Can the original site of your cancer tell you where it might spread next?

This study looked at the original site of cancer and whether the area it may spread to can be predicted.

The location of metastases (where cancer has spread) is an important predictor for survival. It also helps determine the treatment strategy used. If metastases are not detected, it is most often surgery that is used to remove cancer.

The colon is divided into the left, right and sigmoid colon. It is not known whether the original location of a tumor in the colon affects the pattern of cancer spread. Understanding the pattern could be useful for monitoring patients for any cancer spread.

This study compared the original tumor location and the site of metastasis in 947 patients with colon cancer.

All patients underwent surgical removal of their tumors. Patients were followed for an average of 42 months.

Overall survival rate was almost the same for all three sites of colon cancer.

Patients with right-sided colon cancer had an overall lower rate of cancer spread (24.8%). In particular these patients had particularly low rates of cancer spread to their lungs (4.7%) and liver (15.6%).

The opposite was true for patients with left-sided colon cancer (31.5% rate of cancer spread). These patients had a higher rate of cancer spread to the liver (21.3%) and twice as many to their lungs (8.7%). No patients with left-sided cancer had a brain metastasis.

Patients with sigmoid colon cancer had the highest number of liver (17.1%) and lung (12.2%) metastases. These patients were also 4 times as likely to have their cancer spread to their brain and 2.3 times as likely to have lung tumors.
 

The authors of this study concluded that there was significant differences in the spread of colon cancer depending on the original site of the disease (left, right or sigmoid colon). This could be useful for monitoring patients with colon cancer and predicting its risk of spread.

While the study looked at a large number of people, there was not enough people to analyze genetic mutations. The study should be repeated with a larger amount of patients to verify the results and get an insight into the genetics of the spread of cancer.