Original research
Impact of prior cancer history on the overall survival of younger patients with lung cancer

https://doi.org/10.1136/esmoopen-2019-000608Get rights and content
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ABSTRACT

Background

Patients with a history of prior cancer are frequently excluded from cancer trials. Previous studies indicated that prior cancer does not adversely impact clinical outcomes for patients with lung cancer older than 65 years. However, it remains unknown whether these results are applicable to patients with lung cancer aged younger than 65 years old. The study aimed to investigate the impact of prior cancer history on younger patients with lung cancer.

Methods

We identified younger patients with lung cancer (<65 years) diagnosed between 2004 and 2009 in the Surveillance, Epidemiology, and End Results database. Propensity score matching was performed to balance differences in baseline characteristics between groups. Kaplan-Meier method and the Cox proportional hazards model were used to evaluate the impact of prior cancer on overall survival (OS).

Results

Among 103 370 eligible patients with lung cancer, 15.18% had a history of prior cancer. Lung and bronchus (25.83%), breast (14.13%), prostate (8.85%) and cervix uteri (4.74%) were the most common prior cancer types. Of prior cancers, 61.56% are localised and regional stages. More than 67.98% of prior cancers were diagnosed within 5 years of the index lung cancer diagnosis. The median times of diagnosis for prior cancers were 38 months. Patients with prior cancer had the same/non-inferior OS as that of patients without a prior cancer diagnosis (propensity score-adjusted HR=1.01, 95% CI=0.99 to 1.04, p=0.324). Subgroup analyses stratified by timing of prior cancer displayed almost the same tendency (p>0.05). Interestingly, early-stage patients with a history of prior cancer had adverse survival curves (p<0.05). Advanced-stage patients with prior cancer had non-inferior survival (p>0.05).

Conclusions

A prior cancer diagnosis has a heterogeneous effect on the survival of patients with lung cancer aged <65 years across different stages, but further prospective studies are still warranted.

lung cancer
younger patients
prior cancer
SEER

Cited by (0)

JL, HZ and YZ contributed equally.

JL, HZ and YZ are joint first authors.

Presented at: This study was previously presented as an abstract at International Association for the Study of Lung Cancer Asia Conference on Lung Cancer 2018.

Contributors: JL, HZ, and YZ contributed equally to this work and should be regarded as cofirst authors. LZ, JL, HZ and YZ and were responsible for the conception and design of the study, the interpretation of data, drafting and writing of the article; WF, YY, SH, GC and SZ were responsible for acquisition, analysis and interpretation of data and drafting the text, and also participated in the drafting of the article; JS, WX, ZZ and XC were responsible for the interpretation of the data and drawing the figures. HZ and YH were responsible for the revision of the intellectual content. All authors participated in the final approval of the article and agreed to be accountable for all aspects of the work.

Funding: This work was supported by the National Key R&D Program of China (grant numbers 2016YFC0905500 and 2016YFC0905503), the Chinese National Natural Science Foundation project (grant numbers 81872499 and 81772476), the Science and Technology Program of Guangdong (grant number 2017B020227001) and the Science and Technology Program of Guangzhou (grant numbers 201607020031 and 201704020072).

Competing interests: None declared.

Patient consent for publication: Not required.

Provenance and peer review: Not commissioned; externally peer reviewed.

Data availability statement: Data are available in a public, open access repository.