METHODS
Eighty-four patients" medical records with HNC who underwent radical radiotherapy/ concurrent
chemoradiotherapy were retrospectively included in the study. Blood tests were analyzed at the
treatment's beginning, middle, and end. The degree of lymphopenia was categorized according to the
Common Terminology Criteria for Adverse Events. The OS, DFS, and DMFS were calculated with the
Kaplan-Meier method. In addition, univariate and multivariate Cox regression analyses were used to
investigate the relationship between lymphopenia and survival.
RESULTS
The median follow-up time of patients was 20 months (range, 3-103). Forty-five deaths and a median
1-year OS of 76% were found. There was no difference in OS (median 27 months vs. 32 months,
p=0.674) and DFS (30 months vs. 31 months, p=0.350) between patients who developed and did not develop
lymphopenia during radiotherapy. However, survival was significantly worse in patients with G3
lymphopenia than in G1-2 patients (median 21 months vs. 49 months, p=0.033). When patients with an
NLR of ≥4.9 and <4.9 were compared, no difference in OS (p=0.156) and DFS (p=0.830) was observed
between these two groups. However, DMFS (43.1 months vs. 66.6 months, respectively, p=0.052) was
worse in patients with high NLR (≥4.9).
CONCLUSION
Treatment-related G3 lymphopenia and high NLR rate are poor prognostic factors in patients with HNC.
Keywords: Chemoradiotherapy; head and neck cancer; lymphopenia; neutrophil to lymphocyte ratio; overall survival
Effect of radiation on lymphocytes may vary depending
on the dose of radiation, the size and number
of radiotherapy fields and the simultaneous administration
of chemotherapy.[
Compared to the fatal effect of immunosuppression
after whole-body radiotherapy, focal radiotherapy's
lymphopenia effects are not known for certain.[
In some studies, it has been shown that low lymphocyte
count throughout treatment is associated with
poor clinical outcomes, particularly overall survival
(OS), disease-specific survival, and progression-free
survival (PFS) in head-and-neck, lung, rectal, and pancreatic
cancers.[
In recent years, clinical studies measuring the inflammatory
response in cancer patients have been
started to determine the poor prognosis. One of the
biomarkers showing systemic inflammation is the
NLR. In these studies, high NLR was reported as an
independent prognostic factor indicating decreased
survival in cancer.[
This study investigated the prognostic effect of lymphopenia,
and NLR observed during radiotherapy on
OS and disease-free survival (DFS) in patients with
head-and-neck cancer (HNC) who underwent radical
radiotherapy/chemoradiotherapy.
Statistical Analysis
Statistical analyses were performed using IBM®
SPSS® 22 (SPSS Inc., Chicago, IL, USA) software. The
conformity of the variables to the normal distribution
was examined using analytical methods (Kolmogorov?
Smirnov/Shapiro?Wilk tests). Pearson's
Chi-square or Fisher's exact Chi-square test was used
to analyze all categorical data. Logistic regression
analysis was performed to determine risk factors.
Kaplan-Meier survival analysis and log-rank (mantel-
cox) test were applied for survival analyses (OS
and DFS). For univariate and multivariate survival
modeling, Cox regression analyses were performed,
and the hazard ratio was calculated. P<0.05 was considered
statistically significant.
This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the local ethics committee where this research was conducted (date: June 15, 2021; number: 2021/06-19). Patient consent information was taken.
Lymphopenia was detected during radiotherapy in
50 (59.5%) of the patients. Grade 1 lymphopenia developed
in 10 (11.9%) patients, Grade 2 in 17 (20.2%), and Grade 3 in 23 (27.4%) patients, whereas G4 was not
observed in any patient. When we grouped the cases
with lymphopenia, 27 (32.1%) had Grade 1-2, and 23
(27.4%) had Grade 3 (Table
Considering the risk factors related to the development
of lymphopenia, in the male gender (p=0.008,
OR: 4.6), in Stage III-IV cases (p<0.0001, OR: 7.4),
in those who received concomitant chemotherapy
(p=0.016, OR: 3.2), in patients without comorbidity
(p=0.044, OR: 0.34). Moreover, those with NLR value ≥4.9 (p<0.0001, OR: 9) were found to develop more
lymphopenia (Table
There was no difference in OS (median 27 months vs. 32 months, p=0.674) and DFS (30 months vs. 31 months, p=0.350) between patients who developed and did not develop lymphopenia during radiotherapy. However, survival was significantly worse in patients with Grade 3 lymphopenia than in Grade 1-2 patients (median 21 months vs. 49 months, p=0.033).
In addition, there was no difference in DFS between
these two groups (p=0.115) (Fig.
Univariate survival analyses for patients with and
without lymphopenia are detailed in Table
In multivariate survival analyses, these factors were found to be unrelated for survival in patients who developed lymphopenia while smoking (HR: 0.14 [0.02- 0.78], p=0.026) and using IMRT as a radiotherapy modality (HR: 15.01 [2.66-84.64], p=0.002) decreased DFS. In patients without lymphopenia, advanced stage (HR: 26.30 [2.67-258.83, p=0.005) and oropharyngeal tumors were associated with worse survival compared to non-oropharyngeal tumors (HR: 15.21 [1.44-160,67], p=0.024), whereas advanced stage (HR: 14.35 [1.02- 202.92], p=0.049), use of IMRT (HR: 0.03 [0.00-072], p=0.031) and concurrent chemotherapy (HR: 11.69 [2.05-66.54], p=0.006) were associated with worse DFS.
According to the neutrophil-to-lymphocyte ratio,
when patients with ≥4.9 and <4.9 were compared,
there was no difference in OS (p=0.156) and DFS
(p=0.830). However, patients with high NLR (≥4.9)
had worse distant metastasis-free survival (DMFS)
(43.1 months vs. 66.6 months, p=0.052, respectively)
(Fig.
N/L: Neutrophil-to-lymphocyte ratio
Xie et al.[
In the study of Byun et al.,[
In the study of Davuluri et al.,[
In the study of Suzuki et al.,[
In the study of Liu et al.,[
Abravan et al.[
Recent studies emphasize that inflammatory markers
in peripheral blood (neutrophils, white blood cells,
lymphocytes, and monocytes counts, neutrophil-tolymphocyte
ratio, platelet-lymphocyte ratio, and lymphocyte-
monocyte ratio) may play a key role in predicting
survival.[
Charles et al.[
In their study, Li et al.[
In our study, the presence of early-stage disease,
administration of radiochemotherapy, and the presence
of lymphopenia were found to be risk factors
for high NLR. While no correlation was found between
NLR and survival and DFS, a borderline increased
risk of distant metastases (p=0.053) was
found in the high NLR group.
Peer-review: Externally peer-reviewed.
Conflict of Interest: All authors declared no conflict of interest.
Ethics Committee Approval: The study was approved by the Tepecik Training and Research Hospital Ethics Committee (no: 2021/06-19, date: 15/06/2021).
Financial Support: None declared.
Authorship contributions: Concept - M.E.; Design - M.E.; Supervision - M.E.; Materials - M.P.; Data collection and/or processing - M.P.; Data analysis and/or interpretation - M.E., M.P.; Literature search - M.E., Z.G.; Writing - M.E., Z.G.; Critical review - M.E.