EAU 2021 | Long-term outcomes of DSNB for cN0 penile cancer

Hi, good morning everybody, my name is Edoardo Pozzi. I’m a Urology resident at San Raffaele hospital in Milan, Italy. And today I’m very happy to present to you the results of this collaborative study between University College London Hospital and the Christie NHS Foundation Trust in Manchester.

It’s a study about the longer-term outcomes and the feasibility of dynamic sentinel lymph node biopsy for clinical impalpable penile cancer patients. So, to do this, we enrolled 509 patients with clinically impalpable disease at presentation, so, without palpable lymph nodes in the groin, with penile cancer, squamous cell carcinoma with a pathological T stage of T1G2 or above. And we assess again, the diagnostic accuracy of the staging technique, and also we assess the cancer-specific survival and the recurrence-free survival of these patients.

Also, we assess the cancer-specific survival and recurrence-free survival of those that had the positive completion radical lymph node dissection, because whenever you have a positive dynamic sentinel lymph node biopsy, then the patients should be offered, and must undergo a completion, radical inguinal lymph node dissection.

So, as I said, we enrolled retrospectively 509 penile cancer patients, undergo dynamic sentinel lymph node biopsy. We collected all the social demographics, characteristics, including age, type of primary surgery, complications, T stage tumor grade. Then we collected the number of true positives, true negatives, false negatives and false positives. It is important to note, that the false negative was defined as any inguinal lymph node recurrence within 12 months from a previously negative dynamic sentinel lymph node biopsy. Then the sensitivity and specificity of dynamic sentinel lymph node biopsy were calculated. And Kaplan-Meier analysis were used to estimate the five-year cancer-specific survival, and recurrence-free survival rates. Both of those with dynamic sentinel for undergoing dynamic sentinel lymph node biopsy and those undergoing completion radical lymph node dissection.

So, to give overall data, the median age of our cohort was 64, with an interquartile range of 53 to 71 years. The median follow-up for cancer-specific survival and recurrence-free survival was 62.5 months. We didn’t have in our cohort T4 stage patients. We had, the majority of them were T1, 378. And the G2 was the mostly represented grade in our cohort. Surprisingly enough, the false negatives were only 3 in our cohort, which is a very low false negative rate compared to the studies done in the, in the literature. There’s the main explanation that we can give to this very low false negative rate is that both the Christie’s and the University College London Hospital in the UK are two referral centers for this very rare disease. And these are as referral centers, many expert surgeons perform these procedures. So, that’s why we have these explanation of a very false, that could be a speculation of why we had these very low, false negative rate.

So, we concluded that the dynamic sentinel lymph node sensitivity was 92.5%. Whereas the specificity of dynamic sentinel lymph node biopsy was at 100%, because the false positive rate was 0, as the histopathologist would not identify cancer as inflammation or inflammation as cancer because they are, as they are very trained to analyze the tissues of this very rare disease, that a false positive would be something very very rare. And this is of course, a limitation that should be addressed in our study.

The possibility of complication of dynamic sentinel lymph node biopsy after his operation were very low, with a wound infection rate only occurring in 7% of all patients. And a positive histology dynamic sentinel lymph node biopsy was found in 37 patients. And again, a positive histology in completion radical inguinal lymphadenectomy was found in 34 patients.

So in conclusions, we found that in our dynamic sentinel lymph node biopsy is a feasible procedure. It is nothing very new, as it was very proven in the literature, but we had, the strength of our study was that this was a two-center study rather than a single one, single center study. And we analyzed a very large cohort of patients. So, we confirm that the dynamic sentinel lymph node biopsy should be offered to all patients coming to the office and seeking medical help for penile cancer. With that confirmed, the histopathological T stage of T1G2 or above, and clinical impalpable disease at presentation. Thank you.