Radical radiotherapy applied with the intent of cure, aims to control local disease and cure non-small cell lung cancer. The subtypes of NSCLC are squamous cell carcinoma and adenocarcinoma. The patterns of relapse and control rates for adenocarcinoma and SCC were determined. A radical radiotherapy database covering the years 2004 to 2016, was examined to determine the very first sites of relapse. About 537 patients with known pathological subtype were involved in this study. In 7% of the patients, the site of the first relapse was uncertain. Of the remainder, 41% had adenocarcinoma, and 59% had SCC. At a follow-up after 16 months, it was found that 58% of all patients had relapsed.

There was a noticeable difference in the observed relapse patterns, with a higher rate of the first relapse locally in SCC and a higher rate of the brain’s first relapse for adenocarcinoma. The actuarial local control rate was worse for SCC. The brain metastasis-free survival was worse for adenocarcinoma. There was a noticeable difference in the relapse patterns between the NSCLC histological subtypes, indicating that these were separate entities. Adenocarcinoma displays a higher rate of cerebral relapse, whereas squamous carcinomas display a higher local relapse rate. Although reported observations may have impacted the follow-up policy and strategies in place to improve disease control.

Ref:  https://www.clinicaloncologyonline.net/article/S0936-6555(19)30288-2/fulltext