Many people say their mind goes blank when, while undergoing tests after a colorectal cancer diagnosis, they hear the words "it has spread to the liver too." Spreading to another organ means what we commonly call stage 4. Yet in the consultation room, the doctor's words can be surprisingly calm. "Let's first see whether it can be removed by surgery." Colorectal cancer that has spread to the liver is somewhat different from the spread of other cancers, and knowing this part first can lighten your heart considerably.
Why the liver? Because the structure is such that blood flowing from the colon passes through the liver on its way back, cancer cells that break off tend to settle in the liver first. So liver metastasis in colorectal cancer is not a rare event but rather a common route. The key point is that having liver metastasis does not immediately mean "surgery is over, let's just use drugs." If the metastatic mass is gathered on one side of the liver and the liver remaining after removal is sufficient to do its job, the path opens to remove the original colon cancer and the liver metastasis together by surgery. When this is possible, we describe it as 'resectable.'
The criterion for judgment is often the location and the volume of remaining liver rather than the number of tumors. Even if there are two or three metastases, if they are clustered in one segment they are easy to remove, while even a single one wrapped around a large blood vessel becomes tricky. So even if you are told at the first imaging that "it is difficult now," it is too early to be discouraged. It is actually not uncommon for surgery that was impossible at first to become possible once chemotherapy is done first to shrink the mass. This is called 'conversion therapy,' a strategy of clearing the way with chemotherapy and finishing with surgery. If the remaining liver looks like it will be insufficient, methods such as blocking the blood vessels going to the side to be removed in advance to grow the opposite side of the liver before surgery are even brought into play.
There is more than one treatment method. If the tumor is small or in a location where surgery is burdensome, procedures that burn it away with radiofrequency or microwave, or methods that inject chemotherapy and embolic material directly through the blood vessels going to the liver, are used alone or combined with surgery. What matters is that all these decisions are made by surgery, medical oncology, and radiology gathered together to look at the case as a team. Because the line of 'resectable' can change depending on who is looking at the same images, if you were told at one hospital that it is difficult, having it checked once more at a place well equipped for multidisciplinary care is not a wasted trip.
Of course, not all liver metastases can be removed. When the cancer is spread throughout the entire liver or has also spread extensively to other organs such as the lungs, the weight is placed on slowing progression with systemic treatment and protecting quality of life rather than on surgery. Still, colorectal cancer liver metastasis is a representative case where the formula "metastasis = inoperable" does not hold, and it is worth remembering that there are clearly patients who can expect long-term survival if it is removed well.
What is written here is meant to aid general understanding, and only medical staff who have directly seen your images and tests can tell you whether your liver metastasis is in a removable state, so be sure to discuss it with your attending physician.