ESTRO 36 Abstract Book

S301 ESTRO 36 _______________________________________________________________________________________________

2. Kunkler IH, Canney P, van Tienhoven G et al. MRC/EORTC (BIG 2-4) SUPREMO trial management group. Elucidating the role of chest wall irradiation in ‘intermediate-risk’ breast cancer: the MRC/EORTC SUPREMO trial. Clin Oncol 2008;20:31-34. 3. Russell NS, Kunkler IH, van Tienhoven G. Determining the indications for postmastectomy radiotherapy: moving from 20 th century clinical staging to 21 st century biological criteria. Ann Oncol 2015;26:1043-4. 4. Bartelink H, Maingon P, Poortmans P et al. Whole breast irradiation with or without a boost for patients with breast-conserving surgery for early breast cancer:20-year follow-up of a randomised phase 3 trial. Lancet Oncol 2015;16:47-56. 5. Hughes KS, Schnaper LA, Berry D et al. Lumpectomy plus tamoxifen with or without irradiation in women 70 years of age or older with early breast cancer. N Eng J Med 2004;351:971-977. 6. Hughes KS, Schnaper LA,Bellon JR et al. Lumpectomy plus tamoxifen with or without irradiation in women aged 70 years or older with early breast cancer:longterm follow up of the CALGB 9343 trial. J Clin Oncol 2013;31:2382-7. 7. Kunkler IH, Williams LJ, Jack WJ Breast conserving surgery with or without irradiation in women aged 65 years or older with early breast cancer (PRIME 11): a randomised controlled trial. Lancet Oncol 2015;16:266-273. 8. Kirwan CC, Coles CC, Bliss J et al. It’s PRIMETIME. Postoperative avoidance of radiotherapy: biomarker selection of women at very low risk of local recurrence. Clin Oncol 2016;28:594-596. 9. Harris JR.The PRECISION trial (profiling early breast cancer for radiotherapy omission). A phase 11 study of breast-conserving surgery without adjuvant radiotherapy for favorable-risk breast cancer. Available at: http://clinicaltrials.gov/ct2/show/NCT02653755.2016 SP-0563 Radiotherapy in older patients with GBM G. Minniti 1 1 Azienda Ospedaliera Sant' Andrea, UOC Radioterapia, Rome, Italy The incidence of glioblastoma in the elderly population has increased over the last few decades. Current treatment includes surgery, radiotherapy (RT) and chemotherapy, but the optimal management of disease remains a matter of debate. RT remains an effective treatment in elderly patients with GBM and either standard RT or hypofractionated RT are associated with longer survival than supportive care only. Randomized studies comparing standard RT versus hypofractionated radiation schedules show similar survival benefits, although short-courses RT are associated with a better safety profile. Hypofractionated RT should be chosen in older patients with newly diagnosed GBM, especially in those with poor performance status or older than 70 years old. Temozolomide (TMZ) is a safe and effective treatment option alternative to RT. Recent randomized studies indicates that chemotherapy with the alkylating agent temozolomide is a safe and effective therapeutic option in patients of 60 years or older with newly diagnosed glioblastoma. Decisions regarding the choice between RT and TMZ chemotherapy should be based on the assessment of O6-Methylguanine-DNA methyltransferase (MGMT) promoter gene. Patients with MGMT methylated tumors receive the most significant survival benefit from treatment with TMZ; by contrast, chemotherapy produces no benefit in patients with MGMT unmethylated tumors, suggesting that RT is a better option in these patients. Few studies have reported survival benefit in elderly patients treated with a combination of standard RT with concomitant and adjuvant TMZ. Although this may represent a feasible therapeutic approach in selected patients of 60-70 years old with good performance status, the potential toxicity of standard RT and chemotherapy for large irradiated brain volumes, and the modest survival

advantages in this age group as compared with younger patients, do not support the use of aggressive treatments in the majority of elderly patients. An abbreviated course of RT plus TMZ may represent a feasible treatment associated with similar survival benefit and improved quality of life. Results from an EORTC large randomized study comparing a short course of RT (40 Gy in 15 daily fractions) with or without concomitant and adjuvant TMZ in elderly patients older than 65 years old with newly diagnosed GBM indicate that RT+TMZ is a safe and effective treatment in older GBM patients. Currently, several questions regarding the risks and benefit of combined chemoradiation remains unanswered. Lung cancer is a problem of the elderly: 30% of the lung cancer patients are older than 75 years. Due to underrepresentation of elderly patients in clinical trials there is a lack of evidence to select the optimal treatment strategy. For the subgroup of elderly presenting with stage I peripheral lung cancer, stereotactic radiotherapy has shown to be an effective and well tolerated treatment option. For the other patients with stage I or II disease, fractionated radiotherapy is generally offered for elderly that are considered inoperable. With respect to the 35% of elderly patients with stage III disease, pulmonologists and radiation oncologists are faced with the challenge to judge which treatment option would be best for each individual patient. Although concurrent radiochemotherapy (RCHT) is the standard treatment for stage III disease, evidence for this treatment was gained in clinical trials that mostly excluded elderly patients. 1 Furthermore, the survival gain obtained with combined RCHT comes with a significant increase in toxicity. The lack of evidence on the optimal treatment strategy in elderly stage III NSCLC patients contributes to the difference between treatment guidelines and the treatment offered in routine clinical practice. Subgroup analyses of the limited number of elderly stage III NSCLC patients included in clinical trials indicate that fit elderly patients may benefit from intensified treatment such as concurrent RCHT, but their value is limited due to a restricted number of patients and potential selection bias. Data on the influence of age on treatment induced toxicity are conflicting. A recent retrospective study reflecting current clinical practice showed that despite the fact that relatively fit and younger elderly were assigned to concurrent RCHT, tolerance was worse and OS was not significantly better compared to sequential RCHT 2 . Since limited information on geriatric characteristics was available in this retrospective study, prospective studies including geriatric assessments are urgently needed to gather evidence on treatment options, quality of life and survival. Different geriatric assessments have been developed to discern frail, vulnerable and fit elderly patients that may help in the selection of the most appropriate treatment 3,4 , but these have not been validated for RCHT in elderly lung cancer patients, are time consuming and difficult to implement in routine oncology practice. These issues are largely addressed in the multicentre prospective randomized NVALT25-ELDAPT trial (NCT02284308), which has recently started in the Netherlands , focusing on treatment options for unselected stage III NSCLC patients ≥ 75 years This trial aims to incorporate geriatric assessment strategies to guide treatment selection, build evidence on the treatment resulting in the most optimal balance between QoL and survival, and develop a short and clinically applicable geriatric screening instrument to implement in future lung cancer care. The results of ELDAPT can SP-0564 Lung J. Van Loon 1 1 MAASTRO Clinic, Maastricht, The Netherlands