Cancerous tumors lead to cancer spreading

Surgery for cancer doesn’t make it spread. Cancer by the nature of the disease spreads (metastasis). If a cancer or cancerous tumor is left untouched it will eventually spread.

When a cancer metastasizes after surgery, it’s because it was discovered too late and by the time surgery was performed there were already small foci of cancer going around the body via the blood and lymph system.

For most cancers the number of lymph nodes attached to the cancer removed that contain cancer in them is predictive of a higher metastatic risk. The more cancer in greater number of nodes, the higher the risk.

There are certain situations where a surgical complication of certain types of cancer can increase recurrence risk. This include the famous morcellation of the uterus containing an previously undiagnosed uterine sarcoma and rupturing an ovarian mass containing cancer. But it’s not as if the cure rate for either is 100% if removed intact. Intact ovarian cysts containing cancer may have recurrence risks in the 10–30% range depending on grade. Uterine sarcomas with an open hysterectomy can have cure rates lower than 30% depending on size and grade.

What we do know, is that an unoperated invasive ovarian cancer or uterine sarcoma has a cure rate of zero without surgery. That’s because of the natural history of those cancers, and a very large majority of other cancers as well.

Tumor

Cancerous tumors may also be called malignant tumors. Many cancers form solid tumors, but cancers of the blood, such as leukemias, generally do not. Benign tumors do not spread into, or invade, nearby tissues. When removed, benign tumors usually don’t grow back, whereas cancerous tumors sometimes do.