Determination of peripheral immune cell activity during treatment with either surgery or radiotherapy in patients with early stage non-small cell lung cancer.

An anatomical surgical resection is considered to be the standard of care in
fit patients who present with early stage non-small cell lung cancer (NSCLC).
However, surgery is less frequently performed in both elderly patients (aged
>=75 years), who represent the fastest-growing group of patients with stage I/II
NSCLC, and in patients who have significant co-mobidity. Following the
introduction of stereotactic ablative radiotherapy (SABR), an outpatient
treatment that is typically delivered in between 3-8 fractions, the median
survival of all elderly patients undergoing radiotherapy in The Netherlands
increased by 9.3 months. Randomized trials comparing SABR and surgery have yet
to be completed and results of the ongoing ACOSOG Z4032 studies will not be
available in the within 5 years. A recent data retrospective study comparing
both modalities has raised interesting questions about the impact of local
therapy on recurrence patterns. It was found that a better loco-regional
disease control rate was achieved with SABR.

To study the effect of surgery and SABR on both immunostimulatory (with primary
endpoint CD8 positive cells)and immunosuppressive cells in peripheral blood in
patients with early stage non-small cell lung cancer who are treated with
either modality.

The study will be conducted as a prospective multi centre observational pilot
study of the *immune score* from histological biopsies or resection specimen in
patients either treated with SABR or surgery. The study is not to compare both
modalities, for which a randomised trial is needed, but to study the immune
score before and after radiotherapy and surgery as a pilot study.

Only risks in participation are the risks with drawing blood. Subjects will not
have any benefits. This pilot experiment will be used to generate data which
may be explored in a larger series of patients.