Association of lymph node promotion activity to cervical lymph node
yield of oral cancer patients in Asian country: A
difference-in-differences analysis
Abstract
Objectives: High quality of lymph node yield could increase survival but
strategies to improve it was seldom reported. This study was aim to
assess the impact of a lymph node promotion activi-ty (LNPA) in oral
cancer surgery through a difference-in-differences research design.
Design: A retrospective based study. Setting: Medical center in Taiwan.
Subjects and methods: A total of 400 oral cancer patients underwent
primary tumor resection and neck dissection including elective neck
dissection (END) and radical neck dissection (RND) were recruited after
propensity score matching by clinical T and N category between 2009
Janu-ary and 2018 October. Oral cancer patients were treated by two
independent departments in our institute. Since 2015 Oct, a LNPA was
initiated in one department (target group), and another department was
as a control group. The impact of LNPA on LN yield and regional
recurrence were analyzed and compared between these two groups by
difference-in-differences (DID) linear regression analysis. Results: The
mean age was 55.2+11.1 years, and 92% were male. 180 (45%) oral cancer
patients had T3-4 disease, and 128 (32%) patients had N2-3 disease. In
DID analysis, a lower LN yield among the target group before 2015 Oct
(coefficient=-11.05, p<0.001). LNPA launched after 2015 Oct in
target group showed a positive promotion of LN yield (coefficient=13.24,
p<0.001). Moreover, a borderline protective effect of LNPA on
regional recurrence among those with cN0 disease (coefficient= -9.4%,
p=0.087) was noted. Conclusion: Strategy, like LNPA was associated
increased LN yield and decreased regional re-currence in oral cancer.
This kind of activity to promote surgeons to improve their quality of
neck dissection was feasible and could be applied widespread.