Effect of timing, technique and molecular features on brain control with local therapies in oncogene-driven lung cancer

BACKGROUND

The improved efficacy of tyrosine kinase inhibitors (TKI) mandates reappraisal of local therapy (LT) for brain metastases (BM) of oncogene-driven non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

This study included all epidermal growth factor receptor-mutated (EGFR⁺, n = 108) and anaplastic lymphoma kinase-rearranged (ALK⁺, n = 33) TKI-naive NSCLC patients diagnosed with BM in the Thoraxklinik Heidelberg between 2009 and 2019. Eighty-seven patients (62%) received early LT, while 54 (38%) received delayed (n = 34; 24%) or no LT (n = 20; 14%). LT comprised stereotactic (SRT; n = 40; 34%) or whole-brain radiotherapy (WBRT; n = 77; 66%), while neurosurgical resection was carried out in 19 cases.

RESULTS

Median overall survival (OS) was 49.1 months for ALK⁺ and 19.5 months for EGFR⁺ patients (P = 0.001), with similar median intracranial progression-free survival (icPFS) (15.7 versus 14.0 months, respectively; P = 0.80). Despite the larger and more symptomatic BM (P < 0.001) of patients undergoing early LT, these experienced longer icPFS [hazard ratio (HR) 0.52; P = 0.024], but not OS (HR 1.63; P = 0.12), regardless of the radiotherapy technique (SRT versus WBRT) and number of lesions. High-risk oncogene variants, i.e. non-del19 EGFR mutations and 'short' EML4-ALK fusions (mainly variant 3, E6:A20), were associated with earlier intracranial progression (HR 2.97; P = 0.001). The longer icPFS with early LT was also evident in separate analyses of the EGFR⁺ and ALK⁺ subsets.

CONCLUSIONS

Despite preferential use for cases with poor prognostic factors, early LT prolongs the icPFS, but not OS, in TKI-treated EGFR⁺/ALK⁺ NSCLC. Considering the lack of survival benefit, and the neurocognitive effects of WBRT, patients presenting with polytopic BM may benefit from delaying radiotherapy, or from radiosurgery of multiple or selected lesions. For SRT candidates, the improved tumor control with earlier radiotherapy should be weighed against the potential toxicity and the enhanced intracranial activity of newer TKI. High-risk EGFR/ALK variants are associated with earlier intracranial failure and identify patients who could benefit from more aggressive management.

Monocarboxylate transporter-1 (MCT1) protein expression in head and neck cancer affects clinical outcome

Treatment of locally advanced, unresectable head and neck squamous cell carcinoma (HNSCC) often yields only modest results with radiochemotherapy (RCT) as standard of care. Prognostic features related to outcome upon RCT might be highly valuable to improve treatment. Monocarboxylate transporters-1 and -4 (MCT1/MCT4) were evaluated as potential biomarkers. A cohort of HNSCC patients without signs for distant metastases was assessed eliciting 82 individuals eligible whereof 90% were diagnosed with locally advanced stage IV. Tumor specimens were stained for MCT1 and MCT4 in the cell membrane by immunohistochemistry. Obtained data were evaluated with respect to overall (OS) and progression-free survival (PFS). Protein expression of MCT1 and MCT4 in cell membrane was detected in 16% and 85% of the tumors, respectively. Expression of both transporters was not statistically different according to the human papilloma virus (HPV) status. Positive staining for MCT1 (n = 13, negative in n = 69) strongly worsened PFS with a hazard ratio (HR) of 3.1 (95%-confidence interval 1.6-5.7, p < 0.001). OS was likewise affected with a HR of 3.8 (2.0-7.3, p < 0.001). Multivariable Cox regression confirmed these findings. We propose MCT1 as a promising biomarker in HNSCC treated by primary RCT.

