Colorectal/GI
CME
Felipe Lopez-Ramirez, MD (he/him/his)
Research fellow
Mercy Medical Center
Baltimore, Maryland, United States
Disclosure(s): No financial relationships to disclose
Felipe Lopez-Ramirez, MD (he/him/his)
Research fellow
Mercy Medical Center
Baltimore, Maryland, United States
Disclosure(s): No financial relationships to disclose
Armando Sardi, MD, FACS (he/him/his)
Director
The Institute for Cancer Care, Mercy Medical Center
Baltimore, Maryland, United States
Disclosure(s): No financial relationships to disclose
Mary Caitlin King, BS
Research Supervisor
Mercy Medical Center, United States
Disclosure information not submitted.
Andrei Nikiforchin, MD (he/him/his)
Research Fellow
The Institute for Cancer Care, Mercy Medical Center
Baltimore, Maryland, United States
Disclosure information not submitted.
Philipp Barakat, MD
Research Fellow
Mercy Medical Center, United States
Disclosure information not submitted.
Luis Felipe Falla Zuniga, MD
Research Fellow
Mercy Medical Center, United States
Disclosure information not submitted.
Carol Nieroda, MD
Research Advisor
Mercy Medical Center, United States
Disclosure information not submitted.
Vadim Gushchin, MD, FACS
Director, HIPEC Program at Mercy
Mercy Medical Center, United States
Disclosure information not submitted.
Lymph node (LN) metastasis is a known negative prognostic factor in appendix cancer (AC) patients. However, currently the minimum number of LN required to properly determine LN status is extrapolated from colorectal studies and data specific to AC is limited. We aimed to define the lowest number of LN required for appropriate AC staging and its impact on oncologic outcomes.
Methods: Patients with high-grade epithelial tumors of the appendix from the National Cancer Database (NCDB 2004-2019) undergoing surgical resection with complete information about LN examination were included. Logistic regression assessed the odds of positive LN (LN+) for different numbers of LN examined, adjusted by sex and age. Cox-regressions were performed stratified by LN status, adjusted by age, sex, tumor grade, stage, mucinous histology, and documented adjuvant systemic chemotherapy (ASC).
Results:
Of 4,516 included patients, 1,876 (41.5%) were LN+. Harvesting 10 LN was the minimum number without decreased odds of LN+ compared to the reference category (≥21 LN). Examined LN were ≥10 in 1,642 (87.5%) LN+ patients and 2,156 (81.6%) LN negative (LN-) patients. For patients with complete information about ASC, 1,231/1,690 (72.8%) of the LN+ patients vs 935/2,395 (39.0%) LN- patients received ASC (p < 0.01).
Median follow-up was 80.4 (CI95%: 77.3–83.3) months. In LN+ patients, median overall survival (OS) was 25.7 (CI95%: 21.1–28.8) months in patients with < 10 LN examined vs 42.5 (CI95%: 38.7–46.6) in those with ≥10 LN (p < 0.01). In LN- patients, median OS was 83.7 (CI95%: 73.3–116) months in patients with < 10 LN vs 154.2 (CI95%: 133.0–Not Reached) in those with ≥10 examined LN (p < 0.01). Adjusted Cox-regressions showed adequate LN examination (≥10 LN) to be associated with longer OS (HR 0.62, p< 0.01) for LN- patients and, to a lesser extent, in LN+ patients (HR 0.83, p=0.05).
Conclusions:
In AC patients, examination of at least 10 LN in the surgical specimen showed increased odds of finding LN+ and was associated with longer OS in both LN+ and LN- disease. To avoid understaging and guide adjuvant therapy, an adequate number of regional LN must be assessed.