Robot-assisted surgery and identification of lymph node tumors in prostate cancer

The authors aimed to determine patient and cancer outcome following treatment with pelvic lymph node dissection and robot-assisted prostate surgery.

In some prostate cancer patients tumors can spread into the lymph nodes (sites that hold cells used to fight infection). A pelvic lymph node dissection is used to determine the likelihood of lymph node tumors occurring by determining the severity of the cancer present using tissue samples taken from the prostate. It is commonly used in combination with prostate surgery. 

Prostate surgery is a common treatment for prostate cancer that involves surgically removing the prostate gland. In some cases this surgery can be carried out by a robot controlled by the surgeon. It reduces healing time, is more precise and results in less bleeding and pain due to the smaller incisions used.

The aim of this study was to determine patient and cancer outcome after treatment with pelvic lymph node dissection and robot-assisted prostate surgery.

Of 1,740 patients who underwent prostate surgery and lymph node dissection, 108 patients (6%) had lymph nodes that were positive for cancer. These patients were evaluated in this study with a follow-up time of 26 months.

64% had 1 positive node, 17% had 2 positive nodes and 17% had more than 2 positive nodes. 60% of patients who did not receive additional cancer treatment experienced biochemical recurrence (prostate specific antigen (PSA – protein elevated in the blood when prostate cancer is present) levels increased despite treatment). The average time to cancer recurrence was 8 months.

Overall after 1 year the probability of being free from biochemical recurrence was 42% and the 3-year probability was 28%. Patients with 1 positive node had an average of 12 months until cancer recurrence, patients with 2 positive nodes had 7 months and patients with more than 2 positive nodes had 2 months.

In patients with more than 2 positive nodes nearly all recurrences occurred within 6 months after treatment, and the likelihood of being biochemical recurrence-free at 12 months was 18%, compared to 46% in patients with 2 or less. Men with 2 or less positive nodes had a significantly better chance of being biochemical recurrence-free compared to patients with more than 2 positive nodes.

Patients with a Gleason score (grading system from 1-10 that compares the differences between normal and cancerous cells) of 8-10 had an increased risk and were over twice as likely to experience biochemical recurrence compared to patients with scores lower than 8. 

The authors concluded that pelvic lymph node dissection during prostate surgery helps identify lymph node tumors and that patients with more than 2 positive nodes were more at risk of cancer recurrence.

This was the first study of its kind and requires further validation to be widely applied.

If you are considering prostate surgery please consult your doctor for potential risks and benefits.