METHODS
We analyzed data of the advanced NSCLC patients with ROS1 mutation retrospectively. We determined
the clinicopathological features of the patients. We evaluated the parameters affecting the prognosis with
survival analyzes.
RESULTS
The research enlisted the participation of 21 patients. Median progression-free survival with crizotinib
treatment was found 26.1 (95% Confidence interval [CI], 8.1-44.1) months. Median overall survival
was 35.2 (95% CI, 13.5-56.9) months. Treatment-related Grade 1-2 adverse effects were observed in 9
(42.9%) patients and Grade 3-4 adverse effects were detected in 1 (4.8%) patient. Clinicopathological
parameters affecting survival were evaluated; age (p=0.02) and liver metastasis (p=0.03) were defined as
prognostic parameters. ROS1 positivity rate (p=0.08) was not found to be a prognostic factor.
CONCLUSION
In patients with ROS1 fusion-positive metastatic NSCLC, crizotinib was shown to be both efficacious
and safe. We also found that in this patient group, age and the existence of liver metastases are prognostic
factors.
Keywords: Crizotinib; non-small cell lung cancer; prognosis; ROS1 fusion
ROS1 gene fusion was first detected in glioblastoma
cells in 1987 and NSCLC cells in 2007 and is
located on chromosome 6q21.[
The patients were given crizotinib 250 mg twice a day. The efficacy of the treatment was evaluated clinically and radiologically every 2 or 3 months. Treatment responses were analyzed according to the RECIST 1.1 guideline. The Common Terminology Criteria for Adverse Events standards were used to record and assess treatment-related adverse events.
The Ministry of Health's death notification system was used to verify the patients" death status. The time from onset of metastatic disease to death from any cause was defined as overall survival (OS). The period from the start of crizotinib to disease progression was used to calculate progression-free survival (PFS). The factors affecting OS were analyzed with clinical and pathological parameters. In addition, the relationship between ROS1 positivity rate and treatment response was evaluated.
Statistical Analysis
SPSS 25 was used to conduct all statistical analyses.
Numbers and percentages were used to represent
categorical data, whereas a median value (minimummaximum)
was used to represent continuous variables.
The survival analysis and curve were calculated using
the Kaplan-Meier technique. Prognostic univariate and
multivariate analyses in terms of OS were obtained by
applying the Cox-regression method. ROC analysis
was performed to evaluate the effect of ROS1 positivity
rate on treatment response. Statistical significance was
accepted as p<0.05.
The objective response rate with crizotinib treatment
was found as 55.5% and the disease control rate
was 83.3% after correction due to missing data (Table
Survival Outcomes and Prognosis>br>
The average period of follow-up was 17 months. Ten
(48.6%) patients died during the study period. Crizotinib-
related median PFS was 26.1 (95% CI, 8.1-44.1)
months (Fig.
PFS: Progression-free survival.
OS: Overall survival.
The presence of brain metastasis is an indication
of poor prognosis in lung cancer. The brain metastases
incidence in NSCLC patients with ROS1 mutation
is around 30-40%, and this rate was similar to that of
other driver mutations.[
Study Limitations
Some data were missing due to the fact that it was a retrospective
study, and the number of patients was low
due to the fact that ROS1 mutation is a rare mutation.
The small number of patients limited the multivariate
analysis for OS by evaluating more parameters. All
these situations were limitations of the study.
Peer-review: Externally peer-reviewed.
Conflict of Interest: All authors declared no conflict of interest.
Ethics Committee Approval: The study was approved by the İstanbul University İstanbul Faculty of Medicine Ethics Committee (no: 266748, date: 28/06/2021).
Financial Support: None declared.
Authorship contributions: Concept - İ.D., N.K., N.P., A.A.; Design - İ.D., F.F., E.A., S.V., P.S.; Supervision - S.V., P.S., A.A.; Funding - None; Materials - İ.D., N.K., N.P., F.F., E.A.; Data collection and/or processing - İ.D., N.K., N.P., F.F., E.A.; Data analysis and/or interpretation - İ.D., N.K., N.P., A.A.; Literature search - İ.D., N.K., N.P., F.F., S.V.; Writing - İ.D., A.A.; Critical review - S.V., P.S., A.A.