Primary liver cancer refers to malignant tumors that originate in the liver, while metastatic liver cancer refers to malignant tumors from other parts of the body that have spread to the liver. As to which is easier to treat, it is generally difficult to determine and depends on the control of the primary lesion in cases of metastatic liver cancer; both might be challenging to treat. However, if the lesion in primary liver cancer is relatively small, there may still be an opportunity for surgical treatment. In general, metastatic liver cancer is not amenable to curative surgery because the primary lesion also requires treatment. But in terms of the rate of progression or severity, metastatic liver cancer might progress more slowly, while primary liver cancer generally progresses quite rapidly, making it also very difficult to treat.