Second Primary Lung Adenocarcinoma After Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma.

Fen Xue,Xiaoshuang Niu,Xiayun He,Chaosu Hu

doi:10.3389/fonc.2022.801090

Abstract

ObjectiveThe improvement of the efficacy of intensity-modulated radiotherapy (IMRT) for nasopharyngeal cancer (NPC) has prolonged the survival of patients, and the incidence of the second tumor has gradually increased. Among them, second primary lung adenocarcinoma (SPLAC) attributes the highest incidence. This study aimed to determine the long-term risk of SPLAC in NPC patients after IMRT.MethodsFrom May 2005 to May 2018, a total of 1,102 non-metastatic NPC patients who received IMRT in our hospital were enrolled, and the incidence and efficacy of SPLAC were followed up in the long term.ResultsOver a median follow-up period of 66 months, a total of 22 cases of SPLAC were observed, with an incidence of 2.0%. The 1-, 2-, 3-, 4-, and 5-year cumulative risks of SPLAC were 0.4%, 0.7%, 0.8%, 1.1%, and 1.7%, respectively. During follow-up, 90.9% (20/22) of the SPLAC detected was in early stage, and the recurrence rate of surgery alone was 5.3% (1/19).ConclusionIn NPC patients, the proportion of SPLAC after IMRT was similar to that of the normal population, and most of them were found in early stage during follow-up, with good surgical efficacy.

Highlights

Compared to the era of 2-dimensional radiotherapy (2DRT), the efficacy of treatment for nasopharyngeal carcinoma (NPC) has been significantly improved by intensity-modulated radiotherapy (IMRT), and IMRT has become the main treatment for NPC
During follow-up, 22 second primary lung adenocarcinoma (SPLAC) cases were observed with a crude incidence of 2.0% (22/1102)
The baseline data were similar in age, sex, stage, and with or without chemotherapy for NPC patients with or without SPLAC (Table 1)

Summary

Introduction

Compared to the era of 2-dimensional radiotherapy (2DRT), the efficacy of treatment for nasopharyngeal carcinoma (NPC) has been significantly improved by intensity-modulated radiotherapy (IMRT), and IMRT has become the main treatment for NPC. The incidence of the second primary tumor after IMRT in NPC patients was 3.0%–9.2%, with second primary lung adenocarcinoma (SPLAC) contributing the highest incidence [6, 7]. With the prolongation of survival, the incidence of the second primary tumor gradually increased. Zhang et al [6] conducted a long-term follow-up study of 6,377 NPC patients who received IMRT and found that 189 (3.0%) patients developed the second primary tumor. There are rare reports about the incidence and outcome of SPLAC after IMRT for NPC. We conducted this retrospective study to compare the difference of SPLAC incidence and outcome between NPC survivors after treatment and the general population

Results

Discussion

Conclusion