tang, while the most frequently prescribed was Jia Wei Xiao Yao San.

What stands out is that the formulas chiefly used were not aimed at attacking the tumor directly, but at improving the body's internal environment. Formulas with multidimensional effects — easing fatigue, improving sleep quality, aiding digestion, relieving anxiety, correcting anemia — were the ones that lowered the risk of death. What does this mean? By relieving the side effects that inevitably follow chemotherapy, radiation, and surgery — digestive trouble, bowel dysfunction, anxiety, fatigue, sleep disturbance — herbal medicine helped patients carry their standard treatment through to the end. We must remember the two-way strategy of "fu zheng qu xie" (扶正祛邪): keeping the cancer in check while strengthening the body's own capacity to resist disease.

Don't put off the benefits of herbal medicine any longer

Like other studies, this one once again clearly shows that the effect becomes more evident when herbal medicine is added to standard therapy. It is worth remembering that, especially when herbal medicine that cares for the body is continued from early on, the benefit was clear in the advanced stages. If you are undergoing treatment for colorectal cancer or are about to begin, we close by encouraging you to consult thoroughly with a Korean-medicine specialist and steadily continue an herbal medicine prescription suited to you.

* What is immortal time bias? It is a common statistical illusion in observational research. Because "a person who received a certain treatment" must have stayed alive until the moment they started it, that treatment can appear more favorable to survival than it really is. For example, someone who took herbal medicine for 30 or more days must have survived at least that period, so without correction the effect of herbal medicine can be overstated. This study removed that bias by counting survival only from 3 months after diagnosis, so that the effect of herbal medicine would not be exaggerated.