Initial Results of a Multicenter Phase II Trial of Stereotactic Ablative Radiation Therapy for Oligometastatic Cancer
Mené sur 147 patients atteints d'un cancer avec 1 à 5 oligométastases (âge médian : 66,4 ans ; durée médiane de suivi : 41,3 mois), cet essai multicentrique de phase II évalue l'efficacité, du point de vue de la survie sans progression locale, de la survie sans progression distante et de la survie globale, et la toxicité d'une radiothérapie stéréotaxique ablative ciblant les métastases
Background : Oligometastatic disease has emerged as a potentially curable state in the spectrum of cancer progression. Aggressive local therapy such as stereotactic ablative radiation therapy (SABR) may improve oncologic outcomes. Herein, we report the initial oncologic outcomes and patient-reported quality of life (PR-QoL) from a phase II multi-center trial for patients with oliogmetastatic disease. Methods : Patients with oligometastatic disease (1-5 metastases) were prospectively recruited between 2011-2017. SABR dose and fractionation was dependent upon the lesion size and location. Patient follow-up occurred within 6 weeks of completion of SABR and at 3-month intervals. Patients received FACT-G questionnaire at baseline and at each follow-up to assess for PR-QoL. Median follow-up was calculated by reverse Kaplan-Meier method. Overall survival (OS), local progression-free survival (LPFS), and distant progression-free survival (DPFS) were calculated using Kaplan-Meier. Results : We enrolled 147 patients with oligometastatic cancer with a median age of 66.4 years (IQR: 59.9-74.6). The most common primary tumors included: lung (21.8%, non-small cell: n=29, small cell: n=3), colorectal adenocarcinoma (21.1%), and head & neck (10.9%, squamous cell carcinoma: n=11). In a median follow-up of 41.3 months (IQR: 14.6-59.0), the median OS was 42.3 months (95% CI: 27.4-NE) with 5-year OS of 43%. 5-year LPFS and DPFS were 74% and 17%, respectively. Acute grade 2+ and 3+ toxicity were 7.5% and 2.0%, respectively and late grade 2+ and 3+ toxicity were both 1.4%. There was no significant change in quality of life at completion, 6 weeks, 3 months, and 9 months after treatment. At 6 and 12 months patients were found to have statistically significant improvement in PR-QoL. Conclusion : This multi-center prospective phase II study demonstrates SABR for recurrent oligometastatic cancer is a feasible and tolerable treatment option with minimal acute and late grade 3 toxicity. Additionally, PR-QoL was not adversely affected.