P05.07 Effect of Tumor-Treating Fields plus Short-Course Radiation with or without Temozolomide in Elderly Patients with Glioblastoma (GERAS Trial)

BACKGROUND

Despite advances in the therapy of glioblastomas (GBM) in the last decades, the most common malignancy of glial origin is still associated with poor prognosis. At present, maximal safe resection followed by adjuvant chemoradiotherapy (CRT) with temozolomide (TMZ) is the standard of care. After completion of CRT, patients usually receive 6 maintenance cycles of TMZ that may be complemented by Tumor-Treating Fields (TTFields). Regardless of age and other prognostic factors, the recent EF-14 trial has shown that addition of TTFields to the maintenance therapy significantly increases overall survival in all patient subgroups. In the EF-14 trial, TTFields were used during maintenance therapy, however a potential benefit of concomitant TTFields therapy during CRT remains unclear. In elderly patients aged >65–70 years, depending on performance status, hypofractionated (chemo)radiotherapy with or without TMZ is the recommended treatment.The primary aim of the GERAS trials is to investigate the optimal time point to start TTFields therapy in elderly patients, as well as feasibility and safety of treatment with the TTFields device in elderly patients with newly diagnosed glioblastoma during hypofractionated (chemo)radiotherapy. Secondary endpoints include progression-free survival at 6 months, overall survival and quality of life during combined treatment.

MATERIAL AND METHODS

The GERAS trial is a single centre, randomized, two-arm, phase I/II trial that will recruit a total of 64 patients. Patients undergo stratified randomization into treatment arm A or control arm B.Patients in arm A start TTFields therapy at the beginning of hypofractionated radiotherapy with or without TMZ and continue treatment during maintenance chemotherapy. Patients in arm B receive hypofractionated radiotherapy with or without TMZ and begin TTFields therapy together with maintenance chemotherapy. Patients in both arms will be trained in using the TTFields device by certified device support specialists. Follow-up includes MRI imaging four weeks after (chemo)radiotherapy and then every 12 weeks as well as regular lab testing according to the current standard of care. Patients will be assessed for neurological status, neurocognitive function, compliance with TTFields therapy and adverse events during, four weeks after (C)RT and then every 12 weeks for up to 52 weeks.

RESULTS

Not applicable due to ongoing trial.

CONCLUSION

With TTFields, a new element in the maintenance therapy of glioblastomas has found its way into clinical routine. The GERAS trial aims to determine the optimal time point to start TTFields therapy as well as the safety and feasibility of concomitant TTFields- and hypofractionated (C)RT in elderly patients. This may lead the way for further phase II/III trials that evaluate survival benefits in this subpopulation of elderly patients treated with hypofractionated (C)RT.

Chemoradiation in patients with unresectable extrahepatic and hilar cholangiocarcinoma or at high risk for disease recurrence after resection : Analysis of treatment efficacy and failure in patients receiving postoperative or primary chemoradiation

BACKGROUND

The purpose of this work was to determine efficacy, toxicity, and patterns of recurrence after concurrent chemoradiation (CRT) in patients with extrahepatic bile duct cancer (EHBDC) and hilar cholangiocarcinoma (Klatskin tumours) in case of incomplete resection or unresectable disease.

PATIENTS AND METHODS

From 2003-2010, 25 patients with nonmetastasized EHBDC and hilar cholangiocarcinoma were treated with radiotherapy and CRT at our institution in an postoperative setting (10 patients, 9 patients with R1 resections) or in case of unresectable disease (15 patients). Median age was 63 years (range 38-80 years) and there were 20 men and 5 women. Median applied dose was 45 Gy in both patient groups.

RESULTS

Patients at high risk (9 times R1 resection, 1 pathologically confirmed lymphangiosis) for tumour recurrence after curative surgery had a median time to disease progression of 8.7 months and an estimated mean overall survival of 23.2 months (6 of 10 patients are still under observation). Patients undergoing combined chemoradiation in case of unresectable primary tumours are still having a poor prognosis with a progression-free survival of 7.1 months and a median overall survival of 12.0 months. The main site of progression was systemic (liver, peritoneum) in both patient groups.

CONCLUSION

Chemoradiation with gemcitabine is safe and can be applied safely in either patients with EHBDC or Klatskin tumours at high risk for tumour recurrence after resection and patients with unresectable tumours. Escalation of systemic and local treatment should be investigated in future clinical trials.