Prognostic analysis of esophageal cancer in elderly patients: metastatic lymph node ratio versus 2010 AJCC classification by lymph nodes
World Journal of Surgical Oncology
Prognostic analysis of esophageal cancer in elderly patients: metastatic lymph node ratio versus 2010 AJCC classification by lymph nodes
Ji-Feng Feng 0 1
Ying Huang 2
Lu Chen 3
Qiang Zhao 0 1
0 Key Laboratory Diagnosis and Treatment Technology on Thoracic Oncology , Hangzhou, Zhejiang Province 310022 , China
1 Department of Thoracic Surgery, Zhejiang Cancer Hospital , No.38 Guangji Road, Banshan Bridge, Hangzhou 310022 , China
2 Department of Nursing, Zhejiang Cancer Hospital , Hangzhou , China
3 Department of Gynecologic Surgery, Zhejiang Cancer Hospital , Hangzhou , China
Background: Recent studies have proposed a new prognostic factor (metastatic lymph node ratio, or MLNR) for patients with esophageal cancer (EC). However, to the best of our knowledge, there have been no studies conducted to date regarding MLNR in elderly patients. The aim of this study was to determine the prognostic value of MLNR staging compared with the 2010 American Joint Committee on Cancer (AJCC) N staging in elderly patients with EC. Methods: From January 2001 to December 2009, a retrospective analysis of 132 consecutive patients older than 70 years of age with esophageal squamous cell carcinoma (ESCC) was conducted. Prognostic factors for disease-specific survival were analyzed. Receiver operating characteristic curves were also plotted to verify the accuracy of MLNR staging and N staging for survival prediction. Results: The disease-specific survival rates of N0, N1, N2 and N3 patients according to the AJCC Cancer Staging Manual Seventh Edition N staging were 65.5%, 42.9%, 22.2% and 0, respectively (N0 vs N1, P = 0.017; N1 vsN2, = 0.050; N2 vs N3, P < 0.001). The disease-specific survival rates of MLNR0, MLNR1, MLNR2 and MLNR3 patients were 65.5%, 45.0%, 21.1% and 0, respectively (MLNR0 vsMLNR1, P = 0.026; MLNR1 vs MLNR2, P = 0.033; MLNR2 vs MLNR3, P = 0.015). The areas under the curve were 0.731 for the 2010 AJCC N staging and 0.737 for the MLNR staging. Conclusion: MLNR is an independent predictor of survival in elderly patients with ESCC. MLNR staging predicts survival after EC similarly to the 2010 AJCC N classifications and should be considered an alternative to current N staging.
Esophageal cancer; Lymph node ratio; Overall survival; TNM classification
Background
Esophageal cancer (EC) is the eighth most common type
of cancer worldwide. In China, EC is the fourth most
common cause of mortality, with 11 deaths per 100,000 in
2005 [
1
]. However, esophageal squamous cell carcinoma
(ESCC) accounts for most EC cases in China, in contrast to
the predominance of adenocarcinoma in the Western
world [
2
]. Although advances have occurred in
multidisciplinary treatment, surgical resection remains the treatment
modality of choice. One of the main determinants of
survival for patients undergoing esophagectomy is nodal
status. However, the best method of characterizing the
extent of local lymph node metastases remains an area of
controversy.
Recent studies have proposed a new prognostic factor
(metastatic lymph node ratio, or MLNR) for EC patients
[
3-5
]. Controversy exists concerning the optimal cutoff
points for the MLNR to predict overall survival. The
different study sizes, variable inclusion criteria and, most
important, unreliable statistical methods used to determine
the cutoff points between groups have contributed to this
controversy. However, to the best of our knowledge, there
have been no studies conducted to date regarding MLNR
in elderly patients with EC.
The aim of this study was to determine the prognostic
value of MLNR staging compared with the 2010 American
Tumor size (mean ± SD, cm)
Tumor location
aESCC, esophageal squamous cell carcinoma; MLNR metastatic lymph node
ratio; NMLN, number of metastatic lymph nodes; TLN, total lymph node.
Joint Committee on Cancer (AJCC) classification system
by lymph nodes in elderly patients with ESCC.
Methods
Patients
We conducted a retrospective analysis of patients treated
from January 2001 to December 2009. The sample
population comprised 132 patients older than 70 years of age
with ESCC who underwent curative esophagectomy in
the Department of Thoracic Surgery, Zhejiang Cancer
Hospital, Hangzhou, China. Patients who had received
pre- and or postoperative chemotherapy and/or
radiotherapy were excluded. We also excluded patients with
non-ESCC and gastroesophageal junction carcinoma, as
well as patients who underwent surgical exploration
without curative esophagectomy.
All of the above patients were followed up by posting
letters or by telephone interviews. The last follow-up was
on 30 November 2011. The clinicopathological and
followup findings were collected and recorded in the database. All
subjects gave their written informed consent to the study
protocol, which was approved by the ethical committees of
Zhejiang Cancer Hospital, Hangzhou, China.
Surgery
All patients were treated with radical resection. The
standard surgical (...truncated)