Time-varying effect of sex on prognosis of lung adenocarcinoma surgical patients in China

Evaluation of sex inequity in lung-cancer-specific survival

BACKGROUND

Whether sex is an independent prognostic factor in lung cancer survival is the subject of ongoing debate. Both large national registries and single hospital studies have shown conflicting findings. In this study, we explore the impact of sex on lung-cancer-specific survival in an unselected population that is well-characterized with respect to stage and other covariates.

MATERIAL AND METHODS

All patients diagnosed with lung cancer at a single hospital serving a whole and defined region in Southern Norway during the 10 years 2007-2016 were included. Follow-up data were available for at least 56 months for all patients. Analyses were adjusted for stage, treatment, performance status, smoking, age, histology, epidermal growth factor receptor/anaplastic lymphoma kinase/immunotherapy treatment and period. Differences in lung-cancer-specific survival by sex were explored using restricted mean survival times (RMST).

RESULTS

Of the 1,261 patients diagnosed with lung cancer, 596 (47%) were females and 665 (53%) males, with mean ages of 68.5 and 69.5 years, respectively. The observed 5-year lung-cancer-specific survival rate was 27.4% (95% CI 23.7, 31.2) in females and 21.4% (95% CI 18.2, 24.8) in males. However, after adjustment for covariates, no significant differences by sex were observed. The 5-year RMST was 0.9 months shorter (95% CI -2.1, 0.31, p = 0.26) in males compared to females.

INTERPRETATION

In this cohort, sex was not associated with a difference in lung-cancer-specific survival after adjusting for clinical and biological factors. Imbalance in stage at diagnosis was the main contributor to the observed difference in lung-cancer-specific survival by sex.

Prognostic value of GPC5 polymorphism rs2352028 and clinical characteristics in Chinese lung cancer patients

Background: GPC5 rs2352028 is associated with the risk of lung cancer, but its relationship with lung cancer prognosis is unclear. Materials & methods: The authors collected blood samples from 888 patients with lung cancer and used a Cox proportional hazards model to analyze the association between prognosis and GPC5 polymorphism rs2352028. Results: GPC5 rs2352028 C > T was associated with a better prognosis. Patients with CT genotype had longer overall survival than those with CC genotype. Additionally, older and early-stage patients with CT + TT genotype had a lower risk of death than those with CC genotype. Conclusion: GPC5 rs2352028 C > T may play a protective role in patients with lung cancer and GPC5 rs2352028 may be a potential genetic marker for lung cancer prognosis.

Time-varying effect of sex on prognosis of lung adenocarcinoma surgical patients in China

Background

Little is known about the prognostic advantage of sex for pulmonary adenocarcinoma among Chinese patients. In this study, we aimed to investigate the true sex differences in prognosis by adjusting for confounders and to explore whether the differences were time‐varying.

Methods

We identified 4438 lung adenocarcinoma patients who underwent surgery at a regional Cancer Center of China from 2008 to 2016, retrospectively. Sex, age group, smoking history, year of diagnosis and pathological stage were collected. Time‐dependent Cox regression models with inverse probability of treatment weighting (IPTW) based on propensity score were used to assess the effect of sex and account for confounders. Landmark analyses were conducted to assess survival before, and after, five years.

Results

Of these patients, 1761 (39.7%) were men and 2677 (60.3%) were women. Median follow‐up time was 52.6 months. After IPTW adjustment, women were found to have significantly better survival than men varying with time in both crude and IPTW models (hazard ratio [HR] [t] = 0.453*1.015^t, where t is the length of time from treatment and its unit is month, p < 0.001). Women had significantly better survival than men within 0–5 years after surgery (HR = 0.763, 95% CI: 0.649–0.897, p = 0.001), whereas there was no difference after five years (HR = 1.135, 95% CI: 0.803–1.605, p = 0.472). In subgroup analysis, women in the 61–71+ age group, in the more than 20 year packs group, pathological stage 0–IB group, and 2013–2016 diagnosis period group revealed the same prognostic pattern.

Conclusions

Compared with men, women had better survival after surgical resection of lung adenocarcinoma, especially those who were older and nonsmokers or heavy‐smokers and were pathological stage 0–IB in early years, while the advantage for women diminished with time.