Waiting for Genetic Test Results May Improve Survival in Lung Cancer

Lung cancer is one of the most common cancers worldwide. Genetic testing to determine eligibility for newer targeted drugs and immunotherapies helps us better understand how patients will respond. This study examines how waiting for test results may affect treatment outcomes.

Waiting for Genomic Test Results Is Better for Patients

Starting treatment for advanced non-small cell lung cancer (NSCLC) before genomic test results are available may adversely affect outcomes.

On 9 August 2023,  JCO Oncology Practice published a study in which researchers found better overall survival and time to next treatment or death among patients who started treatment after genomic testing identified an actionable oncogenic driver (genetic mutation).

Study Details

1. Data Source: Researchers used real-world data from 510 patients in the Integra Connect Database. Patients had newly diagnosed stage IV NSCLC and mutations in EGFR, ALK, ROS1, BRAF, MET, RET, ERBB2, or NTRK.
   • Of the patients, 88.8% had nonsquamous and 6.5% had squamous lung cancer.
   • The most common oncogenic mutations were EGFR (56%), BRAF (15%), MET (8%), HER2 (8%), ALK (6%), RET (2%), ROS1 (1%), and NTRK (1%).
   • Women accounted for 60% of patients.
   • Never-smokers accounted for 43%.
2. Patient Groups: Patients were divided into three groups:
   • Group 1 (379 patients): Those who started treatment after genomic test results identified actionable oncogenic drivers.
   • Group 2 (47 patients): Those who started before results were available but switched to an appropriate targeted treatment within 35 days.
   • Group 3 (84 patients): Those who started before results were available and did not switch treatment within 35 days.
3. Overall Survival Results:
   • Median overall survival was 28.8 months for those starting treatment after receiving test results.
   • For those switching within 35 days, it was 21.7 months (HR, 1.12; P=0.59).
   • For those not switching within 35 days, it was 15.3 months (HR, 1.62; P=0.003).
   • Overall survival was significantly longer in patients starting treatment after receiving results than in the other groups.
4. Time to Next Treatment or Death:
   • The median was 13 months for those starting after receiving test results.
   • For those switching within 35 days, it was 5.5 months (HR, 1.73; P=0.002).
   • For those not switching within 35 days, it was 6.4 months (HR, 1.71; P=0.0002).
   • Time to next treatment or death was significantly longer in patients starting after receiving results than in the other two groups.

Conclusion and Recommendations

These results suggest that even an initial chemotherapy treatment while awaiting results may adversely affect outcomes. The researchers state that doctors should wait for test results before deciding on treatment, to provide appropriate therapy as early as possible and reduce exposure to ineffective or unsuitable treatments.

This study may support more effective treatment decisions and represent an important step in advanced non-small cell lung cancer care.