Surgery alone may not be enough in rectal cancer: Chemotherapy and radiation are associated with improved outcomes

This study investigated the outcomes of stage 3 rectal cancer patients with lymph node metastasis (cancer spread) who did not undergo chemotherapy and radiation (CRT) before surgery. Researchers suggested that these patients have worse outcomes when compared to patients who have undergone CRT. 

CRT followed by surgery is the standard treatment for patients with locally advanced rectal cancer. Before undergoing treatment, patients undergo different imaging techniques, such as magnetic resonance imaging (MRI, uses magnetic fields to image inside the body), to determine the stage and spread of the cancer. However, the accuracy of this method is limited. Prior studies suggested that up to 15% of lymph nodes metastases are too small to be detected by MRI. These patients with apparently no lymph node metastasis might be treated with surgery without prior CRT. It is not clear whether this is effective at controlling cancer progression.

The objective of this study was to evaluate the outcomes of patients with stage 3 rectal cancer with lymph node metastasis who underwent surgery but not CRT.

This study included information about 218 patients. Out of 218 patients, 77 had lymph nodes metastases detected after surgery. 18 of these patients did not receive further treatment, 21 received CRT and 38 received chemotherapy alone. 

Patients with positive lymph nodes detected later who underwent surgery had poorer cancer outcomes. 5-year overall survival (time from treatment until death from any cause) rates were 42% for the surgery alone group, compared to 73% of those who were treated further.

5-year disease-free survival (time from treatment until disase progression) rates were 43% for the surgery alone group, compared to 67% for those treated further. Local and distant recurrence rates were lower in patients who were treated with chemotherapy and/or radiation after surgery.

Patients treated after surgery were 3.4 times more likely to have a longer overall survival. They were 3.6 times more likely to have a longer disease free survival.

This study showed that patients with stage 3 rectal cancer and lymph node metastasis who underwent CRT have improved outcomes when compared to the surgery alone group.