Identifying patient factors that can predict the risk of local disease progression

This study looked at patients factors which would help predict local disease control for patients with inoperable non-small-cell lung cancer (NSCLC) who have been treated with chemoradiation therapy. The authors concluded that patients with squamous NSCLC, large tumor volume and first-line chemotherapy had a higher risk of worse local disease control after chemoradiation therapy.

For patients with NSCLC, surgery is not always an option. These patients are usually treated with a combination of radiation and chemotherapy. Researchs has shown that high dose radiation with chemotherapy is beneficial for some types of cancers in stopping local disease progression. However, for patients with advanced NSCLC this benefit has not been shown. It is possible that some patients are at a higher risk of local disease progression (LP) and this is affecting the success rate of high dose chemoradiation. It would be helpful to know what facters could predict the success of treatment.

This study aimed to identify factors that could predict the risk of LP in patients with stage III NSCLC treated with chemoradiation therapy.

491 patients were included in the trial. Patients were followed for up to 5 years after treatment. Average overall survival (OS, time from finishing treatment until death) was 21 months. By 5 years after treatment, the OS rate was 31.6% and 32.9% of patients had LP.

Patients were grouped according to radiation dose (low, moderate, high and very high dose). High dose radiation (67-70 Gy) resulted in 83% improvment in the odds of LP-free survival (LPFS, time from finishing treatment to local disease progression) compared to low-dose (60-63 Gy) and 2-fold improvment compared to moderate dose radiation (64-66 Gy). There was no benefit to very high dose radiation (71-74 Gy).

Patients with squamous cell NSCLC, large tumor volume and first-line chemotherapy before chemoradiation were all associated with worse LPFS.

Patients with better LPFS had better OS by nearly 3 fold.

73 patients had grade 3 or above esophagitis (inflammation of the esophagus) and 50 patients had grade 3 or above pneumonitis (inflammation in the lung).

The authors concluded that patients with better LPFS had better OS and that squamous cell NSCLC, large tumor volumes and induction chemotherapy were predictors of worse LPFS. They also state that high dose radiation of 67 to 70 Gy was associated with improved LPFS.